Commit graph

3149 commits

Author SHA1 Message Date
Paolo Bonzini
1c2af4968e Merge tag 'kvm-for-3.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into kvm-next 2014-03-04 15:58:00 +01:00
Andrew Jones
332967a3ea x86: kvm: introduce periodic global clock updates
commit 0061d53daf introduced a mechanism to execute a global clock
update for a vm. We can apply this periodically in order to propagate
host NTP corrections. Also, if all vcpus of a vm are pinned, then
without an additional trigger, no guest NTP corrections can propagate
either, as the current trigger is only vcpu cpu migration.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-03-04 11:50:54 +01:00
Andrew Jones
7e44e4495a x86: kvm: rate-limit global clock updates
When we update a vcpu's local clock it may pick up an NTP correction.
We can't wait an indeterminate amount of time for other vcpus to pick
up that correction, so commit 0061d53daf introduced a global clock
update. However, we can't request a global clock update on every vcpu
load either (which is what happens if the tsc is marked as unstable).
The solution is to rate-limit the global clock updates. Marcelo
calculated that we should delay the global clock updates no more
than 0.1s as follows:

Assume an NTP correction c is applied to one vcpu, but not the other,
then in n seconds the delta of the vcpu system_timestamps will be
c * n. If we assume a correction of 500ppm (worst-case), then the two
vcpus will diverge 50us in 0.1s, which is a considerable amount.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-03-04 11:50:47 +01:00
Paolo Bonzini
ccf9844e5d kvm, vmx: Really fix lazy FPU on nested guest
Commit e504c9098e (kvm, vmx: Fix lazy FPU on nested guest, 2013-11-13)
highlighted a real problem, but the fix was subtly wrong.

nested_read_cr0 is the CR0 as read by L2, but here we want to look at
the CR0 value reflecting L1's setup.  In other words, L2 might think
that TS=0 (so nested_read_cr0 has the bit clear); but if L1 is actually
running it with TS=1, we should inject the fault into L1.

The effective value of CR0 in L2 is contained in vmcs12->guest_cr0, use
it.

Fixes: e504c9098e
Reported-by: Kashyap Chamarty <kchamart@redhat.com>
Reported-by: Stefan Bader <stefan.bader@canonical.com>
Tested-by: Kashyap Chamarty <kchamart@redhat.com>
Tested-by: Anthoine Bourgeois <bourgeois@bertin.fr>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-03-03 12:49:42 +01:00
Paolo Bonzini
1b385cbdd7 kvm, vmx: Really fix lazy FPU on nested guest
Commit e504c9098e (kvm, vmx: Fix lazy FPU on nested guest, 2013-11-13)
highlighted a real problem, but the fix was subtly wrong.

nested_read_cr0 is the CR0 as read by L2, but here we want to look at
the CR0 value reflecting L1's setup.  In other words, L2 might think
that TS=0 (so nested_read_cr0 has the bit clear); but if L1 is actually
running it with TS=1, we should inject the fault into L1.

The effective value of CR0 in L2 is contained in vmcs12->guest_cr0, use
it.

Fixes: e504c9098e
Reported-by: Kashyap Chamarty <kchamart@redhat.com>
Reported-by: Stefan Bader <stefan.bader@canonical.com>
Tested-by: Kashyap Chamarty <kchamart@redhat.com>
Tested-by: Anthoine Bourgeois <bourgeois@bertin.fr>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-27 22:54:11 +01:00
Andrew Honig
a08d3b3b99 kvm: x86: fix emulator buffer overflow (CVE-2014-0049)
The problem occurs when the guest performs a pusha with the stack
address pointing to an mmio address (or an invalid guest physical
address) to start with, but then extending into an ordinary guest
physical address.  When doing repeated emulated pushes
emulator_read_write sets mmio_needed to 1 on the first one.  On a
later push when the stack points to regular memory,
mmio_nr_fragments is set to 0, but mmio_is_needed is not set to 0.

As a result, KVM exits to userspace, and then returns to
complete_emulated_mmio.  In complete_emulated_mmio
vcpu->mmio_cur_fragment is incremented.  The termination condition of
vcpu->mmio_cur_fragment == vcpu->mmio_nr_fragments is never achieved.
The code bounces back and fourth to userspace incrementing
mmio_cur_fragment past it's buffer.  If the guest does nothing else it
eventually leads to a a crash on a memcpy from invalid memory address.

