kernel_randomize_memory() uses __PHYSICAL_MASK_SHIFT to calculate
the maximum amount of system RAM supported. The size of the direct
mapping section is obtained from the smaller one of the below two
values:
(actual system RAM size + padding size) vs (max system RAM size supported)
This calculation is wrong since commit
b83ce5ee91 ("x86/mm/64: Make __PHYSICAL_MASK_SHIFT always 52").
In it, __PHYSICAL_MASK_SHIFT was changed to be 52, regardless of whether
the kernel is using 4-level or 5-level page tables. Thus, it will always
use 4 PB as the maximum amount of system RAM, even in 4-level paging
mode where it should actually be 64 TB.
Thus, the size of the direct mapping section will always
be the sum of the actual system RAM size plus the padding size.
Even when the amount of system RAM is 64 TB, the following layout will
still be used. Obviously KALSR will be weakened significantly.
|____|_______actual RAM_______|_padding_|______the rest_______|
0 64TB ~120TB
Instead, it should be like this:
|____|_______actual RAM_______|_________the rest______________|
0 64TB ~120TB
The size of padding region is controlled by
CONFIG_RANDOMIZE_MEMORY_PHYSICAL_PADDING, which is 10 TB by default.
The above issue only exists when
CONFIG_RANDOMIZE_MEMORY_PHYSICAL_PADDING is set to a non-zero value,
which is the case when CONFIG_MEMORY_HOTPLUG is enabled. Otherwise,
using __PHYSICAL_MASK_SHIFT doesn't affect KASLR.
Fix it by replacing __PHYSICAL_MASK_SHIFT with MAX_PHYSMEM_BITS.
[ bp: Massage commit message. ]
Fixes: b83ce5ee91 ("x86/mm/64: Make __PHYSICAL_MASK_SHIFT always 52")
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Garnier <thgarnie@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: frank.ramsay@hpe.com
Cc: herbert@gondor.apana.org.au
Cc: kirill@shutemov.name
Cc: mike.travis@hpe.com
Cc: thgarnie@google.com
Cc: x86-ml <x86@kernel.org>
Cc: yamada.masahiro@socionext.com
Link: https://lkml.kernel.org/r/20190417083536.GE7065@MiWiFi-R3L-srv
$(call if_changed,...) must have FORCE as a prerequisite.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1554280212-10578-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, when a new resource group is created, the allocation values
of the MBA resource are not initialized and remain meaningless data.
For example:
mkdir /sys/fs/resctrl/p1
cat /sys/fs/resctrl/p1/schemata
MB:0=100;1=100
echo "MB:0=10;1=20" > /sys/fs/resctrl/p1/schemata
cat /sys/fs/resctrl/p1/schemata
MB:0= 10;1= 20
rmdir /sys/fs/resctrl/p1
mkdir /sys/fs/resctrl/p2
cat /sys/fs/resctrl/p2/schemata
MB:0= 10;1= 20
Therefore, when the new group is created, it is reasonable to initialize
MBA resource with default values.
Initialize the MBA resource and cache resources in separate functions.
[ bp: Add newlines between code blocks for better readability. ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: pei.p.jia@intel.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/1555499329-1170-3-git-send-email-xiaochen.shen@intel.com
Carve out per rdt_domain initialization code from rdtgroup_init_alloc()
into a separate function.
No functional change, make the code more readable and save us at least
two indentation levels.
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: pei.p.jia@intel.com
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/1555499329-1170-2-git-send-email-xiaochen.shen@intel.com
In pcibios_irq_init(), the PCI IRQ routing table 'pirq_table' is first
found through pirq_find_routing_table(). If the table is not found and
CONFIG_PCI_BIOS is defined, the table is then allocated in
pcibios_get_irq_routing_table() using kmalloc(). Later, if the I/O APIC is
used, this table is actually not used. In that case, the allocated table
is not freed, which is a memory leak.
Free the allocated table if it is not used.
Signed-off-by: Wenwen Wang <wang6495@umn.edu>
[bhelgaas: added Ingo's reviewed-by, since the only change since v1 was to
use the irq_routing_table local variable name he suggested]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
This code is only for CPUs which are affected by MSBDS, but are *not*
affected by the other two MDS issues.
For such CPUs, enabling the mds_idle_clear mitigation is enough to
mitigate SMT.
However if user boots with 'mds=off' and still has SMT enabled, we should
not report that SMT is mitigated:
$cat /sys//devices/system/cpu/vulnerabilities/mds
Vulnerable; SMT mitigated
But rather:
Vulnerable; SMT vulnerable
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20190412215118.294906495@localhost.localdomain
All stack types on x86 64-bit have guard pages now.
So there is no point in executing probabilistic overflow checks as the
guard pages are a accurate and reliable overflow prevention.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160146.466354762@linutronix.de
The IRQ stack lives in percpu space, so an IRQ handler that overflows it
will overwrite other data structures.
Use vmap() to remap the IRQ stack so that it will have the usual guard
pages that vmap()/vmalloc() allocations have. With this, the kernel will
panic immediately on an IRQ stack overflow.
[ tglx: Move the map code to a proper place and invoke it only when a CPU
is about to be brought online. No point in installing the map at
early boot for all possible CPUs. Fail the CPU bringup if the vmap()
fails as done for all other preparatory stages in CPU hotplug. ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160146.363733568@linutronix.de
Currently, the IRQ stack is hardcoded as the first page of the percpu
area, and the stack canary lives on the IRQ stack. The former gets in
the way of adding an IRQ stack guard page, and the latter is a potential
weakness in the stack canary mechanism.
Split the IRQ stack into its own private percpu pages.
[ tglx: Make 64 and 32 bit share struct irq_stack ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Feng Tang <feng.tang@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jordan Borgner <mail@jordan-borgner.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Maran Wilson <maran.wilson@oracle.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pu Wen <puwen@hygon.cn>
Cc: "Rafael Ávila de Espíndola" <rafael@espindo.la>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: x86-ml <x86@kernel.org>
Cc: xen-devel@lists.xenproject.org
Link: https://lkml.kernel.org/r/20190414160146.267376656@linutronix.de
Preparatory change for disentangling the irq stack union as a
prerequisite for irq stacks with guard pages.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Cc: Yi Wang <wang.yi59@zte.com.cn>
Link: https://lkml.kernel.org/r/20190414160146.177558566@linutronix.de
irq_ctx_init() crashes hard on page allocation failures. While that's ok
during early boot, it's just wrong in the CPU hotplug bringup code.
Check the page allocation failure and return -ENOMEM and handle it at the
call sites. On early boot the only way out is to BUG(), but on CPU hotplug
there is no reason to crash, so just abort the operation.
Rename the function to something more sensible while at it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Pu Wen <puwen@hygon.cn>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: x86-ml <x86@kernel.org>
Cc: xen-devel@lists.xenproject.org
Cc: Yazen Ghannam <yazen.ghannam@amd.com>
Cc: Yi Wang <wang.yi59@zte.com.cn>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Link: https://lkml.kernel.org/r/20190414160146.089060584@linutronix.de
irq_ctx_init() is invoked from native_init_IRQ() or from xen_init_IRQ()
code. There is no reason to have this split. The interrupt stacks must be
allocated no matter what.
Invoke it from init_IRQ() before invoking the native or XEN init
implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Abraham <j.abraham1776@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: x86-ml <x86@kernel.org>
Cc: xen-devel@lists.xenproject.org
Link: https://lkml.kernel.org/r/20190414160146.001162606@linutronix.de
There is no reason to have an u32 array in struct irq_stack. The only
purpose of the array is to size the struct properly.
Preparatory change for sharing struct irq_stack with 64-bit.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Pu Wen <puwen@hygon.cn>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160145.736241969@linutronix.de
On 32-bit IRQ_STACK_SIZE is the same as THREAD_SIZE.
To allow sharing struct irq_stack with 32-bit, define IRQ_STACK_SIZE for
32-bit and use it for struct irq_stack.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160145.632513987@linutronix.de
The current implementation of in_exception_stack() iterates over the
exception stacks array. Most of the time this is an useless exercise, but
even for the actual use cases (perf and ftrace) it takes at least 2
iterations to get to the NMI stack.
As the exception stacks and the guard pages are page aligned the loop can
be avoided completely.
Add a initial check whether the stack pointer is inside the full exception
stack area and leave early if not.
Create a lookup table which describes the stack area. The table index is
the page offset from the beginning of the exception stacks. So for any
given stack pointer the page offset is computed and a lookup in the
description table is performed. If it is inside a guard page, return. If
not, use the descriptor to fill in the info structure.
The table is filled at compile time and for the !KASAN case the interesting
page descriptors exactly fit into a single cache line. Just the last guard
page descriptor is in the next cacheline, but that should not be accessed
in the regular case.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160145.543320386@linutronix.de
The debug IST stack is actually two separate debug stacks to handle #DB
recursion. This is required because the CPU starts always at top of stack
on exception entry, which means on #DB recursion the second #DB would
overwrite the stack of the first.
The low level entry code therefore adjusts the top of stack on entry so a
secondary #DB starts from a different stack page. But the stack pages are
adjacent without a guard page between them.
Split the debug stack into 3 stacks which are separated by guard pages. The
3rd stack is never mapped into the cpu_entry_area and is only there to
catch triple #DB nesting:
--- top of DB_stack <- Initial stack
--- end of DB_stack
guard page
--- top of DB1_stack <- Top of stack after entering first #DB
--- end of DB1_stack
guard page
--- top of DB2_stack <- Top of stack after entering second #DB
--- end of DB2_stack
guard page
If DB2 would not act as the final guard hole, a second #DB would point the
top of #DB stack to the stack below #DB1 which would be valid and not catch
the not so desired triple nesting.
The backing store does not allocate any memory for DB2 and its guard page
as it is not going to be mapped into the cpu_entry_area.
- Adjust the low level entry code so it adjusts top of #DB with the offset
between the stacks instead of exception stack size.
- Make the dumpstack code aware of the new stacks.
- Adjust the in_debug_stack() implementation and move it into the NMI code
where it belongs. As this is NMI hotpath code, it just checks the full
area between top of DB_stack and bottom of DB1_stack without checking
for the guard page. That's correct because the NMI cannot hit a
stackpointer pointing to the guard page between DB and DB1 stack. Even
if it would, then the NMI operation still is unaffected, but the resume
of the debug exception on the topmost DB stack will crash by touching
the guard page.
[ bp: Make exception_stack_names static const char * const ]
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: linux-doc@vger.kernel.org
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160145.439944544@linutronix.de
All usage sites which expected that the exception stacks in the CPU entry
area are mapped linearly are fixed up. Enable guard pages between the
IST stacks.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160145.349862042@linutronix.de
The entry order of the TSS.IST array and the order of the stack
storage/mapping are not required to be the same.
With the upcoming split of the debug stack this is going to fall apart as
the number of TSS.IST array entries stays the same while the actual stacks
are increasing.
Make them separate so that code like dumpstack can just utilize the mapping
order. The IST index is solely required for the actual TSS.IST array
initialization.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160145.241588113@linutronix.de
Convert the TSS.IST setup code to use the cpu entry area information
directly instead of assuming a linear mapping of the IST stacks.
The store to orig_ist[] is no longer required as there are no users
anymore.
This is the last preparatory step towards IST guard pages.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160145.061686012@linutronix.de
The orig_ist[] array is a shadow copy of the IST array in the TSS. The
reason why it exists is that older kernels used two TSS variants with
different pointers into the debug stack. orig_ist[] contains the real
starting points.
There is no point anymore to do so because the same information can be
retrieved using the base address of the cpu entry area mapping and the
offsets of the various exception stacks.
No functional change. Preparation for removing orig_ist.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160144.974900463@linutronix.de
The orig_ist[] array is a shadow copy of the IST array in the TSS. The
reason why it exists is that older kernels used two TSS variants with
different pointers into the debug stack. orig_ist[] contains the real
starting points.
There is no point anymore to do so because the same information can be
retrieved using the base address of the cpu entry area mapping and the
offsets of the various exception stacks.
No functional change. Preparation for removing orig_ist.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160144.885741626@linutronix.de
The orig_ist[] array is a shadow copy of the IST array in the TSS. The
reason why it exists is that older kernels used two TSS variants with
different pointers into the debug stack. orig_ist[] contains the real
starting points.
There is no point anymore to do so because the same information can be
retrieved using the base address of the cpu entry area mapping and the
offsets of the various exception stacks.
