Re: [PATCH] KVM: x86: Add a helper to dedup reporting of unhandled VM-Exits

Gupta, Pankaj
2025-10-31T11:18:42Z

Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>

> ---
> arch/x86/include/asm/kvm_host.h | 1 +
> arch/x86/kvm/svm/svm.c | 7 +------
> arch/x86/kvm/vmx/tdx.c | 6 +-----
> arch/x86/kvm/vmx/vmx.c | 9 +--------
> arch/x86/kvm/x86.c | 12 ++++++++++++
> 5 files changed, 16 insertions(+), 19 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 48598d017d6f..4fbe4b7ce1da 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -2167,6 +2167,7 @@ void __kvm_prepare_emulation_failure_exit(struct kvm_vcpu *vcpu,
> void kvm_prepare_emulation_failure_exit(struct kvm_vcpu *vcpu);
>
> void kvm_prepare_event_vectoring_exit(struct kvm_vcpu *vcpu, gpa_t gpa);
> +void kvm_prepare_unexpected_reason_exit(struct kvm_vcpu *vcpu, u64 exit_reason);
>
> void kvm_enable_efer_bits(u64);
> bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer);
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index f14709a511aa..83e0d4d5f4c5 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -3451,13 +3451,8 @@ static bool svm_check_exit_valid(u64 exit_code)
>
> static int svm_handle_invalid_exit(struct kvm_vcpu *vcpu, u64 exit_code)
> {
> - vcpu_unimpl(vcpu, "svm: unexpected exit reason 0x%llx\n", exit_code);
> dump_vmcb(vcpu);
> - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
> - vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_UNEXPECTED_EXIT_REASON;
> - vcpu->run->internal.ndata = 2;
> - vcpu->run->internal.data[0] = exit_code;
> - vcpu->run->internal.data[1] = vcpu->arch.last_vmentry_cpu;
> + kvm_prepare_unexpected_reason_exit(vcpu, exit_code);
> return 0;
> }
>
> diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
> index 326db9b9c567..079d9f13eddb 100644
> --- a/arch/x86/kvm/vmx/tdx.c
> +++ b/arch/x86/kvm/vmx/tdx.c
> @@ -2145,11 +2145,7 @@ int tdx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t fastpath)
> }
>
> unhandled_exit:
> - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
> - vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_UNEXPECTED_EXIT_REASON;
> - vcpu->run->internal.ndata = 2;
> - vcpu->run->internal.data[0] = vp_enter_ret;
> - vcpu->run->internal.data[1] = vcpu->arch.last_vmentry_cpu;
> + kvm_prepare_unexpected_reason_exit(vcpu, vp_enter_ret);
> return 0;
> }
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 1021d3b65ea0..08f7957ed4c3 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -6642,15 +6642,8 @@ static int __vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
> return kvm_vmx_exit_handlers[exit_handler_index](vcpu);
>
> unexpected_vmexit:
> - vcpu_unimpl(vcpu, "vmx: unexpected exit reason 0x%x\n",
> - exit_reason.full);
> dump_vmcs(vcpu);
> - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
> - vcpu->run->internal.suberror =
> - KVM_INTERNAL_ERROR_UNEXPECTED_EXIT_REASON;
> - vcpu->run->internal.ndata = 2;
> - vcpu->run->internal.data[0] = exit_reason.full;
> - vcpu->run->internal.data[1] = vcpu->arch.last_vmentry_cpu;
> + kvm_prepare_unexpected_reason_exit(vcpu, exit_reason.full);
> return 0;
> }
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index b4b5d2d09634..c826cd05228a 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -9110,6 +9110,18 @@ void kvm_prepare_event_vectoring_exit(struct kvm_vcpu *vcpu, gpa_t gpa)
> }
> EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_prepare_event_vectoring_exit);
>
> +void kvm_prepare_unexpected_reason_exit(struct kvm_vcpu *vcpu, u64 exit_reason)
> +{
> + vcpu_unimpl(vcpu, "unexpected exit reason 0x%llx\n", exit_reason);
> +
> + vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
> + vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_UNEXPECTED_EXIT_REASON;
> + vcpu->run->internal.ndata = 2;
> + vcpu->run->internal.data[0] = exit_reason;
> + vcpu->run->internal.data[1] = vcpu->arch.last_vmentry_cpu;
> +}
> +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_prepare_unexpected_reason_exit);
> +
> static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type)
> {
> struct kvm *kvm = vcpu->kvm;
>
> base-commit: 4cc167c50eb19d44ac7e204938724e685e3d8057