lkml.org 
[lkml]   [2019]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH AUTOSEL 4.19 28/28] kvm: sev: Fail KVM_SEV_INIT if already initialized
Date
From: David Rientjes <rientjes@google.com>

[ 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 <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>
---
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 f1d3fe5a0c65..0976853ed723 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6249,6 +6249,9 @@ 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;
--
2.19.1
\
 
 \ /
  Last update: 2019-02-09 19:54    [W:0.078 / U:0.596 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site