When emulating real mode we play with tr hidden state, but leave
tr.selector alone. That works well, except for save/restore, since
loading TR writes it to the hidden state in vmx->rmode.
Fix by also saving and restoring the tr selector; this makes things
more consistent and allows migration to work during the early
boot stages of Windows XP.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Instead, drop large mappings, which were the reason we dropped shadow.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Avi Kivity <avi@redhat.com>
Signed-off-by: David Sharp <dhsharp@google.com>
LKML-Reference: <1291421609-14665-8-git-send-email-dhsharp@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In the dr_intercept function a new cpu-feature called
decode-assists is implemented and used when available. This
code-path does not advance the guest-rip causing the guest
to dead-loop over mov-dr instructions. This is fixed by this
patch.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The gs_index loading code uses the swapgs instruction to
switch to the user gs_base temporarily. This is unsave in an
lightweight exit-path in KVM on AMD because the
KERNEL_GS_BASE MSR is switches lazily. An NMI happening in
the critical path of load_gs_index may use the wrong GS_BASE
value then leading to unpredictable behavior, e.g. a
triple-fault.
This patch fixes the issue by making sure that load_gs_index
is called only with a valid KERNEL_GS_BASE value loaded in
KVM.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
For GRU and EPT, we need gup-fast to set referenced bit too (this is why
it's correct to return 0 when shadow_access_mask is zero, it requires
gup-fast to set the referenced bit). qemu-kvm access already sets the
young bit in the pte if it isn't zero-copy, if it's zero copy or a shadow
paging EPT minor fault we relay on gup-fast to signal the page is in
use...
We also need to check the young bits on the secondary pagetables for NPT
and not nested shadow mmu as the data may never get accessed again by the
primary pte.
Without this closer accuracy, we'd have to remove the heuristic that
avoids collapsing hugepages in hugepage virtual regions that have not even
a single subpage in use.
->test_young is full backwards compatible with GRU and other usages that
don't have young bits in pagetables set by the hardware and that should
nuke the secondary mmu mappings when ->clear_flush_young runs just like
EPT does.
Removing the heuristic that checks the young bit in
khugepaged/collapse_huge_page completely isn't so bad either probably but
I thought it was worth it and this makes it reliable.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This should work for both hugetlbfs and transparent hugepages.
[akpm@linux-foundation.org: bring forward PageTransCompound() addition for bisectability]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'kvm-updates/2.6.38' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (142 commits)
KVM: Initialize fpu state in preemptible context
KVM: VMX: when entering real mode align segment base to 16 bytes
KVM: MMU: handle 'map_writable' in set_spte() function
KVM: MMU: audit: allow audit more guests at the same time
KVM: Fetch guest cr3 from hardware on demand
KVM: Replace reads of vcpu->arch.cr3 by an accessor
KVM: MMU: only write protect mappings at pagetable level
KVM: VMX: Correct asm constraint in vmcs_load()/vmcs_clear()
KVM: MMU: Initialize base_role for tdp mmus
KVM: VMX: Optimize atomic EFER load
KVM: VMX: Add definitions for more vm entry/exit control bits
KVM: SVM: copy instruction bytes from VMCB
KVM: SVM: implement enhanced INVLPG intercept
KVM: SVM: enhance mov DR intercept handler
KVM: SVM: enhance MOV CR intercept handler
KVM: SVM: add new SVM feature bit names
KVM: cleanup emulate_instruction
KVM: move complete_insn_gp() into x86.c
KVM: x86: fix CR8 handling
KVM guest: Fix kvm clock initialization when it's configured out
...
init_fpu() (which is indirectly called by the fpu switching code) assumes
it is in process context. Rather than makeing init_fpu() use an atomic
allocation, which can cause a task to be killed, make sure the fpu is
already initialized when we enter the run loop.
KVM-Stable-Tag.
Reported-and-tested-by: Kirill A. Shutemov <kas@openvz.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Move the operation of 'writable' to set_spte() to clean up code
[avi: remove unneeded booleanification]
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
It only allows to audit one guest in the system since:
- 'audit_point' is a glob variable
- mmu_audit_disable() is called in kvm_mmu_destroy(), so audit is disabled
after a guest exited
this patch fix those issues then allow to audit more guests at the same time
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Instead of syncing the guest cr3 every exit, which is expensince on vmx
with ept enabled, sync it only on demand.
