| Message ID | 20210916214522.1560893-1-mizhang@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] KVM: SVM: fix missing sev_decommission() in sev_receive_start() | expand |
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,
DECOMMISSION the current SEV context if binding an ASID fails after RECEIVE_START. Per AMD's SEV API, RECEIVE_START generates a new guest context and thus needs to be paired with DECOMMISSION: 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 missing DECOMMISSION can result in subsequent SEV launch failures due to insufficient resource. In particular, both LAUNCH_START and RECEIVE_START command will fail with SEV_RET_RESOURCE_LIMIT error. Note, LAUNCH_START suffered from the same bug, but was previously fixed by [1]. However, the same bug could come back to LAUNCH_START if RECEIVE_START part was not fixed. So add the sev_decommission() function in sev_receive_start. [1] commit 934002cd660b ("KVM: SVM: Call SEV Guest Decommission if ASID binding fails"). Cc: Alper Gun <alpergun@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: David Rienjes <rientjes@google.com> Cc: Marc Orr <marcorr@google.com> Cc: John Allen <john.allen@amd.com> Cc: Peter Gonda <pgonda@google.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Vipin Sharma <vipinsh@google.com> Reviewed-by: Marc Orr <marcorr@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Acked-by: Brijesh Singh <brijesh.singh@amd.com> Fixes: af43cbbf954b ("KVM: SVM: Add support for KVM_SEV_RECEIVE_START command") Signed-off-by: Mingwei Zhang <mizhang@google.com> --- arch/x86/kvm/svm/sev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)