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2016-11-02KVM: VMX: join functions that disable x2apic msr interceptsRadim Krčmář1-36/+15
vmx_disable_intercept_msr_read_x2apic() and vmx_disable_intercept_msr_write_x2apic() differed only in the type. Pass the type to a new function. [Ordered and commented TPR intercept according to Paolo's suggestion.] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-11-02KVM: VMX: remove functions that enable msr interceptsRadim Krčmář1-53/+4
All intercepts are enabled at the beginning, so they can only be used if we disabled an intercept that we wanted to have enabled. This was done for TMCCT to simplify a loop that disables all x2APIC MSR intercepts, but just keeping TMCCT enabled yields better results. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-11-02kvm: nVMX: Update MSR load counts on a VMCS switchJim Mattson1-0/+11
When L0 establishes (or removes) an MSR entry in the VM-entry or VM-exit MSR load lists, the change should affect the dormant VMCS as well as the current VMCS. Moreover, the vmcs02 MSR-load addresses should be initialized. Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-11-02kvm: nVMX: Fetch VM_INSTRUCTION_ERROR from vmcs02 on vmx->failJim Mattson1-1/+5
When forwarding a hardware VM-entry failure to L1, fetch the VM_INSTRUCTION_ERROR field from vmcs02 before loading vmcs01. (Note that there is an implicit assumption that the VM-entry failure was on the first VM-entry to vmcs02 after nested_vmx_run; otherwise, L1 is going to be very confused.) Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Peter Feiner <pfeiner@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-11-02KVM: VMX: Better name x2apic msr bitmapsWanpeng Li1-36/+36
Renames x2apic_apicv_inactive msr_bitmaps to x2apic and original x2apic bitmaps to x2apic_apicv. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-11-02kvm: nVMX: VMCLEAR an active shadow VMCS after last useJim Mattson1-7/+15
After a successful VM-entry with the "VMCS shadowing" VM-execution control set, the shadow VMCS referenced by the VMCS link pointer field in the current VMCS becomes active on the logical processor. A VMCS that is made active on more than one logical processor may become corrupted. Therefore, before an active VMCS can be migrated to another logical processor, the first logical processor must execute a VMCLEAR for the active VMCS. VMCLEAR both ensures that all VMCS data are written to memory and makes the VMCS inactive. Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-By: David Matlack <dmatlack@google.com> Message-Id: <1477668579-22555-1-git-send-email-jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-02KVM: x86: drop TSC offsetting kvm_x86_ops to fix KVM_GET/SET_CLOCKPaolo Bonzini1-36/+3
Since commit a545ab6a0085 ("kvm: x86: add tsc_offset field to struct kvm_vcpu_arch", 2016-09-07) the offset between host and L1 TSC is cached and need not be fished out of the VMCS or VMCB. This means that we can implement adjust_tsc_offset_guest and read_l1_tsc entirely in generic code. The simplification is particularly significant for VMX code, where vmx->nested.vmcs01_tsc_offset was duplicating what is now in vcpu->arch.tsc_offset. Therefore the vmcs01_tsc_offset can be dropped completely. More importantly, this fixes KVM_GET_CLOCK/KVM_SET_CLOCK which, after commit 108b249c453d ("KVM: x86: introduce get_kvmclock_ns", 2016-09-01) called read_l1_tsc while the VMCS was not loaded. It thus returned bogus values on Intel CPUs. Fixes: 108b249c453dd7132599ab6dc7e435a7036c193f Reported-by: Roman Kagan <rkagan@virtuozzo.com> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-01x86/fpu, kvm: Remove host CR0.TS manipulationAndy Lutomirski1-8/+4
Now that x86 always uses eager FPU switching on the host, there's no need for KVM to manipulate the host's CR0.TS. This should be both simpler and faster. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm list <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/b212064922537c05d0c81d931fc4dbe769127ce7.1477951965.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-27kvm: nVMX: Fix kernel panics induced by illegal INVEPT/INVVPID typesJim Mattson1-2/+2
Bitwise shifts by amounts greater than or equal to the width of the left operand are undefined. A malicious guest can exploit this to crash a 32-bit host, due to the BUG_ON(1)'s in handle_{invept,invvpid}. Signed-off-by: Jim Mattson <jmattson@google.com> Message-Id: <1477496318-17681-1-git-send-email-jmattson@google.com> [Change 1UL to 1, to match the range check on the shift count. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-06Merge tag 'kvm-4.9-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-72/+135
