/*
 * Copyright (C) 2018 Intel Corporation. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <types.h>
#include <errno.h>
#include <bits.h>
#include <vm.h>
#include <vtd.h>
#include <ptdev.h>
#include <per_cpu.h>
#include <ioapic.h>

/*
 * lookup a ptdev entry by sid
 * Before adding a ptdev remapping, should lookup by physical sid to check
 * whether the resource has been token by others.
 * When updating a ptdev remapping, should lookup by virtual sid to check
 * whether this resource is valid.
 * @pre: vm must be NULL when lookup by physical sid, otherwise,
 * vm must not be NULL when lookup by virtual sid.
 */
static inline struct ptirq_remapping_info *
ptirq_lookup_entry_by_sid(uint32_t intr_type,
		const union source_id *sid, const struct acrn_vm *vm)
{
	uint16_t idx;
	struct ptirq_remapping_info *entry;
	struct ptirq_remapping_info *entry_found = NULL;

	for (idx = 0U; idx < CONFIG_MAX_PT_IRQ_ENTRIES; idx++) {
		entry = &ptirq_entries[idx];
		if (!is_entry_active(entry)) {
			continue;
		}
		if ((intr_type == entry->intr_type) &&
			((vm == NULL) ?
			(sid->value == entry->phys_sid.value) :
			((vm == entry->vm) &&
			(sid->value == entry->virt_sid.value)))) {
			entry_found = entry;
			break;
		}
	}
	return entry_found;
}

static uint32_t calculate_logical_dest_mask(uint64_t pdmask)
{
	uint32_t dest_mask = 0UL;
	uint64_t pcpu_mask = pdmask;
	uint16_t pcpu_id;

	pcpu_id = ffs64(pcpu_mask);
	while (pcpu_id < MAX_PCPU_NUM) {
		bitmap_clear_nolock(pcpu_id, &pcpu_mask);
		dest_mask |= per_cpu(lapic_ldr, pcpu_id);
		pcpu_id = ffs64(pcpu_mask);
	}
	return dest_mask;
}

/**
 * @pre entry != NULL
 */
static void ptirq_free_irte(const struct ptirq_remapping_info *entry)
{
	struct intr_source intr_src;

	if (entry->intr_type == PTDEV_INTR_MSI) {
		intr_src.is_msi = true;
		intr_src.src.msi.value = entry->phys_sid.msi_id.bdf;
	} else {
		intr_src.is_msi = false;
		intr_src.src.ioapic_id = ioapic_irq_to_ioapic_id(entry->allocated_pirq);
	}

	dmar_free_irte(intr_src, (uint16_t)entry->allocated_pirq);
}

static void ptirq_build_physical_msi(struct acrn_vm *vm, struct ptirq_msi_info *info,
		const struct ptirq_remapping_info *entry, uint32_t vector)
{
	uint64_t vdmask, pdmask;
	uint32_t dest, delmode, dest_mask;
	bool phys;
	union dmar_ir_entry irte;
	union irte_index ir_index;
	int32_t ret;
	struct intr_source intr_src;

	/* get physical destination cpu mask */
	dest = info->vmsi_addr.bits.dest_field;
	phys = (info->vmsi_addr.bits.dest_mode == MSI_ADDR_DESTMODE_PHYS);

	vlapic_calc_dest(vm, &vdmask, false, dest, phys, false);
	pdmask = vcpumask2pcpumask(vm, vdmask);

	/* get physical delivery mode */
	delmode = info->vmsi_data.bits.delivery_mode;
	if ((delmode != MSI_DATA_DELMODE_FIXED) && (delmode != MSI_DATA_DELMODE_LOPRI)) {
		delmode = MSI_DATA_DELMODE_LOPRI;
	}

	dest_mask = calculate_logical_dest_mask(pdmask);

