Commit Graph

30572 Commits

Author SHA1 Message Date
Ard Biesheuvel
b40a142b12 x86: Add support for 64-bit place relative relocations
Add support for R_X86_64_PC64 relocations, which operate on 64-bit
quantities holding a relative symbol reference. Also remove the
definition of R_X86_64_NUM: given that it is currently unused, it
is unclear what the new value should be.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jessica Yu <jeyu@kernel.org>
Link: https://lkml.kernel.org/r/20180919065144.25010-5-ard.biesheuvel@linaro.org
2018-09-27 17:56:47 +02:00
Greg Kroah-Hartman
18d49ec3c6 xen: fixes for 4.19-rc5
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Merge tag 'for-linus-4.19d-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Juergen writes:
  "xen:
   Two small fixes for xen drivers."

* tag 'for-linus-4.19d-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: issue warning message when out of grant maptrack entries
  xen/x86/vpmu: Zero struct pt_regs before calling into sample handling code
2018-09-23 13:32:19 +02:00
Greg Kroah-Hartman
328c6333ba Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Thomas writes:
  "A set of fixes for x86:

   - Resolve the kvmclock regression on AMD systems with memory
     encryption enabled. The rework of the kvmclock memory allocation
     during early boot results in encrypted storage, which is not
     shareable with the hypervisor. Create a new section for this data
     which is mapped unencrypted and take care that the later
     allocations for shared kvmclock memory is unencrypted as well.

   - Fix the build regression in the paravirt code introduced by the
     recent spectre v2 updates.

   - Ensure that the initial static page tables cover the fixmap space
     correctly so early console always works. This worked so far by
     chance, but recent modifications to the fixmap layout can -
     depending on kernel configuration - move the relevant entries to a
     different place which is not covered by the initial static page
     tables.

   - Address the regressions and issues which got introduced with the
     recent extensions to the Intel Recource Director Technology code.

   - Update maintainer entries to document reality"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Expand static page table for fixmap space
  MAINTAINERS: Add X86 MM entry
  x86/intel_rdt: Add Reinette as co-maintainer for RDT
  MAINTAINERS: Add Borislav to the x86 maintainers
  x86/paravirt: Fix some warning messages
  x86/intel_rdt: Fix incorrect loop end condition
  x86/intel_rdt: Fix exclusive mode handling of MBA resource
  x86/intel_rdt: Fix incorrect loop end condition
  x86/intel_rdt: Do not allow pseudo-locking of MBA resource
  x86/intel_rdt: Fix unchecked MSR access
  x86/intel_rdt: Fix invalid mode warning when multiple resources are managed
  x86/intel_rdt: Global closid helper to support future fixes
  x86/intel_rdt: Fix size reporting of MBA resource
  x86/intel_rdt: Fix data type in parsing callbacks
  x86/kvm: Use __bss_decrypted attribute in shared variables
  x86/mm: Add .bss..decrypted section to hold shared variables
2018-09-23 08:10:12 +02:00
Greg Kroah-Hartman
a27fb6d983 This pull request is slightly bigger than usual at this stage, but
I swear I would have sent it the same to Linus!  The main cause for
 this is that I was on vacation until two weeks ago and it took a while
 to sort all the pending patches between 4.19 and 4.20, test them and
 so on.
 
 It's mostly small bugfixes and cleanups, mostly around x86 nested
 virtualization.  One important change, not related to nested
 virtualization, is that the ability for the guest kernel to trap CPUID
 instructions (in Linux that's the ARCH_SET_CPUID arch_prctl) is now
 masked by default.  This is because the feature is detected through an
 MSR; a very bad idea that Intel seems to like more and more.  Some
 applications choke if the other fields of that MSR are not initialized
 as on real hardware, hence we have to disable the whole MSR by default,
 as was the case before Linux 4.12.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Paolo writes:
  "It's mostly small bugfixes and cleanups, mostly around x86 nested
   virtualization.  One important change, not related to nested
   virtualization, is that the ability for the guest kernel to trap
   CPUID instructions (in Linux that's the ARCH_SET_CPUID arch_prctl) is
   now masked by default.  This is because the feature is detected
   through an MSR; a very bad idea that Intel seems to like more and
   more.  Some applications choke if the other fields of that MSR are
   not initialized as on real hardware, hence we have to disable the
   whole MSR by default, as was the case before Linux 4.12."

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (23 commits)
  KVM: nVMX: Fix bad cleanup on error of get/set nested state IOCTLs
  kvm: selftests: Add platform_info_test
  KVM: x86: Control guest reads of MSR_PLATFORM_INFO
  KVM: x86: Turbo bits in MSR_PLATFORM_INFO
  nVMX x86: Check VPID value on vmentry of L2 guests
  nVMX x86: check posted-interrupt descriptor addresss on vmentry of L2
  KVM: nVMX: Wake blocked vCPU in guest-mode if pending interrupt in virtual APICv
  KVM: VMX: check nested state and CR4.VMXE against SMM
  kvm: x86: make kvm_{load|put}_guest_fpu() static
  x86/hyper-v: rename ipi_arg_{ex,non_ex} structures
  KVM: VMX: use preemption timer to force immediate VMExit
  KVM: VMX: modify preemption timer bit only when arming timer
  KVM: VMX: immediately mark preemption timer expired only for zero value
  KVM: SVM: Switch to bitmap_zalloc()
  KVM/MMU: Fix comment in walk_shadow_page_lockless_end()
  kvm: selftests: use -pthread instead of -lpthread
  KVM: x86: don't reset root in kvm_mmu_setup()
  kvm: mmu: Don't read PDPTEs when paging is not enabled
  x86/kvm/lapic: always disable MMIO interface in x2APIC mode
  KVM: s390: Make huge pages unavailable in ucontrol VMs
  ...
2018-09-21 16:21:42 +02:00
Feng Tang
05ab1d8a4b x86/mm: Expand static page table for fixmap space
We met a kernel panic when enabling earlycon, which is due to the fixmap
address of earlycon is not statically setup.