Pull KVM updates from Radim Krčmář: "All architectures: - move `make kvmconfig` stubs from x86 - use 64 bits for debugfs stats ARM: - Important fixes for not using an in-kernel irqchip - handle SError exceptions and present them to guests if appropriate - proxying of GICV access at EL2 if guest mappings are unsafe - GICv3 on AArch32 on ARMv8 - preparations for GICv3 save/restore, including ABI docs - cleanups and a bit of optimizations MIPS: - A couple of fixes in preparation for supporting MIPS EVA host kernels - MIPS SMP host & TLB invalidation fixes PPC: - Fix the bug which caused guests to falsely report lockups - other minor fixes - a small optimization s390: - Lazy enablement of runtime instrumentation - up to 255 CPUs for nested guests - rework of machine check deliver - cleanups and fixes x86: - IOMMU part of AMD's AVIC for vmexit-less interrupt delivery - Hyper-V TSC page - per-vcpu tsc_offset in debugfs - accelerated INS/OUTS in nVMX - cleanups and fixes" * tag 'kvm-4.9-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (140 commits) KVM: MIPS: Drop dubious EntryHi optimisation KVM: MIPS: Invalidate TLB by regenerating ASIDs KVM: MIPS: Split kernel/user ASID regeneration KVM: MIPS: Drop other CPU ASIDs on guest MMU changes KVM: arm/arm64: vgic: Don't flush/sync without a working vgic KVM: arm64: Require in-kernel irqchip for PMU support KVM: PPC: Book3s PR: Allow access to unprivileged MMCR2 register KVM: PPC: Book3S PR: Support 64kB page size on POWER8E and POWER8NVL KVM: PPC: Book3S: Remove duplicate setting of the B field in tlbie KVM: PPC: BookE: Fix a sanity check KVM: PPC: Book3S HV: Take out virtual core piggybacking code KVM: PPC: Book3S: Treat VTB as a per-subcore register, not per-thread ARM: gic-v3: Work around definition of gic_write_bpr1 KVM: nVMX: Fix the NMI IDT-vectoring handling KVM: VMX: Enable MSR-BASED TPR shadow even if APICv is inactive KVM: nVMX: Fix reload apic access page warning kvmconfig: add virtio-gpu to config fragment config: move x86 kvm_guest.config to a common location arm64: KVM: Remove duplicating init code for setting VMID ARM: KVM: Support vgic-v3 ...
2016-09-23KVM: nVMX: Fix the NMI IDT-vectoring handlingWanpeng Li1-15/+16
Run kvm-unit-tests/eventinj.flat in L1: Sending NMI to self After NMI to self FAIL: NMI This test scenario is to test whether VMM can handle NMI IDT-vectoring info correctly. At the beginning, L2 writes LAPIC to send a self NMI, the EPT page tables on both L1 and L0 are empty so: - The L2 accesses memory can generate EPT violation which can be intercepted by L0. The EPT violation vmexit occurred during delivery of this NMI, and the NMI info is recorded in vmcs02's IDT-vectoring info. - L0 walks L1's EPT12 and L0 sees the mapping is invalid, it injects the EPT violation into L1. The vmcs02's IDT-vectoring info is reflected to vmcs12's IDT-vectoring info since it is a nested vmexit. - L1 receives the EPT violation, then fixes its EPT12. - L1 executes VMRESUME to resume L2 which generates vmexit and causes L1 exits to L0. - L0 emulates VMRESUME which is called from L1, then return to L2. L0 merges the requirement of vmcs12's IDT-vectoring info and injects it to L2 through vmcs02. - The L2 re-executes the fault instruction and cause EPT violation again. - Since the L1's EPT12 is valid, L0 can fix its EPT02 - L0 resume L2 The EPT violation vmexit occurred during delivery of this NMI again, and the NMI info is recorded in vmcs02's IDT-vectoring info. L0 should inject the NMI through vmentry event injection since it is caused by EPT02's EPT violation. However, vmx_inject_nmi() refuses to inject NMI from IDT-vectoring info if vCPU is in guest mode, this patch fix it by permitting to inject NMI from IDT-vectoring if it is the L0's responsibility to inject NMI from IDT-vectoring info to L2. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Bandan Das <bsd@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-09-23KVM: VMX: Enable MSR-BASED TPR shadow even if APICv is inactiveWanpeng Li1-38/+94
I observed that kvmvapic(to optimize flexpriority=N or AMD) is used to boost TPR access when testing kvm-unit-test/eventinj.flat tpr case on my haswell desktop (w/ flexpriority, w/o APICv). Commit (8d14695f9542 x86, apicv: add virtual x2apic support) disable virtual x2apic mode completely if w/o APICv, and the author also told me that windows guest can't enter into x2apic mode when he developed the APICv feature several years ago. However, it is not truth currently, Interrupt Remapping and vIOMMU is added to qemu and the developers from Intel test windows 8 can work in x2apic mode w/ Interrupt Remapping enabled recently. This patch enables TPR shadow for virtual x2apic mode to boost windows guest in x2apic mode even if w/o APICv. Can pass the kvm-unit-test. Suggested-by: Radim Krčmář <rkrcmar@redhat.com> Suggested-by: Wincy Van <fanwenyi0529@gmail.com> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Wincy Van <fanwenyi0529@gmail.com> Cc: Yang Zhang <yang.zhang.wz@gmail.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-09-23KVM: nVMX: Fix reload apic access page warningWanpeng Li1-1/+1