[sheng: fix incorrect cr3 seen by Windows XP]
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If a pagetable contains a writeable large spte, all of its sptes will be
write protected, including non-leaf ones, leading to endless pagefaults.
Do not write protect pages above PT_PAGE_TABLE_LEVEL, as the spte fault
paths assume non-leaf sptes are writable.
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
'error' is byte sized, so use a byte register constraint.
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When NX is enabled on the host but not on the guest, we use the entry/exit
msr load facility, which is slow. Optimize it to use entry/exit efer load,
which is ~1200 cycles faster.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
In case of a nested page fault or an intercepted #PF newer SVM
implementations provide a copy of the faulting instruction bytes
in the VMCB.
Use these bytes to feed the instruction emulator and avoid the costly
guest instruction fetch in this case.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When the DecodeAssist feature is available, the linear address
is provided in the VMCB on INVLPG intercepts. Use it directly to
avoid any decoding and emulation.
This is only useful for shadow paging, though.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Newer SVM implementations provide the GPR number in the VMCB, so
that the emulation path is no longer necesarry to handle debug
register access intercepts. Implement the handling in svm.c and
use it when the info is provided.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Newer SVM implementations provide the GPR number in the VMCB, so
that the emulation path is no longer necesarry to handle CR
register access intercepts. Implement the handling in svm.c and
use it when the info is provided.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
the recent APM Vol.2 and the recent AMD CPUID specification describe
new CPUID features bits for SVM. Name them here for later usage.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
emulate_instruction had many callers, but only one used all
parameters. One parameter was unused, another one is now
hidden by a wrapper function (required for a future addition
anyway), so most callers use now a shorter parameter list.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
move the complete_insn_gp() helper function out of the VMX part
into the generic x86 part to make it usable by SVM.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The handling of CR8 writes in KVM is currently somewhat cumbersome.
This patch makes it look like the other CR register handlers
and fixes a possible issue in VMX, where the RIP would be incremented
despite an injected #GP.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
In KVM_CREATE_IRQCHIP, kvm_io_bus_unregister_dev() is called without taking
slots_lock in the error handling path.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
If KVM sees a read-only host page, it will map it as read-only to prevent
breaking a COW. However, if the page was part of a large guest page, KVM
incorrectly extends the write protection to the entire large page frame
instead of limiting it to the normal host page.
This results in the instantiation of a new shadow page with read-only access.
If this happens for a MOVS instruction that moves memory between two normal
pages, within a single large page frame, and mapped within the guest as a
large page, and if, in addition, the source operand is not writeable in the
host (perhaps due to KSM), then KVM will instantiate a read-only direct
shadow page, instantiate an spte for the source operand, then instantiate
a new read/write direct shadow page and instantiate an spte for the
destination operand. Since these two sptes are in different shadow pages,
MOVS will never see them at the same time and the guest will not make
progress.
Fix by mapping the direct shadow page read/write, and only marking the
host page read-only.
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the xsetbv intercept to the AMD part
of KVM. This makes AVX usable in a save way for the guest on
AVX capable AMD hardware.
The patch is tested by using AVX in the guest and host in
parallel and checking for data corruption. I also used the
KVM xsave unit-tests and they all pass.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Large page information has two elements but one of them, write_count, alone
is accessed by a helper function.
This patch replaces this helper function with more generic one which returns
newly named kvm_lpage_info structure and use it to access the other element
rmap_pde.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
In certain use-cases, we want to allocate guests fixed time slices where idle
guest cycles leave the machine idling. There are many approaches to achieve
this but the most direct is to simply avoid trapping the HLT instruction which
lets the guest directly execute the instruction putting the processor to sleep.
Introduce this as a module-level option for kvm-vmx.ko since if you do this
for one guest, you probably want to do it for all.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds the new flush-by-asid of upcoming AMD
processors to the KVM-AMD module.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch replaces all calls to force_new_asid which are
intended to flush the guest-tlb by the more appropriate
function svm_flush_tlb. As a side-effect the force_new_asid
function is removed.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This function is unused and there is svm_flush_tlb which
does the same. So this function can be removed.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Retry #PF for softmmu only when the current vcpu has the same cr3 as the time
when #PF occurs
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Retry #PF is the speculative path, so don't set the accessed bit
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
It's the speculative path if 'no_apf = 1' and we will specially handle this
speculative path in the later patch, so 'prefault' is better to fit the sense.