No functional change. Preparation for removing orig_ist.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160144.784487230@linutronix.de
Store a pointer to the per cpu entry area exception stack mappings to allow
fast retrieval.
Required for converting various places from using the shadow IST array to
directly doing address calculations on the actual mapping address.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160144.680960459@linutronix.de
To allow guard pages between the IST stacks each stack needs to be
mapped individually.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160144.592691557@linutronix.de
At the moment everything assumes a full linear mapping of the various
exception stacks. Adding guard pages to the cpu entry area mapping of the
exception stacks will break that assumption.
As a preparatory step convert both the real storage and the effective
mapping in the cpu entry area from character arrays to structures.
To ensure that both arrays have the same ordering and the same size of the
individual stacks fill the members with a macro. The guard size is the only
difference between the two resulting structures. For now both have guard
size 0 until the preparation of all usage sites is done.
Provide a couple of helper macros which are used in the following
conversions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160144.506807893@linutronix.de
No point in retrieving the entry area pointer over and over. Do it once
and use unsigned int for 'cpu' everywhere.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160144.419653165@linutronix.de
The defines for the exception stack (IST) array in the TSS are using the
SDM convention IST1 - IST7. That causes all sorts of code to subtract 1 for
array indices related to IST. That's confusing at best and does not provide
any value.
Make the indices zero based and fixup the usage sites. The only code which
needs to adjust the 0 based index is the interrupt descriptor setup which
needs to add 1 now.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: linux-doc@vger.kernel.org
Cc: Nicolai Stange <nstange@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160144.331772825@linutronix.de
Nothing uses that and before people get the wrong ideas, get rid of it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160144.139284839@linutronix.de
Commit
d8ba61ba58 ("x86/entry/64: Don't use IST entry for #BP stack")
removed the last user but left the macro around.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160144.050689789@linutronix.de
On x86, stacks go top to bottom, but the stack overflow check uses it
the other way round, which is just confusing. Clean it up and sanitize
the warning string a bit.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160143.961241397@linutronix.de
stack_overflow_check() is using both irq_stack_ptr and irq_stack_union
to find the IRQ stack. That's going to break when vmapped irq stacks are
introduced.
Change it to just use irq_stack_ptr.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160143.872549191@linutronix.de
The get_stack_info() function is off-by-one when checking whether an
address is on a IRQ stack or a IST stack. This prevents an overflowed
IRQ or IST stack from being dumped properly.
[ tglx: Do the same for 32-bit ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160143.785651055@linutronix.de
Commit
37fe6a42b3 ("x86: Check stack overflow in detail")
added a broad check for the full exception stack area, i.e. it considers
the full exception stack area as valid.
That's wrong in two aspects:
1) It does not check the individual areas one by one
2) #DF, NMI and #MCE are not enabling interrupts which means that a
regular device interrupt cannot happen in their context. In fact if a
device interrupt hits one of those IST stacks that's a bug because some
code path enabled interrupts while handling the exception.
Limit the check to the #DB stack and consider all other IST stacks as
'overflow' or invalid.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160143.682135110@linutronix.de
* Fixes for nested VMX with ept=0
* Fixes for AMD (APIC virtualization, NMI injection)
* Fixes for Hyper-V under KVM and KVM under Hyper-V
* Fixes for 32-bit SMM and tests for SMM virtualization
* More array_index_nospec peppering
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"5.1 keeps its reputation as a big bugfix release for KVM x86.
- Fix for a memory leak introduced during the merge window
- Fixes for nested VMX with ept=0
- Fixes for AMD (APIC virtualization, NMI injection)
- Fixes for Hyper-V under KVM and KVM under Hyper-V
- Fixes for 32-bit SMM and tests for SMM virtualization
- More array_index_nospec peppering"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (21 commits)
KVM: x86: avoid misreporting level-triggered irqs as edge-triggered in tracing
KVM: fix spectrev1 gadgets
KVM: x86: fix warning Using plain integer as NULL pointer
selftests: kvm: add a selftest for SMM
selftests: kvm: fix for compilers that do not support -no-pie
selftests: kvm/evmcs_test: complete I/O before migrating guest state
KVM: x86: Always use 32-bit SMRAM save state for 32-bit kernels
KVM: x86: Don't clear EFER during SMM transitions for 32-bit vCPU
KVM: x86: clear SMM flags before loading state while leaving SMM
KVM: x86: Open code kvm_set_hflags
KVM: x86: Load SMRAM in a single shot when leaving SMM
KVM: nVMX: Expose RDPMC-exiting only when guest supports PMU
KVM: x86: Raise #GP when guest vCPU do not support PMU
x86/kvm: move kvm_load/put_guest_xcr0 into atomic context
KVM: x86: svm: make sure NMI is injected after nmi_singlestep
svm/avic: Fix invalidate logical APIC id entry
Revert "svm: Fix AVIC incomplete IPI emulation"
kvm: mmu: Fix overflow on kvm mmu page limit calculation
KVM: nVMX: always use early vmcs check when EPT is disabled
KVM: nVMX: allow tests to use bad virtual-APIC page address
...
In __apic_accept_irq() interface trig_mode is int and actually on some code
paths it is set above u8:
kvm_apic_set_irq() extracts it from 'struct kvm_lapic_irq' where trig_mode
is u16. This is done on purpose as e.g. kvm_set_msi_irq() sets it to
(1 << 15) & e->msi.data
kvm_apic_local_deliver sets it to reg & (1 << 15).
Fix the immediate issue by making 'tm' into u16. We may also want to adjust
__apic_accept_irq() interface and use proper sizes for vector, level,
trig_mode but this is not urgent.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Changed passing argument as "0 to NULL" which resolves below sparse warning
arch/x86/kvm/x86.c:3096:61: warning: Using plain integer as NULL pointer
Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Invoking the 64-bit variation on a 32-bit kenrel will crash the guest,
trigger a WARN, and/or lead to a buffer overrun in the host, e.g.
rsm_load_state_64() writes r8-r15 unconditionally, but enum kvm_reg and
thus x86_emulate_ctxt._regs only define r8-r15 for CONFIG_X86_64.
KVM allows userspace to report long mode support via CPUID, even though
the guest is all but guaranteed to crash if it actually tries to enable
long mode. But, a pure 32-bit guest that is ignorant of long mode will
happily plod along.
SMM complicates things as 64-bit CPUs use a different SMRAM save state
area. KVM handles this correctly for 64-bit kernels, e.g. uses the
legacy save state map if userspace has hid long mode from the guest,
but doesn't fare well when userspace reports long mode support on a
32-bit host kernel (32-bit KVM doesn't support 64-bit guests).
Since the alternative is to crash the guest, e.g. by not loading state
or explicitly requesting shutdown, unconditionally use the legacy SMRAM
save state map for 32-bit KVM. If a guest has managed to get far enough
to handle SMIs when running under a weird/buggy userspace hypervisor,
then don't deliberately crash the guest since there are no downsides
(from KVM's perspective) to allow it to continue running.
Fixes: 660a5d517a ("KVM: x86: save/load state on SMM switch")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Neither AMD nor Intel CPUs have an EFER field in the legacy SMRAM save
state area, i.e. don't save/restore EFER across SMM transitions. KVM
somewhat models this, e.g. doesn't clear EFER on entry to SMM if the
guest doesn't support long mode. But during RSM, KVM unconditionally
clears EFER so that it can get back to pure 32-bit mode in order to
start loading CRs with their actual non-SMM values.
Clear EFER only when it will be written when loading the non-SMM state
so as to preserve bits that can theoretically be set on 32-bit vCPUs,
e.g. KVM always emulates EFER_SCE.
And because CR4.PAE is cleared only to play nice with EFER, wrap that
code in the long mode check as well. Note, this may result in a
compiler warning about cr4 being consumed uninitialized. Re-read CR4
even though it's technically unnecessary, as doing so allows for more
readable code and RSM emulation is not a performance critical path.
Fixes: 660a5d517a ("KVM: x86: save/load state on SMM switch")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
RSM emulation is currently broken on VMX when the interrupted guest has
CR4.VMXE=1. Stop dancing around the issue of HF_SMM_MASK being set when
loading SMSTATE into architectural state, e.g. by toggling it for
problematic flows, and simply clear HF_SMM_MASK prior to loading
architectural state (from SMRAM save state area).
Reported-by: Jon Doron <arilou@gmail.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Fixes: 5bea5123cb ("KVM: VMX: check nested state and CR4.VMXE against SMM")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Prepare for clearing HF_SMM_MASK prior to loading state from the SMRAM
save state map, i.e. kvm_smm_changed() needs to be called after state
has been loaded and so cannot be done automatically when setting
hflags from RSM.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
RSM emulation is currently broken on VMX when the interrupted guest has
CR4.VMXE=1. Rather than dance around the issue of HF_SMM_MASK being set
when loading SMSTATE into architectural state, ideally RSM emulation
itself would be reworked to clear HF_SMM_MASK prior to loading non-SMM
architectural state.
Ostensibly, the only motivation for having HF_SMM_MASK set throughout
the loading of state from the SMRAM save state area is so that the
memory accesses from GET_SMSTATE() are tagged with role.smm. Load
all of the SMRAM save state area from guest memory at the beginning of
RSM emulation, and load state from the buffer instead of reading guest
memory one-by-one.
This paves the way for clearing HF_SMM_MASK prior to loading state,
and also aligns RSM with the enter_smm() behavior, which fills a
buffer and writes SMRAM save state in a single go.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Issue was discovered when running kvm-unit-tests on KVM running as L1 on
top of Hyper-V.
When vmx_instruction_intercept unit-test attempts to run RDPMC to test
RDPMC-exiting, it is intercepted by L1 KVM which it's EXIT_REASON_RDPMC
handler raise #GP because vCPU exposed by Hyper-V doesn't support PMU.
Instead of unit-test expectation to be reflected with EXIT_REASON_RDPMC.
The reason vmx_instruction_intercept unit-test attempts to run RDPMC
even though Hyper-V doesn't support PMU is because L1 expose to L2
support for RDPMC-exiting. Which is reasonable to assume that is
supported only in case CPU supports PMU to being with.
Above issue can easily be simulated by modifying
vmx_instruction_intercept config in x86/unittests.cfg to run QEMU with
"-cpu host,+vmx,-pmu" and run unit-test.
To handle issue, change KVM to expose RDPMC-exiting only when guest
supports PMU.
Reported-by: Saar Amar <saaramar@microsoft.com>
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Before this change, reading a VMware pseduo PMC will succeed even when
PMU is not supported by guest. This can easily be seen by running
kvm-unit-test vmware_backdoors with "-cpu host,-pmu" option.
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
guest xcr0 could leak into host when MCE happens in guest mode. Because
do_machine_check() could schedule out at a few places.
For example:
kvm_load_guest_xcr0
...
kvm_x86_ops->run(vcpu) {
vmx_vcpu_run
vmx_complete_atomic_exit
kvm_machine_check
do_machine_check
do_memory_failure
memory_failure
lock_page
In this case, host_xcr0 is 0x2ff, guest vcpu xcr0 is 0xff. After schedule
out, host cpu has guest xcr0 loaded (0xff).
In __switch_to {
switch_fpu_finish
copy_kernel_to_fpregs
XRSTORS
If any bit i in XSTATE_BV[i] == 1 and xcr0[i] == 0, XRSTORS will
generate #GP (In this case, bit 9). Then ex_handler_fprestore kicks in
and tries to reinitialize fpu by restoring init fpu state. Same story as
last #GP, except we get DOUBLE FAULT this time.
Cc: stable@vger.kernel.org
Signed-off-by: WANG Chao <chao.wang@ucloud.cn>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
I noticed that apic test from kvm-unit-tests always hangs on my EPYC 7401P,
the hanging test nmi-after-sti is trying to deliver 30000 NMIs and tracing
shows that we're sometimes able to deliver a few but never all.
When we're trying to inject an NMI we may fail to do so immediately for
various reasons, however, we still need to inject it so enable_nmi_window()
arms nmi_singlestep mode. #DB occurs as expected, but we're not checking
for pending NMIs before entering the guest and unless there's a different
event to process, the NMI will never get delivered.
Make KVM_REQ_EVENT request on the vCPU from db_interception() to make sure
pending NMIs are checked and possibly injected.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Only clear the valid bit when invalidate logical APIC id entry.
The current logic clear the valid bit, but also set the rest of
the bits (including reserved bits) to 1.
Fixes: 98d90582be ('svm: Fix AVIC DFR and LDR handling')
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This reverts commit bb218fbcfa.