	/* Using phys_irq as index in the corresponding IOMMU */
	irte.entry.lo_64 = 0UL;
	irte.entry.hi_64 = 0UL;
	irte.bits.vector = vector;
	irte.bits.delivery_mode = delmode;
	irte.bits.dest_mode = MSI_ADDR_DESTMODE_LOGICAL;
	irte.bits.rh = MSI_ADDR_RH;
	irte.bits.dest = dest_mask;

	intr_src.is_msi = true;
	intr_src.src.msi.value = entry->phys_sid.msi_id.bdf;
	ret = dmar_assign_irte(intr_src, irte, (uint16_t)entry->allocated_pirq);

	if (ret == 0) {
		/*
		 * Update the MSI interrupt source to point to the IRTE
		 * SHV is set to 0 as ACRN disables MMC (Multi-Message Capable
		 * for MSI devices.
		 */
		info->pmsi_data.full = 0U;
		ir_index.index = (uint16_t)entry->allocated_pirq;

		info->pmsi_addr.full = 0UL;
		info->pmsi_addr.ir_bits.intr_index_high = ir_index.bits.index_high;
		info->pmsi_addr.ir_bits.shv = 0U;
		info->pmsi_addr.ir_bits.intr_format = 0x1U;
		info->pmsi_addr.ir_bits.intr_index_low = ir_index.bits.index_low;
		info->pmsi_addr.ir_bits.constant = 0xFEEU;
	} else {
		/* In case there is no corresponding IOMMU, for example, if the
		 * IOMMU is ignored, pass the MSI info in Compatibility Format
		 */
		info->pmsi_data = info->vmsi_data;
		info->pmsi_data.bits.delivery_mode = delmode;
		info->pmsi_data.bits.vector = vector;

		info->pmsi_addr = info->vmsi_addr;
		info->pmsi_addr.bits.dest_field = dest_mask;
		info->pmsi_addr.bits.rh = MSI_ADDR_RH;
		info->pmsi_addr.bits.dest_mode = MSI_ADDR_DESTMODE_LOGICAL;
	}
	dev_dbg(DBG_LEVEL_IRQ, "MSI %s addr:data = 0x%lx:%x(V) -> 0x%lx:%x(P)",
		(info->pmsi_addr.ir_bits.intr_format != 0U) ? " Remappable Format" : "Compatibility Format",
		info->vmsi_addr.full, info->vmsi_data.full,
		info->pmsi_addr.full, info->pmsi_data.full);
}

static union ioapic_rte
ptirq_build_physical_rte(struct acrn_vm *vm, struct ptirq_remapping_info *entry)
{
	union ioapic_rte rte;
	uint32_t phys_irq = entry->allocated_pirq;
	union source_id *virt_sid = &entry->virt_sid;
	union irte_index ir_index;
	union dmar_ir_entry irte;
	struct intr_source intr_src;
	int32_t ret;

	if (virt_sid->intx_id.ctlr == INTX_CTLR_IOAPIC) {
		uint64_t vdmask, pdmask;
		uint32_t dest, delmode, dest_mask, vector;
		union ioapic_rte virt_rte;
		bool phys;

		vioapic_get_rte(vm, virt_sid->intx_id.gsi, &virt_rte);
		rte = virt_rte;

		/* init polarity & pin state */
		if (rte.bits.intr_polarity == IOAPIC_RTE_INTPOL_ALO) {
			if (entry->polarity == 0U) {
				vioapic_set_irqline_nolock(vm, virt_sid->intx_id.gsi, GSI_SET_HIGH);
			}
			entry->polarity = 1U;
		} else {
			if (entry->polarity == 1U) {
				vioapic_set_irqline_nolock(vm, virt_sid->intx_id.gsi, GSI_SET_LOW);
			}
			entry->polarity = 0U;
		}

		/* physical destination cpu mask */
		phys = (virt_rte.bits.dest_mode == IOAPIC_RTE_DESTMODE_PHY);
		dest = (uint32_t)virt_rte.bits.dest_field;
		vlapic_calc_dest(vm, &vdmask, false, dest, phys, false);
		pdmask = vcpumask2pcpumask(vm, vdmask);

		/* physical delivery mode */
		delmode = virt_rte.bits.delivery_mode;
		if ((delmode != IOAPIC_RTE_DELMODE_FIXED) &&
			(delmode != IOAPIC_RTE_DELMODE_LOPRI)) {
			delmode = IOAPIC_RTE_DELMODE_LOPRI;
		}