Currently the static fixmap setup in head_64.S only covers 2M virtual
address space, while it actually could be in 4M space with different
kernel configurations, e.g. when VSYSCALL emulation is disabled.

So increase the static space to 4M for now by defining FIXMAP_PMD_NUM to 2,
and add a build time check to ensure that the fixmap is covered by the
initial static page tables.

Fixes: 1ad83c858c ("x86_64,vsyscall: Make vsyscall emulation configurable")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: kernel test robot <rong.a.chen@intel.com>
Reviewed-by: Juergen Gross <jgross@suse.com> (Xen parts)
Cc: H Peter Anvin <hpa@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180920025828.23699-1-feng.tang@intel.com
2018-09-20 23:17:22 +02:00
Liran Alon
26b471c7e2 KVM: nVMX: Fix bad cleanup on error of get/set nested state IOCTLs
The handlers of IOCTLs in kvm_arch_vcpu_ioctl() are expected to set
their return value in "r" local var and break out of switch block
when they encounter some error.
This is because vcpu_load() is called before the switch block which
have a proper cleanup of vcpu_put() afterwards.

However, KVM_{GET,SET}_NESTED_STATE IOCTLs handlers just return
immediately on error without performing above mentioned cleanup.

Thus, change these handlers to behave as expected.

Fixes: 8fcc4b5923 ("kvm: nVMX: Introduce KVM_CAP_NESTED_STATE")

Reviewed-by: Mark Kanda <mark.kanda@oracle.com>
Reviewed-by: Patrick Colp <patrick.colp@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 18:54:08 +02:00
Drew Schmitt
6fbbde9a19 KVM: x86: Control guest reads of MSR_PLATFORM_INFO
Add KVM_CAP_MSR_PLATFORM_INFO so that userspace can disable guest access
to reads of MSR_PLATFORM_INFO.

Disabling access to reads of this MSR gives userspace the control to "expose"
this platform-dependent information to guests in a clear way. As it exists
today, guests that read this MSR would get unpopulated information if userspace
hadn't already set it (and prior to this patch series, only the CPUID faulting
information could have been populated). This existing interface could be
confusing if guests don't handle the potential for incorrect/incomplete
information gracefully (e.g. zero reported for base frequency).

Signed-off-by: Drew Schmitt <dasch@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:51:46 +02:00
Drew Schmitt
d84f1cff90 KVM: x86: Turbo bits in MSR_PLATFORM_INFO
Allow userspace to set turbo bits in MSR_PLATFORM_INFO. Previously, only
the CPUID faulting bit was settable. But now any bit in
MSR_PLATFORM_INFO would be settable. This can be used, for example, to
convey frequency information about the platform on which the guest is
running.

Signed-off-by: Drew Schmitt <dasch@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:51:46 +02:00
Krish Sadhukhan
ba8e23db59 nVMX x86: Check VPID value on vmentry of L2 guests
According to section "Checks on VMX Controls" in Intel SDM vol 3C, the
following check needs to be enforced on vmentry of L2 guests:

    If the 'enable VPID' VM-execution control is 1, the value of the
    of the VPID VM-execution control field must not be 0000H.

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Mark Kanda <mark.kanda@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:51:45 +02:00
Krish Sadhukhan
6de84e581c nVMX x86: check posted-interrupt descriptor addresss on vmentry of L2
According to section "Checks on VMX Controls" in Intel SDM vol 3C,
the following check needs to be enforced on vmentry of L2 guests:

   - Bits 5:0 of the posted-interrupt descriptor address are all 0.
   - The posted-interrupt descriptor address does not set any bits
     beyond the processor's physical-address width.

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Mark Kanda <mark.kanda@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Karl Heubaum <karl.heubaum@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:51:44 +02:00
Liran Alon
e6c67d8cf1 KVM: nVMX: Wake blocked vCPU in guest-mode if pending interrupt in virtual APICv
In case L1 do not intercept L2 HLT or enter L2 in HLT activity-state,
it is possible for a vCPU to be blocked while it is in guest-mode.

According to Intel SDM 26.6.5 Interrupt-Window Exiting and
Virtual-Interrupt Delivery: "These events wake the logical processor
if it just entered the HLT state because of a VM entry".
Therefore, if L1 enters L2 in HLT activity-state and L2 has a pending
deliverable interrupt in vmcs12->guest_intr_status.RVI, then the vCPU
should be waken from the HLT state and injected with the interrupt.

In addition, if while the vCPU is blocked (while it is in guest-mode),
it receives a nested posted-interrupt, then the vCPU should also be
waken and injected with the posted interrupt.

