On Intel platforms, this patch adds LMCE to KVM MCE supported
capabilities and handles guest access to LMCE related MSRs.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
[Haozhong: macro KVM_MCE_CAP_SUPPORTED => variable kvm_mce_cap_supported
Only enable LMCE on Intel platform
Check MSR_IA32_FEATURE_CONTROL when handling guest
access to MSR_IA32_MCG_EXT_CTL]
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM currently does not check the value written to guest
MSR_IA32_FEATURE_CONTROL, though bits corresponding to disabled features
may be set. This patch makes KVM to validate individual bits written to
guest MSR_IA32_FEATURE_CONTROL according to enabled features.
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
msr_ia32_feature_control will be used for LMCE and not depend only on
nested anymore, so move it from struct nested_vmx to struct vcpu_vmx.
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Hook the VMX preemption timer to the "hv timer" functionality added
by the previous patch. This includes: checking if the feature is
supported, if the feature is broken on the CPU, the hooks to
setup/clean the VMX preemption timer, arming the timer on vmentry
and handling the vmexit.
A module parameter states if the VMX preemption timer should be
utilized.
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
[Move hv_deadline_tsc to struct vcpu_vmx, use -1 as the "unset" value.
Put all VMX bits here. Enable it by default #yolo. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Prepare to switch from preemption timer to hrtimer in the
vmx_pre/post_block. Current functions are only for posted interrupt,
rename them accordingly.
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The VMX preemption timer can be used to virtualize the TSC deadline timer.
The VMX preemption timer is armed when the vCPU is running, and a VMExit
will happen if the virtual TSC deadline timer expires.
When the vCPU thread is blocked because of HLT, KVM will switch to use
an hrtimer, and then go back to the VMX preemption timer when the vCPU
thread is unblocked.
This solution avoids the complex OS's hrtimer system, and the host
timer interrupt handling cost, replacing them with a little math
(for guest->host TSC and host TSC->preemption timer conversion)
and a cheaper VMexit. This benefits latency for isolated pCPUs.
[A word about performance... Yunhong reported a 30% reduction in average
latency from cyclictest. I made a similar test with tscdeadline_latency
from kvm-unit-tests, and measured
- ~20 clock cycles loss (out of ~3200, so less than 1% but still
statistically significant) in the worst case where the test halts
just after programming the TSC deadline timer
- ~800 clock cycles gain (25% reduction in latency) in the best case
where the test busy waits.
I removed the VMX bits from Yunhong's patch, to concentrate them in the
next patch - Paolo]
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The function to start the tsc deadline timer virtualization will be used
also by the pre_block hook when we use the preemption timer; change it
to a separate function. No logic changes.
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The new created_vcpus field makes it possible to avoid the race between
irqchip and VCPU creation in a much nicer way; just check under kvm->lock
whether a VCPU has already been created.
We can then remove KVM_APIC_ARCHITECTURE too, because at this point the
symbol is only governing the default definition of kvm_vcpu_compatible.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/x86/kvm/iommu.c includes <linux/intel-iommu.h> and <linux/dmar.h>, which
both are unnecessary, in fact incorrect to be here as they are intel specific.
Building kvm on x86 passed after removing above inclusion.
Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Make the function names more similar between KVM_REQ_NMI and KVM_REQ_SMI.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
If the processor exits to KVM while delivering an interrupt,
the hypervisor then requeues the interrupt for the next vmentry.
Trying to enter SMM in this same window causes to enter non-root
mode in emulated SMM (i.e. with IF=0) and with a request to
inject an IRQ (i.e. with a valid VM-entry interrupt info field).
This is invalid guest state (SDM 26.3.1.4 "Check on Guest RIP
and RFLAGS") and the processor fails vmentry.
The fix is to defer the injection from KVM_REQ_SMI to KVM_REQ_EVENT,
like we already do for e.g. NMIs. This patch doesn't change the
name of the process_smi function so that it can be applied to
stable releases. The next patch will modify the names so that
process_nmi and process_smi handle respectively KVM_REQ_NMI and
KVM_REQ_SMI.
This is especially common with Windows, probably due to the
self-IPI trick that it uses to deliver deferred procedure
calls (DPCs).
