sev_decommission is needed in the error path of sev_bind_asid. The purpose
of this function is to clear the firmware context. Missing this step may
cause subsequent SEV launch failures.
Although missing sev_decommission issue has previously been found and was
fixed in sev_launch_start function. It is supposed to be fixed on all
scenarios where a firmware context needs to be freed. According to the AMD
SEV API v0.24 Section 1.3.3:
"The RECEIVE_START command is the only command other than the LAUNCH_START
command that generates a new guest context and guest handle."
The above indicates that RECEIVE_START command also requires calling
sev_decommission if ASID binding fails after RECEIVE_START succeeds.
So add the sev_decommission function in sev_receive_start.
Cc: Alper Gun <alpergun@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brijesh Singh <brijesh.singh@xxxxxxx>
Cc: David Rienjes <rientjes@xxxxxxxxxx>
Cc: Marc Orr <marcorr@xxxxxxxxxx>
Cc: John Allen <john.allen@xxxxxxx>
Cc: Peter Gonda <pgonda@xxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Vipin Sharma <vipinsh@xxxxxxxxxx>
Reviewed-by: Marc Orr <marcorr@xxxxxxxxxx>
Acked-by: Brijesh Singh <brijesh.singh@xxxxxxx>
Fixes: af43cbbf954b ("KVM: SVM: Add support for KVM_SEV_RECEIVE_START command")
Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx>
---
arch/x86/kvm/svm/sev.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 75e0b21ad07c..55d8b9c933c3 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1397,8 +1397,10 @@ static int sev_receive_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
/* Bind ASID to this guest */
ret = sev_bind_asid(kvm, start.handle, error);
- if (ret)
+ if (ret) {
+ sev_decommission(start.handle);
goto e_free_session;
+ }
params.handle = start.handle;
if (copy_to_user((void __user *)(uintptr_t)argp->data,
--
2.33.0.309.g3052b89438-goog
