From: Sean Christopherson Date: Tue, 30 Dec 2025 21:13:45 +0000 (-0800) Subject: KVM: SVM: Limit incorrect check on SVM_EXIT_ERR to running as a VM X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a08ca6691fd3ab40e40eb6600193672d50c7a7ba;p=thirdparty%2Fkernel%2Fstable.git 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 Link: https://patch.msgid.link/20251230211347.4099600-7-seanjc@google.com Signed-off-by: Sean Christopherson --- 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; } /*