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the clean-bit for all LBR related
state. This includes the debugctl, br_from, br_to,
last_excp_from, and last_excp_to msrs.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the clean-bit for the cr2 register in
the vmcb.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the clean-bit defined for the cs, ds,
ss, an es segemnts and the current cpl saved in the vmcb.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the clean-bit for the base and limit
of the gdt and idt in the vmcb.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the clean-bit for the dr6 and dr7
debug registers in the vmcb.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the CRx clean-bit for the vmcb. This
bit covers cr0, cr3, cr4, and efer.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the clean-bit for all nested paging
related state in the vmcb.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the clean-bit for all interrupt
related state in the vmcb. This corresponds to vmcb offset
0x60-0x67.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the clean-bit for the asid in the
vmcb.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds the clean bit for the physical addresses of
the MSRPM and the IOPM. It does not need to be set in the
code because the only place where these values are changed
is the nested-svm vmrun and vmexit path. These functions
already mark the complete VMCB as dirty.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds the clean-bit for intercepts-vectors, the
TSC offset and the pause-filter count to the appropriate
places. The IO and MSR permission bitmaps are not subject to
this bit.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds the infrastructure for the implementation of
the individual clean-bits.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
One more "KVM: MMU: Don't drop accessed bit while updating an spte."
Sptes are accessed by both kvm and hardware.
This patch uses update_spte() to fix the way of removing write access.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
If we execute VMREAD during reboot we'll just skip over it. Instead of
returning garbage, return 0, which has a much smaller chance of confusing
the code. Otherwise we risk a flood of debug printk()s which block the
reboot process if a serial console or netconsole is enabled.
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch replaces the open-coded vmcb-selection for the
TSC calculation with the new get_host_vmcb helper function
introduced in this patchset.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch wraps changes to the misc intercepts of SVM
into seperate functions to abstract nested-svm better and
prepare the implementation of the vmcb-clean-bits feature.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch wraps changes to the exception intercepts of SVM
into seperate functions to abstract nested-svm better and
prepare the implementation of the vmcb-clean-bits feature.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch wraps changes to the DRx intercepts of SVM into
seperate functions to abstract nested-svm better and prepare
the implementation of the vmcb-clean-bits feature.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch wraps changes to the CRx intercepts of SVM into
seperate functions to abstract nested-svm better and prepare
the implementation of the vmcb-clean-bits feature.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch adds a function to recalculate the effective
intercepts masks when the vcpu is in guest-mode and either
the host or the guest intercept masks change.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch prevents that emulation failures which result
from emulating an instruction for an L2-Guest results in
being reported to userspace.
Without this patch a malicious L2-Guest would be able to
kill the L1 by triggering a race-condition between an vmexit
and the instruction emulator.
With this patch the L2 will most likely only kill itself in
this situation.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch replaces the is_nested logic in the SVM module
with the generic notion of guest-mode.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch introduces a generic representation of guest-mode
fpr a vcpu. This currently only exists in the SVM code.
Having this representation generic will help making the
non-svm code aware of nesting when this is necessary.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently page fault cr2 and nesting infomation are carried outside
the fault data structure. Instead they are placed in the vcpu struct,
which results in confusion as global variables are manipulated instead
of passing parameters.
Fix this issue by adding address and nested fields to struct x86_exception,
so this struct can carry all information associated with a fault.
Signed-off-by: Avi Kivity <avi@redhat.com>
Tested-by: Joerg Roedel <joerg.roedel@amd.com>
Tested-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Immediately after we generate an exception, we want a X86EMUL_PROPAGATE_FAULT
constant, so return it from the generation functions.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Instead of checking for X86EMUL_PROPAGATE_FAULT, check for any error,
making the callers more reliable.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If rc == X86EMUL_PROPAGATE_FAULT, we would have returned earlier.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Introduce a structure that can contain an exception to be passed back
to main kvm code.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Quote from Avi:
| I don't think we need to flush immediately; set a "tlb dirty" bit somewhere
| that is cleareded when we flush the tlb. kvm_mmu_notifier_invalidate_page()
| can consult the bit and force a flush if set.
