diff options
authorDavid Rientjes <rientjes@google.com>2019-01-02 12:56:33 -0800
committerRadim Krčmář <rkrcmar@redhat.com>2019-01-11 18:38:07 +0100
commit3f14a89d1132dcae3c8ce6721c6ef51f6e6d9b5f (patch)
parent98938aa8edd66dc95024d7c936a4bc315f6615ff (diff)
kvm: sev: Fail KVM_SEV_INIT if already initialized
By code inspection, it was found that multiple calls to KVM_SEV_INIT could deplete asid bits and overwrite kvm_sev_info's regions_list. Multiple calls to KVM_SVM_INIT is not likely to occur with QEMU, but this should likely be fixed anyway. This code is serialized by kvm->lock. Fixes: 1654efcbc431 ("KVM: SVM: Add KVM_SEV_INIT command") Reported-by: Cfir Cohen <cfir@google.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 307e5bddb6d9..a157ca5b6869 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6278,6 +6278,9 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
int asid, ret;
ret = -EBUSY;
+ if (unlikely(sev->active))
+ return ret;
asid = sev_asid_new();
if (asid < 0)
return ret;

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