However if a guest code can cause the vm to be destroyed in another
vcpu with excellent timing, then kvm_clear_async_pf_completion_queue
can be used by the guest to control the data that's pointed to by the
call to cancel_work_item, which can be used to gain execution.

Fixes: f78146b0f9
Signed-off-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org (3.5+)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-27 19:35:22 +01:00
Takuya Yoshikawa
684851a157 KVM: x86: Break kvm_for_each_vcpu loop after finding the VP_INDEX
No need to scan the entire VCPU array.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-27 19:25:39 +01:00
H. Peter Anvin
840d2830e6 x86, cpufeature: Rename X86_FEATURE_CLFLSH to X86_FEATURE_CLFLUSH
We call this "clflush" in /proc/cpuinfo, and have
cpu_has_clflush()... let's be consistent and just call it that.

Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-mlytfzjkvuf739okyn40p8a5@git.kernel.org
2014-02-27 08:31:30 -08:00
Marcelo Tosatti
404381c583 KVM: MMU: drop read-only large sptes when creating lower level sptes
Read-only large sptes can be created due to read-only faults as
follows:

- QEMU pagetable entry that maps guest memory is read-only
due to COW.
- Guest read faults such memory, COW is not broken, because
it is a read-only fault.
- Enable dirty logging, large spte not nuked because it is read-only.
- Write-fault on such memory causes guest to loop endlessly
(which must go down to level 1 because dirty logging is enabled).

Fix by dropping large spte when necessary.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-26 17:23:32 +01:00
Marcelo Tosatti
d3714010c3 KVM: x86: emulator_cmpxchg_emulated should mark_page_dirty
emulator_cmpxchg_emulated writes to guest memory, therefore it should
update the dirty bitmap accordingly.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-26 10:11:08 +01:00
Liu, Jinsong
390bd528ae KVM: x86: Enable Intel MPX for guest
From 44c2abca2c2eadc6f2f752b66de4acc8131880c4 Mon Sep 17 00:00:00 2001
From: Liu Jinsong <jinsong.liu@intel.com>
Date: Mon, 24 Feb 2014 18:12:31 +0800
Subject: [PATCH v5 3/3] KVM: x86: Enable Intel MPX for guest

This patch enable Intel MPX feature to guest.

Signed-off-by: Xudong Hao <xudong.hao@intel.com>
Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-25 20:17:12 +01:00
Liu, Jinsong
0dd376e709 KVM: x86: add MSR_IA32_BNDCFGS to msrs_to_save
From 5d5a80cd172ea6fb51786369bcc23356b1e9e956 Mon Sep 17 00:00:00 2001
From: Liu Jinsong <jinsong.liu@intel.com>
Date: Mon, 24 Feb 2014 18:11:55 +0800
Subject: [PATCH v5 2/3] KVM: x86: add MSR_IA32_BNDCFGS to msrs_to_save

Add MSR_IA32_BNDCFGS to msrs_to_save, and corresponding logic
to kvm_get/set_msr().

Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-25 20:17:09 +01:00
Liu, Jinsong
da8999d318 KVM: x86: Intel MPX vmx and msr handle
From caddc009a6d2019034af8f2346b2fd37a81608d0 Mon Sep 17 00:00:00 2001
From: Liu Jinsong <jinsong.liu@intel.com>
Date: Mon, 24 Feb 2014 18:11:11 +0800
Subject: [PATCH v5 1/3] KVM: x86: Intel MPX vmx and msr handle

This patch handle vmx and msr of Intel MPX feature.

Signed-off-by: Xudong Hao <xudong.hao@intel.com>
Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-24 12:14:00 +01:00
Liu, Jinsong
56c103ec04 KVM: x86: Fix xsave cpuid exposing bug
From 00c920c96127d20d4c3bb790082700ae375c39a0 Mon Sep 17 00:00:00 2001
From: Liu Jinsong <jinsong.liu@intel.com>
Date: Fri, 21 Feb 2014 23:47:18 +0800
Subject: [PATCH] KVM: x86: Fix xsave cpuid exposing bug

EBX of cpuid(0xD, 0) is dynamic per XCR0 features enable/disable.
Bit 63 of XCR0 is reserved for future expansion.

Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-22 15:53:34 +01:00
Liu, Jinsong
49345f13f0 KVM: x86: expose ADX feature to guest
From 0750e335eb5860b0b483e217e8a08bd743cbba16 Mon Sep 17 00:00:00 2001
From: Liu Jinsong <jinsong.liu@intel.com>
Date: Thu, 20 Feb 2014 17:39:32 +0800
Subject: [PATCH] KVM: x86: expose ADX feature to guest

ADCX and ADOX instructions perform an unsigned addition with Carry flag and
Overflow flag respectively.

Signed-off-by: Xudong Hao <xudong.hao@intel.com>
Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-22 15:53:34 +01:00
Liu, Jinsong
0c79893b2b KVM: x86: expose new instruction RDSEED to guest
From 24ffdce9efebf13c6ed4882f714b2b57ef1141eb Mon Sep 17 00:00:00 2001
From: Liu Jinsong <jinsong.liu@intel.com>
Date: Thu, 20 Feb 2014 17:38:26 +0800
Subject: [PATCH] KVM: x86: expose new instruction RDSEED to guest

RDSEED instruction return a random number, which supplied by a
cryptographically secure, deterministic random bit generator(DRBG).

Signed-off-by: Xudong Hao <xudong.hao@intel.com>
Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-22 15:53:33 +01:00
Radim Krčmář
f303b4ce8b KVM: SVM: fix NMI window after iret
We should open NMI window right after an iret, but SVM exits before it.
We wanted to single step using the trap flag and then open it.
(or we could emulate the iret instead)
We don't do it since commit 3842d135ff (likely), because the iret exit
handler does not request an event, so NMI window remains closed until
the next exit.

Fix this by making KVM_REQ_EVENT request in the iret handler.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-18 10:14:24 +01:00
Takuya Yoshikawa
5befdc385d KVM: Simplify kvm->tlbs_dirty handling
When this was introduced, kvm_flush_remote_tlbs() could be called
without holding mmu_lock.  It is now acknowledged that the function
must be called before releasing mmu_lock, and all callers have already
been changed to do so.

There is no need to use smp_mb() and cmpxchg() any more.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-18 10:07:26 +01:00
Paolo Bonzini
f244d910ea Two new features are added by this patch set:
- The floating interrupt controller (flic) that allows us to inject,
   clear and inspect non-vcpu local interrupts. This also gives us an
   opportunity to fix deficiencies in our existing interrupt definitions.
 - Support for asynchronous page faults via the pfault mechanism. Testing
   show significant guest performance improvements under host swap.
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Merge tag 'kvm-s390-20140130' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

Two new features are added by this patch set:
- The floating interrupt controller (flic) that allows us to inject,
  clear and inspect non-vcpu local interrupts. This also gives us an
  opportunity to fix deficiencies in our existing interrupt definitions.
- Support for asynchronous page faults via the pfault mechanism. Testing
  show significant guest performance improvements under host swap.
2014-02-04 04:23:37 +01:00
Marcelo Tosatti
4f34d683e5 KVM: x86: remove unused last_kernel_ns variable
Remove unused last_kernel_ns variable.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-04 04:20:42 +01:00
Dominik Dingel
e0ead41a6d KVM: async_pf: Provide additional direct page notification
By setting a Kconfig option, the architecture can control when
guest notifications will be presented by the apf backend.
There is the default batch mechanism, working as before, where the vcpu
thread should pull in this information.
Opposite to this, there is now the direct mechanism, that will push the
information to the guest.
This way s390 can use an already existing architecture interface.

Still the vcpu thread should call check_completion to cleanup leftovers.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-01-30 12:51:38 +01:00
Paolo Bonzini
5f66b62095 kvm: x86: move KVM_CAP_HYPERV_TIME outside #ifdef
Self explanatory.