WARNING: CPU: 1 PID: 4230 at kernel/sched/core.c:7564 __might_sleep+0x7e/0x80 do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff8d0de7f9>] prepare_to_swait+0x39/0xa0 CPU: 1 PID: 4230 Comm: qemu-system-x86 Not tainted 4.8.0-rc5+ #47 Call Trace: dump_stack+0x99/0xd0 __warn+0xd1/0xf0 warn_slowpath_fmt+0x4f/0x60 ? prepare_to_swait+0x39/0xa0 ? prepare_to_swait+0x39/0xa0 __might_sleep+0x7e/0x80 __gfn_to_pfn_memslot+0x156/0x480 [kvm] gfn_to_pfn+0x2a/0x30 [kvm] gfn_to_page+0xe/0x20 [kvm] kvm_vcpu_reload_apic_access_page+0x32/0xa0 [kvm] nested_vmx_vmexit+0x765/0xca0 [kvm_intel] ? _raw_spin_unlock_irqrestore+0x36/0x80 vmx_check_nested_events+0x49/0x1f0 [kvm_intel] kvm_arch_vcpu_runnable+0x2d/0xe0 [kvm] kvm_vcpu_check_block+0x12/0x60 [kvm] kvm_vcpu_block+0x94/0x4c0 [kvm] kvm_arch_vcpu_ioctl_run+0x619/0x1aa0 [kvm] ? kvm_arch_vcpu_ioctl_run+0xdf1/0x1aa0 [kvm] kvm_vcpu_ioctl+0x2d3/0x7c0 [kvm] =============================== [ INFO: suspicious RCU usage. ] 4.8.0-rc5+ #47 Not tainted ------------------------------- ./include/linux/kvm_host.h:535 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 1 lock held by qemu-system-x86/4230: #0: (&vcpu->mutex){+.+.+.}, at: [<ffffffffc062975c>] vcpu_load+0x1c/0x60 [kvm] stack backtrace: CPU: 1 PID: 4230 Comm: qemu-system-x86 Not tainted 4.8.0-rc5+ #47 Call Trace: dump_stack+0x99/0xd0 lockdep_rcu_suspicious+0xe7/0x120 gfn_to_memslot+0x12a/0x140 [kvm] gfn_to_pfn+0x12/0x30 [kvm] gfn_to_page+0xe/0x20 [kvm] kvm_vcpu_reload_apic_access_page+0x32/0xa0 [kvm] nested_vmx_vmexit+0x765/0xca0 [kvm_intel] ? _raw_spin_unlock_irqrestore+0x36/0x80 vmx_check_nested_events+0x49/0x1f0 [kvm_intel] kvm_arch_vcpu_runnable+0x2d/0xe0 [kvm] kvm_vcpu_check_block+0x12/0x60 [kvm] kvm_vcpu_block+0x94/0x4c0 [kvm] kvm_arch_vcpu_ioctl_run+0x619/0x1aa0 [kvm] ? kvm_arch_vcpu_ioctl_run+0xdf1/0x1aa0 [kvm] kvm_vcpu_ioctl+0x2d3/0x7c0 [kvm] ? __fget+0xfd/0x210 ? __lock_is_held+0x54/0x70 do_vfs_ioctl+0x96/0x6a0 ? __fget+0x11c/0x210 ? __fget+0x5/0x210 SyS_ioctl+0x79/0x90 do_syscall_64+0x81/0x220 entry_SYSCALL64_slow_path+0x25/0x25 These can be triggered by running kvm-unit-test: ./x86-run x86/vmx.flat The nested preemption timer is based on hrtimer which is started on L2 entry, stopped on L2 exit and evaluated via the new check_nested_events hook. The current logic adds vCPU to a simple waitqueue (TASK_INTERRUPTIBLE) if need to yield pCPU and w/o holding srcu read lock when accesses memslots, both can be in nested preemption timer evaluation path which results in the warning above. This patch fix it by leveraging request bit to async reload APIC access page before vmentry in order to avoid to reload directly during the nested preemption timer evaluation, it is safe since the vmcs01 is loaded and current is nested vmexit. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Yunhong Jiang <yunhong.jiang@intel.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-09-16kvm: x86: drop read_tsc_offset()Luiz Capitulino1-6/+0
The TSC offset can now be read directly from struct kvm_arch_vcpu. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-15Merge branch 'linus' into x86/asm, to pick up recent fixesIngo Molnar1-67/+69
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-07KVM: nVMX: expose INS/OUTS information supportJan Dakinevich1-0/+9
Expose the feature to L1 hypervisor if host CPU supports it, since certain hypervisors requires it for own purposes. According to Intel SDM A.1, if CPU supports the feature, VMX_INSTRUCTION_INFO field of VMCS will contain detailed information about INS/OUTS instructions handling. This field is already copied to VMCS12 for L1 hypervisor (see prepare_vmcs12 routine) independently feature presence. Signed-off-by: Jan Dakinevich <jan.dakinevich@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-07KVM: VMX: not use vmcs_config in setup_vmcs_configPaolo Bonzini1-1/+1
setup_vmcs_config takes a pointer to the vmcs_config global. The indirection is somewhat pointless, but just keep things consistent for now. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-07KVM: x86: ratelimit and decrease severity for guest-triggered printkPaolo Bonzini1-9/+9
These are mostly related to nested VMX. They needn't have a loglevel as high as KERN_WARN, and mustn't be allowed to pollute the host logs. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-07KVM: nVMX: pass valid guest linear-address to the L1Jan Dakinevich1-0/+3
If EPT support is exposed to L1 hypervisor, guest linear-address field of VMCS should contain GVA of L2, the access to which caused EPT violation. Signed-off-by: Jan Dakinevich <jan.dakinevich@gmail.com> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-07KVM: nVMX: make emulated nested preemption timer pinnedWanpeng Li1-1/+1
Commit 61abdbe0bc ("kvm: x86: make lapic hrtimer pinned") pins the emulated lapic timer. This patch does the same for the emulated nested preemption timer to avoid vmexit an unrelated vCPU and the latency of kicking IPI to another vCPU. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Yunhong Jiang <yunhong.jiang@intel.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-07vmx: refine validity check for guest linear addressLiang Li1-1/+1
The validity check for the guest line address is inefficient, check the invalid value instead of enumerating the valid ones. Signed-off-by: Liang Li <liang.z.li@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-08-18kvm: nVMX: fix nested tsc scalingPeter Feiner1-4/+12
When the host supported TSC scaling, L2 would use a TSC multiplier of 0, which causes a VM entry failure. Now L2's TSC uses the same multiplier as L1. Signed-off-by: Peter Feiner <pfeiner@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-08-18KVM: nVMX: postpone VMCS changes on MSR_IA32_APICBASE writeRadim Krčmář1-0/+13