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Introduce a common function to map invalid gpte
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Remove it since we can judge it by using sp->unsync
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Rename it to fit its sense better
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We just need flush tlb if overwrite a writable spte with a read-only one.
And we should move this operation to set_spte() for sync_page path
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We should flush all tlbs after drop spte on sync_page path since
Quote from Avi:
| sync_page
| drop_spte
| kvm_mmu_notifier_invalidate_page
| kvm_unmap_rmapp
| spte doesn't exist -> no flush
| page is freed
| guest can write into freed page?
KVM-Stable-Tag.
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The exit reason alone is insufficient to understand exactly why an exit
occured; add ISA-specific trace parameters for additional information.
Because fetching these parameters is expensive on vmx, and because these
parameters are fetched even if tracing is disabled, we fetch the
parameters via a callback instead of as traditional trace arguments.
Signed-off-by: Avi Kivity <avi@redhat.com>
exit_reason's meaning depend on the instruction set; record it so a trace
taken on one machine can be interpreted on another.
Signed-off-by: Avi Kivity <avi@redhat.com>
cea15c2 ("KVM: Move KVM context switch into own function") split vmx_vcpu_run()
to prevent multiple copies of the context switch from being generated (causing
problems due to a label). This patch folds them back together again and adds
the __noclone attribute to prevent the label from being duplicated.
Signed-off-by: Avi Kivity <avi@redhat.com>
Linear addresses are supposed to already have segment checks performed on them;
if we play with these addresses the checks become invalid.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently the x86 emulator converts the segment register associated with
an operand into a segment base which is added into the operand address.
This loss of information results in us not doing segment limit checks properly.
Replace struct operand's addr.mem field by a segmented_address structure
which holds both the effetive address and segment. This will allow us to
do the limit check at the point of access.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Failed emulation is reported via a tracepoint; the cmps printk is pointless.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Inform user to either disable TXT in the BIOS or do TXT launch
with tboot before enabling KVM since some BIOSes do not set
FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX bit when TXT is enabled.
Signed-off-by: Shane Wang <shane.wang@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If reserved bit is set, we need inject the #PF with PFEC.RSVD=1,
but shadow_notrap_nonpresent_pte injects #PF with PFEC.RSVD=0 only
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This allows Linux to mask cpuid bits if, for example, nx is enabled on only
some cpus.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Instead of querying cpuid directly, use the Linux accessors (boot_cpu_has,
etc.). This allows the things like the clearcpuid kernel command line to
work (when it's fixed wrt scattered cpuid bits).
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If apf is generated in L2 guest and is completed in L1 guest, it will
prefault this apf in L1 guest's mmu context.
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If CR0.PG is changed, the page fault cann't be avoid when the prefault address
is accessed later
And it also fix a bug: it can retry a page enabled #PF in page disabled context
if mmu is shadow page
This idear is from Gleb Natapov
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
IA64 support forces us to abstract the allocation of the kvm structure.
But instead of mixing this up with arch-specific initialization and
doing the same on destruction, split both steps. This allows to move
generic destruction calls into generic code.
It also fixes error clean-up on failures of kvm_create_vm for IA64.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Changed makefile to use the ccflags-y option instead of EXTRA_CFLAGS.
Signed-off-by: Tracey Dent <tdent48227@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
While not mandated by the spec, Linux relies on NMI being blocked by an
IF-enabling STI. VMX also refuses to enter a guest in this state, at
least on some implementations.
Disallow NMI while blocked by STI by checking for the condition, and
requesting an interrupt window exit if it occurs.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
In current code, it checks async pf completion out of the wait context,
like this:
if (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE &&
!vcpu->arch.apf.halted)
r = vcpu_enter_guest(vcpu);
else {
......
