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authorSean Christopherson <seanjc@google.com>2021-05-04 10:17:24 -0700
committerPaolo Bonzini <pbonzini@redhat.com>2021-05-07 06:06:16 -0400
commit5104d7ffcf24749939bea7fdb5378d186473f890 (patch)
tree4edd4687d7b6aa480446cd8d5942037fb203b141 /arch/x86/include/asm
parent2183de4161b90bd3851ccd3910c87b2c9adfc6ed (diff)
KVM: VMX: Disable preemption when probing user return MSRs
Disable preemption when probing a user return MSR via RDSMR/WRMSR. If the MSR holds a different value per logical CPU, the WRMSR could corrupt the host's value if KVM is preempted between the RDMSR and WRMSR, and then rescheduled on a different CPU. Opportunistically land the helper in common x86, SVM will use the helper in a future commit. Fixes: 4be534102624 ("KVM: VMX: Initialize vmx->guest_msrs[] right after allocation") Cc: stable@vger.kernel.org Cc: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210504171734.1434054-6-seanjc@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include/asm')
-rw-r--r--arch/x86/include/asm/kvm_host.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 848956bb3cf1..e8dcbc632cf8 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1777,6 +1777,7 @@ int kvm_pv_send_ipi(struct kvm *kvm, unsigned long ipi_bitmap_low,
unsigned long icr, int op_64_bit);
void kvm_define_user_return_msr(unsigned index, u32 msr);
+int kvm_probe_user_return_msr(u32 msr);
int kvm_set_user_return_msr(unsigned index, u64 val, u64 mask);
u64 kvm_scale_tsc(struct kvm_vcpu *vcpu, u64 tsc);