From 6804b3ecbe20654891324ef82f840ba02d642d6c Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Wed, 2 Jan 2019 12:56:33 -0800 Subject: [PATCH] kvm: sev: Fail KVM_SEV_INIT if already initialized MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit [ Upstream commit 3f14a89d1132dcae3c8ce6721c6ef51f6e6d9b5f ] 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 Signed-off-by: David Rientjes Signed-off-by: Radim Krčmář Signed-off-by: Sasha Levin --- arch/x86/kvm/svm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 02ac8fa..ee8f8d7 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -6256,6 +6256,9 @@ 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; -- 2.7.4