linux-kernel - [PATCH v2 2/2] KVM: nVMX: Validate the IA32

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Date:   Fri, 27 Oct 2017 01:36:49 -0700
From:   Wanpeng Li <kernellwp@...il.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        Wanpeng Li <wanpeng.li@...mail.com>,
        Jim Mattson <jmattson@...gle.com>
Subject: [PATCH v2 2/2] KVM: nVMX: Validate the IA32_BNDCFGS on nested VM-entry

From: Wanpeng Li <wanpeng.li@...mail.com>

According to the SDM, if the "load IA32_BNDCFGS" VM-entry controls is 1, the
following checks are performed on the field for the IA32_BNDCFGS MSR:
 - Bits reserved in the IA32_BNDCFGS MSR must be 0.
 - The linear address in bits 63:12 must be canonical.

Cc: Paolo Bonzini <pbonzini@...hat.com>
Cc: Radim Krčmář <rkrcmar@...hat.com>
Cc: Jim Mattson <jmattson@...gle.com>
Signed-off-by: Wanpeng Li <wanpeng.li@...mail.com>
---
 arch/x86/kvm/vmx.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e6c8ffa..f29f57d 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10805,6 +10805,13 @@ static int check_vmentry_postreqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 			return 1;
 	}
 
+	if (kvm_mpx_supported() &&
+		(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS)) {
+		if (is_noncanonical_address(vmcs12->guest_bndcfgs & PAGE_MASK, vcpu) ||
+		    (vmcs12->guest_bndcfgs & MSR_IA32_BNDCFGS_RSVD))
+			return 1;
+	}
+
 	return 0;
 }
 
-- 
2.7.4