KVM: VMX: Add helpers to toggle/change a bit in VMCS execution controls

Expand the VMCS controls builder macros to generate helpers to change a
bit to the desired value, and use the new helpers when toggling APICv
related controls.

No functional change intended.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
[sean: rewrite changelog]
Tested-by: Xudong Hao <xudong.hao@intel.com>
Link: https://lore.kernel.org/r/20250806195706.1650976-27-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: Dapeng Mi

arch/x86/kvm/vmx/vmx.c

@@ -4356,19 +4356,13 @@ void vmx_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu)
 
 	pin_controls_set(vmx, vmx_pin_based_exec_ctrl(vmx));
 
-	if (kvm_vcpu_apicv_active(vcpu)) {
-		secondary_exec_controls_setbit(vmx,
-					       SECONDARY_EXEC_APIC_REGISTER_VIRT |
-					       SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY);
-		if (enable_ipiv)
-			tertiary_exec_controls_setbit(vmx, TERTIARY_EXEC_IPI_VIRT);
-	} else {
-		secondary_exec_controls_clearbit(vmx,
-						 SECONDARY_EXEC_APIC_REGISTER_VIRT |
-						 SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY);
-		if (enable_ipiv)
-			tertiary_exec_controls_clearbit(vmx, TERTIARY_EXEC_IPI_VIRT);
-	}
+	secondary_exec_controls_changebit(vmx,
+					  SECONDARY_EXEC_APIC_REGISTER_VIRT |
+					  SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY,
+					  kvm_vcpu_apicv_active(vcpu));
+	if (enable_ipiv)
+		tertiary_exec_controls_changebit(vmx, TERTIARY_EXEC_IPI_VIRT,
+						 kvm_vcpu_apicv_active(vcpu));
 
 	vmx_update_msr_bitmap_x2apic(vcpu);
 }

arch/x86/kvm/vmx/vmx.h

@@ -608,6 +608,14 @@ static __always_inline void lname##_controls_clearbit(struct vcpu_vmx *vmx, u##b
 {												\
 	BUILD_BUG_ON(!(val & (KVM_REQUIRED_VMX_##uname | KVM_OPTIONAL_VMX_##uname)));		\
 	lname##_controls_set(vmx, lname##_controls_get(vmx) & ~val);				\
+}												\
+static __always_inline void lname##_controls_changebit(struct vcpu_vmx *vmx, u##bits val,	\
+						       bool set)				\
+{												\
+	if (set)										\
+		lname##_controls_setbit(vmx, val);						\
+	else											\
+		lname##_controls_clearbit(vmx, val);						\
 }
 BUILD_CONTROLS_SHADOW(vm_entry, VM_ENTRY_CONTROLS, 32)
 BUILD_CONTROLS_SHADOW(vm_exit, VM_EXIT_CONTROLS, 32)