[PATCH v2 2/6] nVMX x86: Re-organize the code in nested_check_vmentry_prereqs(), that are related to VM-Execution Control Fields

[Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>]

Separate out the checks in nested_check_vmentry_prereqs(), that are related
to the VM-Execution Control Fields. The re-organized code is easier for
readability, enhancement and maintenance.

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
Reviewed-by: Mihai Carabas <mihai.carabas@xxxxxxxxxx>
Reviewed-by: Mark Kanda <mark.kanda@xxxxxxxxxx>
---
 arch/x86/kvm/vmx.c | 71 ++++++++++++++++++++++++------------------------------
 1 file changed, 32 insertions(+), 39 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 411fcd2..25eb74e 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -12380,42 +12380,22 @@ static int nested_vmx_check_nmi_controls(struct vmcs12 *vmcs12)
 	return 0;
 }
 
-static int nested_check_vmentry_prereqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
+/*
+ * Checks related to VM-Execution Control Fields
+ */
+static int nested_check_vm_execution_ctls(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 
-	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_vmx_check_pml_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,
+	if ((nested_cpu_has_vpid(vmcs12) && !vmcs12->virtual_processor_id) ||
+	    nested_vmx_check_io_bitmap_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_msr_bitmap_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_apic_access_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_tpr_shadow_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_apicv_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_pml_controls(vcpu, vmcs12) ||
+	    nested_vmx_check_shadow_vmcs_controls(vcpu, vmcs12) ||
+	    !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) &&
@@ -12430,11 +12410,9 @@ static int nested_check_vmentry_prereqs(struct kvm_vcpu *vcpu, struct vmcs12 *vm
 				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 (nested_vmx_check_nmi_controls(vmcs12))
-		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+				vmx->nested.msrs.entry_ctls_high) ||
+	    nested_vmx_check_nmi_controls(vmcs12))
+		return -EINVAL;
 
 	if (nested_cpu_has_vmfunc(vmcs12)) {
 		if (vmcs12->vm_function_control &
@@ -12444,11 +12422,26 @@ static int nested_check_vmentry_prereqs(struct kvm_vcpu *vcpu, struct vmcs12 *vm
 		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 -EINVAL;
+
+	return 0;
+}
+
+static int nested_check_vmentry_prereqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
+{
+	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_ctls(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) ||
-- 
2.9.5