To handle these cases, this patch enhances kvm_vcpu_has_events() to also
check if there is a pending interrupt in L2 virtual APICv provided by
L1. That is, it evaluates if there is a pending virtual interrupt for L2
by checking RVI[7:4] > VPPR[7:4] as specified in Intel SDM 29.2.1
Evaluation of Pending Interrupts.

Note that this also handles the case of nested posted-interrupt by the
fact RVI is updated in vmx_complete_nested_posted_interrupt() which is
called from kvm_vcpu_check_block() -> kvm_arch_vcpu_runnable() ->
kvm_vcpu_running() -> vmx_check_nested_events() ->
vmx_complete_nested_posted_interrupt().

Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:51:44 +02:00
Paolo Bonzini
5bea5123cb KVM: VMX: check nested state and CR4.VMXE against SMM
VMX cannot be enabled under SMM, check it when CR4 is set and when nested
virtualization state is restored.

This should fix some WARNs reported by syzkaller, mostly around
alloc_shadow_vmcs.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:51:43 +02:00
Sebastian Andrzej Siewior
822f312d47 kvm: x86: make kvm_{load|put}_guest_fpu() static
The functions
	kvm_load_guest_fpu()
	kvm_put_guest_fpu()

are only used locally, make them static. This requires also that both
functions are moved because they are used before their implementation.
Those functions were exported (via EXPORT_SYMBOL) before commit
e5bb40251a ("KVM: Drop kvm_{load,put}_guest_fpu() exports").

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:51:43 +02:00
Vitaly Kuznetsov
a1efa9b700 x86/hyper-v: rename ipi_arg_{ex,non_ex} structures
These structures are going to be used from KVM code so let's make
their names reflect their Hyper-V origin.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:51:42 +02:00
Sean Christopherson
d264ee0c2e KVM: VMX: use preemption timer to force immediate VMExit
A VMX preemption timer value of '0' is guaranteed to cause a VMExit
prior to the CPU executing any instructions in the guest.  Use the
preemption timer (if it's supported) to trigger immediate VMExit
in place of the current method of sending a self-IPI.  This ensures
that pending VMExit injection to L1 occurs prior to executing any
instructions in the guest (regardless of nesting level).

When deferring VMExit injection, KVM generates an immediate VMExit
from the (possibly nested) guest by sending itself an IPI.  Because
hardware interrupts are blocked prior to VMEnter and are unblocked
(in hardware) after VMEnter, this results in taking a VMExit(INTR)
before any guest instruction is executed.  But, as this approach
relies on the IPI being received before VMEnter executes, it only
works as intended when KVM is running as L0.  Because there are no
architectural guarantees regarding when IPIs are delivered, when
running nested the INTR may "arrive" long after L2 is running e.g.
L0 KVM doesn't force an immediate switch to L1 to deliver an INTR.

For the most part, this unintended delay is not an issue since the
events being injected to L1 also do not have architectural guarantees
regarding their timing.  The notable exception is the VMX preemption
timer[1], which is architecturally guaranteed to cause a VMExit prior
to executing any instructions in the guest if the timer value is '0'
at VMEnter.  Specifically, the delay in injecting the VMExit causes
the preemption timer KVM unit test to fail when run in a nested guest.

Note: this approach is viable even on CPUs with a broken preemption
timer, as broken in this context only means the timer counts at the
wrong rate.  There are no known errata affecting timer value of '0'.

[1] I/O SMIs also have guarantees on when they arrive, but I have
    no idea if/how those are emulated in KVM.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
[Use a hook for SVM instead of leaving the default in x86.c - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:51:42 +02:00
Sean Christopherson
f459a707ed KVM: VMX: modify preemption timer bit only when arming timer
Provide a singular location where the VMX preemption timer bit is
set/cleared so that future usages of the preemption timer can ensure
the VMCS bit is up-to-date without having to modify unrelated code
paths.  For example, the preemption timer can be used to force an
immediate VMExit.  Cache the status of the timer to avoid redundant
VMREAD and VMWRITE, e.g. if the timer stays armed across multiple
VMEnters/VMExits.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:51:41 +02:00
Sean Christopherson
4c008127e4 KVM: VMX: immediately mark preemption timer expired only for zero value
A VMX preemption timer value of '0' at the time of VMEnter is
architecturally guaranteed to cause a VMExit prior to the CPU
executing any instructions in the guest.  This architectural
definition is in place to ensure that a previously expired timer
is correctly recognized by the CPU as it is possible for the timer
to reach zero and not trigger a VMexit due to a higher priority
VMExit being signalled instead, e.g. a pending #DB that morphs into
a VMExit.

Whether by design or coincidence, commit f4124500c2 ("KVM: nVMX:
Fully emulate preemption timer") special cased timer values of '0'
and '1' to ensure prompt delivery of the VMExit.  Unlike '0', a
timer value of '1' has no has no architectural guarantees regarding
when it is delivered.

Modify the timer emulation to trigger immediate VMExit if and only
if the timer value is '0', and document precisely why '0' is special.
Do this even if calibration of the virtual TSC failed, i.e. VMExit
will occur immediately regardless of the frequency of the timer.
Making only '0' a special case gives KVM leeway to be more aggressive
in ensuring the VMExit is injected prior to executing instructions in
the nested guest, and also eliminates any ambiguity as to why '1' is
a special case, e.g. why wasn't the threshold for a "short timeout"
set to 10, 100, 1000, etc...