As Oren Twaig pointed out the old discussion:
https://patchwork.kernel.org/patch/8292231/
that the change coud potentially cause an extra IPI to be sent to
the destination vcpu because the AVIC hardware already set the IRR bit
before the incomplete IPI #VMEXIT with id=1 (target vcpu is not running).
Since writting to ICR and ICR2 will also set the IRR. If something triggers
the destination vcpu to get scheduled before the emulation finishes, then
this could result in an additional IPI.
Also, the issue mentioned in the commit bb218fbcfa was misdiagnosed.
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reported-by: Oren Twaig <oren@scalemp.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM bases its memory usage limits on the total number of guest pages
across all memslots. However, those limits, and the calculations to
produce them, use 32 bit unsigned integers. This can result in overflow
if a VM has more guest pages that can be represented by a u32. As a
result of this overflow, KVM can use a low limit on the number of MMU
pages it will allocate. This makes KVM unable to map all of guest memory
at once, prompting spurious faults.
Tested: Ran all kvm-unit-tests on an Intel Haswell machine. This patch
introduced no new failures.
Signed-off-by: Ben Gardon <bgardon@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The remaining failures of vmx.flat when EPT is disabled are caused by
incorrectly reflecting VMfails to the L1 hypervisor. What happens is
that nested_vmx_restore_host_state corrupts the guest CR3, reloading it
with the host's shadow CR3 instead, because it blindly loads GUEST_CR3
from the vmcs01.
For simplicity let's just always use hardware VMCS checks when EPT is
disabled. This way, nested_vmx_restore_host_state is not reached at
all (or at least shouldn't be reached).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The Kconfig text contains a spelling mistake, fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-janitors@vger.kernel.org
Link: http://lkml.kernel.org/r/20190416105751.18899-1-colin.king@canonical.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Hyper-V TLFS suggests an optimization to avoid imminent VMExit on EOI:
"The OS performs an EOI by atomically writing zero to the EOI Assist field
of the virtual VP assist page and checking whether the "No EOI required"
field was previously zero. If it was, the OS must write to the
HV_X64_APIC_EOI MSR thereby triggering an intercept into the hypervisor."
Implement the optimization in Linux.
Tested-by: Long Li <longli@microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Kelley (EOSG) <Michael.H.Kelley@microsoft.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Simon Xiao <sixiao@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-hyperv@vger.kernel.org
Link: http://lkml.kernel.org/r/20190403170309.4107-1-vkuznets@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add perf core PMU support for Intel Tremont CPU.
The init code is based on Goldmont plus.
The generic purpose counter 0 and fixed counter 0 have less skid.
Force :ppp events on generic purpose counter 0.
Force instruction:ppp on generic purpose counter 0 and fixed counter 0.
Updates LLC cache event table and OFFCORE_RESPONSE mask.
Adaptive PEBS, which is already enabled on ICL, is also supported
on Tremont. No extra code required.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: https://lkml.kernel.org/r/1554922629-126287-3-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add Intel Icelake uncore support:
- The init code is based on Skylake
- Add new PCI id for IMC
- New MSR address for CBOX
- Get CBOX# from CNL_UNC_CBO_CONFIG MSR directly
- Create a new PMU for fixed clocktick counter
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: https://lkml.kernel.org/r/20190402194509.2832-13-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add Icelake core PMU perf code, including constraint tables and the main
enable code.
Icelake expanded the generic counters to always 8 even with HT on, but a
range of events cannot be scheduled on the extra 4 counters.
Add new constraint ranges to describe this to the scheduler.
The number of constraints that need to be checked is larger now than
with earlier CPUs.
At some point we may need a new data structure to look them up more
efficiently than with linear search. So far it still seems to be
acceptable however.
Icelake added a new fixed counter SLOTS. Full support for it is added
later in the patch series.
The cache events table is identical to Skylake.
Compare to PEBS instruction event on generic counter, fixed counter 0
has less skid. Force instruction:ppp always in fixed counter 0.
Originally-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: https://lkml.kernel.org/r/20190402194509.2832-9-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Icelake extended the general counters to 8, even when SMT is enabled.
However only a (large) subset of the events can be used on all 8
counters.
The events that can or cannot be used on all counters are organized
in ranges.
A lot of scheduler constraints are required to handle all this.
To avoid blowing up the tables add event code ranges to the constraint
tables, and a new inline function to match them.
Originally-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> # developer hat on
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> # maintainer hat on
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: https://lkml.kernel.org/r/20190402194509.2832-8-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With adaptive PEBS the CPU can directly supply the LBR information,
so we don't need to read it again. But the LBRs still need to be
enabled. Add a special count to the cpuc that distinguishes these
two cases, and avoid reading the LBRs unnecessarily when PEBS is
active.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: https://lkml.kernel.org/r/20190402194509.2832-7-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Adaptive PEBS is a new way to report PEBS sampling information. Instead
of a fixed size record for all PEBS events it allows to configure the
PEBS record to only include the information needed. Events can then opt
in to use such an extended record, or stay with a basic record which
only contains the IP.
The major new feature is to support LBRs in PEBS record.
Besides normal LBR, this allows (much faster) large PEBS, while still
supporting callstacks through callstack LBR. So essentially a lot of
profiling can now be done without frequent interrupts, dropping the
overhead significantly.
The main requirement still is to use a period, and not use frequency
mode, because frequency mode requires reevaluating the frequency on each
overflow.
The floating point state (XMM) is also supported, which allows efficient
profiling of FP function arguments.
Introduce specific drain function to handle variable length records.
Use a new callback to parse the new record format, and also handle the
STATUS field now being at a different offset.
Add code to set up the configuration register. Since there is only a
single register, all events either get the full super set of all events,
or only the basic record.
Originally-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: https://lkml.kernel.org/r/20190402194509.2832-6-kan.liang@linux.intel.com
[ Renamed GPRS => GP. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The drain_pebs() could be called twice in a short period for auto-reload
event in pmu::read(). The intel_pmu_save_and_restart_reload() should be
called to update the event->count.
This case should also be handled on Icelake. Extract the code for
later reuse.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: https://lkml.kernel.org/r/20190402194509.2832-5-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Extract some code related to memory profiling from the PEBS record
parser into separate functions. It can be reused by the upcoming
adaptive PEBS parser. No functional changes.
Rename intel_hsw_weight to intel_get_tsx_weight, and
intel_hsw_transaction to intel_get_tsx_transaction. Because the input is
not the hsw pebs format anymore.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: https://lkml.kernel.org/r/20190402194509.2832-4-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Starting from Icelake, XMM registers can be collected in PEBS record.
But current code only output the pt_regs.
Add a new struct x86_perf_regs for both pt_regs and xmm_regs. The
xmm_regs will be used later to keep a pointer to PEBS record which has
XMM information.
XMM registers are 128 bit. To simplify the code, they are handled like
two different registers, which means setting two bits in the register
bitmap. This also allows only sampling the lower 64bit bits in XMM.
The index of XMM registers starts from 32. There are 16 XMM registers.
So all reserved space for regs are used. Remove REG_RESERVED.
Add PERF_REG_X86_XMM_MAX, which stands for the max number of all x86
regs including both GPRs and XMM.
Add REG_NOSUPPORT for 32bit to exclude unsupported registers.
Previous platforms can not collect XMM information in PEBS record.
Adding pebs_no_xmm_regs to indicate the unsupported platforms.
The common code still validates the supported registers. However, it
cannot check model specific registers, e.g. XMM. Add extra check in
x86_pmu_hw_config() to reject invalid config of regs_user and regs_intr.
The regs_user never supports XMM collection.
The regs_intr only supports XMM collection when sampling PEBS event on
icelake and later platforms.
Originally-by: Andi Kleen <ak@linux.intel.com>
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: https://lkml.kernel.org/r/20190402194509.2832-3-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
PEBS_REGS used as mask for the supported registers for large PEBS.
However, the mask cannot filter the sample_regs_user/sample_regs_intr
correctly.
(1ULL << PERF_REG_X86_*) should be used to replace PERF_REG_X86_*, which
is only the index.
Rename PEBS_REGS to PEBS_GP_REGS, because the mask is only for general
purpose registers.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Fixes: 2fe1bc1f50 ("perf/x86: Enable free running PEBS for REGS_USER/INTR")
Link: https://lkml.kernel.org/r/20190402194509.2832-2-kan.liang@linux.intel.com
[ Renamed it to PEBS_GP_REGS - as 'GPRS' is used elsewhere ;-) ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As mentioned in the comment, there are some special cases where we can simply
clear the TPR shadow bit from the CPU-based execution controls in the vmcs02.
Handle them so that we can remove some XFAILs from vmx.flat.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Revert the following commit:
515ab7c413: ("x86/mm: Align TLB invalidation info")
I found out (the hard way) that under some .config options (notably L1_CACHE_SHIFT=7)
and compiler combinations this on-stack alignment leads to a 320 byte
stack usage, which then triggers a KASAN stack warning elsewhere.
Using 320 bytes of stack space for a 40 byte structure is ludicrous and
clearly not right.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Nadav Amit <namit@vmware.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 515ab7c413 ("x86/mm: Align TLB invalidation info")
Link: http://lkml.kernel.org/r/20190416080335.GM7905@worktop.programming.kicks-ass.net
[ Minor changelog edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Upon reboot, the Acer TravelMate X514-51T laptop appears to complete the
shutdown process, but then it hangs in BIOS POST with a black screen.
The problem is intermittent - at some points it has appeared related to
Secure Boot settings or different kernel builds, but ultimately we have
not been able to identify the exact conditions that trigger the issue to
come and go.
Besides, the EFI mode cannot be disabled in the BIOS of this model.
However, after extensive testing, we observe that using the EFI reboot
method reliably avoids the issue in all cases.
So add a boot time quirk to use EFI reboot on such systems.
Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=203119
Signed-off-by: Jian-Hong Pan <jian-hong@endlessm.com>
Signed-off-by: Daniel Drake <drake@endlessm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Cc: linux@endlessm.com
Link: http://lkml.kernel.org/r/20190412080152.3718-1-jian-hong@endlessm.com
[ Fix !CONFIG_EFI build failure, clarify the code and the changelog a bit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Xose Vazquez Perez reported boot warnings when NX is disabled on the kernel command line.
__early_set_fixmap() triggers this warning:
attempted to set unsupported pgprot: 8000000000000163
bits: 8000000000000000
supported: 7fffffffffffffff
WARNING: CPU: 0 PID: 0 at arch/x86/include/asm/pgtable.h:537
__early_set_fixmap+0xa2/0xff
because it uses __default_kernel_pte_mask to mask out unsupported bits.
Use __supported_pte_mask instead.
Disabling NX on the command line also triggers the NX warning in the page
table mapping check:
WARNING: CPU: 1 PID: 1 at arch/x86/mm/dump_pagetables.c:262 note_page+0x2ae/0x650
....
Make the warning depend on NX set in __supported_pte_mask.
Reported-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Tested-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1904151037530.1729@nanos.tec.linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y, we compile the kernel with
-fdata-sections, which also splits the .bss section.
The new section, with a new .bss.* name, which pattern gets missed by the
main x86 linker script which only expects the '.bss' name. This results
in the discarding of the second part and a too small, truncated .bss
section and an unhappy, non-working kernel.
Use the common BSS_MAIN macro in the linker script to properly capture
and merge all the generated BSS sections.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20190415164956.124067-1-samitolvanen@google.com
[ Extended the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Mikhail reported a lockdep splat related to the AMD specific ssb_state
lock:
CPU0 CPU1
lock(&st->lock);
local_irq_disable();
lock(&(&sighand->siglock)->rlock);
lock(&st->lock);
<Interrupt>
lock(&(&sighand->siglock)->rlock);
*** DEADLOCK ***
The connection between sighand->siglock and st->lock comes through seccomp,
which takes st->lock while holding sighand->siglock.
Make sure interrupts are disabled when __speculation_ctrl_update() is
invoked via prctl() -> speculation_ctrl_update(). Add a lockdep assert to
catch future offenders.
Fixes: 1f50ddb4f4 ("x86/speculation: Handle HT correctly on AMD")
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Cc: Thomas Lendacky <thomas.lendacky@amd.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1904141948200.4917@nanos.tec.linutronix.de
Terminating the last trace entry with ULONG_MAX is a completely pointless
exercise and none of the consumers can rely on it because it's
inconsistently implemented across architectures. In fact quite some of the
callers remove the entry and adjust stack_trace.nr_entries afterwards.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Link: https://lkml.kernel.org/r/20190410103643.750954603@linutronix.de
When cache allocation is supported and the user creates a new resctrl
resource group, the allocations of the new resource group are
initialized to all regions that it can possibly use. At this time these
regions are all that are shareable by other resource groups as well as
regions that are not currently used. The new resource group's mode is
also initialized to reflect this initialization and set to "shareable".
