hv: extend lapic pass-through for DM launched VM

This commit extend lapic pass-through for DM launched VM, generally for hard RT scenarios.
Similar to the partition mode, the vlapic is working under the xapic mode at first, only
when x2apic mode is enabled, lapic is passed through, because the physical LAPICs are
under x2apic mode.

Main changes includes:
- add is_lapic_pt() to check if a vm is created with lapic pt or not, to combine
  codes of partition mode and DM launched vm with lapic passthrough, including:
  - reuse the irq delievery function and rename it to dispatch_interrupt_lapic_pt();
  - reuse switch_apicv_mode_x2apic();
  - reuse ICR handling codes to avoid malicious IPI;
- intercept ICR/APICID/LDR msr access when lapic_pt;
- for vm with lapic passthrough, irq is always disabled under root mode.

Tracked-On: #2351
Signed-off-by: Yan, Like <like.yan@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/include/arch/x86/guest/vm.h

@@ -176,6 +176,11 @@ struct vpci_vdev_array {
 #define MAX_BOOTARGS_SIZE	1024U
 #define MAX_CONFIG_NAME_SIZE	32U
 
+/*
+ * PRE_LAUNCHED_VM is launched by ACRN hypervisor, with LAPIC_PT;
+ * SOS_VM is launched by ACRN hypervisor, without LAPIC_PT;
+ * NORMAL_VM is launched by ACRN devicemodel, with/without LAPIC_PT depends on usecases.
+ */
 enum acrn_vm_type {
 	UNDEFINED_VM = 0,
 	PRE_LAUNCHED_VM,
@@ -332,4 +337,9 @@ static inline struct acrn_vm_config *get_vm_config(uint16_t vm_id)
 #endif
 }
 
+static inline bool is_lapic_pt(const struct acrn_vm *vm)
+{
+	return ((vm_configs[vm->vm_id].guest_flags & LAPIC_PASSTHROUGH) != 0U);
+}
+
 #endif /* VM_H_ */