If vmcs12 does not intercept APIC_BASE writes, then KVM will handle the write with vmcs02 as the current VMCS. This will incorrectly apply modifications intended for vmcs01 to vmcs02 and L2 can use it to gain access to L0's x2APIC registers by disabling virtualized x2APIC while using msr bitmap that assumes enabled. Postpone execution of vmx_set_virtual_x2apic_mode until vmcs01 is the current VMCS. An alternative solution would temporarily make vmcs01 the current VMCS, but it requires more care. Fixes: 8d14695f9542 ("x86, apicv: add virtual x2apic support") Reported-by: Jim Mattson <jmattson@google.com> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-08-18KVM: nVMX: fix msr bitmaps to prevent L2 from accessing L0 x2APICRadim Krčmář1-63/+44
msr bitmap can be used to avoid a VM exit (interception) on guest MSR accesses. In some configurations of VMX controls, the guest can even directly access host's x2APIC MSRs. See SDM 29.5 VIRTUALIZING MSR-BASED APIC ACCESSES. L2 could read all L0's x2APIC MSRs and write TPR, EOI, and SELF_IPI. To do so, L1 would first trick KVM to disable all possible interceptions by enabling APICv features and then would turn those features off; nested_vmx_merge_msr_bitmap() only disabled interceptions, so VMX would not intercept previously enabled MSRs even though they were not safe with the new configuration. Correctly re-enabling interceptions is not enough as a second bug would still allow L1+L2 to access host's MSRs: msr bitmap was shared for all VMCSs, so L1 could trigger a race to get the desired combination of msr bitmap and VMX controls. This fix allocates a msr bitmap for every L1 VCPU, allows only safe x2APIC MSRs from L1's msr bitmap, and disables msr bitmaps if they would have to intercept everything anyway. Fixes: 3af18d9c5fe9 ("KVM: nVMX: Prepare for using hardware MSR bitmap") Reported-by: Jim Mattson <jmattson@google.com> Suggested-by: Wincy Van <fanwenyi0529@gmail.com> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-08-10x86: Apply more __ro_after_init and constKees Cook1-1/+1
Guided by grsecurity's analogous __read_only markings in arch/x86, this applies several uses of __ro_after_init to structures that are only updated during __init, and const for some structures that are never updated. Additionally extends __init markings to some functions that are only used during __init, and cleans up some missing C99 style static initializers. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brad Spengler <spender@grsecurity.net> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Brown <david.brown@linaro.org> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Emese Revfy <re.emese@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathias Krause <minipli@googlemail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: PaX Team <pageexec@freemail.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20160808232906.GA29731@www.outflux.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-04nvmx: mark ept single context invalidation as supportedBandan Das1-7/+7
Commit 4b855078601f ("KVM: nVMX: Don't advertise single context invalidation for invept") removed advertising single context invalidation since the spec does not mandate it. However, some hypervisors (such as ESX) require it to be present before willing to use ept in a nested environment. Advertise it and fallback to the global case. Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-08-04nvmx: remove comment about missing nested vpid supportBandan Das1-1/+0
Nested vpid is already supported and both single/global modes are advertised to the guest Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-08-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-46/+340
Pull KVM updates from Paolo Bonzini: - ARM: GICv3 ITS emulation and various fixes. Removal of the old VGIC implementation. - s390: support for trapping software breakpoints, nested virtualization (vSIE), the STHYI opcode, initial extensions for CPU model support. - MIPS: support for MIPS64 hosts (32-bit guests only) and lots of cleanups, preliminary to this and the upcoming support for hardware virtualization extensions. - x86: support for execute-only mappings in nested EPT; reduced vmexit latency for TSC deadline timer (by about 30%) on Intel hosts; support for more than 255 vCPUs. - PPC: bugfixes. * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (302 commits) KVM: PPC: Introduce KVM_CAP_PPC_HTM MIPS: Select HAVE_KVM for MIPS64_R{2,6} MIPS: KVM: Reset CP0_PageMask during host TLB flush MIPS: KVM: Fix ptr->int cast via KVM_GUEST_KSEGX() MIPS: KVM: Sign extend MFC0/RDHWR results MIPS: KVM: Fix 64-bit big endian dynamic translation MIPS: KVM: Fail if ebase doesn't fit in CP0_EBase MIPS: KVM: Use 64-bit CP0_EBase when appropriate MIPS: KVM: Set CP0_Status.KX on MIPS64 MIPS: KVM: Make entry code MIPS64 friendly MIPS: KVM: Use kmap instead of CKSEG0ADDR() MIPS: KVM: Use virt_to_phys() to get commpage PFN MIPS: Fix definition of KSEGX() for 64-bit KVM: VMX: Add VMCS to CPU's loaded VMCSs before VMPTRLD kvm: x86: nVMX: maintain internal copy of current VMCS KVM: PPC: Book3S HV: Save/restore TM state in H_CEDE KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures KVM: arm64: vgic-its: Simplify MAPI error handling KVM: arm64: vgic-its: Make vgic_its_cmd_handle_mapi similar to other handlers KVM: arm64: vgic-its: Turn device_id validation into generic ID validation ...