The new resource group's mode is currently repeatedly initialized within
the loop that configures the hardware with the resource group's default
allocations.
Move the initialization of the resource group's mode outside the
hardware configuration loop. The resource group's mode is now
initialized only once as the final step to reflect that its configured
allocations are "shareable".
Fixes: 95f0b77efa ("x86/intel_rdt: Initialize new resource group with sane defaults")
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: pei.p.jia@intel.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/1554839629-5448-1-git-send-email-xiaochen.shen@intel.com
Pull x86 fixes from Ingo Molnar:
"Fix typos in user-visible resctrl parameters, and also fix assembly
constraint bugs that might result in miscompilation"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm: Use stricter assembly constraints in bitops
x86/resctrl: Fix typos in the mba_sc mount option
Pull perf fixes from Ingo Molnar:
"Six kernel side fixes: three related to NMI handling on AMD systems, a
race fix, a kexec initialization fix and a PEBS sampling fix"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix perf_event_disable_inatomic() race
x86/perf/amd: Remove need to check "running" bit in NMI handler
x86/perf/amd: Resolve NMI latency issues for active PMCs
x86/perf/amd: Resolve race condition when disabling PMC
perf/x86/intel: Initialize TFA MSR
perf/x86/intel: Fix handling of wakeup_events for multi-entry PEBS
The task's initial PKRU value is set partly for fpu__clear()/
copy_init_pkru_to_fpregs(). It is not part of init_fpstate.xsave and
instead it is set explicitly.
If the user removes the PKRU state from XSAVE in the signal handler then
__fpu__restore_sig() will restore the missing bits from `init_fpstate'
and initialize the PKRU value to 0.
Add the `init_pkru_value' to `init_fpstate' so it is set to the init
value in such a case.
In theory copy_init_pkru_to_fpregs() could be removed because restoring
the PKRU at return-to-userland should be enough.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-28-bigeasy@linutronix.de
If a task is scheduled out and receives a signal then it won't be
able to take the fastpath because the registers aren't available. The
slowpath is more expensive compared to XRSTOR + XSAVE which usually
succeeds.
Here are some clock_gettime() numbers from a bigger box with AVX512
during bootup:
- __fpregs_load_activate() takes 140ns - 350ns. If it was the most recent
FPU context on the CPU then the optimisation in __fpregs_load_activate()
will skip the load (which was disabled during the test).
- copy_fpregs_to_sigframe() takes 200ns - 450ns if it succeeds. On a
pagefault it is 1.8us - 3us usually in the 2.6us area.
- The slowpath takes 1.5us - 6us. Usually in the 2.6us area.
My testcases (including lat_sig) take the fastpath without
__fpregs_load_activate(). I expect this to be the majority.
Since the slowpath is in the >1us area it makes sense to load the
registers and attempt to save them directly. The direct save may fail
but should only happen on the first invocation or after fork() while the
page is read-only.
[ bp: Massage a bit. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-27-bigeasy@linutronix.de
Try to save the FPU registers directly to the userland stack frame if
the CPU holds the FPU registers for the current task. This has to be
done with the pagefault disabled because we can't fault (while the FPU
registers are locked) and therefore the operation might fail. If it
fails try the slowpath which can handle faults.
[ bp: Massage a bit. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-26-bigeasy@linutronix.de
The previous commits refactor the restoration of the FPU registers so
that they can be loaded from in-kernel memory. This overhead can be
avoided if the load can be performed without a pagefault.
Attempt to restore FPU registers by invoking
copy_user_to_fpregs_zeroing(). If it fails try the slowpath which can
handle pagefaults.
[ bp: Add a comment over the fastpath to be able to find one's way
around the function. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-25-bigeasy@linutronix.de
Defer loading of FPU state until return to userspace. This gives
the kernel the potential to skip loading FPU state for tasks that
stay in kernel mode, or for tasks that end up with repeated
invocations of kernel_fpu_begin() & kernel_fpu_end().
The fpregs_lock/unlock() section ensures that the registers remain
unchanged. Otherwise a context switch or a bottom half could save the
registers to its FPU context and the processor's FPU registers would
became random if modified at the same time.
KVM swaps the host/guest registers on entry/exit path. This flow has
been kept as is. First it ensures that the registers are loaded and then
saves the current (host) state before it loads the guest's registers. The
swap is done at the very end with disabled interrupts so it should not
change anymore before theg guest is entered. The read/save version seems
to be cheaper compared to memcpy() in a micro benchmark.
Each thread gets TIF_NEED_FPU_LOAD set as part of fork() / fpu__copy().
For kernel threads, this flag gets never cleared which avoids saving /
restoring the FPU state for kernel threads and during in-kernel usage of
the FPU registers.
[
bp: Correct and update commit message and fix checkpatch warnings.
s/register/registers/ where it is used in plural.
minor comment corrections.
remove unused trace_x86_fpu_activate_state() TP.
]
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: Babu Moger <Babu.Moger@amd.com>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Waiman Long <longman@redhat.com>
Cc: x86-ml <x86@kernel.org>
Cc: Yi Wang <wang.yi59@zte.com.cn>
Link: https://lkml.kernel.org/r/20190403164156.19645-24-bigeasy@linutronix.de
The ia32_fxstate case (32bit with fxsr) and the other (64bit frames or
32bit frames without fxsr) restore both from kernel memory and sanitize
the content.
The !ia32_fxstate version restores missing xstates from "init state"
while the ia32_fxstate doesn't and skips it.
Merge the two code paths and keep the !ia32_fxstate one. Copy only the
user_i387_ia32_struct data structure in the ia32_fxstate.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-23-bigeasy@linutronix.de
The 64-bit case (both 64-bit and 32-bit frames) loads the new state from
user memory.
However, doing this is not desired if the FPU state is going to be
restored on return to userland: it would be required to disable
preemption in order to avoid a context switch which would set
TIF_NEED_FPU_LOAD. If this happens before the restore operation then the
loaded registers would become volatile.
Furthermore, disabling preemption while accessing user memory requires
to disable the pagefault handler. An error during FXRSTOR would then
mean that either a page fault occurred (and it would have to be retried
with enabled page fault handler) or a #GP occurred because the xstate is
bogus (after all, the signal handler can modify it).
In order to avoid that mess, copy the FPU state from userland, validate
it and then load it. The copy_kernel_…() helpers are basically just
like the old helpers except that they operate on kernel memory and the
fault handler just sets the error value and the caller handles it.
copy_user_to_fpregs_zeroing() and its helpers remain and will be used
later for a fastpath optimisation.
[ bp: Clarify commit message. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-22-bigeasy@linutronix.de
Start refactoring __fpu__restore_sig() by inlining
copy_user_to_fpregs_zeroing(). The original function remains and will be
used to restore from userland memory if possible.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-21-bigeasy@linutronix.de
During the context switch the xstate is loaded which also includes the
PKRU value.
If xstate is restored on return to userland it is required
that the PKRU value in xstate is the same as the one in the CPU.
Save the PKRU in xstate during modification.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-20-bigeasy@linutronix.de
The FPU registers need only to be saved if TIF_NEED_FPU_LOAD is not set.
Otherwise this has been already done and can be skipped.
[ bp: Massage a bit. ]
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-19-bigeasy@linutronix.de
copy_fpstate_to_sigframe() stores the registers directly to user space.
This is okay because the FPU registers are valid and saving them
directly avoids saving them into kernel memory and making a copy.
However, this cannot be done anymore if the FPU registers are going
to be restored on the return to userland. It is possible that the FPU
registers will be invalidated in the middle of the save operation and
this should be done with disabled preemption / BH.
Save the FPU registers to the task's FPU struct and copy them to the
user memory later on.
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-18-bigeasy@linutronix.de
Add TIF_NEED_FPU_LOAD. This flag is used for loading the FPU registers
before returning to userland. It must not be set on systems without a
FPU.
If this flag is cleared, the CPU's FPU registers hold the latest,
up-to-date content of the current task's (current()) FPU registers.
The in-memory copy (union fpregs_state) is not valid.
If this flag is set, then all of CPU's FPU registers may hold a random
value (except for PKRU) and it is required to load the content of the
FPU registers on return to userland.
Introduce it now as a preparatory change before adding the main feature.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-17-bigeasy@linutronix.de
While most of a task's FPU state is only needed in user space, the
protection keys need to be in place immediately after a context switch.
The reason is that any access to userspace memory while running in
kernel mode also needs to abide by the memory permissions specified in
the protection keys.
The "eager switch" is a preparation for loading the FPU state on return
to userland. Instead of decoupling PKRU state from xstate, update PKRU
within xstate on write operations by the kernel.
For user tasks the PKRU should be always read from the xsave area and it
should not change anything because the PKRU value was loaded as part of
FPU restore.
For kernel threads the default "init_pkru_value" will be written. Before
this commit, the kernel thread would end up with a random value which it
inherited from the previous user task.
[ bigeasy: save pkru to xstate, no cache, don't use __raw_xsave_addr() ]
[ bp: update commit message, sort headers properly in asm/fpu/xstate.h ]
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-16-bigeasy@linutronix.de
write_pkru() checks if the current value is the same as the expected
value. So instead of just checking if the current and new value is zero
(and skip the write in such a case) we can benefit from that.
Remove the zero check of PKRU, __write_pkru() provides such a check now.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-15-bigeasy@linutronix.de
According to Dave Hansen, WRPKRU is more expensive than RDPKRU. It has
a higher cycle cost and it's also practically a (light) speculation
barrier.
As an optimisation read the current PKRU value and only write the new
one if it is different.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-14-bigeasy@linutronix.de
Dave Hansen asked for __read_pkru() and __write_pkru() to be
symmetrical.
As part of the series __write_pkru() will read back the value and only
write it if it is different.
In order to make both functions symmetrical, move the function
containing only the opcode asm into a function called like the
instruction itself.
__write_pkru() will just invoke wrpkru() but in a follow-up patch will
also read back the value.
[ bp: Convert asm opcode wrapper names to rd/wrpkru(). ]
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-13-bigeasy@linutronix.de
This is the ancient loading interface which requires special tools to be
used. The bigger problem with it is that it is as inadequate for proper
loading of microcode as the late microcode loading interface is because
it happens just as late.
iucode_tool's manpage already warns people that it is deprecated.
Deprecate it and turn it off by default along with a big fat warning in
the Kconfig help. It will go away sometime in the future.
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Link: https://lkml.kernel.org/r/20190405133010.24249-4-bp@alien8.de
Commit
2613f36ed9 ("x86/microcode: Attempt late loading only when new microcode is present")
added the new define UCODE_NEW to denote that an update should happen
only when newer microcode (than installed on the system) has been found.
But it missed adjusting that for the old /dev/cpu/microcode loading
interface. Fix it.
Fixes: 2613f36ed9 ("x86/microcode: Attempt late loading only when new microcode is present")
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jann Horn <jannh@google.com>
Link: https://lkml.kernel.org/r/20190405133010.24249-3-bp@alien8.de
As reported by 0-DAY kernel test infrastructure:
arch/x86//kernel/ima_arch.c: In function 'arch_get_ima_policy':
>> arch/x86//kernel/ima_arch.c:78:4: error: implicit declaration of
function 'set_module_sig_enforced' [-Werror=implicit-function-declaration]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Change generic_load_microcode() to use the iov_iter API instead of a
clumsy open-coded version which has to pay attention to __user data
or kernel data, depending on the loading method. This allows to avoid
explicit casting between user and kernel pointers.
Because the iov_iter API makes it hard to read the same location twice,
as a side effect, also fix a double-read of the microcode header (which
could e.g. lead to out-of-bounds reads in microcode_sanity_check()).
Not that it matters much, only root is allowed to load microcode
anyway...
[ bp: Massage a bit, sort function-local variables. ]
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190404111128.131157-1-jannh@google.com
After changing the argument of __raw_xsave_addr() from a mask to
number Dave suggested to check if it makes sense to do the same for
get_xsave_addr(). As it turns out it does.
Only get_xsave_addr() needs the mask to check if the requested feature
is part of what is supported/saved and then uses the number again. The
shift operation is cheaper compared to fls64() (find last bit set).
Also, the feature number uses less opcode space compared to the mask. :)
Make the get_xsave_addr() argument a xfeature number instead of a mask
and fix up its callers.