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:26:46 +02:00
Andy Shevchenko
a101c9d63e KVM: SVM: Switch to bitmap_zalloc()
Switch to bitmap_zalloc() to show clearly what we are allocating.
Besides that it returns pointer of bitmap type instead of opaque void *.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:26:45 +02:00
Tianyu Lan
9a9845867c KVM/MMU: Fix comment in walk_shadow_page_lockless_end()
kvm_commit_zap_page() has been renamed to kvm_mmu_commit_zap_page()
This patch is to fix the commit.

Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:26:45 +02:00
Wei Yang
83b20b28c6 KVM: x86: don't reset root in kvm_mmu_setup()
Here is the code path which shows kvm_mmu_setup() is invoked after
kvm_mmu_create(). Since kvm_mmu_setup() is only invoked in this code path,
this means the root_hpa and prev_roots are guaranteed to be invalid. And
it is not necessary to reset it again.

    kvm_vm_ioctl_create_vcpu()
        kvm_arch_vcpu_create()
            vmx_create_vcpu()
                kvm_vcpu_init()
                    kvm_arch_vcpu_init()
                        kvm_mmu_create()
        kvm_arch_vcpu_setup()
            kvm_mmu_setup()
                kvm_init_mmu()

This patch set reset_roots to false in kmv_mmu_setup().

Fixes: 50c28f21d0
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:26:44 +02:00
Junaid Shahid
d35b34a9a7 kvm: mmu: Don't read PDPTEs when paging is not enabled
kvm should not attempt to read guest PDPTEs when CR0.PG = 0 and
CR4.PAE = 1.

Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:26:43 +02:00
Vitaly Kuznetsov
d176620277 x86/kvm/lapic: always disable MMIO interface in x2APIC mode
When VMX is used with flexpriority disabled (because of no support or
if disabled with module parameter) MMIO interface to lAPIC is still
available in x2APIC mode while it shouldn't be (kvm-unit-tests):

PASS: apic_disable: Local apic enabled in x2APIC mode
PASS: apic_disable: CPUID.1H:EDX.APIC[bit 9] is set
FAIL: apic_disable: *0xfee00030: 50014

The issue appears because we basically do nothing while switching to
x2APIC mode when APIC access page is not used. apic_mmio_{read,write}
only check if lAPIC is disabled before proceeding to actual write.

When APIC access is virtualized we correctly manipulate with VMX controls
in vmx_set_virtual_apic_mode() and we don't get vmexits from memory writes
in x2APIC mode so there's no issue.

Disabling MMIO interface seems to be easy. The question is: what do we
do with these reads and writes? If we add apic_x2apic_mode() check to
apic_mmio_in_range() and return -EOPNOTSUPP these reads and writes will
go to userspace. When lAPIC is in kernel, Qemu uses this interface to
inject MSIs only (see kvm_apic_mem_write() in hw/i386/kvm/apic.c). This
somehow works with disabled lAPIC but when we're in xAPIC mode we will
get a real injected MSI from every write to lAPIC. Not good.

The simplest solution seems to be to just ignore writes to the region
and return ~0 for all reads when we're in x2APIC mode. This is what this
patch does. However, this approach is inconsistent with what currently
happens when flexpriority is enabled: we allocate APIC access page and
create KVM memory region so in x2APIC modes all reads and writes go to
this pre-allocated page which is, btw, the same for all vCPUs.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-20 00:26:43 +02:00
Boris Ostrovsky
70513d5875 xen/x86/vpmu: Zero struct pt_regs before calling into sample handling code
Otherwise we may leak kernel stack for events that sample user
registers.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: stable@vger.kernel.org
2018-09-19 11:26:53 -04:00
Dan Carpenter
571d0563c8 x86/paravirt: Fix some warning messages
The first argument to WARN_ONCE() is a condition.

Fixes: 5800dc5c19 ("x86/paravirt: Fix spectre-v2 mitigations for paravirt guests")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alok Kataria <akataria@vmware.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: virtualization@lists.linux-foundation.org
Cc: kernel-janitors@vger.kernel.org
Link: https://lkml.kernel.org/r/20180919103553.GD9238@mwanda
2018-09-19 13:22:04 +02:00
Greg Kroah-Hartman
4ca719a338 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Crypto stuff from Herbert:
  "This push fixes a potential boot hang in ccp and an incorrect
   CPU capability check in aegis/morus on x86."

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: x86/aegis,morus - Do not require OSXSAVE for SSE2
  crypto: ccp - add timeout support in the SEV command
2018-09-19 08:29:42 +02:00
Reinette Chatre
ffb2315fd2 x86/intel_rdt: Fix incorrect loop end condition
In order to determine a sane default cache allocation for a new CAT/CDP
resource group, all resource groups are checked to determine which cache
portions are available to share. At this time all possible CLOSIDs
that can be supported by the resource is checked. This is problematic
if the resource supports more CLOSIDs than another CAT/CDP resource. In
this case, the number of CLOSIDs that could be allocated are fewer than
the number of CLOSIDs that can be supported by the resource.

Limit the check of closids to that what is supported by the system based
on the minimum across all resources.

Fixes: 95f0b77ef ("x86/intel_rdt: Initialize new resource group with sane defaults")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-10-git-send-email-fenghua.yu@intel.com
2018-09-18 23:38:07 +02:00
Reinette Chatre
939b90b20b x86/intel_rdt: Fix exclusive mode handling of MBA resource
It is possible for a resource group to consist out of MBA as well as
CAT/CDP resources. The "exclusive" resource mode only applies to the
CAT/CDP resources since MBA allocations cannot be specified to overlap
or not. When a user requests a resource group to become "exclusive" then it
can only be successful if there are CAT/CDP resources in the group
and none of their CBMs associated with the group's CLOSID overlaps with
any other resource group.