		/* update physical delivery mode, dest mode(logical) & vector */
		vector = irq_to_vector(phys_irq);
		dest_mask = calculate_logical_dest_mask(pdmask);

		irte.entry.lo_64 = 0UL;
		irte.entry.hi_64 = 0UL;
		irte.bits.vector = vector;
		irte.bits.delivery_mode = delmode;
		irte.bits.dest_mode = IOAPIC_RTE_DESTMODE_LOGICAL;
		irte.bits.dest = dest_mask;
		irte.bits.trigger_mode = rte.bits.trigger_mode;

		intr_src.is_msi = false;
		intr_src.src.ioapic_id = ioapic_irq_to_ioapic_id(phys_irq);
		ret = dmar_assign_irte(intr_src, irte, (uint16_t)phys_irq);

		if (ret == 0) {
			ir_index.index = (uint16_t)phys_irq;
			rte.ir_bits.vector = vector;
			rte.ir_bits.constant = 0U;
			rte.ir_bits.intr_index_high = ir_index.bits.index_high;
			rte.ir_bits.intr_format = 1U;
			rte.ir_bits.intr_index_low = ir_index.bits.index_low;
		} else {
			rte.bits.dest_mode = IOAPIC_RTE_DESTMODE_LOGICAL;
			rte.bits.delivery_mode = delmode;
			rte.bits.vector = vector;
			rte.bits.dest_field = dest_mask;
		}

		dev_dbg(DBG_LEVEL_IRQ, "IOAPIC RTE %s = 0x%x:%x(V) -> 0x%x:%x(P)",
			(rte.ir_bits.intr_format != 0U) ? "Remappable Format" : "Compatibility Format",
			virt_rte.u.hi_32, virt_rte.u.lo_32,
			rte.u.hi_32, rte.u.lo_32);
	} else {
		enum vpic_trigger trigger;
		union ioapic_rte phys_rte;

		/* just update trigger mode */
		ioapic_get_rte(phys_irq, &phys_rte);
		rte = phys_rte;
		rte.bits.trigger_mode = IOAPIC_RTE_TRGRMODE_EDGE;
		vpic_get_irqline_trigger_mode(vm_pic(vm), (uint32_t)virt_sid->intx_id.gsi, &trigger);
		if (trigger == LEVEL_TRIGGER) {
			rte.bits.trigger_mode = IOAPIC_RTE_TRGRMODE_LEVEL;
		}

		dev_dbg(DBG_LEVEL_IRQ, "IOAPIC RTE %s = 0x%x:%x(P) -> 0x%x:%x(P)",
			(rte.ir_bits.intr_format != 0U) ? "Remappable Format" : "Compatibility Format",
			phys_rte.u.hi_32, phys_rte.u.lo_32,
			rte.u.hi_32, rte.u.lo_32);
	}

	return rte;
}

/* add msix entry for a vm, based on msi id (phys_bdf+msix_index)
 * - if the entry not be added by any vm, allocate it
 * - if the entry already be added by sos_vm, then change the owner to current vm
 * - if the entry already be added by other vm, return NULL
 */
static struct ptirq_remapping_info *add_msix_remapping(struct acrn_vm *vm,
	uint16_t virt_bdf, uint16_t phys_bdf, uint32_t entry_nr)
{
	struct ptirq_remapping_info *entry;
	DEFINE_MSI_SID(phys_sid, phys_bdf, entry_nr);
	DEFINE_MSI_SID(virt_sid, virt_bdf, entry_nr);

	entry = ptirq_lookup_entry_by_sid(PTDEV_INTR_MSI, &phys_sid, NULL);
	if (entry == NULL) {
		if (ptirq_lookup_entry_by_sid(PTDEV_INTR_MSI, &virt_sid, vm) != NULL) {
			pr_err("MSIX re-add vbdf%x", virt_bdf);
		} else {
			entry = ptirq_alloc_entry(vm, PTDEV_INTR_MSI);
			if (entry != NULL) {
				entry->phys_sid.value = phys_sid.value;
				entry->virt_sid.value = virt_sid.value;
				entry->release_cb = ptirq_free_irte;

				/* update msi source and active entry */
				if (ptirq_activate_entry(entry, IRQ_INVALID) < 0) {
					ptirq_release_entry(entry);
					entry = NULL;
				}
			}
		}
	} else if (entry->vm != vm) {
		if (is_sos_vm(entry->vm)) {
			entry->vm = vm;
			entry->virt_sid.msi_id.bdf = virt_bdf;
		} else {
			pr_err("MSIX pbdf%x idx=%d already in vm%d with vbdf%x, not able to add into vm%d with vbdf%x",
				entry->phys_sid.msi_id.bdf, entry->phys_sid.msi_id.entry_nr, entry->vm->vm_id,
				entry->virt_sid.msi_id.bdf, vm->vm_id, virt_bdf);