2016-08-01KVM: VMX: Add VMCS to CPU's loaded VMCSs before VMPTRLDJim Mattson1-11/+15
Kexec needs to know the addresses of all VMCSs that are active on each CPU, so that it can flush them from the VMCS caches. It is safe to record superfluous addresses that are not associated with an active VMCS, but it is not safe to omit an address associated with an active VMCS. After a call to vmcs_load, the VMCS that was loaded is active on the CPU. The VMCS should be added to the CPU's list of active VMCSs before it is loaded. Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-08-01kvm: x86: nVMX: maintain internal copy of current VMCSDavid Matlack1-3/+28
KVM maintains L1's current VMCS in guest memory, at the guest physical page identified by the argument to VMPTRLD. This makes hairy time-of-check to time-of-use bugs possible,as VCPUs can be writing the the VMCS page in memory while KVM is emulating VMLAUNCH and VMRESUME. The spec documents that writing to the VMCS page while it is loaded is "undefined". Therefore it is reasonable to load the entire VMCS into an internal cache during VMPTRLD and ignore writes to the VMCS page -- the guest should be using VMREAD and VMWRITE to access the current VMCS. To adhere to the spec, KVM should flush the current VMCS during VMPTRLD, and the target VMCS during VMCLEAR (as given by the operand to VMCLEAR). Since this implementation of VMCS caching only maintains the the current VMCS, VMCLEAR will only do a flush if the operand to VMCLEAR is the current VMCS pointer. KVM will also flush during VMXOFF, which is not mandated by the spec, but also not in conflict with the spec. Signed-off-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-29Merge tag 'libnvdimm-for-4.8' of ↵Linus Torvalds1-28/+4
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: - Replace pcommit with ADR / directed-flushing. The pcommit instruction, which has not shipped on any product, is deprecated. Instead, the requirement is that platforms implement either ADR, or provide one or more flush addresses per nvdimm. ADR (Asynchronous DRAM Refresh) flushes data in posted write buffers to the memory controller on a power-fail event. Flush addresses are defined in ACPI 6.x as an NVDIMM Firmware Interface Table (NFIT) sub-structure: "Flush Hint Address Structure". A flush hint is an mmio address that when written and fenced assures that all previous posted writes targeting a given dimm have been flushed to media. - On-demand ARS (address range scrub). Linux uses the results of the ACPI ARS commands to track bad blocks in pmem devices. When latent errors are detected we re-scrub the media to refresh the bad block list, userspace can also request a re-scrub at any time. - Support for the Microsoft DSM (device specific method) command format. - Support for EDK2/OVMF virtual disk device memory ranges. - Various fixes and cleanups across the subsystem. * tag 'libnvdimm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (41 commits) libnvdimm-btt: Delete an unnecessary check before the function call "__nd_device_register" nfit: do an ARS scrub on hitting a latent media error nfit: move to nfit/ sub-directory nfit, libnvdimm: allow an ARS scrub to be triggered on demand libnvdimm: register nvdimm_bus devices with an nd_bus driver pmem: clarify a debug print in pmem_clear_poison x86/insn: remove pcommit Revert "KVM: x86: add pcommit support" nfit, tools/testing/nvdimm/: unify shutdown paths libnvdimm: move ->module to struct nvdimm_bus_descriptor nfit: cleanup acpi_nfit_init calling convention nfit: fix _FIT evaluation memory leak + use after free tools/testing/nvdimm: add manufacturing_{date|location} dimm properties tools/testing/nvdimm: add virtual ramdisk range acpi, nfit: treat virtual ramdisk SPA as pmem region pmem: kill __pmem address space pmem: kill wmb_pmem() libnvdimm, pmem: use nvdimm_flush() for namespace I/O writes fs/dax: remove wmb_pmem() libnvdimm, pmem: flush posted-write queues on shutdown ...