Furthermore, use xfeature_nr and xfeature_mask consistently.
This results in the following changes to the kvm code:
feature -> xfeature_mask
index -> xfeature_nr
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Siarhei Liakh <Siarhei.Liakh@concurrent-rt.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-12-bigeasy@linutronix.de
Most users of __raw_xsave_addr() use a feature number, shift it to a
mask and then __raw_xsave_addr() shifts it back to the feature number.
Make __raw_xsave_addr() use the feature number as an argument.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-11-bigeasy@linutronix.de
Add a helper function that ensures the floating point registers for the
current task are active. Use with preemption disabled.
While at it, add fpregs_lock/unlock() helpers too, to be used in later
patches.
[ bp: Add a comment about its intended usage. ]
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-10-bigeasy@linutronix.de
user_fpu_begin() sets fpu_fpregs_owner_ctx to task's fpu struct. This is
always the case since there is no lazy FPU anymore.
fpu_fpregs_owner_ctx is used during context switch to decide if it needs
to load the saved registers or if the currently loaded registers are
valid. It could be skipped during a
taskA -> kernel thread -> taskA
switch because the switch to the kernel thread would not alter the CPU's
sFPU tate.
Since this field is always updated during context switch and
never invalidated, setting it manually (in user context) makes no
difference. A kernel thread with kernel_fpu_begin() block could
set fpu_fpregs_owner_ctx to NULL but a kernel thread does not use
user_fpu_begin().
This is a leftover from the lazy-FPU time.
Remove user_fpu_begin(), it does not change fpu_fpregs_owner_ctx's
content.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-9-bigeasy@linutronix.de
The struct fpu.initialized member is always set to one for user tasks
and zero for kernel tasks. This avoids saving/restoring the FPU
registers for kernel threads.
The ->initialized = 0 case for user tasks has been removed in previous
changes, for instance, by doing an explicit unconditional init at fork()
time for FPU-less systems which was otherwise delayed until the emulated
opcode.
The context switch code (switch_fpu_prepare() + switch_fpu_finish())
can't unconditionally save/restore registers for kernel threads. Not
only would it slow down the switch but also load a zeroed xcomp_bv for
XSAVES.
For kernel_fpu_begin() (+end) the situation is similar: EFI with runtime
services uses this before alternatives_patched is true. Which means that
this function is used too early and it wasn't the case before.
For those two cases, use current->mm to distinguish between user and
kernel thread. For kernel_fpu_begin() skip save/restore of the FPU
registers.
During the context switch into a kernel thread don't do anything. There
is no reason to save the FPU state of a kernel thread.
The reordering in __switch_to() is important because the current()
pointer needs to be valid before switch_fpu_finish() is invoked so ->mm
is seen of the new task instead the old one.
N.B.: fpu__save() doesn't need to check ->mm because it is called by
user tasks only.
[ bp: Massage. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: Babu Moger <Babu.Moger@amd.com>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-8-bigeasy@linutronix.de
In commit
72a671ced6 ("x86, fpu: Unify signal handling code paths for x86 and x86_64 kernels")
the 32bit and 64bit path of the signal delivery code were merged.
The 32bit version:
int save_i387_xstate_ia32(void __user *buf)
…
if (cpu_has_xsave)
return save_i387_xsave(fp);
if (cpu_has_fxsr)
return save_i387_fxsave(fp);
The 64bit version:
int save_i387_xstate(void __user *buf)
…
if (user_has_fpu()) {
if (use_xsave())
err = xsave_user(buf);
else
err = fxsave_user(buf);
if (unlikely(err)) {
__clear_user(buf, xstate_size);
return err;
The merge:
int save_xstate_sig(void __user *buf, void __user *buf_fx, int size)
…
if (user_has_fpu()) {
/* Save the live register state to the user directly. */
if (save_user_xstate(buf_fx))
return -1;
/* Update the thread's fxstate to save the fsave header. */
if (ia32_fxstate)
fpu_fxsave(&tsk->thread.fpu);
I don't think that we needed to save the FPU registers to ->thread.fpu
because the registers were stored in buf_fx. Today the state will be
restored from buf_fx after the signal was handled (I assume that this
was also the case with lazy-FPU).
Since commit
66463db4fc ("x86, fpu: shift drop_init_fpu() from save_xstate_sig() to handle_signal()")
it is ensured that the signal handler starts with clear/fresh set of FPU
registers which means that the previous store is futile.
Remove the copy_fxregs_to_kernel() call because task's FPU state is
cleared later in handle_signal() via fpu__clear().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-7-bigeasy@linutronix.de
Spurious interrupt support was added to perf in the following commit, almost
a decade ago:
63e6be6d98 ("perf, x86: Catch spurious interrupts after disabling counters")
The two previous patches (resolving the race condition when disabling a
PMC and NMI latency mitigation) allow for the removal of this older
spurious interrupt support.
Currently in x86_pmu_stop(), the bit for the PMC in the active_mask bitmap
is cleared before disabling the PMC, which sets up a race condition. This
race condition was mitigated by introducing the running bitmap. That race
condition can be eliminated by first disabling the PMC, waiting for PMC
reset on overflow and then clearing the bit for the PMC in the active_mask
bitmap. The NMI handler will not re-enable a disabled counter.
If x86_pmu_stop() is called from the perf NMI handler, the NMI latency
mitigation support will guard against any unhandled NMI messages.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org> # 4.14.x-
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lkml.kernel.org/r/Message-ID:
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The QUEUED_LOCK_STAT option to report queued spinlocks event counts
was previously allowed only on x86 architecture. To make the locking
event counting code more useful, it is now renamed to a more generic
LOCK_EVENT_COUNTS config option. This new option will be available to
all the architectures that use qspinlock at the moment.
Other locking code can now start to use the generic locking event
counting code by including lock_events.h and put the new locking event
names into the lock_events_list.h header file.
My experience with lock event counting is that it gives valuable insight
on how the locking code works and what can be done to make it better. I
would like to extend this benefit to other locking code like mutex and
rwsem in the near future.
The PV qspinlock specific code will stay in qspinlock_stat.h. The
locking event counters will now reside in the <debugfs>/lock_event_counts
directory.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20190404174320.22416-9-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add missing instruction suffixes and use rmwcc.h just like was (more or less)
recently done for bitops.h as well, see:
22636f8c95: x86/asm: Add instruction suffixes to bitops
288e4521f0: x86/asm: 'Simplify' GEN_*_RMWcc() macros
No change in functionality intended.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/5C9B93870200007800222289@prv1-mh.provo.novell.com
[ Cleaned up the changelog a bit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With lazy-FPU support the (now named variable) ->initialized was set to
true if the CPU's FPU registers were holding a valid state of the
FPU registers for the active process. If it was set to false then the
FPU state was saved in fpu->state and the FPU was deactivated.
With lazy-FPU gone, ->initialized is always true for user threads and
kernel threads never call this function so ->initialized is always true
in copy_fpstate_to_sigframe().
The using_compacted_format() check is also a leftover from the lazy-FPU
time. In the
->initialized == false
case copy_to_user() would copy the compacted buffer while userland would
expect the non-compacted format instead. So in order to save the FPU
state in the non-compacted form it issues XSAVE to save the *current*
FPU state.
If the FPU is not enabled, the attempt raises the FPU trap, the trap
restores the FPU contents and re-enables the FPU and XSAVE is invoked
again and succeeds.
*This* does not longer work since commit
bef8b6da95 ("x86/fpu: Handle #NM without FPU emulation as an error")
Remove the check for ->initialized because it is always true and remove
the false condition. Update the comment to reflect that the state is
always live.
[ bp: Massage. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-6-bigeasy@linutronix.de
fpu__clear() only initializes the state if the CPU has FPU support.
This initialisation is also required for FPU-less systems and takes
place in math_emulate(). Since fpu__initialize() only performs the
initialization if ->initialized is zero it does not matter that it
is invoked each time an opcode is emulated. It makes the removal of
->initialized easier if the struct is also initialized in the FPU-less
case at the same time.
Move fpu__initialize() before the FPU feature check so it is also
performed in the FPU-less case too.
[ bp: Massage a bit. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: Bill Metzenthen <billm@melbpc.org.au>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-5-bigeasy@linutronix.de
The preempt_disable() section was introduced in commit
a10b6a16cd ("x86/fpu: Make the fpu state change in fpu__clear() scheduler-atomic")
and it was said to be temporary.
fpu__initialize() initializes the FPU struct to its initial value and
then sets ->initialized to 1. The last part is the important one.
The content of the state does not matter because it gets set via
copy_init_fpstate_to_fpregs().
A preemption here has little meaning because the registers will always be
set to the same content after copy_init_fpstate_to_fpregs(). A softirq
with a kernel_fpu_begin() could also force to save FPU's registers after
fpu__initialize() without changing the outcome here.
Remove the preempt_disable() section in fpu__clear(), preemption here
does not hurt.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-4-bigeasy@linutronix.de
There are no users of fpu__restore() so it is time to remove it. The
comment regarding fpu__restore() and TS bit is stale since commit
b3b0870ef3 ("i387: do not preload FPU state at task switch time")
and has no meaning since.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: Babu Moger <Babu.Moger@amd.com>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: linux-doc@vger.kernel.org
Cc: Nicolai Stange <nstange@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-3-bigeasy@linutronix.de
This is a preparation for the removal of the ->initialized member in the
fpu struct.
__fpu__restore_sig() is deactivating the FPU via fpu__drop() and then
setting manually ->initialized followed by fpu__restore(). The result is
that it is possible to manipulate fpu->state and the state of registers
won't be saved/restored on a context switch which would overwrite
fpu->state:
fpu__drop(fpu):
...
fpu->initialized = 0;
preempt_enable();
<--- context switch
Don't access the fpu->state while the content is read from user space
and examined/sanitized. Use a temporary kmalloc() buffer for the
preparation of the FPU registers and once the state is considered okay,
load it. Should something go wrong, return with an error and without
altering the original FPU registers.
The removal of fpu__initialize() is a nop because fpu->initialized is
already set for the user task.
[ bp: Massage a bit. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-2-bigeasy@linutronix.de
ACPICA commit 92ec0935f27e217dff0b176fca02c2ec3d782bb5
ACPI_COMPARE_NAME changed to ACPI_COMPARE_NAMESEG
This clarifies (1) this is a compare on 4-byte namesegs, not
a generic compare. Improves understanding of the code.
Link: https://github.com/acpica/acpica/commit/92ec0935
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Erik Schmauss <erik.schmauss@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Now that we removed support for the NULL device argument in the DMA API,
there is no need to cater for that in the x86 code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
x86 maps mmiowb() to barrier(), but this is superfluous because a
compiler barrier is already implied by spin_unlock(). Since x86 also
includes asm-generic/io.h in its asm/io.h file, remove the definition
entirely and pick up the dummy definition from core code.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Hook up asm-generic/mmiowb.h to Kbuild for all architectures so that we
can subsequently include asm/mmiowb.h from core code.
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Using static_cpu_has() is pointless on those paths, convert them to the
boot_cpu_has() variant.
No functional changes.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Link: https://lkml.kernel.org/r/20190330112022.28888-5-bp@alien8.de
Using static_cpu_has() is pointless on those paths, convert them to the
boot_cpu_has() variant.
No functional changes.
Reported-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Juergen Gross <jgross@suse.com> # for paravirt
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Thomas Lendacky <Thomas.Lendacky@amd.com>
Cc: linux-edac@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: virtualization@lists.linux-foundation.org
Cc: x86@kernel.org
Link: https://lkml.kernel.org/r/20190330112022.28888-3-bp@alien8.de
The x86_64 implementation of Poly1305 produces the wrong result on some
inputs because poly1305_4block_avx2() incorrectly assumes that when
partially reducing the accumulator, the bits carried from limb 'd4' to
limb 'h0' fit in a 32-bit integer. This is true for poly1305-generic
which processes only one block at a time. However, it's not true for
the AVX2 implementation, which processes 4 blocks at a time and
therefore can produce intermediate limbs about 4x larger.
Fix it by making the relevant calculations use 64-bit arithmetic rather
than 32-bit. Note that most of the carries already used 64-bit
arithmetic, but the d4 -> h0 carry was different for some reason.
To be safe I also made the same change to the corresponding SSE2 code,
though that only operates on 1 or 2 blocks at a time. I don't think
it's really needed for poly1305_block_sse2(), but it doesn't hurt
because it's already x86_64 code. It *might* be needed for
poly1305_2block_sse2(), but overflows aren't easy to reproduce there.
