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| author | Paolo Bonzini <pbonzini@redhat.com> | 2022-02-09 12:56:05 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-08 15:24:03 +0300 |
| commit | 48306afcac2a027163c6a8d10bd7a1d9d10efe37 (patch) | |
| tree | e0b2b03d01119421e280e9028a746e87e4fbe822 /arch/x86 | |
| parent | 273ad0cf568493f11f5401422b8943d6c79773c6 (diff) | |
| download | linux-48306afcac2a027163c6a8d10bd7a1d9d10efe37.tar.xz | |
KVM: x86: Reinitialize context if host userspace toggles EFER.LME
commit d6174299365ddbbf491620c0b8c5ca1a6ef2eea5 upstream.
While the guest runs, EFER.LME cannot change unless CR0.PG is clear, and
therefore EFER.NX is the only bit that can affect the MMU role. However,
set_efer accepts a host-initiated change to EFER.LME even with CR0.PG=1.
In that case, the MMU has to be reset.
Fixes: 11988499e62b ("KVM: x86: Skip EFER vs. guest CPUID checks for host-initiated writes")
Cc: stable@vger.kernel.org
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/mmu.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 3 |
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index e9688a9f7b57..7bb165c23233 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -49,6 +49,7 @@ X86_CR4_LA57) #define KVM_MMU_CR0_ROLE_BITS (X86_CR0_PG | X86_CR0_WP) +#define KVM_MMU_EFER_ROLE_BITS (EFER_LME | EFER_NX) static __always_inline u64 rsvd_bits(int s, int e) { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 61bc54748f22..3e606a6940dc 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1605,8 +1605,7 @@ static int set_efer(struct kvm_vcpu *vcpu, struct msr_data *msr_info) return r; } - /* Update reserved bits */ - if ((efer ^ old_efer) & EFER_NX) + if ((efer ^ old_efer) & KVM_MMU_EFER_ROLE_BITS) kvm_mmu_reset_context(vcpu); return 0; |