diff options
| author | Sean Christopherson <seanjc@google.com> | 2025-12-31 00:13:45 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2026-01-14 04:37:03 +0300 |
| commit | a08ca6691fd3ab40e40eb6600193672d50c7a7ba (patch) | |
| tree | ac1c6c23869f2a5b42faa67363614d01890d8001 | |
| parent | d7507a94a07202234236d7f94bed6015ca645ae6 (diff) | |
| download | linux-a08ca6691fd3ab40e40eb6600193672d50c7a7ba.tar.xz | |
KVM: SVM: Limit incorrect check on SVM_EXIT_ERR to running as a VM
Limit KVM's incorrect check for VMXEXIT_INVALID, a.k.a. SVM_EXIT_ERR, to
running as a VM, as detected by X86_FEATURE_HYPERVISOR. The exit_code and
all failure codes, e.g. VMXEXIT_INVALID, are 64-bit values, and so checking
only bits 31:0 could result in false positives when running on non-broken
hardware, e.g. in the extremely unlikely scenario exit code 0xffffffffull
is ever generated by hardware.
Keep the 32-bit check to play nice with running on broken KVM (for years,
KVM has not set bits 63:32 when synthesizing nested SVM VM-Exits).
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230211347.4099600-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/svm/svm.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index a22433680c73..338fc4f5cc4c 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -426,7 +426,10 @@ static __always_inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu) static inline bool svm_is_vmrun_failure(u64 exit_code) { - return (u32)exit_code == (u32)SVM_EXIT_ERR; + if (cpu_feature_enabled(X86_FEATURE_HYPERVISOR)) + return (u32)exit_code == (u32)SVM_EXIT_ERR; + + return exit_code == SVM_EXIT_ERR; } /* |