From: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Date: Thu, 9 Apr 2020 20:50:33 +0000 (-0400)
Subject: KVM: nSVM: Check for CR0.CD and CR0.NW on VMRUN of nested guests
X-Git-Tag: v5.8-rc1~168^2~148
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4f233371f6bb1578340b6c7034ddf7b76606d4ae;p=thirdparty%2Fkernel%2Flinux.git

KVM: nSVM: Check for CR0.CD and CR0.NW on VMRUN of nested guests

According to section "Canonicalization and Consistency Checks" in APM vol. 2,
the following guest state combination is illegal:

	"CR0.CD is zero and CR0.NW is set"

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Message-Id: <20200409205035.16830-2-krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index c62893102777b..3e5bd739a6f67 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -207,6 +207,10 @@ static bool nested_vmcb_checks(struct vmcb *vmcb)
 	if ((vmcb->save.efer & EFER_SVME) == 0)
 		return false;
 
+	if (((vmcb->save.cr0 & X86_CR0_CD) == 0) &&
+	    (vmcb->save.cr0 & X86_CR0_NW))
+		return false;
+
 	if ((vmcb->control.intercept & (1ULL << INTERCEPT_VMRUN)) == 0)
 		return false;