KVM: nVMX: Move the checks for VM-Execution Control Fields to a separate helper function

.. to improve readability and maintainability, and to align the code as per
the layout of the checks in chapter "VM Entries" in Intel SDM vol 3C.
Signed-off-by: NKrish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: NMihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: NMark Kanda <mark.kanda@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/nested.c

@@ -2444,94 +2444,90 @@ static bool valid_ept_address(struct kvm_vcpu *vcpu, u64 address)
 	return true;
 }
 
-static int nested_vmx_check_vmentry_prereqs(struct kvm_vcpu *vcpu,
-					struct vmcs12 *vmcs12)
+/*
+ * Checks related to VM-Execution Control Fields
+ */
+static int nested_check_vm_execution_controls(struct kvm_vcpu *vcpu,
+                                              struct vmcs12 *vmcs12)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
-	bool ia32e;
-
-	if (vmcs12->guest_activity_state != GUEST_ACTIVITY_ACTIVE &&
-	    vmcs12->guest_activity_state != GUEST_ACTIVITY_HLT)
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
-
-	if (nested_cpu_has_vpid(vmcs12) && !vmcs12->virtual_processor_id)
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
-
-	if (nested_vmx_check_io_bitmap_controls(vcpu, vmcs12))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
-
-	if (nested_vmx_check_msr_bitmap_controls(vcpu, vmcs12))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
-
-	if (nested_vmx_check_apic_access_controls(vcpu, vmcs12))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
-
-	if (nested_vmx_check_tpr_shadow_controls(vcpu, vmcs12))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
-
-	if (nested_vmx_check_apicv_controls(vcpu, vmcs12))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
 
-	if (nested_vmx_check_msr_switch_controls(vcpu, vmcs12))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
-
-	if (!nested_cpu_has_preemption_timer(vmcs12) &&
-	    nested_cpu_has_save_preemption_timer(vmcs12))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
-
-	if (nested_vmx_check_pml_controls(vcpu, vmcs12))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
-
-	if (nested_vmx_check_unrestricted_guest_controls(vcpu, vmcs12))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
-
-	if (nested_vmx_check_mode_based_ept_exec_controls(vcpu, vmcs12))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
-
-	if (nested_vmx_check_shadow_vmcs_controls(vcpu, vmcs12))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
-
-	if (!vmx_control_verify(vmcs12->cpu_based_vm_exec_control,
-				vmx->nested.msrs.procbased_ctls_low,
-				vmx->nested.msrs.procbased_ctls_high) ||
-	    (nested_cpu_has(vmcs12, CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) &&
-	     !vmx_control_verify(vmcs12->secondary_vm_exec_control,
-				 vmx->nested.msrs.secondary_ctls_low,
-				 vmx->nested.msrs.secondary_ctls_high)) ||
-	    !vmx_control_verify(vmcs12->pin_based_vm_exec_control,
+	if (!vmx_control_verify(vmcs12->pin_based_vm_exec_control,
 				vmx->nested.msrs.pinbased_ctls_low,
 				vmx->nested.msrs.pinbased_ctls_high) ||
-	    !vmx_control_verify(vmcs12->vm_exit_controls,
-				vmx->nested.msrs.exit_ctls_low,
-				vmx->nested.msrs.exit_ctls_high) ||
-	    !vmx_control_verify(vmcs12->vm_entry_controls,
-				vmx->nested.msrs.entry_ctls_low,
-				vmx->nested.msrs.entry_ctls_high))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+	    !vmx_control_verify(vmcs12->cpu_based_vm_exec_control,
+				vmx->nested.msrs.procbased_ctls_low,
+				vmx->nested.msrs.procbased_ctls_high))
+		return -EINVAL;
 
