Re: [PATCH 1/4] KVM: x86: mark synthetic SMM vmexit as SVM_EXIT_SW

Sean Christopherson
2022-03-01T16:31:19Z

On Tue, Mar 01, 2022, Maxim Levitsky wrote:
> Use a dummy unused vmexit reason to mark the 'VM exit' that is happening
> when kvm exits to handle SMM, which is not a real VM exit.

Why not use "62h VMEXIT_SMI"?

> This makes it a bit easier to read the KVM trace, and avoids
> other potential problems.

What other potential problems?

> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
> ---
> arch/x86/kvm/svm/svm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 7038c76fa8410..c08fd7f4f3414 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -4218,7 +4218,7 @@ static int svm_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
> svm->vmcb->save.rsp = vcpu->arch.regs[VCPU_REGS_RSP];
> svm->vmcb->save.rip = vcpu->arch.regs[VCPU_REGS_RIP];
>
> - ret = nested_svm_vmexit(svm);
> + ret = nested_svm_simple_vmexit(svm, SVM_EXIT_SW);
> if (ret)
> return ret;
>
> --
> 2.26.3
>