Reported-by: Laszlo Ersek <lersek@redhat.com>
Reported-by: Michał Zegan <webczat_200@poczta.onet.pl>
Fixes: 64d6067057
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Intel CPUs having Turbo Boost feature implement an MSR to provide a
control interface via rdmsr/wrmsr instructions. One could detect the
presence of this feature by issuing one of these instructions and
handling the #GP exception which is generated in case the referenced MSR
is not implemented by the CPU.
KVM's vCPU model behaves exactly as a real CPU in this case by injecting
a fault when MSR_IA32_PERF_CTL is called (which KVM does not support).
However, some operating systems use this register during an early boot
stage in which their kernel is not capable of handling #GP correctly,
causing #DP and finally a triple fault effectively resetting the vCPU.
This patch implements a dummy handler for MSR_IA32_PERF_CTL to avoid the
crashes.
Signed-off-by: Dmitry Bilunov <kmeaw@yandex-team.ru>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
In theory, nothing prevents the compiler from write-tearing PTEs, or
split PTE writes. These partially-modified PTEs can be fetched by other
cores and cause mayhem. I have not really encountered such case in
real-life, but it does seem possible.
For example, the compiler may try to do something creative for
kvm_set_pte_rmapp() and perform multiple writes to the PTE.
Signed-off-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
(kvm_stat had nothing to do with QEMU in the first place -- the tool
only interprets debugfs)
- expose per-vm statistics in debugfs and support them in kvm_stat
(KVM always collected per-vm statistics, but they were summarised into
global statistics)
x86:
- fix dynamic APICv (VMX was improperly configured and a guest could
access host's APIC MSRs, CVE-2016-4440)
- minor fixes
ARM changes from Christoffer Dall:
"This set of changes include the new vgic, which is a reimplementation
of our horribly broken legacy vgic implementation. The two
implementations will live side-by-side (with the new being the
configured default) for one kernel release and then we'll remove the
legacy one.
Also fixes a non-critical issue with virtual abort injection to
guests."
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull second batch of KVM updates from Radim Krčmář:
"General:
- move kvm_stat tool from QEMU repo into tools/kvm/kvm_stat (kvm_stat
had nothing to do with QEMU in the first place -- the tool only
interprets debugfs)
- expose per-vm statistics in debugfs and support them in kvm_stat
(KVM always collected per-vm statistics, but they were summarised
into global statistics)
x86:
- fix dynamic APICv (VMX was improperly configured and a guest could
access host's APIC MSRs, CVE-2016-4440)
- minor fixes
ARM changes from Christoffer Dall:
- new vgic reimplementation of our horribly broken legacy vgic
implementation. The two implementations will live side-by-side
(with the new being the configured default) for one kernel release
and then we'll remove the legacy one.
- fix for a non-critical issue with virtual abort injection to guests"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (70 commits)
tools: kvm_stat: Add comments
tools: kvm_stat: Introduce pid monitoring
KVM: Create debugfs dir and stat files for each VM
MAINTAINERS: Add kvm tools
tools: kvm_stat: Powerpc related fixes
tools: Add kvm_stat man page
tools: Add kvm_stat vm monitor script
kvm:vmx: more complete state update on APICv on/off
KVM: SVM: Add more SVM_EXIT_REASONS
KVM: Unify traced vector format
svm: bitwise vs logical op typo
KVM: arm/arm64: vgic-new: Synchronize changes to active state
KVM: arm/arm64: vgic-new: enable build
KVM: arm/arm64: vgic-new: implement mapped IRQ handling
KVM: arm/arm64: vgic-new: Wire up irqfd injection
KVM: arm/arm64: vgic-new: Add vgic_v2/v3_enable
KVM: arm/arm64: vgic-new: vgic_init: implement map_resources
KVM: arm/arm64: vgic-new: vgic_init: implement vgic_init
KVM: arm/arm64: vgic-new: vgic_init: implement vgic_create
KVM: arm/arm64: vgic-new: vgic_init: implement kvm_vgic_hyp_init
...
The function to update APICv on/off state (in particular, to deactivate
it when enabling Hyper-V SynIC) is incomplete: it doesn't adjust
APICv-related fields among secondary processor-based VM-execution
controls. As a result, Windows 2012 guests get stuck when SynIC-based
auto-EOI interrupt intersected with e.g. an IPI in the guest.
