[PATCH 5.4 290/408] KVM: x86: emulating RDPID failure shall return #UD rather than #GP

Greg Kroah-Hartman
2020-10-27T14:52:34Z

From: Robert Hoo <robert.hu@linux.intel.com>

[ Upstream commit a9e2e0ae686094571378c72d8146b5a1a92d0652 ]

Per Intel's SDM, RDPID takes a #UD if it is unsupported, which is more or
less what KVM is emulating when MSR_TSC_AUX is not available. In fact,
there are no scenarios in which RDPID is supposed to #GP.

Fixes: fb6d4d340e ("KVM: x86: emulate RDPID")
Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>
Message-Id: <1598581422-76264-1-git-send-email-robert.hu@linux.intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/kvm/emulate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index cc7823e7ef96c..484c32b7f79ff 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3617,7 +3617,7 @@ static int em_rdpid(struct x86_emulate_ctxt *ctxt)
u64 tsc_aux = 0;

if (ctxt->ops->get_msr(ctxt, MSR_TSC_AUX, &tsc_aux))
- return emulate_gp(ctxt, 0);
+ return emulate_ud(ctxt);
ctxt->dst.val = tsc_aux;
return X86EMUL_CONTINUE;
}
--
2.25.1