			pr_err("msix entry pbdf%x idx%d already in vm%d", phys_bdf, entry_nr, entry->vm->vm_id);
			entry = NULL;
		}
	} else {
		/* The mapping has already been added to the VM. No action
		 * required. */
	}

	dev_dbg(DBG_LEVEL_IRQ, "VM%d MSIX add vector mapping vbdf%x:pbdf%x idx=%d",
		vm->vm_id, virt_bdf, phys_bdf, entry_nr);

	return entry;
}

/* deactive & remove mapping entry of vbdf:entry_nr for vm */
static void
remove_msix_remapping(const struct acrn_vm *vm, uint16_t virt_bdf, uint32_t entry_nr)
{
	struct ptirq_remapping_info *entry;
	DEFINE_MSI_SID(virt_sid, virt_bdf, entry_nr);
	struct intr_source intr_src;

	entry = ptirq_lookup_entry_by_sid(PTDEV_INTR_MSI, &virt_sid, vm);
	if (entry != NULL) {
		if (is_entry_active(entry)) {
			/*TODO: disable MSIX device when HV can in future */
			ptirq_deactivate_entry(entry);
		}

		intr_src.is_msi = true;
		intr_src.src.msi.value = entry->phys_sid.msi_id.bdf;
		dmar_free_irte(intr_src, (uint16_t)entry->allocated_pirq);

		dev_dbg(DBG_LEVEL_IRQ,
			"VM%d MSIX remove vector mapping vbdf-pbdf:0x%x-0x%x idx=%d",
			entry->vm->vm_id, virt_bdf,
			entry->phys_sid.msi_id.bdf, entry_nr);

		ptirq_release_entry(entry);
	}

}

/* add intx entry for a vm, based on intx id (phys_pin)
 * - if the entry not be added by any vm, allocate it
 * - if the entry already be added by sos_vm, then change the owner to current vm
 * - if the entry already be added by other vm, return NULL
 */
static struct ptirq_remapping_info *add_intx_remapping(struct acrn_vm *vm, uint32_t virt_gsi,
		uint32_t phys_gsi, enum intx_ctlr vgsi_ctlr)
{
	struct ptirq_remapping_info *entry = NULL;
	DEFINE_INTX_SID(phys_sid, phys_gsi, INTX_CTLR_IOAPIC);
	DEFINE_INTX_SID(virt_sid, virt_gsi, vgsi_ctlr);
	uint32_t phys_irq = ioapic_gsi_to_irq(phys_gsi);

	entry = ptirq_lookup_entry_by_sid(PTDEV_INTR_INTX, &phys_sid, NULL);
	if (entry == NULL) {
		if (ptirq_lookup_entry_by_sid(PTDEV_INTR_INTX, &virt_sid, vm) == NULL) {
			entry = ptirq_alloc_entry(vm, PTDEV_INTR_INTX);
			if (entry != NULL) {
				entry->phys_sid.value = phys_sid.value;
				entry->virt_sid.value = virt_sid.value;
				entry->release_cb = ptirq_free_irte;

				/* activate entry */
				if (ptirq_activate_entry(entry, phys_irq) < 0) {
					ptirq_release_entry(entry);
					entry = NULL;
				}
			}
		} else {
			pr_err("INTX re-add vpin %d", virt_gsi);
		}
	} else if (entry->vm != vm) {
		if (is_sos_vm(entry->vm)) {
			entry->vm = vm;
			entry->virt_sid.value = virt_sid.value;
			entry->polarity = 0U;
		} else {
			pr_err("INTX gsi%d already in vm%d with vgsi%d, not able to add into vm%d with vgsi%d",
					phys_gsi, entry->vm->vm_id, entry->virt_sid.intx_id.gsi, vm->vm_id, virt_gsi);
			entry = NULL;
		}
	} else {
		/* The mapping has already been added to the VM. No action
		 * required. */
	}