Fix the "exclusive" mode setting by failing if there isn't any CAT/CDP
resource in the group and ensuring that the CBM checking is only done on
CAT/CDP resources.

Fixes: 49f7b4efa ("x86/intel_rdt: Enable setting of exclusive mode")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-9-git-send-email-fenghua.yu@intel.com
2018-09-18 23:38:07 +02:00
Reinette Chatre
f0df4e1acf x86/intel_rdt: Fix incorrect loop end condition
A loop is used to check if a CAT resource's CBM of one CLOSID
overlaps with the CBM of another CLOSID of the same resource. The loop
is run over all CLOSIDs supported by the resource.

The problem with running the loop over all CLOSIDs supported by the
resource is that its number of supported CLOSIDs may be more than the
number of supported CLOSIDs on the system, which is the minimum number of
CLOSIDs supported across all resources.

Fix the loop to only consider the number of system supported CLOSIDs,
not all that are supported by the resource.

Fixes: 49f7b4efa ("x86/intel_rdt: Enable setting of exclusive mode")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-8-git-send-email-fenghua.yu@intel.com
2018-09-18 23:38:06 +02:00
Reinette Chatre
32d736abed x86/intel_rdt: Do not allow pseudo-locking of MBA resource
A system supporting pseudo-locking may have MBA as well as CAT
resources of which only the CAT resources could support cache
pseudo-locking. When the schemata to be pseudo-locked is provided it
should be checked that that schemata does not attempt to pseudo-lock a
MBA resource.

Fixes: e0bdfe8e3 ("x86/intel_rdt: Support creation/removal of pseudo-locked region")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-7-git-send-email-fenghua.yu@intel.com
2018-09-18 23:38:06 +02:00
Reinette Chatre
70479c012b x86/intel_rdt: Fix unchecked MSR access
When a new resource group is created, it is initialized with sane
defaults that currently assume the resource being initialized is a CAT
resource. This code path is also followed by a MBA resource that is not
allocated the same as a CAT resource and as a result we encounter the
following unchecked MSR access error:

unchecked MSR access error: WRMSR to 0xd51 (tried to write 0x0000
000000000064) at rIP: 0xffffffffae059994 (native_write_msr+0x4/0x20)
Call Trace:
mba_wrmsr+0x41/0x80
update_domains+0x125/0x130
rdtgroup_mkdir+0x270/0x500

Fix the above by ensuring the initial allocation is only attempted on a
CAT resource.

Fixes: 95f0b77ef ("x86/intel_rdt: Initialize new resource group with sane defaults")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-6-git-send-email-fenghua.yu@intel.com
2018-09-18 23:38:06 +02:00
Reinette Chatre
47d53b184a x86/intel_rdt: Fix invalid mode warning when multiple resources are managed
When multiple resources are managed by RDT, the number of CLOSIDs used
is the minimum of the CLOSIDs supported by each resource. In the function
rdt_bit_usage_show(), the annotated bitmask is created to depict how the
CAT supporting caches are being used. During this annotated bitmask
creation, each resource group is queried for its mode that is used as a
label in the annotated bitmask.

The maximum number of resource groups is currently assumed to be the
number of CLOSIDs supported by the resource for which the information is
being displayed. This is incorrect since the number of active CLOSIDs is
the minimum across all resources.

If information for a cache instance with more CLOSIDs than another is
being generated we thus encounter a warning like:

invalid mode for closid 8
WARNING: CPU: 88 PID: 1791 at [SNIP]/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
:827 rdt_bit_usage_show+0x221/0x2b0

Fix this by ensuring that only the number of supported CLOSIDs are
considered.

Fixes: e651901187 ("x86/intel_rdt: Introduce "bit_usage" to display cache allocations details")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-5-git-send-email-fenghua.yu@intel.com
2018-09-18 23:38:05 +02:00
Reinette Chatre
c793da8e4c x86/intel_rdt: Global closid helper to support future fixes
The number of CLOSIDs supported by a system is the minimum number of
CLOSIDs supported by any of its resources. Care should be taken when
iterating over the CLOSIDs of a resource since it may be that the number
of CLOSIDs supported on the system is less than the number of CLOSIDs
supported by the resource.

Introduce a helper function that can be used to query the number of
CLOSIDs that is supported by all resources, irrespective of how many
CLOSIDs are supported by a particular resource.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-4-git-send-email-fenghua.yu@intel.com
2018-09-18 23:38:05 +02:00
Reinette Chatre
f968dc119a x86/intel_rdt: Fix size reporting of MBA resource
Chen Yu reported a divide-by-zero error when accessing the 'size'
resctrl file when a MBA resource is enabled.

divide error: 0000 [#1] SMP PTI
CPU: 93 PID: 1929 Comm: cat Not tainted 4.19.0-rc2-debug-rdt+ #25
RIP: 0010:rdtgroup_cbm_to_size+0x7e/0xa0
Call Trace:
rdtgroup_size_show+0x11a/0x1d0
seq_read+0xd8/0x3b0

Quoting Chen Yu's report: This is because for MB resource, the
r->cache.cbm_len is zero, thus calculating size in rdtgroup_cbm_to_size()
will trigger the exception.