In addition, the MSR intercept bitmap isn't updated every time "virtualize
x2APIC mode" is toggled. This path can only be triggered by a malicious
guest, because Windows didn't use x2APIC but rather their own synthetic
APIC access MSRs; however a guest running in a SynIC-enabled VM could
switch to x2APIC and thus obtain direct access to host APIC MSRs
(CVE-2016-4440).
The patch fixes those omissions.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Reported-by: Steve Rutherford <srutherford@google.com>
Reported-by: Yang Zhang <yang.zhang.wz@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
These were supposed to be a bitwise operation but there is a typo.
The result is mostly harmless, but sparse correctly complains.
Fixes: 44a95dae1d ('KVM: x86: Detect and Initialize AVIC support')
Fixes: 18f40c53e1 ('svm: Add VMEXIT handlers for AVIC')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- x86: miscellaneous fixes, AVIC support (local APIC virtualization,
AMD version)
- s390: polling for interrupts after a VCPU goes to halted state is
now enabled for s390; use hardware provided information about facility
bits that do not need any hypervisor activity, and other fixes for
cpu models and facilities; improve perf output; floating interrupt
controller improvements.
- MIPS: miscellaneous fixes
- PPC: bugfixes only
- ARM: 16K page size support, generic firmware probing layer for
timer and GIC
Christoffer Dall (KVM-ARM maintainer) says:
"There are a few changes in this pull request touching things outside
KVM, but they should all carry the necessary acks and it made the
merge process much easier to do it this way."
though actually the irqchip maintainers' acks didn't make it into the
patches. Marc Zyngier, who is both irqchip and KVM-ARM maintainer,
later acked at http://mid.gmane.org/573351D1.4060303@arm.com
"more formally and for documentation purposes".
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"Small release overall.
x86:
- miscellaneous fixes
- AVIC support (local APIC virtualization, AMD version)
s390:
- polling for interrupts after a VCPU goes to halted state is now
enabled for s390
- use hardware provided information about facility bits that do not
need any hypervisor activity, and other fixes for cpu models and
facilities
- improve perf output
- floating interrupt controller improvements.
MIPS:
- miscellaneous fixes
PPC:
- bugfixes only
ARM:
- 16K page size support
- generic firmware probing layer for timer and GIC
Christoffer Dall (KVM-ARM maintainer) says:
"There are a few changes in this pull request touching things
outside KVM, but they should all carry the necessary acks and it
made the merge process much easier to do it this way."
though actually the irqchip maintainers' acks didn't make it into the
patches. Marc Zyngier, who is both irqchip and KVM-ARM maintainer,
later acked at http://mid.gmane.org/573351D1.4060303@arm.com ('more
formally and for documentation purposes')"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (82 commits)
KVM: MTRR: remove MSR 0x2f8
KVM: x86: make hwapic_isr_update and hwapic_irr_update look the same
svm: Manage vcpu load/unload when enable AVIC
svm: Do not intercept CR8 when enable AVIC
svm: Do not expose x2APIC when enable AVIC
KVM: x86: Introducing kvm_x86_ops.apicv_post_state_restore
svm: Add VMEXIT handlers for AVIC
svm: Add interrupt injection via AVIC
KVM: x86: Detect and Initialize AVIC support
svm: Introduce new AVIC VMCB registers
KVM: split kvm_vcpu_wake_up from kvm_vcpu_kick
KVM: x86: Introducing kvm_x86_ops VCPU blocking/unblocking hooks
KVM: x86: Introducing kvm_x86_ops VM init/destroy hooks
KVM: x86: Rename kvm_apic_get_reg to kvm_lapic_get_reg
KVM: x86: Misc LAPIC changes to expose helper functions
KVM: shrink halt polling even more for invalid wakeups
KVM: s390: set halt polling to 80 microseconds
KVM: halt_polling: provide a way to qualify wakeups during poll
KVM: PPC: Book3S HV: Re-enable XICS fast path for irqfd-generated interrupts
kvm: Conditionally register IRQ bypass consumer
...
MSR 0x2f8 accessed the 124th Variable Range MTRR ever since MTRR support
was introduced by 9ba075a664 ("KVM: MTRR support").
0x2f8 became harmful when 910a6aae4e ("KVM: MTRR: exactly define the
size of variable MTRRs") shrinked the array of VR MTRRs from 256 to 8,
which made access to index 124 out of bounds. The surrounding code only
WARNs in this situation, thus the guest gained a limited read/write
access to struct kvm_arch_vcpu.