kvm_vcpu_block(vcpu)
^- waiting until 'async_pf.done' is not empty
}
kvm_check_async_pf_completion(vcpu)
^- delete list from async_pf.done
So, if we check aysnc pf completion first, it can be blocked at
kvm_vcpu_block
Fixed by mark the vcpu is unhalted in kvm_check_async_pf_completion()
path
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Tracing 'async' and *pfn is useless, since 'async' is always true,
and '*pfn' is always "fault_pfn'
We can trace 'gva' and 'gfn' instead, it can help us to see the
life-cycle of an async_pf
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently the exit is unhandled, so guest halts with error if it tries
to execute INVD instruction. Call into emulator when INVD instruction
is executed by a guest instead. This instruction is not needed by ordinary
guests, but firmware (like OpenBIOS) use it and fail.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Micro optimization to avoid calling wbinvd twice on the CPU that has to
emulate it. As we might be preempted between smp_call_function_many and
the local wbinvd, the cache might be filled again so that real work
could be done uselessly.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently x86's kvm_vm_ioctl_get_dirty_log() needs to allocate a bitmap by
vmalloc() which will be used in the next logging and this has been causing
bad effect to VGA and live-migration: vmalloc() consumes extra systime,
triggers tlb flush, etc.
This patch resolves this issue by pre-allocating one more bitmap and switching
between two bitmaps during dirty logging.
Performance improvement:
I measured performance for the case of VGA update by trace-cmd.
The result was 1.5 times faster than the original one.
In the case of live migration, the improvement ratio depends on the workload
and the guest memory size. In general, the larger the memory size is the more
benefits we get.
Note:
This does not change other architectures's logic but the allocation size
becomes twice. This will increase the actual memory consumption only when
the new size changes the number of pages allocated by vmalloc().
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
As suggested by Andrea, pass r/w error code to gup(), upgrading read fault
to writable if host pte allows it.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This can happen in the following scenario:
vcpu0 vcpu1
read fault
gup(.write=0)
gup(.write=1)
reuse swap cache, no COW
set writable spte
use writable spte
set read-only spte
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The EPT present/writable bits use the same position as normal
pagetable bits.
Since direct_map passes ACC_ALL to mmu_set_spte, thus always setting
the writable bit on sptes, use the generic PT_PRESENT shadow_base_pte.
Also pass present/writable error code information from EPT violation
to generic pagefault handler.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
After an interrupt injection, the PPR changes, and we have to reflect that
into the vapic. This causes a KVM_REQ_EVENT to be set, which causes the
whole interrupt injection routine to be run again (harmlessly).
Optimize by only setting KVM_REQ_EVENT if the ppr was lowered; otherwise
there is no chance that a new injection is needed.
Signed-off-by: Avi Kivity <avi@redhat.com>
ldt is never used in the kernel context; same goes for fs (x86_64) and gs
(i386). So save/restore them in the heavyweight exit path instead
of the lightweight path.
By itself, this doesn't buy us much, but it paves the way for moving vmload
and vmsave to the heavyweight exit path, since they modify the same registers.
[jan: fix copy/pase mistake on i386]
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Saving guest registers is just a memory copy, and does not need to be in the
critical section. Move outside the critical section to improve latency a
bit.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
gcc 4.5 with some special options is able to duplicate the VMX
context switch asm in vmx_vcpu_run(). This results in a compile error
because the inline asm sequence uses an on local label. The non local
label is needed because other code wants to set up the return address.
This patch moves the asm code into an own function and marks
that explicitely noinline to avoid this problem.
Better would be probably to just move it into an .S file.
The diff looks worse than the change really is, it's all just
code movement and no logic change.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
It has no user outside mmu.c and also no prototype.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If guest indicates that it can handle async pf in kernel mode too send
it, but only if interrupts are enabled.
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If guest can detect that it runs in non-preemptable context it can
handle async PFs at any time, so let host know that it can send async
PF even if guest cpu is not in userspace.
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Send async page fault to a PV guest if it accesses swapped out memory.
Guest will choose another task to run upon receiving the fault.
Allow async page fault injection only when guest is in user mode since
otherwise guest may be in non-sleepable context and will not be able
to reschedule.
Vcpu will be halted if guest will fault on the same page again or if
vcpu executes kernel code.
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When async PF capability is detected hook up special page fault handler
that will handle async page fault events and bypass other page faults to
regular page fault handler. Also add async PF handling to nested SVM
emulation. Async PF always generates exit to L1 where vcpu thread will
be scheduled out until page is available.
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Keep track of memslots changes by keeping generation number in memslots
structure. Provide kvm_write_guest_cached() function that skips
gfn_to_hva() translation if memslots was not changed since previous
invocation.
