kvm: nVMX: Aesthetic cleanup of handle_vmread and handle_vmwrite

Apply reverse fir tree declaration order, shorten some variable names
to avoid line wrap, reformat a block comment, delete an extra blank
line, and use BIT(10) instead of (1u << 10).
Signed-off-by: Jim Mattson <jmattson@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Peter Shier <pshier@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Reviewed-by: Jon Cargille <jcargill@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/nested.c

@@ -4751,17 +4751,17 @@ static int handle_vmresume(struct kvm_vcpu *vcpu)
 
 static int handle_vmread(struct kvm_vcpu *vcpu)
 {
-	unsigned long field;
-	u64 field_value;
-	struct vcpu_vmx *vmx = to_vmx(vcpu);
-	unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
-	u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
-	int len;
-	gva_t gva = 0;
 	struct vmcs12 *vmcs12 = is_guest_mode(vcpu) ? get_shadow_vmcs12(vcpu)
 						    : get_vmcs12(vcpu);
+	unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
+	u32 instr_info = vmcs_read32(VMX_INSTRUCTION_INFO);
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	struct x86_exception e;
+	unsigned long field;
+	u64 value;
+	gva_t gva = 0;
 	short offset;
+	int len;
 
 	if (!nested_vmx_check_permission(vcpu))
 		return 1;
@@ -4776,7 +4776,7 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
 		return nested_vmx_failInvalid(vcpu);
 
 	/* Decode instruction info and find the field to read */
-	field = kvm_register_readl(vcpu, (((vmx_instruction_info) >> 28) & 0xf));
+	field = kvm_register_readl(vcpu, (((instr_info) >> 28) & 0xf));
 
 	offset = vmcs_field_to_offset(field);
 	if (offset < 0)
@@ -4786,24 +4786,23 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
 	if (!is_guest_mode(vcpu) && is_vmcs12_ext_field(field))
 		copy_vmcs02_to_vmcs12_rare(vcpu, vmcs12);
 
-	/* Read the field, zero-extended to a u64 field_value */
-	field_value = vmcs12_read_any(vmcs12, field, offset);
+	/* Read the field, zero-extended to a u64 value */
+	value = vmcs12_read_any(vmcs12, field, offset);
 
 	/*
 	 * Now copy part of this value to register or memory, as requested.
 	 * Note that the number of bits actually copied is 32 or 64 depending
 	 * on the guest's mode (32 or 64 bit), not on the given field's length.
 	 */
-	if (vmx_instruction_info & (1u << 10)) {
-		kvm_register_writel(vcpu, (((vmx_instruction_info) >> 3) & 0xf),
-			field_value);
+	if (instr_info & BIT(10)) {
+		kvm_register_writel(vcpu, (((instr_info) >> 3) & 0xf), value);
 	} else {
 		len = is_64_bit_mode(vcpu) ? 8 : 4;
 		if (get_vmx_mem_address(vcpu, exit_qualification,
-				vmx_instruction_info, true, len, &gva))
+					instr_info, true, len, &gva))
 			return 1;
 		/* _system ok, nested_vmx_check_permission has verified cpl=0 */
-		if (kvm_write_guest_virt_system(vcpu, gva, &field_value, len, &e))
+		if (kvm_write_guest_virt_system(vcpu, gva, &value, len, &e))
 			kvm_inject_page_fault(vcpu, &e);
 	}
 
@@ -4836,24 +4835,25 @@ static bool is_shadow_field_ro(unsigned long field)
 
 static int handle_vmwrite(struct kvm_vcpu *vcpu)
 {
+	struct vmcs12 *vmcs12 = is_guest_mode(vcpu) ? get_shadow_vmcs12(vcpu)
+						    : get_vmcs12(vcpu);
+	unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
+	u32 instr_info = vmcs_read32(VMX_INSTRUCTION_INFO);
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	struct x86_exception e;
 	unsigned long field;
-	int len;
+	short offset;
 	gva_t gva;
-	struct vcpu_vmx *vmx = to_vmx(vcpu);
-	unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
-	u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
+	int len;
 
-	/* The value to write might be 32 or 64 bits, depending on L1's long
+	/*
+	 * The value to write might be 32 or 64 bits, depending on L1's long
 	 * mode, and eventually we need to write that into a field of several
 	 * possible lengths. The code below first zero-extends the value to 64
-	 * bit (field_value), and then copies only the appropriate number of
+	 * bit (value), and then copies only the appropriate number of
 	 * bits into the vmcs12 field.
 	 */
-	u64 field_value = 0;
-	struct x86_exception e;
-	struct vmcs12 *vmcs12 = is_guest_mode(vcpu) ? get_shadow_vmcs12(vcpu)
-						    : get_vmcs12(vcpu);
-	short offset;
+	u64 value = 0;
 
 	if (!nested_vmx_check_permission(vcpu))
 		return 1;
@@ -4867,22 +4867,20 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
 	     get_vmcs12(vcpu)->vmcs_link_pointer == -1ull))
 		return nested_vmx_failInvalid(vcpu);
 
-	if (vmx_instruction_info & (1u << 10))
-		field_value = kvm_register_readl(vcpu,
-			(((vmx_instruction_info) >> 3) & 0xf));
+	if (instr_info & BIT(10))
+		value = kvm_register_readl(vcpu, (((instr_info) >> 3) & 0xf));
 	else {
 		len = is_64_bit_mode(vcpu) ? 8 : 4;
 		if (get_vmx_mem_address(vcpu, exit_qualification,
-				vmx_instruction_info, false, len, &gva))
+					instr_info, false, len, &gva))
 			return 1;
-		if (kvm_read_guest_virt(vcpu, gva, &field_value, len, &e)) {
+		if (kvm_read_guest_virt(vcpu, gva, &value, len, &e)) {
 			kvm_inject_page_fault(vcpu, &e);
 			return 1;
 		}
 	}
 
-
-	field = kvm_register_readl(vcpu, (((vmx_instruction_info) >> 28) & 0xf));
+	field = kvm_register_readl(vcpu, (((instr_info) >> 28) & 0xf));
 
 	offset = vmcs_field_to_offset(field);
 	if (offset < 0)
@@ -4914,9 +4912,9 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
 	 * the stripped down value, L2 sees the full value as stored by KVM).
 	 */
 	if (field >= GUEST_ES_AR_BYTES && field <= GUEST_TR_AR_BYTES)
-		field_value &= 0x1f0ff;
+		value &= 0x1f0ff;
 
-	vmcs12_write_any(vmcs12, field, offset, field_value);
+	vmcs12_write_any(vmcs12, field, offset, value);
 
 	/*
 	 * Do not track vmcs12 dirty-state if in guest-mode as we actually
@@ -4933,7 +4931,7 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
 			preempt_disable();
 			vmcs_load(vmx->vmcs01.shadow_vmcs);
 
-			__vmcs_writel(field, field_value);
+			__vmcs_writel(field, value);
 
 			vmcs_clear(vmx->vmcs01.shadow_vmcs);
 			vmcs_load(vmx->loaded_vmcs->vmcs);