	/*
	 * ptirq entry is either created or transferred from SOS VM to Post-launched VM
	 */

	if (entry != NULL) {
		dev_dbg(DBG_LEVEL_IRQ, "VM%d INTX add pin mapping vgsi%d:pgsi%d",
			entry->vm->vm_id, virt_gsi, phys_gsi);
	}

	return entry;
}

/* deactive & remove mapping entry of vpin for vm */
static void remove_intx_remapping(const struct acrn_vm *vm, uint32_t virt_gsi, enum intx_ctlr vgsi_ctlr)
{
	uint32_t phys_irq;
	struct ptirq_remapping_info *entry;
	struct intr_source intr_src;
	DEFINE_INTX_SID(virt_sid, virt_gsi, vgsi_ctlr);

	entry = ptirq_lookup_entry_by_sid(PTDEV_INTR_INTX, &virt_sid, vm);
	if (entry != NULL) {
		if (is_entry_active(entry)) {
			phys_irq = entry->allocated_pirq;
			/* disable interrupt */
			ioapic_gsi_mask_irq(phys_irq);

			ptirq_deactivate_entry(entry);
			intr_src.is_msi = false;
			intr_src.src.ioapic_id = ioapic_irq_to_ioapic_id(phys_irq);

			dmar_free_irte(intr_src, (uint16_t)phys_irq);
			dev_dbg(DBG_LEVEL_IRQ,
				"deactive %s intx entry:pgsi=%d, pirq=%d ",
				(vgsi_ctlr == INTX_CTLR_PIC) ? "vPIC" : "vIOAPIC",
				entry->phys_sid.intx_id.gsi, phys_irq);
			dev_dbg(DBG_LEVEL_IRQ, "from vm%d vgsi=%d\n",
				entry->vm->vm_id, virt_gsi);
		}

		ptirq_release_entry(entry);
	}
}

static void ptirq_handle_intx(struct acrn_vm *vm,
		const struct ptirq_remapping_info *entry)
{
	const union source_id *virt_sid = &entry->virt_sid;
	switch (virt_sid->intx_id.ctlr) {
	case INTX_CTLR_IOAPIC:
	{
		union ioapic_rte rte;
		bool trigger_lvl = false;

		/* INTX_CTLR_IOAPIC means we have vioapic enabled */
		vioapic_get_rte(vm, (uint32_t)virt_sid->intx_id.gsi, &rte);
		if (rte.bits.trigger_mode == IOAPIC_RTE_TRGRMODE_LEVEL) {
			trigger_lvl = true;
		}

		if (trigger_lvl) {
			if (entry->polarity != 0U) {
				vioapic_set_irqline_lock(vm, virt_sid->intx_id.gsi, GSI_SET_LOW);
			} else {
				vioapic_set_irqline_lock(vm, virt_sid->intx_id.gsi, GSI_SET_HIGH);
			}
		} else {
			if (entry->polarity != 0U) {
				vioapic_set_irqline_lock(vm, virt_sid->intx_id.gsi, GSI_FALLING_PULSE);
			} else {
				vioapic_set_irqline_lock(vm, virt_sid->intx_id.gsi, GSI_RAISING_PULSE);
			}
		}

		dev_dbg(DBG_LEVEL_PTIRQ,
			"dev-assign: irq=0x%x assert vr: 0x%x vRTE=0x%lx",
			entry->allocated_pirq,
			irq_to_vector(entry->allocated_pirq),
			rte.full);
		break;
	}
	case INTX_CTLR_PIC:
	{
		enum vpic_trigger trigger;

		/* INTX_CTLR_PIC means we have vpic enabled */
		vpic_get_irqline_trigger_mode(vm_pic(vm), virt_sid->intx_id.gsi, &trigger);
		if (trigger == LEVEL_TRIGGER) {
			vpic_set_irqline(vm_pic(vm), virt_sid->intx_id.gsi, GSI_SET_HIGH);
		} else {
			vpic_set_irqline(vm_pic(vm), virt_sid->intx_id.gsi, GSI_RAISING_PULSE);
		}
		break;
	}
	default:
		/*
		 * In this switch statement, virt_sid->intx_id.ctlr shall
		 * either be INTX_CTLR_IOAPIC or INTX_CTLR_PIC.
		 * Gracefully return if prior case clauses have not been met.
		 */
		break;
	}
}

void ptirq_softirq(uint16_t pcpu_id)
{
	while (1) {
		struct ptirq_remapping_info *entry = ptirq_dequeue_softirq(pcpu_id);
		struct ptirq_msi_info *msi;

		if (entry == NULL) {
			break;
		}

		msi = &entry->msi;

		/* skip any inactive entry */
		if (!is_entry_active(entry)) {
			/* service next item */
			continue;
		}