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When page is swapped in it is mapped into guest memory only after guest
tries to access it again and generate another fault. To save this fault
we can map it immediately since we know that guest is going to access
the page. Do it only when tdp is enabled for now. Shadow paging case is
more complicated. CR[034] and EFER registers should be switched before
doing mapping and then switched back.
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If a guest accesses swapped out memory do not swap it in from vcpu thread
context. Schedule work to do swapping and put vcpu into halted state
instead.
Interrupts will still be delivered to the guest and if interrupt will
cause reschedule guest will continue to run another task.
[avi: remove call to get_user_pages_noio(), nacked by Linus; this
makes everything synchrnous again]
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
gameport: use this_cpu_read instead of lookup
x86: udelay: Use this_cpu_read to avoid address calculation
x86: Use this_cpu_inc_return for nmi counter
x86: Replace uses of current_cpu_data with this_cpu ops
x86: Use this_cpu_ops to optimize code
vmstat: User per cpu atomics to avoid interrupt disable / enable
irq_work: Use per cpu atomics instead of regular atomics
cpuops: Use cmpxchg for xchg to avoid lock semantics
x86: this_cpu_cmpxchg and this_cpu_xchg operations
percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
percpu,x86: relocate this_cpu_add_return() and friends
connector: Use this_cpu operations
xen: Use this_cpu_inc_return
taskstats: Use this_cpu_ops
random: Use this_cpu_inc_return
fs: Use this_cpu_inc_return in buffer.c
highmem: Use this_cpu_xx_return() operations
vmstat: Use this_cpu_inc_return for vm statistics
x86: Support for this_cpu_add, sub, dec, inc_return
percpu: Generic support for this_cpu_add, sub, dec, inc_return
...
Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.
The only bit of EFER that affects the mmu is NX, and this is already
accounted for (LME only takes effect when changing cr0).
Based on a patch by Hillf Danton.
Signed-off-by: Avi Kivity <avi@redhat.com>
isr_ack is never initialized. So, until the first PIC reset, interrupts
may fail to be injected. This can cause Windows XP to fail to boot, as
reported in the fallout from the fix to
https://bugzilla.kernel.org/show_bug.cgi?id=21962.
Reported-and-tested-by: Nicolas Prochazka <prochazka.nicolas@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Go through x86 code and replace __get_cpu_var and get_cpu_var
instances that refer to a scalar and are not used for address
determinations.
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
We use the physical address instead of the base gfn for the four
PAE page directories we use in unpaged mode. When the guest accesses
an address above 1GB that is backed by a large host page, a BUG_ON()
in kvm_mmu_set_gfn() triggers.
Resolves: https://bugzilla.kernel.org/show_bug.cgi?id=21962
Reported-and-tested-by: Nicolas Prochazka <prochazka.nicolas@gmail.com>
KVM-Stable-Tag.
Signed-off-by: Avi Kivity <avi@redhat.com>
To support xsave properly for the guest the SVM module need
software support for it. As long as this is not present do
not report the xsave as supported feature in cpuid.
As a side-effect this patch moves the bit() helper function
into the x86.h file so that it can be used in svm.c too.
KVM-Stable-Tag.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
CPUID's OSXSAVE is a mirror of CR4.OSXSAVE bit. We need to update the CPUID
after migration.
KVM-Stable-Tag.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
We now use load_gs_index() to load gs safely; unfortunately this also
changes MSR_KERNEL_GS_BASE, which we managed separately. This resulted
in confusion and breakage running 32-bit host userspace on a 64-bit kernel.
Fix by
- saving guest MSR_KERNEL_GS_BASE before we we reload the host's gs
- doing the host save/load unconditionally, instead of only when in guest
long mode
Things can be cleaned up further, but this is the minmal fix for now.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If fs or gs refer to the ldt, they must be reloaded after the ldt. Reorder
the code to that effect.
Userspace code that uses the ldt with kvm is nonexistent, so this doesn't fix
a user-visible bug.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
smp_call_function_many is specified to be called only with preemption
disabled. Fulfill this requirement.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Structures kvm_vcpu_events, kvm_debugregs, kvm_pit_state2 and
kvm_clock_data are copied to userland with some padding and reserved
fields unitialized. It leads to leaking of contents of kernel stack
memory. We have to initialize them to zero.