Reported-by: Radim Krcmar <rkrcmar@redhat.com>
Cc: Vadim Rozenfeld <vrozenfe@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-29 18:10:45 +01:00
Jan Kiszka
58cb628dbe KVM: x86: Validate guest writes to MSR_IA32_APICBASE
Check for invalid state transitions on guest-initiated updates of
MSR_IA32_APICBASE. This address both enabling of the x2APIC when it is
not supported and all invalid transitions as described in SDM section
10.12.5. It also checks that no reserved bit is set in APICBASE by the
guest.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
[Use cpuid_maxphyaddr instead of guest_cpuid_get_phys_bits. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-27 14:39:44 +01:00
Vadim Rozenfeld
b3af1e889e KVM: x86: mark hyper-v vapic assist page as dirty
Signed-off-by: Vadim Rozenfeld <vrozenfe@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-24 16:51:15 +01:00
Vadim Rozenfeld
b94b64c9a7 KVM: x86: mark hyper-v hypercall page as dirty
Signed-off-by: Vadim Rozenfeld <vrozenfe@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-23 19:00:04 +01:00
Linus Torvalds
7ebd3faa9b First round of KVM updates for 3.14; PPC parts will come next week.
Nothing major here, just bugfixes all over the place.  The most
 interesting part is the ARM guys' virtualized interrupt controller
 overhaul, which lets userspace get/set the state and thus enables
 migration of ARM VMs.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "First round of KVM updates for 3.14; PPC parts will come next week.

  Nothing major here, just bugfixes all over the place.  The most
  interesting part is the ARM guys' virtualized interrupt controller
  overhaul, which lets userspace get/set the state and thus enables
  migration of ARM VMs"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (67 commits)
  kvm: make KVM_MMU_AUDIT help text more readable
  KVM: s390: Fix memory access error detection
  KVM: nVMX: Update guest activity state field on L2 exits
  KVM: nVMX: Fix nested_run_pending on activity state HLT
  KVM: nVMX: Clean up handling of VMX-related MSRs
  KVM: nVMX: Add tracepoints for nested_vmexit and nested_vmexit_inject
  KVM: nVMX: Pass vmexit parameters to nested_vmx_vmexit
  KVM: nVMX: Leave VMX mode on clearing of feature control MSR
  KVM: VMX: Fix DR6 update on #DB exception
  KVM: SVM: Fix reading of DR6
  KVM: x86: Sync DR7 on KVM_SET_DEBUGREGS
  add support for Hyper-V reference time counter
  KVM: remove useless write to vcpu->hv_clock.tsc_timestamp
  KVM: x86: fix tsc catchup issue with tsc scaling
  KVM: x86: limit PIT timer frequency
  KVM: x86: handle invalid root_hpa everywhere
  kvm: Provide kvm_vcpu_eligible_for_directed_yield() stub
  kvm: vfio: silence GCC warning
  KVM: ARM: Remove duplicate include
  arm/arm64: KVM: relax the requirements of VMA alignment for THP
  ...
2014-01-22 21:40:43 -08:00
Randy Dunlap
94491620e1 kvm: make KVM_MMU_AUDIT help text more readable
Make KVM_MMU_AUDIT kconfig help text readable and collapse
two spaces between words down to one space.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-20 12:59:26 +01:00
Jan Kiszka
3edf1e698f KVM: nVMX: Update guest activity state field on L2 exits
Set guest activity state in L1's VMCS according to the VCPUs mp_state.
This ensures we report the correct state in case we L2 executed HLT or
if we put L2 into HLT state and it was now woken up by an event.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-17 10:22:18 +01:00
Jan Kiszka
7af40ad37b KVM: nVMX: Fix nested_run_pending on activity state HLT
When we suspend the guest in HLT state, the nested run is no longer
pending - we emulated it completely. So only set nested_run_pending
after checking the activity state.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-17 10:22:17 +01:00
Jan Kiszka
cae501397a KVM: nVMX: Clean up handling of VMX-related MSRs
This simplifies the code and also stops issuing warning about writing to
unhandled MSRs when VMX is disabled or the Feature Control MSR is
locked - we do handle them all according to the spec.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-17 10:22:16 +01:00
Jan Kiszka
542060ea79 KVM: nVMX: Add tracepoints for nested_vmexit and nested_vmexit_inject
Already used by nested SVM for tracing nested vmexit: kvm_nested_vmexit
marks exits from L2 to L0 while kvm_nested_vmexit_inject marks vmexits
that are reflected to L1.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-17 10:22:15 +01:00
Jan Kiszka
533558bcb6 KVM: nVMX: Pass vmexit parameters to nested_vmx_vmexit
Instead of fixing up the vmcs12 after the nested vmexit, pass key
parameters already when calling nested_vmx_vmexit. This will help
tracing those vmexits.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-17 10:22:14 +01:00
Jan Kiszka
42124925c1 KVM: nVMX: Leave VMX mode on clearing of feature control MSR
When userspace sets MSR_IA32_FEATURE_CONTROL to 0, make sure we leave
root and non-root mode, fully disabling VMX. The register state of the
VCPU is undefined after this step, so userspace has to set it to a
proper state afterward.