This bug was originally detected by my patches that improve testmgr to
fuzz algorithms against their generic implementation. But also add a
test vector which reproduces it directly (in the AVX2 case).
Fixes: b1ccc8f4b6 ("crypto: poly1305 - Add a four block AVX2 variant for x86_64")
Fixes: c70f4abef0 ("crypto: poly1305 - Add a SSE2 SIMD variant for x86_64")
Cc: <stable@vger.kernel.org> # v4.3+
Cc: Martin Willi <martin@strongswan.org>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The ->digest() method of crct10dif-pclmul reads the current CRC value
from the shash_desc context. But this value is uninitialized, causing
crypto_shash_digest() to compute the wrong result. Fix it.
Probably this wasn't noticed before because lib/crc-t10dif.c only uses
crypto_shash_update(), not crypto_shash_digest(). Likewise,
crypto_shash_digest() is not yet tested by the crypto self-tests because
those only test the ahash API which only uses shash init/update/final.
Fixes: 0b95a7f857 ("crypto: crct10dif - Glue code to cast accelerated CRCT10DIF assembly as a crypto transform")
Cc: <stable@vger.kernel.org> # v3.11+
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The Performance and Energy Bias Hint (EPB) is expected to be set by
user space through the generic MSR interface, but that interface is
not particularly nice and there are security concerns regarding it,
so it is not always available.
For this reason, add a sysfs interface for reading and updating the
EPB, in the form of a new attribute, energy_perf_bias, located
under /sys/devices/system/cpu/cpu#/power/ for online CPUs that
support the EPB feature.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Borislav Petkov <bp@suse.de>
The current handling of MSR_IA32_ENERGY_PERF_BIAS in the kernel is
problematic, because it may cause changes made by user space to that
MSR (with the help of the x86_energy_perf_policy tool, for example)
to be lost every time a CPU goes offline and then back online as well
as during system-wide power management transitions into sleep states
and back into the working state.
The first problem is that if the current EPB value for a CPU going
online is 0 ('performance'), the kernel will change it to 6 ('normal')
regardless of whether or not this is the first bring-up of that CPU.
That also happens during system-wide resume from sleep states
(including, but not limited to, hibernation). However, the EPB may
have been adjusted by user space this way and the kernel should not
blindly override that setting.
The second problem is that if the platform firmware resets the EPB
values for any CPUs during system-wide resume from a sleep state,
the kernel will not restore their previous EPB values that may
have been set by user space before the preceding system-wide
suspend transition. Again, that behavior may at least be confusing
from the user space perspective.
In order to address these issues, rework the handling of
MSR_IA32_ENERGY_PERF_BIAS so that the EPB value is saved on CPU
offline and restored on CPU online as well as (for the boot CPU)
during the syscore stages of system-wide suspend and resume
transitions, respectively.
However, retain the policy by which the EPB is set to 6 ('normal')
on the first bring-up of each CPU if its initial value is 0, based
on the observation that 0 may mean 'not initialized' just as well as
'performance' in that case.
While at it, move the MSR_IA32_ENERGY_PERF_BIAS handling code into
a separate file and document it in Documentation/admin-guide.
Fixes: abe48b1082 (x86, intel, power: Initialize MSR_IA32_ENERGY_PERF_BIAS)
Fixes: b51ef52df7 (x86/cpu: Restore MSR_IA32_ENERGY_PERF_BIAS after resume)
Reported-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
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Merge tag 'for-linus-5.1b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
"One minor fix and a small cleanup for the xen privcmd driver"
* tag 'for-linus-5.1b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: Prevent buffer overflow in privcmd ioctl
xen: use struct_size() helper in kzalloc()
There's a number of problems with how arch/x86/include/asm/bitops.h
is currently using assembly constraints for the memory region
bitops are modifying:
1) Use memory clobber in bitops that touch arbitrary memory
Certain bit operations that read/write bits take a base pointer and an
arbitrarily large offset to address the bit relative to that base.
Inline assembly constraints aren't expressive enough to tell the
compiler that the assembly directive is going to touch a specific memory
location of unknown size, therefore we have to use the "memory" clobber
to indicate that the assembly is going to access memory locations other
than those listed in the inputs/outputs.
To indicate that BTR/BTS instructions don't necessarily touch the first
sizeof(long) bytes of the argument, we also move the address to assembly
inputs.
This particular change leads to size increase of 124 kernel functions in
a defconfig build. For some of them the diff is in NOP operations, other
end up re-reading values from memory and may potentially slow down the
execution. But without these clobbers the compiler is free to cache
the contents of the bitmaps and use them as if they weren't changed by
the inline assembly.
2) Use byte-sized arguments for operations touching single bytes.
Passing a long value to ANDB/ORB/XORB instructions makes the compiler
treat sizeof(long) bytes as being clobbered, which isn't the case. This
may theoretically lead to worse code in the case of heavy optimization.
Practical impact:
I've built a defconfig kernel and looked through some of the functions
generated by GCC 7.3.0 with and without this clobber, and didn't spot
any miscompilations.
However there is a (trivial) theoretical case where this code leads to
miscompilation:
https://lkml.org/lkml/2019/3/28/393
using just GCC 8.3.0 with -O2. It isn't hard to imagine someone writes
such a function in the kernel someday.
So the primary motivation is to fix an existing misuse of the asm
directive, which happens to work in certain configurations now, but
isn't guaranteed to work under different circumstances.
[ --mingo: Added -stable tag because defconfig only builds a fraction
of the kernel and the trivial testcase looks normal enough to
be used in existing or in-development code. ]
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: <stable@vger.kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: James Y Knight <jyknight@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20190402112813.193378-1-glider@google.com
[ Edited the changelog, tidied up one of the defines. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The current code builds identity mapping for the real mode trampoline by
borrowing page tables from the direct mapping section if KASLR is
enabled. It copies present entries of the first PUD table in 4-level paging
mode, or the first P4D table in 5-level paging mode.
However, there's only a very small area under low 1 MB reserved for the
real mode trampoline in reserve_real_mode() so it makes no sense to build
up a really large mapping for it.
Reduce it to one PUD (1GB) entry. This matches the randomization
granularity in 4-level paging mode and allows to change the randomization
granularity in 5-level paging mode from 512GB to 1GB later.
[ tglx: Massaged changelog and comments ]
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: dave.hansen@linux.intel.com
Cc: luto@kernel.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: hpa@zytor.com
Cc: keescook@chromium.org
Cc: thgarnie@google.com
Link: https://lkml.kernel.org/r/20190308025616.21440-2-bhe@redhat.com
Referring to the "VIRTUALIZING MSR-BASED APIC ACCESSES" chapter of the
SDM, when "virtualize x2APIC mode" is 1 and "APIC-register
virtualization" is 0, a RDMSR of 808H should return the VTPR from the
virtual APIC page.
However, for nested, KVM currently fails to disable the read intercept
for this MSR. This means that a RDMSR exit takes precedence over
"virtualize x2APIC mode", and KVM passes through L1's TPR to L2,
instead of sourcing the value from L2's virtual APIC page.
This patch fixes the issue by disabling the read intercept, in VMCS02,
for the VTPR when "APIC-register virtualization" is 0.
The issue described above and fix prescribed here, were verified with
a related patch in kvm-unit-tests titled "Test VMX's virtualize x2APIC
mode w/ nested".
Signed-off-by: Marc Orr <marcorr@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Fixes: c992384bde ("KVM: vmx: speed up MSR bitmap merge")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The nested_vmx_prepare_msr_bitmap() function doesn't directly guard the
x2APIC MSR intercepts with the "virtualize x2APIC mode" MSR. As a
result, we discovered the potential for a buggy or malicious L1 to get
access to L0's x2APIC MSRs, via an L2, as follows.
1. L1 executes WRMSR(IA32_SPEC_CTRL, 1). This causes the spec_ctrl
variable, in nested_vmx_prepare_msr_bitmap() to become true.
2. L1 disables "virtualize x2APIC mode" in VMCS12.
3. L1 enables "APIC-register virtualization" in VMCS12.
Now, KVM will set VMCS02's x2APIC MSR intercepts from VMCS12, and then
set "virtualize x2APIC mode" to 0 in VMCS02. Oops.
This patch closes the leak by explicitly guarding VMCS02's x2APIC MSR
intercepts with VMCS12's "virtualize x2APIC mode" control.
The scenario outlined above and fix prescribed here, were verified with
a related patch in kvm-unit-tests titled "Add leak scenario to
virt_x2apic_mode_test".
Note, it looks like this issue may have been introduced inadvertently
during a merge---see 15303ba5d1.
Signed-off-by: Marc Orr <marcorr@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This ensures that the address and length provided to DBG_DECRYPT and
DBG_ENCRYPT do not cause an overflow.
At the same time, pass the actual number of pages pinned in memory to
sev_unpin_memory() as a cleanup.
Reported-by: Cfir Cohen <cfir@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
get_num_contig_pages() could potentially overflow int so make its type
consistent with its usage.
Reported-by: Cfir Cohen <cfir@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Since the enabling and disabling of IRQs within preempt_schedule_irq() is
contained in a need_resched() loop, there is no need for the outer
architecture specific loop.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20190311224752.8337-14-valentin.schneider@arm.com
One of the more common cases of allocation size calculations is finding the
size of a structure that has a zero-sized array at the end, along with
memory for some number of elements for that array. For example:
struct foo {
int stuff;
struct boo entry[];
};
instance = vzalloc(sizeof(struct foo) + count * sizeof(struct boo));
Instead of leaving these open-coded and prone to type mistakes, use the new
struct_size() helper:
instance = vzalloc(struct_size(instance, entry, count));
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20190403184230.GA5295@embeddedor
The LLVM linker (ld.lld) defaults to removing local relocations, which
causes KASLR boot failures. ld.bfd and ld.gold already handle this
correctly. This adds the explicit instruction "--discard-none" during
the link phase. There is no change in output for ld.bfd and ld.gold,
but ld.lld now produces an image with all the needed relocations.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: clang-built-linux@googlegroups.com
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190404214027.GA7324@beast
Link: https://github.com/ClangBuiltLinux/linux/issues/404
The "call" variable comes from the user in privcmd_ioctl_hypercall().
It's an offset into the hypercall_page[] which has (PAGE_SIZE / 32)
elements. We need to put an upper bound on it to prevent an out of
bounds access.
Cc: stable@vger.kernel.org
Fixes: 1246ae0bb9 ("xen: add variable hypercall caller")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Parsing entries in an ACPI table had assumed a generic header
structure. There is no standard ACPI header, though, so less common
layouts with different field sizes required custom parsers to go through
their subtable entry list.
Create the infrastructure for adding different table types so parsing
the entries array may be more reused for all ACPI system tables and
the common code doesn't need to be duplicated.
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Tested-by: Brice Goglin <Brice.Goglin@inria.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The first two arguments of __user_atomic_cmpxchg_inatomic() are:
- @uval is a kernel pointer into which the old value should be stored
- @ptr is the user pointer on which the cmpxchg should operate
This means that casting @uval to __typeof__(ptr) is wrong. Since @uval
is only used once inside the macro, just get rid of __uval and use
(uval) directly.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190329214652.258477-4-jannh@google.com
Currently, we have two different implementation of rwsem:
1) CONFIG_RWSEM_GENERIC_SPINLOCK (rwsem-spinlock.c)
2) CONFIG_RWSEM_XCHGADD_ALGORITHM (rwsem-xadd.c)
As we are going to use a single generic implementation for rwsem-xadd.c
and no architecture-specific code will be needed, there is no point
in keeping two different implementations of rwsem. In most cases, the
performance of rwsem-spinlock.c will be worse. It also doesn't get all
the performance tuning and optimizations that had been implemented in
rwsem-xadd.c over the years.
For simplication, we are going to remove rwsem-spinlock.c and make all
architectures use a single implementation of rwsem - rwsem-xadd.c.
All references to RWSEM_GENERIC_SPINLOCK and RWSEM_XCHGADD_ALGORITHM
in the code are removed.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: nios2-dev@lists.rocketboards.org
Cc: openrisc@lists.librecores.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Link: https://lkml.kernel.org/r/20190322143008.21313-3-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As the generic rwsem-xadd code is using the appropriate acquire and
release versions of the atomic operations, the arch specific rwsem.h
files will not be that much faster than the generic code as long as the
atomic functions are properly implemented. So we can remove those arch
specific rwsem.h and stop building asm/rwsem.h to reduce maintenance
effort.