Fix this issue in the 'size' file by getting correct memory bandwidth value
which is in MBps when MBA software controller is enabled or in percentage
when MBA software controller is disabled.

Fixes: d9b48c86eb ("x86/intel_rdt: Display resource groups' allocations in bytes")
Reported-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Chen Yu <yu.c.chen@intel.com>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Link: https://lkml.kernel.org/r/20180904174614.26682-1-yu.c.chen@intel.com
Link: https://lkml.kernel.org/r/1537048707-76280-3-git-send-email-fenghua.yu@intel.com
2018-09-18 23:38:05 +02:00
Xiaochen Shen
753694a8df x86/intel_rdt: Fix data type in parsing callbacks
Each resource is associated with a parsing callback to parse the data
provided from user space when writing schemata file.

The 'data' parameter in the callbacks is defined as a void pointer which
is error prone due to lack of type check.

parse_bw() processes the 'data' parameter as a string while its caller
actually passes the parameter as a pointer to struct rdt_cbm_parse_data.
Thus, parse_bw() takes wrong data and causes failure of parsing MBA
throttle value.

To fix the issue, the 'data' parameter in all parsing callbacks is defined
and handled as a pointer to struct rdt_parse_data (renamed from struct
rdt_cbm_parse_data).

Fixes: 7604df6e16 ("x86/intel_rdt: Support flexible data to parsing callbacks")
Fixes: 9ab9aa15c3 ("x86/intel_rdt: Ensure requested schemata respects mode")
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-2-git-send-email-fenghua.yu@intel.com
2018-09-18 23:38:05 +02:00
Brijesh Singh
6a1cac56f4 x86/kvm: Use __bss_decrypted attribute in shared variables
The recent removal of the memblock dependency from kvmclock caused a SEV
guest regression because the wall_clock and hv_clock_boot variables are
no longer mapped decrypted when SEV is active.

Use the __bss_decrypted attribute to put the static wall_clock and
hv_clock_boot in the .bss..decrypted section so that they are mapped
decrypted during boot.

In the preparatory stage of CPU hotplug, the per-cpu pvclock data pointer
assigns either an element of the static array or dynamically allocated
memory for the pvclock data pointer. The static array are now mapped
decrypted but the dynamically allocated memory is not mapped decrypted.
However, when SEV is active this memory range must be mapped decrypted.

Add a function which is called after the page allocator is up, and
allocate memory for the pvclock data pointers for the all possible cpus.
Map this memory range as decrypted when SEV is active.

Fixes: 368a540e02 ("x86/kvmclock: Remove memblock dependency")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Link: https://lkml.kernel.org/r/1536932759-12905-3-git-send-email-brijesh.singh@amd.com
2018-09-15 20:48:46 +02:00
Brijesh Singh
b3f0907c71 x86/mm: Add .bss..decrypted section to hold shared variables
kvmclock defines few static variables which are shared with the
hypervisor during the kvmclock initialization.

When SEV is active, memory is encrypted with a guest-specific key, and
if the guest OS wants to share the memory region with the hypervisor
then it must clear the C-bit before sharing it.

Currently, we use kernel_physical_mapping_init() to split large pages
before clearing the C-bit on shared pages. But it fails when called from
the kvmclock initialization (mainly because the memblock allocator is
not ready that early during boot).

Add a __bss_decrypted section attribute which can be used when defining
such shared variable. The so-defined variables will be placed in the
.bss..decrypted section. This section will be mapped with C=0 early
during boot.

The .bss..decrypted section has a big chunk of memory that may be unused
when memory encryption is not active, free it when memory encryption is
not active.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Radim Krčmář<rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Link: https://lkml.kernel.org/r/1536932759-12905-2-git-send-email-brijesh.singh@amd.com
2018-09-15 20:48:45 +02:00
Linus Torvalds
27c5a778df Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingol Molnar:
 "Misc fixes:

   - EFI crash fix

   - Xen PV fixes

   - do not allow PTI on 2-level 32-bit kernels for now

   - documentation fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/APM: Fix build warning when PROC_FS is not enabled
  Revert "x86/mm/legacy: Populate the user page-table with user pgd's"
  x86/efi: Load fixmap GDT in efi_call_phys_epilog() before setting %cr3
  x86/xen: Disable CPU0 hotplug for Xen PV
  x86/EISA: Don't probe EISA bus for Xen PV guests
  x86/doc: Fix Documentation/x86/earlyprintk.txt
2018-09-15 08:02:46 -10:00
Randy Dunlap
002b87d2aa x86/APM: Fix build warning when PROC_FS is not enabled
Fix build warning in apm_32.c when CONFIG_PROC_FS is not enabled:

../arch/x86/kernel/apm_32.c:1643:12: warning: 'proc_apm_show' defined but not used [-Wunused-function]
 static int proc_apm_show(struct seq_file *m, void *v)

Fixes: 3f3942aca6 ("proc: introduce proc_create_single{,_data}")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jiri Kosina <jikos@kernel.org>
Link: https://lkml.kernel.org/r/be39ac12-44c2-4715-247f-4dcc3c525b8b@infradead.org
2018-09-15 10:16:25 +02:00
Joerg Roedel
61a6bd83ab Revert "x86/mm/legacy: Populate the user page-table with user pgd's"
This reverts commit 1f40a46cf4.

