From: Sean Christopherson Date: Thu, 13 Nov 2025 22:56:13 +0000 (-0800) Subject: KVM: nSVM: Clear exit_code_hi in VMCB when synthesizing nested VM-Exits X-Git-Tag: v6.19-rc2~18^2^2~3 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=da01f64e7470988f8607776aa7afa924208863fb;p=thirdparty%2Fkernel%2Flinux.git KVM: nSVM: Clear exit_code_hi in VMCB when synthesizing nested VM-Exits Explicitly clear exit_code_hi in the VMCB when synthesizing "normal" nested VM-Exits, as the full exit code is a 64-bit value (spoiler alert), and all exit codes for non-failing VMRUN use only bits 31:0. Cc: Jim Mattson Cc: Yosry Ahmed Cc: stable@vger.kernel.org Reviewed-by: Yosry Ahmed Link: https://patch.msgid.link/20251113225621.1688428-2-seanjc@google.com Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 9d29b2e7e855d..eeeb4ae4c617e 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2435,6 +2435,7 @@ static bool check_selective_cr0_intercepted(struct kvm_vcpu *vcpu, if (cr0 ^ val) { svm->vmcb->control.exit_code = SVM_EXIT_CR0_SEL_WRITE; + svm->vmcb->control.exit_code_hi = 0; ret = (nested_svm_exit_handled(svm) == NESTED_EXIT_DONE); } @@ -4611,6 +4612,7 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu, if (static_cpu_has(X86_FEATURE_NRIPS)) vmcb->control.next_rip = info->next_rip; vmcb->control.exit_code = icpt_info.exit_code; + vmcb->control.exit_code_hi = 0; vmexit = nested_svm_exit_handled(svm); ret = (vmexit == NESTED_EXIT_DONE) ? X86EMUL_INTERCEPTED diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index dd78e64023450..e66a16e59b1a5 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -764,9 +764,10 @@ int nested_svm_vmexit(struct vcpu_svm *svm); static inline int nested_svm_simple_vmexit(struct vcpu_svm *svm, u32 exit_code) { - svm->vmcb->control.exit_code = exit_code; - svm->vmcb->control.exit_info_1 = 0; - svm->vmcb->control.exit_info_2 = 0; + svm->vmcb->control.exit_code = exit_code; + svm->vmcb->control.exit_code_hi = 0; + svm->vmcb->control.exit_info_1 = 0; + svm->vmcb->control.exit_info_2 = 0; return nested_svm_vmexit(svm); }