In patch v1 Jan Kiszka suggested to fill reserved fields with zeros
instead of memset'ting the whole struct. It makes sense as these
fields are explicitly marked as padding. No more fields need zeroing.
KVM-Stable-Tag.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
drop_spte should not attempt to rmap_remove a non present shadow pte.
This fixes a BUG_ON seen on kvm-autotest.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Reported-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
I have observed the following bug trigger:
1. userspace calls GET_DIRTY_LOG
2. kvm_mmu_slot_remove_write_access is called and makes a page ro
3. page fault happens and makes the page writeable
fault is logged in the bitmap appropriately
4. kvm_vm_ioctl_get_dirty_log swaps slot pointers
a lot of time passes
5. guest writes into the page
6. userspace calls GET_DIRTY_LOG
At point (5), bitmap is clean and page is writeable,
thus, guest modification of memory is not logged
and GET_DIRTY_LOG returns an empty bitmap.
The rule is that all pages are either dirty in the current bitmap,
or write-protected, which is violated here.
It seems that just moving kvm_mmu_slot_remove_write_access down
to after the slot pointer swap should fix this bug.
KVM-Stable-Tag.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
* 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (321 commits)
KVM: Drop CONFIG_DMAR dependency around kvm_iommu_map_pages
KVM: Fix signature of kvm_iommu_map_pages stub
KVM: MCE: Send SRAR SIGBUS directly
KVM: MCE: Add MCG_SER_P into KVM_MCE_CAP_SUPPORTED
KVM: fix typo in copyright notice
KVM: Disable interrupts around get_kernel_ns()
KVM: MMU: Avoid sign extension in mmu_alloc_direct_roots() pae root address
KVM: MMU: move access code parsing to FNAME(walk_addr) function
KVM: MMU: audit: check whether have unsync sps after root sync
KVM: MMU: audit: introduce audit_printk to cleanup audit code
KVM: MMU: audit: unregister audit tracepoints before module unloaded
KVM: MMU: audit: fix vcpu's spte walking
KVM: MMU: set access bit for direct mapping
KVM: MMU: cleanup for error mask set while walk guest page table
KVM: MMU: update 'root_hpa' out of loop in PAE shadow path
KVM: x86 emulator: Eliminate compilation warning in x86_decode_insn()
KVM: x86: Fix constant type in kvm_get_time_scale
KVM: VMX: Add AX to list of registers clobbered by guest switch
KVM guest: Move a printk that's using the clock before it's ready
KVM: x86: TSC catchup mode
...
Originally, SRAR SIGBUS is sent to QEMU-KVM via touching the poisoned
page. But commit 9605456919 prevents the
signal from being sent. So now the signal is sent via
force_sig_info_fault directly.
[marcelo: use send_sig_info instead]
Reported-by: Dean Nelson <dnelson@redhat.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Now we have MCG_SER_P (and corresponding SRAO/SRAR MCE) support in
kernel and QEMU-KVM, the MCG_SER_P should be added into
KVM_MCE_CAP_SUPPORTED to make all these code really works.
Reported-by: Dean Nelson <dnelson@redhat.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
get_kernel_ns() wants preemption disabled. It doesn't make a lot of sense
during the get/set ioctls (no way to make them non-racy) but the callee wants
it.
Signed-off-by: Avi Kivity <avi@redhat.com>
Move access code parsing from caller site to FNAME(walk_addr) function
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
After root synced, all unsync sps are synced, this patch add a check to make
sure it's no unsync sps in VCPU's page table
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Introduce audit_printk, and record audit point instead audit name
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
After nested nested paging, it may using long mode to shadow 32/PAE paging
guest, so this patch fix it
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Set access bit while setup up direct page table if it's nonpaing or npt enabled,
it's good for CPU's speculate access
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The value of 'vcpu->arch.mmu.pae_root' is not modified, so we can update
'root_hpa' out of the loop.
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Eliminate:
arch/x86/kvm/emulate.c:801: warning: ‘sv’ may be used uninitialized in this
function
on gcc 4.1.2
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Older gcc versions complain about the improper type (for x86-32), 4.5
seems to fix this silently. However, we should better use the right type
initially.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
By chance this caused no harm so far. We overwrite AX during switch
to/from guest context, so we must declare this.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