		/* handle real request */
		if (entry->intr_type == PTDEV_INTR_INTX) {
			ptirq_handle_intx(entry->vm, entry);
		} else {
			if (msi != NULL) {
				/* TODO: msi destmode check required */
				(void)vlapic_intr_msi(entry->vm, msi->vmsi_addr.full, msi->vmsi_data.full);
				dev_dbg(DBG_LEVEL_PTIRQ, "dev-assign: irq=0x%x MSI VR: 0x%x-0x%x",
					entry->allocated_pirq,
					msi->vmsi_data.bits.vector,
					irq_to_vector(entry->allocated_pirq));
				dev_dbg(DBG_LEVEL_PTIRQ, " vmsi_addr: 0x%lx vmsi_data: 0x%x",
					msi->vmsi_addr.full,
					msi->vmsi_data.full);
			}
		}
	}
}

void ptirq_intx_ack(struct acrn_vm *vm, uint32_t virt_gsi, enum intx_ctlr vgsi_ctlr)
{
	uint32_t phys_irq;
	struct ptirq_remapping_info *entry;
	DEFINE_INTX_SID(virt_sid, virt_gsi, vgsi_ctlr);

	entry = ptirq_lookup_entry_by_sid(PTDEV_INTR_INTX, &virt_sid, vm);
	if (entry != NULL) {
		phys_irq = entry->allocated_pirq;

		/* NOTE: only Level trigger will process EOI/ACK and if we got here
		 * means we have this vioapic or vpic or both enabled
		 */
		switch (vgsi_ctlr) {
		case INTX_CTLR_IOAPIC:
			if (entry->polarity != 0U) {
				vioapic_set_irqline_lock(vm, virt_gsi, GSI_SET_HIGH);
			} else {
				vioapic_set_irqline_lock(vm, virt_gsi, GSI_SET_LOW);
			}
			break;
		case INTX_CTLR_PIC:
			vpic_set_irqline(vm_pic(vm), virt_gsi, GSI_SET_LOW);
			break;
		default:
			/*
			 * In this switch statement, vgsi_ctlr shall either be
			 * INTX_CTLR_IOAPIC or INTX_CTLR_PIC.
			 * Gracefully return if prior case clauses have not been met.
			 */
			break;
		}

		dev_dbg(DBG_LEVEL_PTIRQ, "dev-assign: irq=0x%x acked vr: 0x%x",
				phys_irq, irq_to_vector(phys_irq));
		ioapic_gsi_unmask_irq(phys_irq);
	}
}

/* Main entry for PCI device assignment with MSI and MSI-X
 * MSI can up to 8 vectors and MSI-X can up to 1024 Vectors
 * We use entry_nr to indicate coming vectors
 * entry_nr = 0 means first vector
 * user must provide bdf and entry_nr
 */
int32_t ptirq_prepare_msix_remap(struct acrn_vm *vm, uint16_t virt_bdf, uint16_t phys_bdf,
				uint16_t entry_nr, struct ptirq_msi_info *info)
{
	struct ptirq_remapping_info *entry;
	DEFINE_MSI_SID(virt_sid, virt_bdf, entry_nr);
	int32_t ret = -ENODEV;
	union pci_bdf vbdf;

	/*
	 * adds the mapping entries at runtime, if the
	 * entry already be held by others, return error.
	 */
	spinlock_obtain(&ptdev_lock);
	entry = ptirq_lookup_entry_by_sid(PTDEV_INTR_MSI, &virt_sid, vm);
	if (entry == NULL) {
		entry = add_msix_remapping(vm, virt_bdf, phys_bdf, entry_nr);
		if (entry == NULL) {
			pr_err("dev-assign: msi entry exist in others");
		}
	}
	spinlock_release(&ptdev_lock);

	if (entry != NULL) {
		ret = 0;
		/* build physical config MSI, update to info->pmsi_xxx */
		if (is_lapic_pt_configured(vm)) {
			enum vm_vlapic_state vlapic_state = check_vm_vlapic_state(vm);
			if (vlapic_state == VM_VLAPIC_X2APIC) {
				/*
				 * All the vCPUs are in x2APIC mode and LAPIC is Pass-through
				 * Use guest vector to program the interrupt source
				 */
				ptirq_build_physical_msi(vm, info, entry, (uint32_t)info->vmsi_data.bits.vector);
			} else if (vlapic_state == VM_VLAPIC_XAPIC) {
				/*
				 * All the vCPUs are in xAPIC mode and LAPIC is emulated
				 * Use host vector to program the interrupt source
				 */
				ptirq_build_physical_msi(vm, info, entry, irq_to_vector(entry->allocated_pirq));
			} else if (vlapic_state == VM_VLAPIC_TRANSITION) {
				/*
				 * vCPUs are in middle of transition, so do not program interrupt source
				 * TODO: Devices programmed during transistion do not work after transition
				 * as device is not programmed with interrupt info. Need to implement a
				 * method to get interrupts working after transition.
				 */
				ret = -EFAULT;
			} else {
				/* Do nothing for VM_VLAPIC_DISABLED */
				ret = -EFAULT;
			}
		} else {
			ptirq_build_physical_msi(vm, info, entry, irq_to_vector(entry->allocated_pirq));
		}

