On Thu, Apr 08, 2021, Tom Lendacky wrote: > On 4/8/21 12:10 PM, Sean Christopherson wrote: > > On Thu, Apr 08, 2021, Tom Lendacky wrote: > >> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c > >> index 83e00e524513..7ac67615c070 100644 > >> --- a/arch/x86/kvm/svm/sev.c > >> +++ b/arch/x86/kvm/svm/sev.c > >> @@ -2105,5 +2105,8 @@ void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector) > >> * the guest will set the CS and RIP. Set SW_EXIT_INFO_2 to a > >> * non-zero value. > >> */ > >> + if (WARN_ON_ONCE(!svm->ghcb)) > > > > Isn't this guest triggerable? I.e. send a SIPI without doing the reset hold? > > If so, this should not WARN. > > Yes, it is a guest triggerable event. But a guest shouldn't be doing that, > so I thought adding the WARN_ON_ONCE() just to detect it wasn't bad. > Definitely wouldn't want a WARN_ON(). WARNs are intended only for host issues, e.g. a malicious guest shouldn't be able to crash the host when running with panic_on_warn.
