KVM: nVMX: checks for address bits beyond MAXPHYADDR on VM-entry

On each VM-entry CPU should check the following VMCS fields for zero bits
beyond physical address width:
-  APIC-access address
-  virtual-APIC address
-  posted-interrupt descriptor address
This patch adds these checks required by Intel SDM.
Signed-off-by: NEugene Korenevsky <ekorenevsky@gmail.com>
Message-Id: <20150329205627.GA1244@gnote>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx.c

@@ -8622,10 +8622,11 @@ static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu,
 					struct vmcs12 *vmcs12)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	int maxphyaddr = cpuid_maxphyaddr(vcpu);
 
 	if (nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) {
-		/* TODO: Also verify bits beyond physical address width are 0 */
-		if (!PAGE_ALIGNED(vmcs12->apic_access_addr))
+		if (!PAGE_ALIGNED(vmcs12->apic_access_addr) ||
+		    vmcs12->apic_access_addr >> maxphyaddr)
 			return false;
 
 		/*
@@ -8641,8 +8642,8 @@ static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu,
 	}
 
 	if (nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW)) {
-		/* TODO: Also verify bits beyond physical address width are 0 */
-		if (!PAGE_ALIGNED(vmcs12->virtual_apic_page_addr))
+		if (!PAGE_ALIGNED(vmcs12->virtual_apic_page_addr) ||
+		    vmcs12->virtual_apic_page_addr >> maxphyaddr)
 			return false;
 
 		if (vmx->nested.virtual_apic_page) /* shouldn't happen */
@@ -8665,7 +8666,8 @@ static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu,
 	}
 
 	if (nested_cpu_has_posted_intr(vmcs12)) {
-		if (!IS_ALIGNED(vmcs12->posted_intr_desc_addr, 64))
+		if (!IS_ALIGNED(vmcs12->posted_intr_desc_addr, 64) ||
+		    vmcs12->posted_intr_desc_addr >> maxphyaddr)
 			return false;
 
 		if (vmx->nested.pi_desc_page) { /* shouldn't happen */
@@ -9386,7 +9388,6 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
 	}
 
 	if (!nested_get_vmcs12_pages(vcpu, vmcs12)) {
-		/*TODO: Also verify bits beyond physical address width are 0*/
 		nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
 		return 1;
 	}