Currently, only x86, alpha and ia64 have implemented architecture
specific fast paths. I don't have access to alpha and ia64 systems for
testing, but they are legacy systems that are not likely to be updated
to the latest kernel anyway.
By using a rwsem microbenchmark, the total locking rates on a 4-socket
56-core 112-thread x86-64 system before and after the patch were as
follows (mixed means equal # of read and write locks):
Before Patch After Patch
# of Threads wlock rlock mixed wlock rlock mixed
------------ ----- ----- ----- ----- ----- -----
1 29,201 30,143 29,458 28,615 30,172 29,201
2 6,807 13,299 1,171 7,725 15,025 1,804
4 6,504 12,755 1,520 7,127 14,286 1,345
8 6,762 13,412 764 6,826 13,652 726
16 6,693 15,408 662 6,599 15,938 626
32 6,145 15,286 496 5,549 15,487 511
64 5,812 15,495 60 5,858 15,572 60
There were some run-to-run variations for the multi-thread tests. For
x86-64, using the generic C code fast path seems to be a little bit
faster than the assembly version with low lock contention. Looking at
the assembly version of the fast paths, there are assembly to/from C
code wrappers that save and restore all the callee-clobbered registers
(7 registers on x86-64). The assembly generated from the generic C
code doesn't need to do that. That may explain the slight performance
gain here.
The generic asm rwsem.h can also be merged into kernel/locking/rwsem.h
with no code change as no other code other than those under
kernel/locking needs to access the internal rwsem macros and functions.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: nios2-dev@lists.rocketboards.org
Cc: openrisc@lists.librecores.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Link: https://lkml.kernel.org/r/20190322143008.21313-2-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In save_xstate_epilog(), use __user when type-casting userspace
pointers.
In setup_sigcontext() and x32_setup_rt_frame(), cast the userspace
pointers to 'unsigned long __user *' before writing into them. These
pointers are originally '__u32 __user *' or '__u64 __user *', causing
sparse to complain when a userspace pointer is written into them. The
casts are okay because the pointers always point to pointer-sized
values.
Thanks to Luc Van Oostenryck and Al Viro for explaining this to me.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mukesh Ojha <mojha@codeaurora.org>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190329214652.258477-3-jannh@google.com
On AMD processors, the detection of an overflowed PMC counter in the NMI
handler relies on the current value of the PMC. So, for example, to check
for overflow on a 48-bit counter, bit 47 is checked to see if it is 1 (not
overflowed) or 0 (overflowed).
When the perf NMI handler executes it does not know in advance which PMC
counters have overflowed. As such, the NMI handler will process all active
PMC counters that have overflowed. NMI latency in newer AMD processors can
result in multiple overflowed PMC counters being processed in one NMI and
then a subsequent NMI, that does not appear to be a back-to-back NMI, not
finding any PMC counters that have overflowed. This may appear to be an
unhandled NMI resulting in either a panic or a series of messages,
depending on how the kernel was configured.
To mitigate this issue, add an AMD handle_irq callback function,
amd_pmu_handle_irq(), that will invoke the common x86_pmu_handle_irq()
function and upon return perform some additional processing that will
indicate if the NMI has been handled or would have been handled had an
earlier NMI not handled the overflowed PMC. Using a per-CPU variable, a
minimum value of the number of active PMCs or 2 will be set whenever a
PMC is active. This is used to indicate the possible number of NMIs that
can still occur. The value of 2 is used for when an NMI does not arrive
at the LAPIC in time to be collapsed into an already pending NMI. Each
time the function is called without having handled an overflowed counter,
the per-CPU value is checked. If the value is non-zero, it is decremented
and the NMI indicates that it handled the NMI. If the value is zero, then
the NMI indicates that it did not handle the NMI.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org> # 4.14.x-
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lkml.kernel.org/r/Message-ID:
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On AMD processors, the detection of an overflowed counter in the NMI
handler relies on the current value of the counter. So, for example, to
check for overflow on a 48 bit counter, bit 47 is checked to see if it
is 1 (not overflowed) or 0 (overflowed).
There is currently a race condition present when disabling and then
updating the PMC. Increased NMI latency in newer AMD processors makes this
race condition more pronounced. If the counter value has overflowed, it is
possible to update the PMC value before the NMI handler can run. The
updated PMC value is not an overflowed value, so when the perf NMI handler
does run, it will not find an overflowed counter. This may appear as an
unknown NMI resulting in either a panic or a series of messages, depending
on how the kernel is configured.
To eliminate this race condition, the PMC value must be checked after
disabling the counter. Add an AMD function, amd_pmu_disable_all(), that
will wait for the NMI handler to reset any active and overflowed counter
after calling x86_pmu_disable_all().
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org> # 4.14.x-
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lkml.kernel.org/r/Message-ID:
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Stephane reported that the TFA MSR is not initialized by the kernel,
but the TFA bit could set by firmware or as a leftover from a kexec,
which makes the state inconsistent.
Reported-by: Stephane Eranian <eranian@google.com>
Tested-by: Nelson DSouza <nelson.dsouza@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: tonyj@suse.com
Link: https://lkml.kernel.org/r/20190321123849.GN6521@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now that we have objtool validating AC=1 state for all x86_64 code,
we can once again guarantee clean flags on schedule.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Linus noticed all users of __ASM_STAC/__ASM_CLAC are with
__stringify(). Just make them a string.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Introduce common helpers for when we need to safely suspend a
uaccess section; for instance to generate a {KA,UB}SAN report.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Make issuing a TLB invalidate for page-table pages the normal case.
The reason is twofold:
- too many invalidates is safer than too few,
- most architectures use the linux page-tables natively
and would thus require this.
Make it an opt-out, instead of an opt-in.
No change in behavior intended.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Provide a generic tlb_flush() implementation that relies on
flush_tlb_range(). This is a little awkward because flush_tlb_range()
assumes a VMA for range invalidation, but we no longer have one.
Audit of all flush_tlb_range() implementations shows only vma->vm_mm
and vma->vm_flags are used, and of the latter only VM_EXEC (I-TLB
invalidates) and VM_HUGETLB (large TLB invalidate) are used.
Therefore, track VM_EXEC and VM_HUGETLB in two more bits, and create a
'fake' VMA.
This allows architectures that have a reasonably efficient
flush_tlb_range() to not require any additional effort.
No change in behavior intended.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When an event is programmed with attr.wakeup_events=N (N>0), it means
the caller is interested in getting a user level notification after
N samples have been recorded in the kernel sampling buffer.
With precise events on Intel processors, the kernel uses PEBS.
The kernel tries minimize sampling overhead by verifying
if the event configuration is compatible with multi-entry PEBS mode.
If so, the kernel is notified only when the buffer has reached its threshold.
Other PEBS operates in single-entry mode, the kenrel is notified for each
PEBS sample.
The problem is that the current implementation look at frequency
mode and event sample_type but ignores the wakeup_events field. Thus,
it may not be possible to receive a notification after each precise event.
This patch fixes this problem by disabling multi-entry PEBS if wakeup_events
is non-zero.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: kan.liang@intel.com
Link: https://lkml.kernel.org/r/20190306195048.189514-1-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Occasionally GCC is less agressive with inlining and the following is
observed:
arch/x86/kernel/signal.o: warning: objtool: restore_sigcontext()+0x3cc: call to force_valid_ss.isra.5() with UACCESS enabled
arch/x86/kernel/signal.o: warning: objtool: do_signal()+0x384: call to frame_uc_flags.isra.0() with UACCESS enabled
Cure this by moving this code out of the AC=1 region, since it really
isn't needed for the user access.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If GCC out-of-lines it, the STAC and CLAC are in different fuctions
and objtool gets upset.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
drivers/xen/privcmd.o: warning: objtool: privcmd_ioctl()+0x1414: call to hypercall_page() with UACCESS enabled
Some Xen hypercalls allow parameter buffers in user land, so they need
to set AC=1. Avoid the warning for those cases.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andrew.cooper3@citrix.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
New tooling got confused about this:
arch/x86/lib/memcpy_64.o: warning: objtool: .fixup+0x7: return with UACCESS enabled
While the code isn't wrong, it is tedious (if at all possible) to
figure out what function a particular chunk of .fixup belongs to.
This then confuses the objtool uaccess validation. Instead of
returning directly from the .fixup, jump back into the right function.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
By writing the function in asm we avoid cross object code flow and
objtool no longer gets confused about a 'stray' CLAC.
Also; the asm version is actually _simpler_.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Objtool spotted that we call native_load_gs_index() with AC set.
Re-arrange the code to avoid that.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Effectively reverts commit:
2c7577a758 ("sched/x86_64: Don't save flags on context switch")
Specifically because SMAP uses FLAGS.AC which invalidates the claim
that the kernel has clean flags.
In particular; while preemption from interrupt return is fine (the
IRET frame on the exception stack contains FLAGS) it breaks any code
that does synchonous scheduling, including preempt_enable().
This has become a significant issue ever since commit:
5b24a7a2aa ("Add 'unsafe' user access functions for batched accesses")
provided for means of having 'normal' C code between STAC / CLAC,
exposing the FLAGS.AC state. So far this hasn't led to trouble,
however fix it before it comes apart.
Reported-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
Fixes: 5b24a7a2aa ("Add 'unsafe' user access functions for batched accesses")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
By computing the 'committed' index earlier, we can use it to validate
the cached constraint state.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now that cpuc->event_constraint[] is retained, we can avoid calling
get_event_constraints() over and over again.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The current code unconditionally clears cpuc->event_constraint[i]
before calling get_event_constraints(.idx=i). The only site that cares
is intel_get_event_constraints() where the c1 load will always be
NULL.
However, always calling get_event_constraints() on all events is
wastefull, most times it will return the exact same result. Therefore
retain the logic in intel_get_event_constraints() and change the
generic code to only clear the constraint on put.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Stephane Eranian <eranian@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Avoid the POPCNT by noting we can decrement the weight for each
cleared bit.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Stephane Eranian <eranian@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The flag PERF_X86_EVENT_COMMITTED is used to find uncommitted events
for which to call put_event_constraint() when scheduling fails.
These are the newly added events to the list, and must form, per
definition, the tail of cpuc->event_list[]. By computing the list
index of the last successfull schedule, then iteration can start there
and the flag is redundant.
There are only 3 callers of x86_schedule_events(), notably:
- x86_pmu_add()
- x86_pmu_commit_txn()
- validate_group()
For x86_pmu_add(), cpuc->n_events isn't updated until after
schedule_events() succeeds, therefore cpuc->n_events points to the
desired index.
For x86_pmu_commit_txn(), cpuc->n_events is updated, but we can
trivially compute the desired value with cpuc->n_txn -- the number of
events added in this transaction.
For validate_group(), we can make the rule for x86_pmu_add() work by
simply setting cpuc->n_events to 0 before calling schedule_events().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Stephane Eranian <eranian@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There is a special case for validate_events() where we'll call
x86_pmu.get_constraints(.idx=-1). It's purpose, up until recent, seems
to be to avoid taking a previous constraint from
cpuc->event_constraint[] in intel_get_event_constraints().
(I could not find any other get_event_constraints() implementation
using @idx)
However, since that cpuc is freshly allocated, that array will in fact
be initialized with NULL pointers, achieving the very same effect.
Therefore remove this exception.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Stephane Eranian <eranian@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
validate_group() calls x86_schedule_events(.assign=NULL) and therefore
will not call intel_tfa_commit_scheduling(). So there is no point in
checking cpuc->is_fake, we'll never get there.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
MDS is vulnerable with SMT. Make that clear with a one-time printk
whenever SMT first gets enabled.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
arch_smt_update() now has a dependency on both Spectre v2 and MDS
mitigations. Move its initial call to after all the mitigation decisions
have been made.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Add the mds=full,nosmt cmdline option. This is like mds=full, but with
SMT disabled if the CPU is vulnerable.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Let's reserve EHL stolen memory for graphics.
ElkhartLake is a gen11 platform which is compatible with
ICL changes.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20190315191938.22211-2-rodrigo.vivi@intel.com
The user can control the MBA memory bandwidth in MBps (Mega
Bytes per second) units of the MBA Software Controller (mba_sc)
by using the "mba_MBps" mount option. For details, see
Documentation/x86/resctrl_ui.txt.
However, commit
23bf1b6be9 ("kernfs, sysfs, cgroup, intel_rdt: Support fs_context")
changed the mount option name from "mba_MBps" to "mba_mpbs" by mistake.
