Commit Graph

1679 Commits

Author SHA1 Message Date
Avi Kivity
8c28d03165 KVM: Push struct x86_exception into walk_addr()
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:30:01 +02:00
Avi Kivity
ab9ae31387 KVM: Push struct x86_exception info the various gva_to_gpa variants
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:59 +02:00
Avi Kivity
35d3d4a1dd KVM: x86 emulator: simplify exception generation
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>
2011-01-12 11:29:58 +02:00
Avi Kivity
db297e3d8e KVM: x86 emulator: tighen up ->read_std() and ->write_std() error checks
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>
2011-01-12 11:29:56 +02:00
Avi Kivity
42438e364c KVM: x86 emulator: drop dead pf injection in emulate_popf()
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>
2011-01-12 11:29:55 +02:00
Avi Kivity
bcc55cba9f KVM: x86 emulator: make emulator memory callbacks return full exception
This way, they can return #GP, not just #PF.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:54 +02:00
Avi Kivity
da9cb575b1 KVM: x86 emulator: introduce struct x86_exception to communicate faults
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>
2011-01-12 11:29:53 +02:00
Xiao Guangrong
a4ee1ca4a3 KVM: MMU: delay flush all tlbs on sync_page path
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>
2011-01-12 11:29:51 +02:00
Xiao Guangrong
407c61c6bd KVM: MMU: abstract invalid guest pte mapping
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>
2011-01-12 11:29:49 +02:00
Xiao Guangrong
a4a8e6f76e KVM: MMU: remove 'clear_unsync' parameter
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>
2011-01-12 11:29:48 +02:00
Lai Jiangshan
9bdbba13b8 KVM: MMU: rename 'reset_host_protection' to 'host_writable'
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>
2011-01-12 11:29:46 +02:00
Xiao Guangrong
b330aa0c7d KVM: MMU: don't drop spte if overwrite it from W to RO
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>
2011-01-12 11:29:45 +02:00
Xiao Guangrong
30bfb3c425 KVM: MMU: fix forgot flush tlbs on sync_page path
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>
2011-01-12 11:29:43 +02:00
Avi Kivity
586f960796 KVM: Add instruction-set-specific exit qualifications to kvm_exit trace
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>
2011-01-12 11:29:41 +02:00
Avi Kivity
aa17911e3c KVM: Record instruction set in kvm_exit tracepoint
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>
2011-01-12 11:29:40 +02:00
Avi Kivity
104f226bfd KVM: VMX: Fold __vmx_vcpu_run() into vmx_vcpu_run()
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>
2011-01-12 11:29:37 +02:00
Avi Kivity
30b31ab682 KVM: x86 emulator: do not perform address calculations on linear addresses
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>
2011-01-12 11:29:36 +02:00
Avi Kivity
90de84f50b KVM: x86 emulator: preserve an operand's segment identity
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>
2011-01-12 11:29:35 +02:00
Avi Kivity
d53db5efc2 KVM: x86 emulator: drop DPRINTF()
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>
2011-01-12 11:29:33 +02:00
Avi Kivity
8a6bcaa6ef KVM: x86 emulator: drop unused #ifndef __KERNEL__
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:32 +02:00
Shane Wang
f9335afea5 KVM: VMX: Inform user about INTEL_TXT dependency
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>
2011-01-12 11:29:31 +02:00
Xiao Guangrong
e730b63cc0 KVM: MMU: don't mark spte notrap if reserved bit set
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>
2011-01-12 11:29:27 +02:00
Avi Kivity
945ee35e07 KVM: Mask KVM_GET_SUPPORTED_CPUID data with Linux cpuid info
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>
2011-01-12 11:29:17 +02:00
Avi Kivity
2a6b20b83d KVM: SVM: Replace svm_has() by standard Linux cpuid accessors
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>
2011-01-12 11:29:16 +02:00
Xiao Guangrong
c4806acdce KVM: MMU: fix apf prefault if nested guest is enabled
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>
2011-01-12 11:29:14 +02:00
Xiao Guangrong
060c2abe6c KVM: MMU: support apf for nonpaing guest
Let's support apf for nonpaing guest

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:29:13 +02:00
Xiao Guangrong
e5f3f02796 KVM: MMU: clear apfs if page state is changed
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>
2011-01-12 11:29:12 +02:00
Xiao Guangrong
5054c0de66 KVM: MMU: fix missing post sync audit
Add AUDIT_POST_SYNC audit for long mode shadow page