2016-07-24Merge branch 'for-4.8/libnvdimm' into libnvdimm-for-nextDan Williams1-28/+4
2016-07-23Revert "KVM: x86: add pcommit support"Dan Williams1-28/+4
This reverts commit 8b3e34e46aca9b6d349b331cd9cf71ccbdc91b2e. Given the deprecation of the pcommit instruction, the relevant VMX features and CPUID bits are not going to be rolled into the SDM. Remove their usage from KVM. Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-07-16KVM: VMX: handle PML full VMEXIT that occurs during event deliveryCao, Lei1-0/+1
With PML enabled, guest will shut down if a PML full VMEXIT occurs during event delivery. According to Intel SDM 27.2.3, PML full VMEXIT can occur when event is being delivered through IDT, so KVM should not exit to user space with error. Instead, it should let EXIT_REASON_PML_FULL go through and the event will be re-injected on the next VMENTRY. Signed-off-by: Lei Cao <lei.cao@stratus.com> Cc: stable@vger.kernel.org Fixes: 843e4330573c ("KVM: VMX: Add PML support in VMX") [Shortened the summary and Cc'd stable.] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-07-14KVM: nVMX: Fix memory corruption when using VMCS shadowingJim Mattson1-2/+17
When freeing the nested resources of a vcpu, there is an assumption that the vcpu's vmcs01 is the current VMCS on the CPU that executes nested_release_vmcs12(). If this assumption is violated, the vcpu's vmcs01 may be made active on multiple CPUs at the same time, in violation of Intel's specification. Moreover, since the vcpu's vmcs01 is not VMCLEARed on every CPU on which it is active, it can linger in a CPU's VMCS cache after it has been freed and potentially repurposed. Subsequent eviction from the CPU's VMCS cache on a capacity miss can result in memory corruption. It is not sufficient for vmx_free_vcpu() to call vmx_load_vmcs01(). If the vcpu in question was last loaded on a different CPU, it must be migrated to the current CPU before calling vmx_load_vmcs01(). Signed-off-by: Jim Mattson <jmattson@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-14kvm: vmx: ensure VMCS is current while enabling PMLPeter Feiner1-32/+24
Between loading the new VMCS and enabling PML, the CPU was unpinned. If the vCPU thread were migrated to another CPU in the interim (e.g., due to preemption or sleeping alloc_page), then the VMWRITEs to enable PML would target the wrong VMCS -- or no VMCS at all: [ 2087.266950] vmwrite error: reg 200e value 3fe1d52000 (err -506126336) [ 2087.267062] vmwrite error: reg 812 value 1ff (err 511) [ 2087.267125] vmwrite error: reg 401e value 12229c00 (err 304258048) This patch ensures that the VMCS remains current while enabling PML by doing the VMWRITEs while the CPU is pinned. Allocation of the PML buffer is hoisted out of the critical section. Signed-off-by: Peter Feiner <pfeiner@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-14KVM: x86: add KVM_CAP_X2APIC_APIRadim Krčmář1-1/+1
KVM_CAP_X2APIC_API is a capability for features related to x2APIC enablement. KVM_X2APIC_API_32BIT_FORMAT feature can be enabled to extend APIC ID in get/set ioctl and MSI addresses to 32 bits. Both are needed to support x2APIC. The feature has to be enableable and disabled by default, because get/set ioctl shifted and truncated APIC ID to 8 bits by using a non-standard protocol inspired by xAPIC and the change is not backward-compatible. Changes to MSI addresses follow the format used by interrupt remapping unit. The upper address word, that used to be 0, contains upper 24 bits of the LAPIC address in its upper 24 bits. Lower 8 bits are reserved as 0. Using the upper address word is not backward-compatible either as we didn't check that userspace zeroed the word. Reserved bits are still not explicitly checked, but non-zero data will affect LAPIC addresses, which will cause a bug. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-14KVM: VMX: optimize APIC ID read with APICvRadim Krčmář1-3/+0
The register is in hardware-compatible format now, so there is not need to intercept. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-14kvm: vmx: advertise support for ept execute onlyBandan Das1-0/+3
MMU now knows about execute only mappings, so advertise the feature to L1 hypervisors Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-14kvm: mmu: track read permission explicitly for shadow EPT page tablesBandan Das1-6/+9