0x2f8 is not a valid VR MTRR MSR, because KVM has/advertises only 16 VR
MTRR MSRs, 0x200-0x20f. Every VR MTRR is set up using two MSRs, 0x2f8
was treated as a PHYSBASE and 0x2f9 would be its PHYSMASK, but 0x2f9 was
not implemented in KVM, therefore 0x2f8 could never do anything useful
and getting rid of it is safe.
This fixes CVE-2016-3713.
Fixes: 910a6aae4e ("KVM: MTRR: exactly define the size of variable MTRRs")
Cc: stable@vger.kernel.org
Reported-by: David Matlack <dmatlack@google.com>
Signed-off-by: Andy Honig <ahonig@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Neither APICv nor AVIC actually need the first argument of
hwapic_isr_update, but the vCPU makes more sense than passing the
pointer to the whole virtual machine! In fact in the APICv case it's
just happening that the vCPU is used implicitly, through the loaded VMCS.
The second argument instead is named differently, make it consistent.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When a vcpu is loaded/unloaded to a physical core, we need to update
host physical APIC ID information in the Physical APIC-ID table
accordingly.
Also, when vCPU is blocking/un-blocking (due to halt instruction),
we need to make sure that the is-running bit in set accordingly in the
physical APIC-ID table.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
[Return void from new functions, add WARN_ON when they returned negative
errno; split load and put into separate function as they have almost
nothing in common. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When enable AVIC:
* Do not intercept CR8 since this should be handled by AVIC HW.
* Also, we don't need to sync cr8/V_TPR and APIC backing page.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
[Rename svm_in_nested_interrupt_shadow to svm_nested_virtualize_tpr. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Since AVIC only virtualizes xAPIC hardware for the guest, this patch
disable x2APIC support in guest CPUID.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Adding kvm_x86_ops hooks to allow APICv to do post state restore.
This is required to support VM save and restore feature.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch introduces VMEXIT handlers, avic_incomplete_ipi_interception()
and avic_unaccelerated_access_interception() along with two trace points
(trace_kvm_avic_incomplete_ipi and trace_kvm_avic_unaccelerated_access).
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch introduces a new mechanism to inject interrupt using AVIC.
Since VINTR is not supported when enable AVIC, we need to inject
interrupt via APIC backing page instead.
This patch also adds support for AVIC doorbell, which is used by
KVM to signal a running vcpu to check IRR for injected interrupts.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch introduces AVIC-related data structure, and AVIC
initialization code.
There are three main data structures for AVIC:
* Virtual APIC (vAPIC) backing page (per-VCPU)
* Physical APIC ID table (per-VM)
* Logical APIC ID table (per-VM)
Currently, AVIC is disabled by default. Users can manually
enable AVIC via kernel boot option kvm-amd.avic=1 or during
kvm-amd module loading with parameter avic=1.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
[Avoid extra indentation (Boris). - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Adding function pointers in struct kvm_x86_ops for processor-specific
layer to provide hooks for when KVM initialize and destroy VM.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rename kvm_apic_get_reg to kvm_lapic_get_reg to be consistent with
the existing kvm_lapic_set_reg counterpart.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull x86 asm updates from Ingo Molnar:
"The main changes in this cycle were:
- MSR access API fixes and enhancements (Andy Lutomirski)
- early exception handling improvements (Andy Lutomirski)
- user-space FS/GS prctl usage fixes and improvements (Andy
Lutomirski)
- Remove the cpu_has_*() APIs and replace them with equivalents
(Borislav Petkov)
- task switch micro-optimization (Brian Gerst)
- 32-bit entry code simplification (Denys Vlasenko)
- enhance PAT handling in enumated CPUs (Toshi Kani)
... and lots of other cleanups/fixlets"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
x86/arch_prctl/64: Restore accidentally removed put_cpu() in ARCH_SET_GS
x86/entry/32: Remove asmlinkage_protect()
x86/entry/32: Remove GET_THREAD_INFO() from entry code
x86/entry, sched/x86: Don't save/restore EFLAGS on task switch
x86/asm/entry/32: Simplify pushes of zeroed pt_regs->REGs
selftests/x86/ldt_gdt: Test set_thread_area() deletion of an active segment
x86/tls: Synchronize segment registers in set_thread_area()
x86/asm/64: Rename thread_struct's fs and gs to fsbase and gsbase
x86/arch_prctl/64: Remove FSBASE/GSBASE < 4G optimization
x86/segments/64: When load_gs_index fails, clear the base
x86/segments/64: When loadsegment(fs, ...) fails, clear the base
x86/asm: Make asm/alternative.h safe from assembly
x86/asm: Stop depending on ptrace.h in alternative.h
x86/entry: Rename is_{ia32,x32}_task() to in_{ia32,x32}_syscall()
x86/asm: Make sure verify_cpu() has a good stack
x86/extable: Add a comment about early exception handlers
x86/msr: Set the return value to zero when native_rdmsr_safe() fails
x86/paravirt: Make "unsafe" MSR accesses unsafe even if PARAVIRT=y
x86/paravirt: Add paravirt_{read,write}_msr()
x86/msr: Carry on after a non-"safe" MSR access fails
...