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:29:11 +02:00
Jan Kiszka
d89f5eff70 KVM: Clean up vm creation and release
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>
2011-01-12 11:29:09 +02:00
Tracey Dent
9d893c6bc1 KVM: x86: Makefile clean up
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>
2011-01-12 11:29:08 +02:00
Avi Kivity
30bd0c4c6c KVM: VMX: Disallow NMI while blocked by STI
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>
2011-01-12 11:29:04 +02:00
Xiao Guangrong
e6d53e3b0d KVM: avoid unnecessary wait for a async pf
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>
2011-01-12 11:29:00 +02:00
Xiao Guangrong
c7d28c2404 KVM: fix searching async gfn in kvm_async_pf_gfn_slot
Don't search later slots if the slot is empty

Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:28:59 +02:00
Xiao Guangrong
c9b263d2be KVM: fix tracing kvm_try_async_get_page
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>
2011-01-12 11:28:56 +02:00
Gleb Natapov
ec25d5e66e KVM: handle exit due to INVD in VMX
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>
2011-01-12 11:28:53 +02:00
Jan Kiszka
2eec734374 KVM: x86: Avoid issuing wbinvd twice
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>
2011-01-12 11:28:52 +02:00
Takuya Yoshikawa
515a01279a KVM: pre-allocate one more dirty bitmap to avoid vmalloc()
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>
2011-01-12 11:28:46 +02:00
Marcelo Tosatti
612819c3c6 KVM: propagate fault r/w information to gup(), allow read-only memory
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>
2011-01-12 11:28:40 +02:00
Marcelo Tosatti
7905d9a5ad KVM: MMU: flush TLBs on writable -> read-only spte overwrite
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>
2011-01-12 11:23:39 +02:00
Marcelo Tosatti
982c25658c KVM: MMU: remove kvm_mmu_set_base_ptes
Unused.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:23:38 +02:00
Marcelo Tosatti
ff1fcb9ebd KVM: VMX: remove setting of shadow_base_ptes for EPT
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>
2011-01-12 11:23:37 +02:00
Avi Kivity
83bcacb1a5 KVM: Avoid double interrupt injection with vapic
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>
2011-01-12 11:23:36 +02:00
Avi Kivity
82ca2d108b KVM: SVM: Fold save_host_msrs() and load_host_msrs() into their callers
This abstraction only serves to obfuscate.  Remove.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:34 +02:00
Avi Kivity
dacccfdd6b KVM: SVM: Move fs/gs/ldt save/restore to heavyweight exit path
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>
2011-01-12 11:23:33 +02:00
Avi Kivity
afe9e66f82 KVM: SVM: Move svm->host_gs_base into a separate structure
More members will join it soon.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:31 +02:00
Avi Kivity
13c34e073b KVM: SVM: Move guest register save out of interrupts disabled section
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>
2011-01-12 11:23:29 +02:00
Andi Kleen
f56f536956 KVM: Move KVM context switch into own function
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>
2011-01-12 11:23:26 +02:00
Jan Kiszka
7e1fbeac6f KVM: x86: Mark kvm_arch_setup_async_pf static
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>
2011-01-12 11:23:25 +02:00
Gleb Natapov
fc5f06fac6 KVM: Send async PF when guest is not in userspace too.
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>
2011-01-12 11:23:22 +02:00
Gleb Natapov
6adba52742 KVM: Let host know whether the guest can handle async PF in non-userspace context.
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>
2011-01-12 11:23:21 +02:00
Gleb Natapov
7c90705bf2 KVM: Inject asynchronous page fault into a PV guest if page is swapped out.
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>
2011-01-12 11:23:17 +02:00
Gleb Natapov
631bc48782 KVM: Handle async PF in a guest.
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>
2011-01-12 11:23:16 +02:00
Gleb Natapov
344d9588a9 KVM: Add PV MSR to enable asynchronous page faults delivery.
Guest enables async PF vcpu functionality using this MSR.

Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:12 +02:00
Gleb Natapov
49c7754ce5 KVM: Add memory slot versioning and use it to provide fast guest write interface
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>
2011-01-12 11:23:08 +02:00
Gleb Natapov
56028d0861 KVM: Retry fault before vmentry
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>
2011-01-12 11:23:06 +02:00
Gleb Natapov
af585b921e KVM: Halt vcpu if page it tries to access is swapped out
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>
2011-01-12 11:21:39 +02:00
Avi Kivity
010c520e20 KVM: Don't reset mmu context unnecessarily when updating EFER
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>
2011-01-02 12:05:15 +02:00
Avi Kivity
d0dfc6b74a KVM: i8259: initialize isr_ack
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>
2011-01-02 11:52:48 +02:00
Avi Kivity
649497d1a3 KVM: MMU: Fix incorrect direct gfn for unpaged mode shadow
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>
2010-12-29 12:35:29 +02:00
Avi Kivity
3e26f23091 KVM: Fix preemption counter leak in kvm_timer_init()
Based on a patch from Thomas Meyer.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-12-16 12:39:31 +02:00
Joerg Roedel
24d1b15f72 KVM: SVM: Do not report xsave in supported cpuid
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>
2010-12-08 17:28:37 +02:00
Sheng Yang
3ea3aa8cf6 KVM: Fix OSXSAVE after migration
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>
2010-12-08 17:28:31 +02:00
Avi Kivity
c8770e7ba6 KVM: VMX: Fix host userspace gsbase corruption
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>
2010-11-17 19:48:05 -02:00
Avi Kivity
0a77fe4c18 KVM: Correct ordering of ldt reload wrt fs/gs reload
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>
2010-11-17 19:47:59 -02:00
Jan Kiszka
453d9c57e2 KVM: x86: Issue smp_call_function_many with preemption disabled
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>
2010-11-05 14:42:27 -02:00
Vasiliy Kulikov
97e69aa62f KVM: x86: fix information leak to userland
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>
2010-11-05 14:42:27 -02:00
Marcelo Tosatti
eb45fda45f KVM: MMU: fix rmap_remove on non present sptes
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>
2010-11-05 14:42:26 -02:00
Michael S. Tsirkin
edde99ce05 KVM: Write protect memory after slot swap
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>
2010-11-05 14:42:25 -02:00
Linus Torvalds
1765a1fe5d Merge branch 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* '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
  ...
2010-10-24 12:47:25 -07:00
Huang Ying
77db5cbd29 KVM: MCE: Send SRAR SIGBUS directly
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>
2010-10-24 10:53:15 +02:00
Huang Ying
5854dbca9b KVM: MCE: Add MCG_SER_P into KVM_MCE_CAP_SUPPORTED
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>
2010-10-24 10:53:15 +02:00
Nicolas Kaiser
9611c18777 KVM: fix typo in copyright notice
Fix typo in copyright notice.

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:14 +02:00
Avi Kivity
395c6b0a9d KVM: Disable interrupts around get_kernel_ns()
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>
2010-10-24 10:53:14 +02:00
Avi Kivity
7ebaf15eef KVM: MMU: Avoid sign extension in mmu_alloc_direct_roots() pae root address
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:14 +02:00
Xiao Guangrong
3377078027 KVM: MMU: move access code parsing to FNAME(walk_addr) function
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>
2010-10-24 10:53:14 +02:00
Xiao Guangrong
6903074c36 KVM: MMU: audit: check whether have unsync sps after root sync
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>
2010-10-24 10:53:14 +02:00
Xiao Guangrong
38904e1287 KVM: MMU: audit: introduce audit_printk to cleanup audit code
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>
2010-10-24 10:53:13 +02:00
Xiao Guangrong
c42fffe3a3 KVM: MMU: audit: unregister audit tracepoints before module unloaded
fix:

Call Trace:
 [<ffffffffa01e46ba>] ? kvm_mmu_pte_write+0x229/0x911 [kvm]
 [<ffffffffa01c6ba9>] ? gfn_to_memslot+0x39/0xa0 [kvm]
 [<ffffffffa01c6c26>] ? mark_page_dirty+0x16/0x2e [kvm]
 [<ffffffffa01c6d6f>] ? kvm_write_guest_page+0x67/0x7f [kvm]
 [<ffffffff81066fbd>] ? local_clock+0x2a/0x3b
 [<ffffffffa01d52ce>] emulator_write_phys+0x46/0x54 [kvm]
 ......
Code:  Bad RIP value.
RIP  [<ffffffffa0172056>] 0xffffffffa0172056
 RSP <ffff880134f69a70>
CR2: ffffffffa0172056

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:13 +02:00
Xiao Guangrong
98224bf1d1 KVM: MMU: audit: fix vcpu's spte walking
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>
2010-10-24 10:53:12 +02:00
Xiao Guangrong
33f91edb92 KVM: MMU: set access bit for direct mapping
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>
2010-10-24 10:53:11 +02:00
Xiao Guangrong
20bd40dc64 KVM: MMU: cleanup for error mask set while walk guest page table
Small cleanup for set page fault error code

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:53:10 +02:00
Xiao Guangrong
6292757fb0 KVM: MMU: update 'root_hpa' out of loop in PAE shadow path
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>
2010-10-24 10:53:09 +02:00
Sheng Yang
7129eecac1 KVM: x86 emulator: Eliminate compilation warning in x86_decode_insn()
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>
2010-10-24 10:53:09 +02:00
Jan Kiszka
50933623e5 KVM: x86: Fix constant type in kvm_get_time_scale
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>
2010-10-24 10:53:08 +02:00
Jan Kiszka
07d6f555d5 KVM: VMX: Add AX to list of registers clobbered by guest switch
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>
2010-10-24 10:53:07 +02:00
Zachary Amsden
c285545f81 KVM: x86: TSC catchup mode
Negate the effects of AN TYM spell while kvm thread is preempted by tracking
conversion factor to the highest TSC rate and catching the TSC up when it has
fallen behind the kernel view of time.  Note that once triggered, we don't
turn off catchup mode.