This enables to reboot a VM while it is running some hypervisor code.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-17 10:22:13 +01:00
Jan Kiszka
8246bf52c7 KVM: VMX: Fix DR6 update on #DB exception
According to the SDM, only bits 0-3 of DR6 "may" be cleared by "certain"
debug exception. So do update them on #DB exception in KVM, but leave
the rest alone, only setting BD and BS in addition to already set bits
in DR6. This also aligns us with kvm_vcpu_check_singlestep.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-17 10:22:12 +01:00
Jan Kiszka
73aaf249ee KVM: SVM: Fix reading of DR6
In contrast to VMX, SVM dose not automatically transfer DR6 into the
VCPU's arch.dr6. So if we face a DR6 read, we must consult a new vendor
hook to obtain the current value. And as SVM now picks the DR6 state
from its VMCB, we also need a set callback in order to write updates of
DR6 back.

Fixes a regression of 020df0794f.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-17 10:22:10 +01:00
Jan Kiszka
9926c9fdbd KVM: x86: Sync DR7 on KVM_SET_DEBUGREGS
Whenever we change arch.dr7, we also have to call kvm_update_dr7. In
case guest debugging is off, this will synchronize the new state into
hardware.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-17 10:22:09 +01:00
Vadim Rozenfeld
e984097b55 add support for Hyper-V reference time counter
Signed-off: Peter Lieven <pl@kamp.de>
Signed-off: Gleb Natapov
Signed-off: Vadim Rozenfeld <vrozenfe@redhat.com>

After some consideration I decided to submit only Hyper-V reference
counters support this time. I will submit iTSC support as a separate
patch as soon as it is ready.

v1 -> v2
1. mark TSC page dirty as suggested by
    Eric Northup <digitaleric@google.com> and Gleb
2. disable local irq when calling get_kernel_ns,
    as it was done by Peter Lieven <pl@amp.de>
3. move check for TSC page enable from second patch
    to this one.

v3 -> v4
    Get rid of ref counter offset.

v4 -> v5
    replace __copy_to_user with kvm_write_guest
    when updateing iTSC page.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-17 10:22:08 +01:00
Paolo Bonzini
aab6d7ce37 KVM: remove useless write to vcpu->hv_clock.tsc_timestamp
After the previous patch from Marcelo, the comment before this write
became obsolete.  In fact, the write is unnecessary.  The calls to
kvm_write_tsc ultimately result in a master clock update as soon as
all TSCs agree and the master clock is re-enabled.  This master
clock update will rewrite tsc_timestamp.

So, together with the comment, delete the dead write too.

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-15 18:08:25 +01:00
Marcelo Tosatti
f25e656d31 KVM: x86: fix tsc catchup issue with tsc scaling
To fix a problem related to different resolution of TSC and system clock,
the offset in TSC units is approximated by

delta = vcpu->hv_clock.tsc_timestamp 	- 	vcpu->last_guest_tsc

(Guest TSC value at 			(Guest TSC value at last VM-exit)
the last kvm_guest_time_update
call)

Delta is then later scaled using mult,shift pair found in hv_clock
structure (which is correct against tsc_timestamp in that
structure).

However, if a frequency change is performed between these two points,
this delta is measured using different TSC frequencies, but scaled using
mult,shift pair for one frequency only.

The end result is an incorrect delta.

The bug which this code works around is not the only cause for
clock backwards events. The global accumulator is still
necessary, so remove the max_kernel_ns fix and rely on the
global accumulator for no clock backwards events.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-15 13:44:46 +01:00
Andrew Jones
0dce7cd67f kvm: x86: fix apic_base enable check
Commit e66d2ae7c6 moved the assignment
vcpu->arch.apic_base = value above a condition with
(vcpu->arch.apic_base ^ value), causing that check
to always fail. Use old_value, vcpu->arch.apic_base's
old value, in the condition instead.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-15 13:42:14 +01:00
Marcelo Tosatti
9ed96e87c5 KVM: x86: limit PIT timer frequency
Limit PIT timer frequency similarly to the limit applied by
LAPIC timer.

