diff mbox series

[v2,06/11] KVM: SEV: disable DEBUG_SWAP by default

Message ID 20240223104009.632194-7-pbonzini@redhat.com
State New
Headers
Series KVM: SEV: allow customizing VMSA features |

Commit Message

Paolo Bonzini Feb. 23, 2024, 10:40 a.m. UTC 
  Disable all VMSA features in KVM_SEV_INIT and KVM_SEV_ES_INIT.  They are
not actually supported by SEV (a SEV guest does not have a VMSA to which
you can apply features) and they cause unexpected changes in measurement
for SEV-ES.

Going on, the way to enable them will be to use a new initialization ioctl
that takes the VMSA features as a parameter.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/svm/sev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Sean Christopherson Feb. 23, 2024, 4:08 p.m. UTC | #1 
On Fri, Feb 23, 2024, Paolo Bonzini wrote:
> Disable all VMSA features in KVM_SEV_INIT and KVM_SEV_ES_INIT.  They are
> not actually supported by SEV (a SEV guest does not have a VMSA to which
> you can apply features) and they cause unexpected changes in measurement
> for SEV-ES.

Sorry :-(

I've done my best to avoid having to deal with attestation, so it's a bit of a
blind spot for me.
diff mbox series

Patch

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index b0e97f9617e3..06e03a6fe7e4 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -267,7 +267,7 @@  static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
 
 	sev->active = true;
 	sev->es_active = argp->id == KVM_SEV_ES_INIT;
-	sev->vmsa_features = sev_supported_vmsa_features;
+	sev->vmsa_features = 0;
 
 	asid = sev_asid_new(sev);
 	if (asid < 0)