It turned out that this patch is not sufficient to enable PTI on 32 bit
systems with legacy 2-level page-tables. In this paging mode the huge-page
PTEs are in the top-level page-table directory, where also the mirroring to
the user-space page-table happens. So every huge PTE exits twice, in the
kernel and in the user page-table.

That means that accessed/dirty bits need to be fetched from two PTEs in
this mode to be safe, but this is not trivial to implement because it needs
changes to generic code just for the sake of enabling PTI with 32-bit
legacy paging. As all systems that need PTI should support PAE anyway,
remove support for PTI when 32-bit legacy paging is used.

Fixes: 7757d607c6 ('x86/pti: Allow CONFIG_PAGE_TABLE_ISOLATION for x86_32')
Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: hpa@zytor.com
Cc: linux-mm@kvack.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Link: https://lkml.kernel.org/r/1536922754-31379-1-git-send-email-joro@8bytes.org
2018-09-14 17:08:45 +02:00
Ondrej Mosnacek
24568b47d4 crypto: x86/aegis,morus - Do not require OSXSAVE for SSE2
It turns out OSXSAVE needs to be checked only for AVX, not for SSE.
Without this patch the affected modules refuse to load on CPUs with SSE2
but without AVX support.

Fixes: 877ccce7cb ("crypto: x86/aegis,morus - Fix and simplify CPUID checks")
Cc: <stable@vger.kernel.org> # 4.18
Reported-by: Zdenek Kaspar <zkaspar82@gmail.com>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-14 14:08:27 +08:00
Guenter Roeck
cf40361ede x86/efi: Load fixmap GDT in efi_call_phys_epilog() before setting %cr3
Commit eeb89e2bb1 ("x86/efi: Load fixmap GDT in efi_call_phys_epilog()")
moved loading the fixmap in efi_call_phys_epilog() after load_cr3() since
it was assumed to be more logical.

Turns out this is incorrect: In efi_call_phys_prolog(), the gdt with its
physical address is loaded first, and when the %cr3 is reloaded in _epilog
from initial_page_table to swapper_pg_dir again the gdt is no longer
mapped.  This results in a triple fault if an interrupt occurs after
load_cr3() and before load_fixmap_gdt(0). Calling load_fixmap_gdt(0) first
restores the execution order prior to commit eeb89e2bb1 and fixes the
problem.

Fixes: eeb89e2bb1 ("x86/efi: Load fixmap GDT in efi_call_phys_epilog()")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: linux-efi@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/1536689892-21538-1-git-send-email-linux@roeck-us.net
2018-09-12 21:53:34 +02:00
Juergen Gross
999696752d x86/xen: Disable CPU0 hotplug for Xen PV
Xen PV guests don't allow CPU0 hotplug, so disable it.

Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boris.ostrovsky@oracle.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20180912174122.24282-1-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-12 21:15:02 +02:00
Boris Ostrovsky
6a92b11169 x86/EISA: Don't probe EISA bus for Xen PV guests
For unprivileged Xen PV guests this is normal memory and ioremap will
not be able to properly map it.

While at it, since ioremap may return NULL, add a test for pointer's
validity.

Reported-by: Andy Smith <andy@strugglers.net>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: hpa@zytor.com
Cc: xen-devel@lists.xenproject.org
Cc: jgross@suse.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180911195538.23289-1-boris.ostrovsky@oracle.com
2018-09-11 23:36:50 +02:00
Jacek Tomaka
16160c1946 perf/x86/intel: Add support/quirk for the MISPREDICT bit on Knights Landing CPUs
Problem: perf did not show branch predicted/mispredicted bit in brstack.

Output of perf -F brstack for profile collected

Before:

 0x4fdbcd/0x4fdc03/-/-/-/0
 0x45f4c1/0x4fdba0/-/-/-/0
 0x45f544/0x45f4bb/-/-/-/0
 0x45f555/0x45f53c/-/-/-/0
 0x7f66901cc24b/0x45f555/-/-/-/0
 0x7f66901cc22e/0x7f66901cc23d/-/-/-/0
 0x7f66901cc1ff/0x7f66901cc20f/-/-/-/0
 0x7f66901cc1e8/0x7f66901cc1fc/-/-/-/0

After:

 0x4fdbcd/0x4fdc03/P/-/-/0
 0x45f4c1/0x4fdba0/P/-/-/0
 0x45f544/0x45f4bb/P/-/-/0
 0x45f555/0x45f53c/P/-/-/0
 0x7f66901cc24b/0x45f555/P/-/-/0
 0x7f66901cc22e/0x7f66901cc23d/P/-/-/0
 0x7f66901cc1ff/0x7f66901cc20f/P/-/-/0
 0x7f66901cc1e8/0x7f66901cc1fc/P/-/-/0

Cause:

As mentioned in Software Development Manual vol 3, 17.4.8.1,
IA32_PERF_CAPABILITIES[5:0] indicates the format of the address that is
stored in the LBR stack. Knights Landing reports 1 (LBR_FORMAT_LIP) as
its format. Despite that, registers containing FROM address of the branch,
do have MISPREDICT bit but because of the format indicated in
IA32_PERF_CAPABILITIES[5:0], LBR did not read MISPREDICT bit.

Solution:

Teach LBR about above Knights Landing quirk and make it read MISPREDICT bit.

