Messages in this thread | | | Date | Tue, 5 Sep 2023 13:58:04 -0700 | Subject | Re: [PATCH] KVM: SEV: Update SEV-ES shutdown intercepts with more metadata | From | Sean Christopherson <> |
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On Tue, Sep 05, 2023, Peter Gonda wrote: > Currently if an SEV-ES VM shuts down userspace sees KVM_RUN struct with > only the INVALID_ARGUMENT. This is a very limited amount of information > to debug the situation. Instead KVM can return a > KVM_SYSTEM_EVENT_SEV_TERM to alert userspace the VM is shutting down and > is not usable any further. This latter point can be enforced using the > kvm_vm_dead() functionality.
Add the kvm_vm_dead() thing in a separate patch. If we want to actually harden KVM against consuming a garbage VMSA then we do need to mark the VM dead, but on the other hand that will block _all_ KVM ioctls(), which will make debug even harder.
> Signed-off-by: Peter Gonda <pgonda@google.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Sean Christopherson <seanjc@google.com> > Cc: Tom Lendacky <thomas.lendacky@amd.com> > Cc: Joerg Roedel <joro@8bytes.org> > Cc: Borislav Petkov <bp@alien8.de> > Cc: x86@kernel.org > Cc: kvm@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > > --- > > I am not sure if this is the right path forward maybe just returning > KVM_EXIT_SHUTDOWN is better. But the current behavior is very unhelpful.
Ya, KVM_EXIT_SHUTDOWN is better, we should leave KVM_SYSTEM_EVENT_SEV_TERM to explicit "requests" from the guest.
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