Some wakeups should not be considered a sucessful poll. For example on
s390 I/O interrupts are usually floating, which means that _ALL_ CPUs
would be considered runnable - letting all vCPUs poll all the time for
transactional like workload, even if one vCPU would be enough.
This can result in huge CPU usage for large guests.
This patch lets architectures provide a way to qualify wakeups if they
should be considered a good/bad wakeups in regard to polls.
For s390 the implementation will fence of halt polling for anything but
known good, single vCPU events. The s390 implementation for floating
interrupts does a wakeup for one vCPU, but the interrupt will be delivered
by whatever CPU checks first for a pending interrupt. We prefer the
woken up CPU by marking the poll of this CPU as "good" poll.
This code will also mark several other wakeup reasons like IPI or
expired timers as "good". This will of course also mark some events as
not sucessful. As KVM on z runs always as a 2nd level hypervisor,
we prefer to not poll, unless we are really sure, though.
This patch successfully limits the CPU usage for cases like uperf 1byte
transactional ping pong workload or wakeup heavy workload like OLTP
while still providing a proper speedup.
This also introduced a new vcpu stat "halt_poll_no_tuning" that marks
wakeups that are considered not good for polling.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Radim Krčmář <rkrcmar@redhat.com> (for an earlier version)
Cc: David Matlack <dmatlack@google.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
[Rename config symbol. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If we don't support a mechanism for bypassing IRQs, don't register as
a consumer. This eliminates meaningless dev_info()s when the connect
fails between producer and consumer, such as on AMD systems where
kvm_x86_ops->update_pi_irte is not implemented
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
an objtool warning for CONFIG_PROFILE_ALL_BRANCHES.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"Two small x86 patches, improving "make kvmconfig" and fixing an
objtool warning for CONFIG_PROFILE_ALL_BRANCHES"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
kvmconfig: add more virtio drivers
x86/kvm: Add stack frame dependency to fastop() inline asm
The kbuild test robot reported this objtool warning [1]:
arch/x86/kvm/emulate.o: warning: objtool: fastop()+0x69: call without frame pointer save/setup
The issue seems to be caused by CONFIG_PROFILE_ALL_BRANCHES. With that
option, for some reason gcc decides not to create a stack frame in
fastop() before doing the inline asm call, which can result in a bad
stack trace.
Force a stack frame to be created if CONFIG_FRAME_POINTER is enabled by
listing the stack pointer as an output operand for the inline asm
statement.
This change has no effect for !CONFIG_PROFILE_ALL_BRANCHES.
[1] https://lists.01.org/pipermail/kbuild-all/2016-March/018249.html
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
After the THP refcounting change, obtaining a compound pages from
get_user_pages() no longer allows us to assume the entire compound page
is immediately mappable from a secondary MMU.
A secondary MMU doesn't want to call get_user_pages() more than once for
each compound page, in order to know if it can map the whole compound
page. So a secondary MMU needs to know from a single get_user_pages()
invocation when it can map immediately the entire compound page to avoid
a flood of unnecessary secondary MMU faults and spurious
atomic_inc()/atomic_dec() (pages don't have to be pinned by MMU notifier
users).
Ideally instead of the page->_mapcount < 1 check, get_user_pages()
should return the granularity of the "page" mapping in the "mm" passed
to get_user_pages(). However it's non trivial change to pass the "pmd"
status belonging to the "mm" walked by get_user_pages up the stack (up
to the caller of get_user_pages). So the fix just checks if there is
not a single pte mapping on the page returned by get_user_pages, and in
turn if the caller can assume that the whole compound page is mapped in
the current "mm" (in a pmd_trans_huge()). In such case the entire
compound page is safe to map into the secondary MMU without additional
get_user_pages() calls on the surrounding tail/head pages. In addition
of being faster, not having to run other get_user_pages() calls also
reduces the memory footprint of the secondary MMU fault in case the pmd
split happened as result of memory pressure.