Signed-off-by: Jacek Tomaka <jacek.tomaka@poczta.fm>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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/20180802013830.10600-1-jacekt@dugeo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-10 10:03:01 +02:00
Linus Torvalds
9a5682765a Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "A set of fixes for x86:

   - Prevent multiplication result truncation on 32bit. Introduced with
     the early timestamp reworrk.

   - Ensure microcode revision storage to be consistent under all
     circumstances

   - Prevent write tearing of PTEs

   - Prevent confusion of user and kernel reegisters when dumping fatal
     signals verbosely

   - Make an error return value in a failure path of the vector
     allocation negative. Returning EINVAL might the caller assume
     success and causes further wreckage.

   - A trivial kernel doc warning fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Use WRITE_ONCE() when setting PTEs
  x86/apic/vector: Make error return value negative
  x86/process: Don't mix user/kernel regs in 64bit __show_regs()
  x86/tsc: Prevent result truncation on 32bit
  x86: Fix kernel-doc atomic.h warnings
  x86/microcode: Update the new microcode revision unconditionally
  x86/microcode: Make sure boot_cpu_data.microcode is up-to-date
2018-09-09 07:05:15 -07:00
Nadav Amit
9bc4f28af7 x86/mm: Use WRITE_ONCE() when setting PTEs
When page-table entries are set, the compiler might optimize their
assignment by using multiple instructions to set the PTE. This might
turn into a security hazard if the user somehow manages to use the
interim PTE. L1TF does not make our lives easier, making even an interim
non-present PTE a security hazard.

Using WRITE_ONCE() to set PTEs and friends should prevent this potential
security hazard.

I skimmed the differences in the binary with and without this patch. The
differences are (obviously) greater when CONFIG_PARAVIRT=n as more
code optimizations are possible. For better and worse, the impact on the
binary with this patch is pretty small. Skimming the code did not cause
anything to jump out as a security hazard, but it seems that at least
move_soft_dirty_pte() caused set_pte_at() to use multiple writes.

Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180902181451.80520-1-namit@vmware.com
2018-09-08 12:30:36 +02:00
Thomas Gleixner
47b7360ce5 x86/apic/vector: Make error return value negative
activate_managed() returns EINVAL instead of -EINVAL in case of
error. While this is unlikely to happen, the positive return value would
cause further malfunction at the call site.

Fixes: 2db1f959d9 ("x86/vector: Handle managed interrupts proper")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
2018-09-08 12:12:40 +02:00
Wanpeng Li
bdf7ffc899 KVM: LAPIC: Fix pv ipis out-of-bounds access
Dan Carpenter reported that the untrusted data returns from kvm_register_read()
results in the following static checker warning:
  arch/x86/kvm/lapic.c:576 kvm_pv_send_ipi()
  error: buffer underflow 'map->phys_map' 's32min-s32max'

KVM guest can easily trigger this by executing the following assembly sequence
in Ring0:

mov $10, %rax
mov $0xFFFFFFFF, %rbx
mov $0xFFFFFFFF, %rdx
mov $0, %rsi
vmcall

As this will cause KVM to execute the following code-path:
vmx_handle_exit() -> handle_vmcall() -> kvm_emulate_hypercall() -> kvm_pv_send_ipi()
which will reach out-of-bounds access.

This patch fixes it by adding a check to kvm_pv_send_ipi() against map->max_apic_id,
ignoring destinations that are not present and delivering the rest. We also check
whether or not map->phys_map[min + i] is NULL since the max_apic_id is set to the
max apic id, some phys_map maybe NULL when apic id is sparse, especially kvm
unconditionally set max_apic_id to 255 to reserve enough space for any xAPIC ID.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
[Add second "if (min > map->max_apic_id)" to complete the fix. -Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-09-07 18:38:43 +02:00
Liran Alon
b5861e5cf2 KVM: nVMX: Fix loss of pending IRQ/NMI before entering L2
Consider the case L1 had a IRQ/NMI event until it executed
VMLAUNCH/VMRESUME which wasn't delivered because it was disallowed
(e.g. interrupts disabled). When L1 executes VMLAUNCH/VMRESUME,
L0 needs to evaluate if this pending event should cause an exit from
L2 to L1 or delivered directly to L2 (e.g. In case L1 don't intercept
EXTERNAL_INTERRUPT).

Usually this would be handled by L0 requesting a IRQ/NMI window
by setting VMCS accordingly. However, this setting was done on
VMCS01 and now VMCS02 is active instead. Thus, when L1 executes
VMLAUNCH/VMRESUME we force L0 to perform pending event evaluation by
requesting a KVM_REQ_EVENT.

Note that above scenario exists when L1 KVM is about to enter L2 but
requests an "immediate-exit". As in this case, L1 will
disable-interrupts and then send a self-IPI before entering L2.

Reviewed-by: Nikita Leshchenko <nikita.leshchenko@oracle.com>
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-09-07 18:38:42 +02:00
Radim Krčmář
564ad0aa85 Fixes for KVM/ARM for Linux v4.19 v2:
- Fix a VFP corruption in 32-bit guest
  - Add missing cache invalidation for CoW pages
  - Two small cleanups
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Merge tag 'kvm-arm-fixes-for-v4.19-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm

Fixes for KVM/ARM for Linux v4.19 v2:

 - Fix a VFP corruption in 32-bit guest
 - Add missing cache invalidation for CoW pages
 - Two small cleanups
2018-09-07 18:38:25 +02:00