Cc: stable@kernel.org
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-15 12:43:54 +01:00
Marcelo Tosatti
37f6a4e237 KVM: x86: handle invalid root_hpa everywhere
Rom Freiman <rom@stratoscale.com> notes other code paths vulnerable to
bug fixed by 989c6b34f6.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-01-15 12:16:16 +01:00
Marcelo Tosatti
26a865f4aa KVM: VMX: fix use after free of vmx->loaded_vmcs
After free_loaded_vmcs executes, the "loaded_vmcs" structure
is kfreed, and now vmx->loaded_vmcs points to a kfreed area.
Subsequent free_loaded_vmcs then attempts to manipulate
vmx->loaded_vmcs.

Switch the order to avoid the problem.

https://bugzilla.redhat.com/show_bug.cgi?id=1047892

Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-01-08 19:14:08 -02:00
Chen Fan
96893977b8 KVM: x86: Fix debug typo error in lapic
fix the 'vcpi' typos when apic_debug is enabled.

Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-01-08 19:09:57 -02:00
Zhihui Zhang
2f0a6397dd KVM: VMX: check use I/O bitmap first before unconditional I/O exit
According to Table C-1 of Intel SDM 3C, a VM exit happens on an I/O instruction when
"use I/O bitmaps" VM-execution control was 0 _and_ the "unconditional I/O exiting"
VM-execution control was 1. So we can't just check "unconditional I/O exiting" alone.
This patch was improved by suggestion from Jan Kiszka.

Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Zhihui Zhang <zzhsuny@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-01-08 19:01:40 -02:00
Jan Kiszka
29bf08f12b KVM: nVMX: Unconditionally uninit the MMU on nested vmexit
Three reasons for doing this: 1. arch.walk_mmu points to arch.mmu anyway
in case nested EPT wasn't in use. 2. this aligns VMX with SVM. But 3. is
most important: nested_cpu_has_ept(vmcs12) queries the VMCS page, and if
one guest VCPU manipulates the page of another VCPU in L2, we may be
fooled to skip over the nested_ept_uninit_mmu_context, leaving mmu in
nested state. That can crash the host later on if nested_ept_get_cr3 is
invoked while L1 already left vmxon and nested.current_vmcs12 became
NULL therefore.

Cc: stable@kernel.org
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-01-02 11:22:14 -02:00
Jan Kiszka
e66d2ae7c6 KVM: x86: Fix APIC map calculation after re-enabling
Update arch.apic_base before triggering recalculate_apic_map. Otherwise
the recalculation will work against the previous state of the APIC and
will fail to build the correct map when an APIC is hardware-enabled
again.

This fixes a regression of 1e08ec4a13.

Cc: stable@vger.kernel.org
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-12-30 18:58:17 -02:00
Marcelo Tosatti
989c6b34f6 KVM: MMU: handle invalid root_hpa at __direct_map
It is possible for __direct_map to be called on invalid root_hpa
(-1), two examples:

1) try_async_pf -> can_do_async_pf
    -> vmx_interrupt_allowed -> nested_vmx_vmexit
2) vmx_handle_exit -> vmx_interrupt_allowed -> nested_vmx_vmexit

Then to load_vmcs12_host_state and kvm_mmu_reset_context.

Check for this possibility, let fault exception be regenerated.

BZ: https://bugzilla.redhat.com/show_bug.cgi?id=924916

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-12-20 19:22:49 +01:00
Jan Kiszka
4c4d563b49 KVM: VMX: Do not skip the instruction if handle_dr injects a fault
If kvm_get_dr or kvm_set_dr reports that it raised a fault, we must not
advance the instruction pointer. Otherwise the exception will hit the
wrong instruction.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-12-20 19:20:39 +01:00
Jan Kiszka
ca3f257ae5 KVM: nVMX: Support direct APIC access from L2
It's a pathological case, but still a valid one: If L1 disables APIC
virtualization and also allows L2 to directly write to the APIC page, we
have to forcibly enable APIC virtualization while in L2 if the in-kernel
APIC is in use.

This allows to run the direct interrupt test case in the vmx unit test
without x2APIC.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-12-18 10:27:09 +01:00