tree 69719a0657181622e05a7557bb4af7713b0473e6
parent 193e02196fad992568b980f28b03e1f4807019eb
author Tom Lendacky <thomas.lendacky@amd.com> 1621273353 -0500
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1622023612 +0200

x86/sev-es: Invalidate the GHCB after completing VMGEXIT

commit a50c5bebc99c525e7fbc059988c6a5ab8680cb76 upstream.

Since the VMGEXIT instruction can be issued from userspace, invalidate
the GHCB after performing VMGEXIT processing in the kernel.

Invalidation is only required after userspace is available, so call
vc_ghcb_invalidate() from sev_es_put_ghcb(). Update vc_ghcb_invalidate()
to additionally clear the GHCB exit code so that it is always presented
as 0 when VMGEXIT has been issued by anything else besides the kernel.

Fixes: 0786138c78e79 ("x86/sev-es: Add a Runtime #VC Exception Handler")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/5a8130462e4f0057ee1184509cd056eedd78742b.1621273353.git.thomas.lendacky@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>