Without this fix after a MADV_DONTNEED (like invoked by QEMU during
postcopy live migration or balloning) or after generic swapping (with a
failure in split_huge_page() that would only result in pmd splitting and
not a physical page split), KVM would map the whole compound page into
the shadow pagetables, despite regular faults or userfaults (like
UFFDIO_COPY) may map regular pages into the primary MMU as result of the
pte faults, leading to the guest mode and userland mode going out of
sync and not working on the same memory at all times.
Any other secondary MMU notifier manager (KVM is just one of the many
MMU notifier users) will need the same information if it doesn't want to
run a flood of get_user_pages_fast and it can support multiple
granularity in the secondary MMU mappings, so I think it is justified to
be exposed not just to KVM.
The other option would be to move transparent_hugepage_adjust to
mm/huge_memory.c but that currently has all kind of KVM data structures
in it, so it's definitely not a cut-and-paste work, so I couldn't do a
fix as cleaner as this one for 4.6.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: "Li, Liang Z" <liang.z.li@intel.com>
Cc: Amit Shah <amit.shah@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Guest should only trust data to be valid when version haven't changed
before and after reads of steal time. Besides not changing, it has to
be an even number. Hypervisor may write an odd number to version field
to indicate that an update is in progress.
kvm_steal_clock() in guest has already done the read side, make write
side in hypervisor more robust by following the above rule.
Reviewed-by: Wincy Van <fanwenyi0529@gmail.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Commit d28bc9dd25 reversed the order of two lines which initialize cr0,
allowing the current (old) cr0 value to mess up vcpu initialization.
This was observed in the checks for cr0 X86_CR0_WP bit in the context of
kvm_mmu_reset_context(). Besides, setting vcpu->arch.cr0 after vmx_set_cr0()
is completely redundant. Change the order back to ensure proper vcpu
initialization.
The combination of booting with ovmf firmware when guest vcpus > 1 and kvm's
ept=N option being set results in a VM-entry failure. This patch fixes that.
Fixes: d28bc9dd25 ("KVM: x86: INIT and reset sequences are different")
Cc: stable@vger.kernel.org
Signed-off-by: Bruce Rogers <brogers@suse.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Unlike ds and es, these are base addresses, not selectors. Rename
them so their meaning is more obvious.
On x86_32, the field is still called fs. Fixing that could make sense
as a future cleanup.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/69a18a51c4cba0ce29a241e570fc618ad721d908.1461698311.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some versions of Intel PT do not support tracing across VMXON, more
specifically, VMXON will clear TraceEn control bit and any attempt to
set it before VMXOFF will throw a #GP, which in the current state of
things will crash the kernel. Namely:
$ perf record -e intel_pt// kvm -nographic
on such a machine will kill it.
To avoid this, notify the intel_pt driver before VMXON and after
VMXOFF so that it knows when not to enable itself.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/87oa9dwrfk.fsf@ashishki-desk.ger.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kvm_make_request and kvm_check_request imply a producer-consumer
relationship; add implicit memory barriers to them. There was indeed
already a place that was adding an explicit smp_mb() to order between
kvm_check_request and the processing of the request. That memory
barrier can be removed (as an added benefit, kvm_check_request can use
smp_mb__after_atomic which is free on x86).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The obsolete sp should not be used on current vCPUs and should not hurt
vCPU's running, so skip it from for_each_gfn_sp() and
for_each_gfn_indirect_valid_sp()
The side effort is we will double check role.invalid in kvm_mmu_get_page()
but i think it is okay as role is well cached
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Since accumulate_steal_time is now only called in record_steal_time, it
doesn't quite make sense to put the delta calculation in a separate
function. The function could be called thousands of times before guest
enables the steal time MSR (though the compiler may optimize out this
function call). And after it's enabled, the MSR enable bit is tested twice
every time. Removing the accumulate_steal_time function also avoids the
necessity of having the accum_steal field.
Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
Signed-off-by: Gavin Guo <gavin.guo@canonical.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