Change it back from to "mba_MBps" because it is user-visible, and
correct "Opt_mba_mpbs" spelling to "Opt_mba_mbps".
[ bp: massage commit message. ]
Fixes: 23bf1b6be9 ("kernfs, sysfs, cgroup, intel_rdt: Support fs_context")
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: dhowells@redhat.com
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: pei.p.jia@intel.com
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/1553896238-22130-1-git-send-email-xiaochen.shen@intel.com
This allows the IS_PINEVIEW_<G|M> macros to be removed and avoid
duplication of device ids already defined in i915_pciids.h.
!IS_MOBILE check can be used in place of existing IS_PINEVIEW_G call
sites.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190326074057.27833-2-tvrtko.ursulin@linux.intel.com
On top of this, a cleanup of kvm_para.h headers, which were exported by
some architectures even though they not support KVM at all. This is
responsible for all the Kbuild changes in the diffstat.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"A collection of x86 and ARM bugfixes, and some improvements to
documentation.
On top of this, a cleanup of kvm_para.h headers, which were exported
by some architectures even though they not support KVM at all. This is
responsible for all the Kbuild changes in the diffstat"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits)
Documentation: kvm: clarify KVM_SET_USER_MEMORY_REGION
KVM: doc: Document the life cycle of a VM and its resources
KVM: selftests: complete IO before migrating guest state
KVM: selftests: disable stack protector for all KVM tests
KVM: selftests: explicitly disable PIE for tests
KVM: selftests: assert on exit reason in CR4/cpuid sync test
KVM: x86: update %rip after emulating IO
x86/kvm/hyper-v: avoid spurious pending stimer on vCPU init
kvm/x86: Move MSR_IA32_ARCH_CAPABILITIES to array emulated_msrs
KVM: x86: Emulate MSR_IA32_ARCH_CAPABILITIES on AMD hosts
kvm: don't redefine flags as something else
kvm: mmu: Used range based flushing in slot_handle_level_range
KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported
KVM: x86: remove check on nr_mmu_pages in kvm_arch_commit_memory_region()
kvm: nVMX: Add a vmentry check for HOST_SYSENTER_ESP and HOST_SYSENTER_EIP fields
KVM: SVM: Workaround errata#1096 (insn_len maybe zero on SMAP violation)
KVM: Reject device ioctls from processes other than the VM's creator
KVM: doc: Fix incorrect word ordering regarding supported use of APIs
KVM: x86: fix handling of role.cr4_pae and rename it to 'gpte_size'
KVM: nVMX: Do not inherit quadrant and invalid for the root shadow EPT
...
Pull x86 fixes from Thomas Gleixner:
"A pile of x86 updates:
- Prevent exceeding he valid physical address space in the /dev/mem
limit checks.
- Move all header content inside the header guard to prevent compile
failures.
- Fix the bogus __percpu annotation in this_cpu_has() which makes
sparse very noisy.
- Disable switch jump tables completely when retpolines are enabled.
- Prevent leaking the trampoline address"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/realmode: Make set_real_mode_mem() static inline
x86/cpufeature: Fix __percpu annotation in this_cpu_has()
x86/mm: Don't exceed the valid physical address space
x86/retpolines: Disable switch jump tables when retpolines are enabled
x86/realmode: Don't leak the trampoline kernel address
x86/boot: Fix incorrect ifdeffery scope
x86/resctrl: Remove unused variable
__pure is used to make gcc do Common Subexpression Elimination (CSE)
and thus save subsequent invocations of a function which does a complex
computation (without side effects). As a simple example:
bool a = _static_cpu_has(x);
bool b = _static_cpu_has(x);
gets turned into
bool a = _static_cpu_has(x);
bool b = a;
However, gcc doesn't do CSE with asm()s when those get inlined - like it
is done with _static_cpu_has() - because, for example, the t_yes/t_no
labels are different for each inlined function body and thus cannot be
detected as equivalent anymore for the CSE heuristic to hit.
However, this all is beside the point because best it should be avoided
to have more than one call to _static_cpu_has(X) in the same function
due to the fact that each such call is an alternatives patch site and it
is simply pointless.
Therefore, drop the __pure attribute as it is not doing anything.
Reported-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org
Link: https://lkml.kernel.org/r/20190307151036.GD26566@zn.tnic
Calling this function has been wrong for a while now:
* Can't call schedule_work() in #MC context.
* mce_notify_irq() either.
* None of that noodling is needed anymore - all it needs to do is kick
the IRQ work which would self-IPI so that once the #MC handler is done,
the work queue will run and process queued MCE records.
So remove it.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86@kernel.org
Link: https://lkml.kernel.org/r/20190325172121.7926-1-bp@alien8.de
sparse complains that LOADED_MM_SWITCHING's definition casts an int to a
pointer:
arch/x86/mm/tlb.c:409:17: warning: non size-preserving integer to pointer cast
Use a pointer-sized integer constant instead.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sai Praneeth <sai.praneeth.prakhya@intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190328230939.15711-1-jannh@google.com
All architectures (arm/arm64, ia64 and x86) do the same here, so unify
the code.
Note: We do not need to call dump_stack_set_arch_desc() in case of
!dmi_available. Both strings, dmi_ids_string and dump_stack_arch_
desc_str are initialized zero and thus nothing would change.
Signed-off-by: Robert Richter <rrichter@marvell.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20190328193429.21373-5-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Most (all?) x86 platforms provide a port IO based reset mechanism, e.g.
OUT 92h or CF9h. Userspace may emulate said mechanism, i.e. reset a
vCPU in response to KVM_EXIT_IO, without explicitly announcing to KVM
that it is doing a reset, e.g. Qemu jams vCPU state and resumes running.
To avoid corruping %rip after such a reset, commit 0967b7bf1c ("KVM:
Skip pio instruction when it is emulated, not executed") changed the
behavior of PIO handlers, i.e. today's "fast" PIO handling to skip the
instruction prior to exiting to userspace. Full emulation doesn't need
such tricks becase re-emulating the instruction will naturally handle
%rip being changed to point at the reset vector.
Updating %rip prior to executing to userspace has several drawbacks:
- Userspace sees the wrong %rip on the exit, e.g. if PIO emulation
fails it will likely yell about the wrong address.
- Single step exits to userspace for are effectively dropped as
KVM_EXIT_DEBUG is overwritten with KVM_EXIT_IO.
- Behavior of PIO emulation is different depending on whether it
goes down the fast path or the slow path.
Rather than skip the PIO instruction before exiting to userspace,
snapshot the linear %rip and cancel PIO completion if the current
value does not match the snapshot. For a 64-bit vCPU, i.e. the most
common scenario, the snapshot and comparison has negligible overhead
as VMCS.GUEST_RIP will be cached regardless, i.e. there is no extra
VMREAD in this case.
All other alternatives to snapshotting the linear %rip that don't
rely on an explicit reset announcenment suffer from one corner case
or another. For example, canceling PIO completion on any write to
%rip fails if userspace does a save/restore of %rip, and attempting to
avoid that issue by canceling PIO only if %rip changed then fails if PIO
collides with the reset %rip. Attempting to zero in on the exact reset
vector won't work for APs, which means adding more hooks such as the
vCPU's MP_STATE, and so on and so forth.
Checking for a linear %rip match technically suffers from corner cases,
e.g. userspace could theoretically rewrite the underlying code page and
expect a different instruction to execute, or the guest hardcodes a PIO
reset at 0xfffffff0, but those are far, far outside of what can be
considered normal operation.
Fixes: 432baf60ee ("KVM: VMX: use kvm_fast_pio_in for handling IN I/O")
Cc: <stable@vger.kernel.org>
Reported-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When userspace initializes guest vCPUs it may want to zero all supported
MSRs including Hyper-V related ones including HV_X64_MSR_STIMERn_CONFIG/
HV_X64_MSR_STIMERn_COUNT. With commit f3b138c5d8 ("kvm/x86: Update SynIC
timers on guest entry only") we began doing stimer_mark_pending()
unconditionally on every config change.
The issue I'm observing manifests itself as following:
- Qemu writes 0 to STIMERn_{CONFIG,COUNT} MSRs and marks all stimers as
pending in stimer_pending_bitmap, arms KVM_REQ_HV_STIMER;
- kvm_hv_has_stimer_pending() starts returning true;
- kvm_vcpu_has_events() starts returning true;
- kvm_arch_vcpu_runnable() starts returning true;
- when kvm_arch_vcpu_ioctl_run() gets into
(vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED) case:
- kvm_vcpu_block() gets in 'kvm_vcpu_check_block(vcpu) < 0' and returns
immediately, avoiding normal wait path;
- -EAGAIN is returned from kvm_arch_vcpu_ioctl_run() immediately forcing
userspace to retry.
So instead of normal wait path we get a busy loop on all secondary vCPUs
before they get INIT signal. This seems to be undesirable, especially given
that this happens even when Hyper-V extensions are not used.
Generally, it seems to be pointless to mark an stimer as pending in
stimer_pending_bitmap and arm KVM_REQ_HV_STIMER as the only thing
kvm_hv_process_stimers() will do is clear the corresponding bit. We may
just not mark disabled timers as pending instead.
Fixes: f3b138c5d8 ("kvm/x86: Update SynIC timers on guest entry only")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Since MSR_IA32_ARCH_CAPABILITIES is emualted unconditionally even if
host doesn't suppot it. We should move it to array emulated_msrs from
arry msrs_to_save, to report to userspace that guest support this msr.
Signed-off-by: Xiaoyao Li <xiaoyao.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The CPUID flag ARCH_CAPABILITIES is unconditioinally exposed to host
userspace for all x86 hosts, i.e. KVM advertises ARCH_CAPABILITIES
regardless of hardware support under the pretense that KVM fully
emulates MSR_IA32_ARCH_CAPABILITIES. Unfortunately, only VMX hosts
handle accesses to MSR_IA32_ARCH_CAPABILITIES (despite KVM_GET_MSRS
also reporting MSR_IA32_ARCH_CAPABILITIES for all hosts).
Move the MSR_IA32_ARCH_CAPABILITIES handling to common x86 code so
that it's emulated on AMD hosts.
Fixes: 1eaafe91a0 ("kvm: x86: IA32_ARCH_CAPABILITIES is always supported")
Cc: stable@vger.kernel.org
Reported-by: Xiaoyao Li <xiaoyao.li@linux.intel.com>
Cc: Jim Mattson <jmattson@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace kvm_flush_remote_tlbs with kvm_flush_remote_tlbs_with_address
in slot_handle_level_range. When range based flushes are not enabled
kvm_flush_remote_tlbs_with_address falls back to kvm_flush_remote_tlbs.
This changes the behavior of many functions that indirectly use
slot_handle_level_range, iff the range based flushes are enabled. The
only potential problem I see with this is that kvm->tlbs_dirty will be
cleared less often, however the only caller of slot_handle_level_range that
checks tlbs_dirty is kvm_mmu_notifier_invalidate_range_start which
checks it and does a kvm_flush_remote_tlbs after calling
kvm_unmap_hva_range anyway.
Tested: Ran all kvm-unit-tests on a Intel Haswell machine with and
without this patch. The patch introduced no new failures.
Signed-off-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* nr_mmu_pages would be non-zero only if kvm->arch.n_requested_mmu_pages is
non-zero.
* nr_mmu_pages is always non-zero, since kvm_mmu_calculate_mmu_pages()
never return zero.
Based on these two reasons, we can merge the two *if* clause and use the
return value from kvm_mmu_calculate_mmu_pages() directly. This simplify
the code and also eliminate the possibility for reader to believe
nr_mmu_pages would be zero.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
According to section "Checks on VMX Controls" in Intel SDM vol 3C, the
following check is performed on vmentry of L2 guests:
On processors that support Intel 64 architecture, the IA32_SYSENTER_ESP
field and the IA32_SYSENTER_EIP field must each contain a canonical
address.
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Errata#1096:
On a nested data page fault when CR.SMAP=1 and the guest data read
generates a SMAP violation, GuestInstrBytes field of the VMCB on a
VMEXIT will incorrectly return 0h instead the correct guest
instruction bytes .
Recommend Workaround:
To determine what instruction the guest was executing the hypervisor
will have to decode the instruction at the instruction pointer.
The recommended workaround can not be implemented for the SEV
guest because guest memory is encrypted with the guest specific key,
and instruction decoder will not be able to decode the instruction
bytes. If we hit this errata in the SEV guest then log the message
and request a guest shutdown.
Reported-by: Venkatesh Srinivas <venkateshs@google.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