-	if (nested_vmx_check_nmi_controls(vmcs12))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+	if (nested_cpu_has(vmcs12, CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) &&
+	    !vmx_control_verify(vmcs12->secondary_vm_exec_control,
+				 vmx->nested.msrs.secondary_ctls_low,
+				 vmx->nested.msrs.secondary_ctls_high))
+		return -EINVAL;
+
+	if (vmcs12->cr3_target_count > nested_cpu_vmx_misc_cr3_count(vcpu) ||
+	    nested_vmx_check_io_bitmap_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_msr_bitmap_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_tpr_shadow_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_apic_access_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_apicv_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_nmi_controls(vmcs12) ||
+	    nested_vmx_check_pml_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_unrestricted_guest_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_mode_based_ept_exec_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_shadow_vmcs_controls(vcpu, vmcs12) ||
+	    (nested_cpu_has_vpid(vmcs12) && !vmcs12->virtual_processor_id))
+		return -EINVAL;
+
+	if (nested_cpu_has_ept(vmcs12) &&
+	    !valid_ept_address(vcpu, vmcs12->ept_pointer))
+		return -EINVAL;
 
 	if (nested_cpu_has_vmfunc(vmcs12)) {
 		if (vmcs12->vm_function_control &
 		    ~vmx->nested.msrs.vmfunc_controls)
-			return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+			return -EINVAL;
 
 		if (nested_cpu_has_eptp_switching(vmcs12)) {
 			if (!nested_cpu_has_ept(vmcs12) ||
 			    !page_address_valid(vcpu, vmcs12->eptp_list_address))
-				return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+				return -EINVAL;
 		}
 	}
 
-	if (vmcs12->cr3_target_count > nested_cpu_vmx_misc_cr3_count(vcpu))
+	return 0;
+}
+
+static int nested_vmx_check_vmentry_prereqs(struct kvm_vcpu *vcpu,
+					    struct vmcs12 *vmcs12)
+{
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	bool ia32e;
+
+	if (vmcs12->guest_activity_state != GUEST_ACTIVITY_ACTIVE &&
+	    vmcs12->guest_activity_state != GUEST_ACTIVITY_HLT)
+		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+
+	if (nested_check_vm_execution_controls(vcpu, vmcs12))
 		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
 
+	if (nested_vmx_check_msr_switch_controls(vcpu, vmcs12))
+		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+ 
 	if (!nested_host_cr0_valid(vcpu, vmcs12->host_cr0) ||
 	    !nested_host_cr4_valid(vcpu, vmcs12->host_cr4) ||
 	    !nested_cr3_valid(vcpu, vmcs12->host_cr3))
 		return VMXERR_ENTRY_INVALID_HOST_STATE_FIELD;
 
+	if (!vmx_control_verify(vmcs12->vm_exit_controls,
+				vmx->nested.msrs.exit_ctls_low,
+				vmx->nested.msrs.exit_ctls_high) ||
+	    !vmx_control_verify(vmcs12->vm_entry_controls,
+				vmx->nested.msrs.entry_ctls_low,
+				vmx->nested.msrs.entry_ctls_high))
+		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+
 	/*
 	 * If the load IA32_EFER VM-exit control is 1, bits reserved in the
 	 * IA32_EFER MSR must be 0 in the field for that register. In addition,
@@ -2603,10 +2599,6 @@ static int nested_vmx_check_vmentry_prereqs(struct kvm_vcpu *vcpu,
 		}
 	}
 
-	if (nested_cpu_has_ept(vmcs12) &&
-	    !valid_ept_address(vcpu, vmcs12->ept_pointer))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
-
 	return 0;
 }
 
@@ -2638,7 +2630,8 @@ static int nested_vmx_check_vmcs_link_ptr(struct kvm_vcpu *vcpu,
 }
 
 static int nested_vmx_check_vmentry_postreqs(struct kvm_vcpu *vcpu,
-					 struct vmcs12 *vmcs12, u32 *exit_qual)
+					     struct vmcs12 *vmcs12,
+					     u32 *exit_qual)
 {
 	bool ia32e;