Commit 6804b3ec authored Jan 02, 2019 by David Rientjes Committed by Greg Kroah-Hartman Feb 20, 2019

kvm: sev: Fail KVM_SEV_INIT if already initialized



[ 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: 1654efcb ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 63715c1f

arch/x86/kvm/svm.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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;