A slightly more clever version of this is possible, which only does catchup
when TSC rate drops, and which specifically targets only CPUs with broken
TSC, but since these all are considered unstable_tsc(), this patch covers
all necessary cases.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:05 +02:00
Zachary Amsden
34c238a1d1 KVM: x86: Rename timer function
This just changes some names to better reflect the usage they
will be given.  Separated out to keep confusion to a minimum.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:05 +02:00
Zachary Amsden
5f4e3f8827 KVM: x86: Make math work for other scales
The math in kvm_get_time_scale relies on the fact that
NSEC_PER_SEC < 2^32.  To use the same function to compute
arbitrary time scales, we must extend the first reduction
step to shrink the base rate to a 32-bit value, and
possibly reduce the scaled rate into a 32-bit as well.

Note we must take care to avoid an arithmetic overflow
when scaling up the tps32 value (this could not happen
with the fixed scaled value of NSEC_PER_SEC, but can
happen with scaled rates above 2^31.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:04 +02:00
Avi Kivity
49e9d557f9 KVM: VMX: Respect interrupt window in big real mode
If an interrupt is pending, we need to stop emulation so we
can inject it.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:02 +02:00
Mohammed Gamal
a92601bb70 KVM: VMX: Emulated real mode interrupt injection
Replace the inject-as-software-interrupt hack we currently have with
emulated injection.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:01 +02:00
Mohammed Gamal
63995653ad KVM: Add kvm_inject_realmode_interrupt() wrapper
This adds a wrapper function kvm_inject_realmode_interrupt() around the
emulator function emulate_int_real() to allow real mode interrupt injection.

[avi: initialize operand and address sizes before emulating interrupts]
[avi: initialize rip for real mode interrupt injection]
[avi: clear interrupt pending flag after emulating interrupt injection]

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:01 +02:00
Hillf Danton
cb16a7b387 KVM: MMU: fix counting of rmap entries in rmap_add()
It seems that rmap entries are under counted.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:59 +02:00
Gleb Natapov
a0a07cd2c5 KVM: SVM: do not generate "external interrupt exit" if other exit is pending
Nested SVM checks for external interrupt after injecting nested exception.
In case there is external interrupt pending the code generates "external
interrupt exit" and overwrites previous exit info. If previously injected
exception already generated exit it will be lost.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:56 +02:00
Avi Kivity
f4f5105087 KVM: Convert PIC lock from raw spinlock to ordinary spinlock
The PIC code used to be called from preempt_disable() context, which
wasn't very good for PREEMPT_RT.  That is no longer the case, so move
back from raw_spinlock_t to spinlock_t.

Signed-off-by: Avi Kivity <avi@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:56 +02:00
Zachary Amsden
28e4639adf KVM: x86: Fix kvmclock bug
If preempted after kvmclock values are updated, but before hardware
virtualization is entered, the last tsc time as read by the guest is
never set.  It underflows the next time kvmclock is updated if there
has not yet been a successful entry / exit into hardware virt.

Fix this by simply setting last_tsc to the newly read tsc value so
that any computed nsec advance of kvmclock is nulled.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:52:56 +02:00
Joerg Roedel
0959ffacf3 KVM: MMU: Don't track nested fault info in error-code
This patch moves the detection whether a page-fault was
nested or not out of the error code and moves it into a
separate variable in the fault struct.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:55 +02:00
Avi Kivity
625831a3f4 KVM: VMX: Move fixup_rmode_irq() to avoid forward declaration
No code changes.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:54 +02:00
Avi Kivity
b463a6f744 KVM: Non-atomic interrupt injection
Change the interrupt injection code to work from preemptible, interrupts
enabled context.  This works by adding a ->cancel_injection() operation
that undoes an injection in case we were not able to actually enter the guest
(this condition could never happen with atomic injection).

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:54 +02:00
Avi Kivity
83422e17c1 KVM: VMX: Parameterize vmx_complete_interrupts() for both exit and entry
Currently vmx_complete_interrupts() can decode event information from vmx
exit fields into the generic kvm event queues.  Make it able to decode
the information from the entry fields as well by parametrizing it.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:52 +02:00
Avi Kivity
537b37e267 KVM: VMX: Move real-mode interrupt injection fixup to vmx_complete_interrupts()
This allows reuse of vmx_complete_interrupts() for cancelling injections.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:52:51 +02:00