linux-kernel - [PATCH 1/2] KVM: SVM: Check for nested vmrun intercept before emulating vmrun

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Date:	Mon, 2 Aug 2010 16:46:44 +0200
From:	Joerg Roedel <joerg.roedel@....com>
To:	Avi Kivity <avi@...hat.com>, Marcelo Tosatti <mtosatti@...hat.com>
CC:	<kvm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	Joerg Roedel <joerg.roedel@....com>
Subject: [PATCH 1/2] KVM: SVM: Check for nested vmrun intercept before emulating vmrun

This patch lets the nested vmrun fail if the L1 hypervisor
has not intercepted vmrun. This fixes the "vmrun intercept
check" unit test.

Signed-off-by: Joerg Roedel <joerg.roedel@....com>
---
 arch/x86/kvm/svm.c |   19 +++++++++++++++++++
 1 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index b44c9cc..083fa88 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2015,6 +2015,14 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
 	return true;
 }
 
+static bool nested_vmcb_checks(struct vmcb *vmcb)
+{
+	if ((vmcb->control.intercept & (1ULL << INTERCEPT_VMRUN)) == 0)
+		return false;
+
+	return true;
+}
+
 static bool nested_svm_vmrun(struct vcpu_svm *svm)
 {
 	struct vmcb *nested_vmcb;
@@ -2029,6 +2037,17 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
 	if (!nested_vmcb)
 		return false;
 
+	if (!nested_vmcb_checks(nested_vmcb)) {
+		nested_vmcb->control.exit_code    = SVM_EXIT_ERR;
+		nested_vmcb->control.exit_code_hi = 0;
+		nested_vmcb->control.exit_info_1  = 0;
+		nested_vmcb->control.exit_info_2  = 0;
+
+		nested_svm_unmap(page);
+
+		return false;
+	}
+
 	trace_kvm_nested_vmrun(svm->vmcb->save.rip - 3, vmcb_gpa,
 			       nested_vmcb->save.rip,
 			       nested_vmcb->control.int_ctl,
-- 
1.7.0.4


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