KVM: VMX: use vmcs_clear/set_bits for debug register exits

Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx.c

@@ -5619,11 +5619,8 @@ static int handle_dr(struct kvm_vcpu *vcpu)
 	}
 
 	if (vcpu->guest_debug == 0) {
-		u32 cpu_based_vm_exec_control;
-
-		cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
-		cpu_based_vm_exec_control &= ~CPU_BASED_MOV_DR_EXITING;
-		vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
+		vmcs_clear_bits(CPU_BASED_VM_EXEC_CONTROL,
+				CPU_BASED_MOV_DR_EXITING);
 
 		/*
 		 * No more DR vmexits; force a reload of the debug registers
@@ -5660,8 +5657,6 @@ static void vmx_set_dr6(struct kvm_vcpu *vcpu, unsigned long val)
 
 static void vmx_sync_dirty_debug_regs(struct kvm_vcpu *vcpu)
 {
-	u32 cpu_based_vm_exec_control;
-
 	get_debugreg(vcpu->arch.db[0], 0);
 	get_debugreg(vcpu->arch.db[1], 1);
 	get_debugreg(vcpu->arch.db[2], 2);
@@ -5670,10 +5665,7 @@ static void vmx_sync_dirty_debug_regs(struct kvm_vcpu *vcpu)
 	vcpu->arch.dr7 = vmcs_readl(GUEST_DR7);
 
 	vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_WONT_EXIT;
-
-	cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
-	cpu_based_vm_exec_control |= CPU_BASED_MOV_DR_EXITING;
-	vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
+	vmcs_set_bits(CPU_BASED_VM_EXEC_CONTROL, CPU_BASED_MOV_DR_EXITING);
 }
 
 static void vmx_set_dr7(struct kvm_vcpu *vcpu, unsigned long val)