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| author | Sean Christopherson <seanjc@google.com> | 2024-08-29 02:20:13 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2024-11-01 19:21:46 +0300 |
| commit | 3ffe874ea3eb4c674334c92303a72c76a1141c42 (patch) | |
| tree | 0d7ce585af4a9a9ec78e949f6590f57a444c5a5c | |
| parent | 6e44d2427b70911514663989963a114d466ca79d (diff) | |
| download | linux-3ffe874ea3eb4c674334c92303a72c76a1141c42.tar.xz | |
KVM: x86: Ensure vcpu->mode is loaded from memory in kvm_vcpu_exit_request()
Wrap kvm_vcpu_exit_request()'s load of vcpu->mode with READ_ONCE() to
ensure the variable is re-loaded from memory, as there is no guarantee the
caller provides the necessary annotations to ensure KVM sees a fresh value,
e.g. the VM-Exit fastpath could theoretically reuse the pre-VM-Enter value.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20240828232013.768446-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/x86.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 7b347e564d10..312d6e08c76b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2144,8 +2144,9 @@ EXPORT_SYMBOL_GPL(kvm_emulate_monitor); static inline bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu) { xfer_to_guest_mode_prepare(); - return vcpu->mode == EXITING_GUEST_MODE || kvm_request_pending(vcpu) || - xfer_to_guest_mode_work_pending(); + + return READ_ONCE(vcpu->mode) == EXITING_GUEST_MODE || + kvm_request_pending(vcpu) || xfer_to_guest_mode_work_pending(); } /* |