To support execute only mappings on behalf of L1 hypervisors, reuse ACC_USER_MASK to signify if the L1 hypervisor has the R bit set. For the nested EPT case, we assumed that the U bit was always set since there was no equivalent in EPT page tables. Strictly speaking, this was not necessary because handle_ept_violation never set PFERR_USER_MASK in the error code (uf=0 in the parlance of update_permission_bitmask). We now have to set both U and UF correctly, respectively in FNAME(gpte_access) and in handle_ept_violation. Also in handle_ept_violation bit 3 of the exit qualification is not enough to detect a present PTE; all three bits 3-5 have to be checked. Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-14kvm: mmu: don't set the present bit unconditionallyBandan Das1-0/+1
To support execute only mappings on behalf of L1 hypervisors, we need to teach set_spte() to honor all three of L1's XWR bits. As a start, add a new variable "shadow_present_mask" that will be set for non-EPT shadow paging and clear for EPT. Signed-off-by: Bandan Das <bsd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-11KVM: VMX: introduce vm_{entry,exit}_control_reset_shadowPaolo Bonzini1-2/+12
There is no reason to read the entry/exit control fields of the VMCS and immediately write back the same value. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-11KVM: nVMX: keep preemption timer enabled during L2 executionPaolo Bonzini1-2/+13
Because the vmcs12 preemption timer is emulated through a separate hrtimer, we can keep on using the preemption timer in the vmcs02 to emulare L1's TSC deadline timer. However, the corresponding bit in the pin-based execution control field must be kept consistent between vmcs01 and vmcs02. On vmentry we copy it into the vmcs02; on vmexit the preemption timer must be disabled in the vmcs01 if a preemption timer vmexit happened while in guest mode. The preemption timer value in the vmcs02 is set by vmx_vcpu_run, so it need not be considered in prepare_vmcs02. Cc: Yunhong Jiang <yunhong.jiang@intel.com> Cc: Haozhong Zhang <haozhong.zhang@intel.com> Tested-by: Wanpeng Li <kernellwp@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-11KVM: nVMX: avoid incorrect preemption timer vmexit in nested guestWanpeng Li1-0/+2
The preemption timer for nested VMX is emulated by hrtimer which is started on L2 entry, stopped on L2 exit and evaluated via the check_nested_events hook. However, nested_vmx_exit_handled is always returning true for preemption timer vmexit. Then, the L1 preemption timer vmexit is captured and be treated as a L2 preemption timer vmexit, causing NULL pointer dereferences or worse in the L1 guest's vmexit handler: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD 0 Oops: 0010 [#1] SMP Call Trace: ? kvm_lapic_expired_hv_timer+0x47/0x90 [kvm] handle_preemption_timer+0xe/0x20 [kvm_intel] vmx_handle_exit+0x169/0x15a0 [kvm_intel] ? kvm_arch_vcpu_ioctl_run+0xd5d/0x19d0 [kvm] kvm_arch_vcpu_ioctl_run+0xdee/0x19d0 [kvm] ? kvm_arch_vcpu_ioctl_run+0xd5d/0x19d0 [kvm] ? vcpu_load+0x1c/0x60 [kvm] ? kvm_arch_vcpu_load+0x57/0x260 [kvm] kvm_vcpu_ioctl+0x2d3/0x7c0 [kvm] do_vfs_ioctl+0x96/0x6a0 ? __fget_light+0x2a/0x90 SyS_ioctl+0x79/0x90 do_syscall_64+0x68/0x180 entry_SYSCALL64_slow_path+0x25/0x25 Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff8800b5263c48> CR2: 0000000000000000 ---[ end trace 9c70c48b1a2bc66e ]--- This can be reproduced readily by preemption timer enabled on L0 and disabled on L1. Return false since preemption timer vmexits must never be reflected to L2. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Yunhong Jiang <yunhong.jiang@intel.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-11KVM: VMX: reflect broken preemption timer in vmcs_configPaolo Bonzini1-3/+2
Simplify cpu_has_vmx_preemption_timer. This is consistent with the rest of setup_vmcs_config and preparatory for the next patch. Tested-by: Wanpeng Li <kernellwp@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-05KVM: x86: Use ARRAY_SIZE instead of dividing sizeof array with sizeof an elementWei Yongjun1-1/+1
Use ARRAY_SIZE instead of dividing sizeof array with sizeof an element Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-01KVM: vmx: fix underflow in TSC deadline calculationPaolo Bonzini1-3/+3
If the TSC deadline timer is programmed really close to the deadline or even in the past, the computation in vmx_set_hv_timer can underflow and cause delta_tsc to be set to a huge value. This generally results in vmx_set_hv_timer returning -ERANGE, but we can fix it by limiting delta_tsc to be positive or zero. Reported-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-01KVM: x86: use guest_exit_irqoffPaolo Bonzini1-3/+1
