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From: Krish Sadhukhan <krish.sadhukhan@oracle.com>
To: kvm@vger.kernel.org
Cc: pbonzini@redhat.com, jmattson@google.com, seanjc@google.com
Subject: [PATCH 1/3] KVM: nSVM: Check addresses of MSR and IO bitmap
Date: Wed, 13 Jan 2021 02:46:31 +0000	[thread overview]
Message-ID: <20210113024633.8488-2-krish.sadhukhan@oracle.com> (raw)
In-Reply-To: <20210113024633.8488-1-krish.sadhukhan@oracle.com>

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

    "The MSR or IOIO intercept tables extend to a physical address that
     is greater than or equal to the maximum supported physical address."

Also check that these addresses are aligned on page boundary.

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
 arch/x86/kvm/svm/nested.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index cb4c6ee10029..389a8108ddb5 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -211,8 +211,11 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu)
 	return true;
-static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
+static bool nested_vmcb_check_controls(struct vcpu_svm *svm,
+				       struct vmcb_control_area *control)
+	int maxphyaddr;
 	if ((vmcb_is_intercept(control, INTERCEPT_VMRUN)) == 0)
 		return false;
@@ -223,6 +226,14 @@ static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
 		return false;
+	maxphyaddr = cpuid_maxphyaddr(&svm->vcpu);
+	if (!IS_ALIGNED(control->msrpm_base_pa, PAGE_SIZE) ||
+	    control->msrpm_base_pa >> maxphyaddr)
+		return false;
+	if (!IS_ALIGNED(control->iopm_base_pa, PAGE_SIZE) ||
+	    control->iopm_base_pa >> maxphyaddr)
+		return false;
 	return true;
@@ -258,7 +269,7 @@ static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
 	if (!kvm_is_valid_cr4(&svm->vcpu, vmcb12->save.cr4))
 		return false;
-	return nested_vmcb_check_controls(&vmcb12->control);
+	return nested_vmcb_check_controls(svm, &vmcb12->control);
 static void load_nested_vmcb_control(struct vcpu_svm *svm,
@@ -1173,7 +1184,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
 		goto out_free;
 	ret = -EINVAL;
-	if (!nested_vmcb_check_controls(ctl))
+	if (!nested_vmcb_check_controls(svm, ctl))
 		goto out_free;

  reply	other threads:[~2021-01-13  2:47 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-13  2:46 [PATCH 0/3] KVM: nSVM: Check addresses of MSR bitmap and IO bitmap tables on vmrun of nested guests Krish Sadhukhan
2021-01-13  2:46 ` Krish Sadhukhan [this message]
2021-01-13 17:43   ` [PATCH 1/3] KVM: nSVM: Check addresses of MSR and IO bitmap Sean Christopherson
2021-01-13  2:46 ` [PATCH 2/3] Test: nSVM: Test MSR and IO bitmap address Krish Sadhukhan
2021-01-13  2:46 ` [PATCH 3/3] Test: SVM: Use ALIGN macro when aligning 'io_bitmap_area' Krish Sadhukhan

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