[Xenial v2 3/5] KVM: nVMX: Don't emulate instructions in guest mode

[Thadeu Lima de Souza Cascardo]

From: Paolo Bonzini <pbonzini at redhat.com>

CVE-2020-2732

[ Upstream commit 07721feee46b4b248402133228235318199b05ec ]

vmx_check_intercept is not yet fully implemented. To avoid emulating
instructions disallowed by the L1 hypervisor, refuse to emulate
instructions by default.

Cc: stable at vger.kernel.org
[Made commit, added commit msg - Oliver]
Signed-off-by: Oliver Upton <oupton at google.com>
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo at canonical.com>
---
 arch/x86/kvm/vmx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 94e4177ef698..b62abefdb82b 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11049,7 +11049,7 @@ static int vmx_check_intercept(struct kvm_vcpu *vcpu,
 	}
 
 	/* TODO: check more intercepts... */
-	return X86EMUL_CONTINUE;
+	return X86EMUL_UNHANDLEABLE;
 }
 
 static void vmx_sched_in(struct kvm_vcpu *vcpu, int cpu)
-- 
2.25.1