This gains a few clock cycles per vmexit. On Intel there is no need anymore to enable the interrupts in vmx_handle_external_intr, since we are using the "acknowledge interrupt on exit" feature. AMD needs to do that, and must be careful to avoid the interrupt shadow. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-01KVM: x86: always use "acknowledge interrupt on exit"Paolo Bonzini1-4/+3
This is necessary to simplify handle_external_intr in the next patch. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-27KVM: nVMX: VMX instructions: fix segment checks when L1 is in long mode.Quentin Casasnovas1-12/+11
I couldn't get Xen to boot a L2 HVM when it was nested under KVM - it was getting a GP(0) on a rather unspecial vmread from Xen: (XEN) ----[ Xen-4.7.0-rc x86_64 debug=n Not tainted ]---- (XEN) CPU: 1 (XEN) RIP: e008:[<ffff82d0801e629e>] vmx_get_segment_register+0x14e/0x450 (XEN) RFLAGS: 0000000000010202 CONTEXT: hypervisor (d1v0) (XEN) rax: ffff82d0801e6288 rbx: ffff83003ffbfb7c rcx: fffffffffffab928 (XEN) rdx: 0000000000000000 rsi: 0000000000000000 rdi: ffff83000bdd0000 (XEN) rbp: ffff83000bdd0000 rsp: ffff83003ffbfab0 r8: ffff830038813910 (XEN) r9: ffff83003faf3958 r10: 0000000a3b9f7640 r11: ffff83003f82d418 (XEN) r12: 0000000000000000 r13: ffff83003ffbffff r14: 0000000000004802 (XEN) r15: 0000000000000008 cr0: 0000000080050033 cr4: 00000000001526e0 (XEN) cr3: 000000003fc79000 cr2: 0000000000000000 (XEN) ds: 0000 es: 0000 fs: 0000 gs: 0000 ss: 0000 cs: e008 (XEN) Xen code around <ffff82d0801e629e> (vmx_get_segment_register+0x14e/0x450): (XEN) 00 00 41 be 02 48 00 00 <44> 0f 78 74 24 08 0f 86 38 56 00 00 b8 08 68 00 (XEN) Xen stack trace from rsp=ffff83003ffbfab0: ... (XEN) Xen call trace: (XEN) [<ffff82d0801e629e>] vmx_get_segment_register+0x14e/0x450 (XEN) [<ffff82d0801f3695>] get_page_from_gfn_p2m+0x165/0x300 (XEN) [<ffff82d0801bfe32>] hvmemul_get_seg_reg+0x52/0x60 (XEN) [<ffff82d0801bfe93>] hvm_emulate_prepare+0x53/0x70 (XEN) [<ffff82d0801ccacb>] handle_mmio+0x2b/0xd0 (XEN) [<ffff82d0801be591>] emulate.c#_hvm_emulate_one+0x111/0x2c0 (XEN) [<ffff82d0801cd6a4>] handle_hvm_io_completion+0x274/0x2a0 (XEN) [<ffff82d0801f334a>] __get_gfn_type_access+0xfa/0x270 (XEN) [<ffff82d08012f3bb>] timer.c#add_entry+0x4b/0xb0 (XEN) [<ffff82d08012f80c>] timer.c#remove_entry+0x7c/0x90 (XEN) [<ffff82d0801c8433>] hvm_do_resume+0x23/0x140 (XEN) [<ffff82d0801e4fe7>] vmx_do_resume+0xa7/0x140 (XEN) [<ffff82d080164aeb>] context_switch+0x13b/0xe40 (XEN) [<ffff82d080128e6e>] schedule.c#schedule+0x22e/0x570 (XEN) [<ffff82d08012c0cc>] softirq.c#__do_softirq+0x5c/0x90 (XEN) [<ffff82d0801602c5>] domain.c#idle_loop+0x25/0x50 (XEN) (XEN) (XEN) **************************************** (XEN) Panic on CPU 1: (XEN) GENERAL PROTECTION FAULT (XEN) [error_code=0000] (XEN) **************************************** Tracing my host KVM showed it was the one injecting the GP(0) when emulating the VMREAD and checking the destination segment permissions in get_vmx_mem_address(): 3) | vmx_handle_exit() { 3) | handle_vmread() { 3) | nested_vmx_check_permission() { 3) | vmx_get_segment() { 3) 0.074 us | vmx_read_guest_seg_base(); 3) 0.065 us | vmx_read_guest_seg_selector(); 3) 0.066 us | vmx_read_guest_seg_ar(); 3) 1.636 us | } 3) 0.058 us | vmx_get_rflags(); 3) 0.062 us | vmx_read_guest_seg_ar(); 3) 3.469 us | } 3) | vmx_get_cs_db_l_bits() { 3) 0.058 us | vmx_read_guest_seg_ar(); 3) 0.662 us | } 3) | get_vmx_mem_address() { 3) 0.068 us | vmx_cache_reg(); 3) | vmx_get_segment() { 3) 0.074 us | vmx_read_guest_seg_base(); 3) 0.068 us | vmx_read_guest_seg_selector(); 3) 0.071 us | vmx_read_guest_seg_ar(); 3) 1.756 us | } 3) | kvm_queue_exception_e() { 3) 0.066 us | kvm_multiple_exception(); 3) 0.684 us | } 3) 4.085 us | } 3) 9.833 us | } 3) + 10.366 us | } Cross-checking the KVM/VMX VMREAD emulation code with the Intel Software Developper Manual Volume 3C - "VMREAD - Read Field from Virtual-Machine Control Structure", I found that we're enforcing that the destination operand is NOT located in a read-only data segment or any code segment when the L1 is in long mode - BUT that check should only happen when it is in protected mode. Shuffling the code a bit to make our emulation follow the specification allows me to boot a Xen dom0 in a nested KVM and start HVM L2 guests without problems. Fixes: f9eb4af67c9d ("KVM: nVMX: VMX instructions: add checks for #GP/#SS exceptions") Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Eugene Korenevsky <ekorenevsky@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>