		if (ret == 0) {
			entry->msi = *info;
			vbdf.value = virt_bdf;
			dev_dbg(DBG_LEVEL_IRQ, "PCI %x:%x.%x MSI VR[%d] 0x%x->0x%x assigned to vm%d",
				vbdf.bits.b, vbdf.bits.d, vbdf.bits.f, entry_nr, info->vmsi_data.bits.vector,
				irq_to_vector(entry->allocated_pirq), entry->vm->vm_id);
		}
	}

	return ret;
}

static void activate_physical_ioapic(struct acrn_vm *vm,
		struct ptirq_remapping_info *entry)
{
	union ioapic_rte rte;
	uint32_t phys_irq = entry->allocated_pirq;
	uint64_t intr_mask;
	bool is_lvl_trigger = false;

	/* disable interrupt */
	ioapic_gsi_mask_irq(phys_irq);

	/* build physical IOAPIC RTE */
	rte = ptirq_build_physical_rte(vm, entry);
	intr_mask = rte.bits.intr_mask;

	/* update irq trigger mode according to info in guest */
	if (rte.bits.trigger_mode == IOAPIC_RTE_TRGRMODE_LEVEL) {
		is_lvl_trigger = true;
	}
	set_irq_trigger_mode(phys_irq, is_lvl_trigger);

	/* set rte entry when masked */
	rte.bits.intr_mask = IOAPIC_RTE_MASK_SET;
	ioapic_set_rte(phys_irq, rte);

	if (intr_mask == IOAPIC_RTE_MASK_CLR) {
		ioapic_gsi_unmask_irq(phys_irq);
	}
}

/* Main entry for PCI/Legacy device assignment with INTx, calling from vIOAPIC
 * or vPIC
 */
int32_t ptirq_intx_pin_remap(struct acrn_vm *vm, uint32_t virt_gsi, enum intx_ctlr vgsi_ctlr)
{
	int32_t status = 0;
	struct ptirq_remapping_info *entry = NULL;
	DEFINE_INTX_SID(virt_sid, virt_gsi, vgsi_ctlr);
	DEFINE_INTX_SID(alt_virt_sid, virt_gsi, vgsi_ctlr);

	/*
	 * virt pin could come from vpic master, vpic slave or vioapic
	 * while phys pin is always means for physical IOAPIC.
	 *
	 * Device Model should pre-hold the mapping entries by calling
	 * ptirq_add_intx_remapping for UOS.
	 *
	 * For SOS(sos_vm), it adds the mapping entries at runtime, if the
	 * entry already be held by others, return error.
	 */

	/* no remap for vuart intx */
	if (!is_vuart_intx(vm, virt_sid.intx_id.gsi)) {
		/* query if we have virt to phys mapping */
		spinlock_obtain(&ptdev_lock);
		entry = ptirq_lookup_entry_by_sid(PTDEV_INTR_INTX, &virt_sid, vm);
		if (entry == NULL) {
			if (is_sos_vm(vm)) {

				/* for sos_vm, there is chance of vpin source switch
				 * between vPIC & vIOAPIC for one legacy phys_pin.
				 *
				 * here checks if there is already mapping entry from
				 * the other vpin source for legacy pin. If yes, then
				 * switch vpin source is needed
				 */
				if (virt_gsi < NR_LEGACY_PIN) {

					if (vgsi_ctlr == INTX_CTLR_PIC) {
						alt_virt_sid.intx_id.ctlr = INTX_CTLR_IOAPIC;
					} else {
						alt_virt_sid.intx_id.ctlr = INTX_CTLR_PIC;
					}

					entry = ptirq_lookup_entry_by_sid(PTDEV_INTR_INTX, &alt_virt_sid, vm);
					if (entry != NULL) {
						entry->virt_sid.value = virt_sid.value;
						dev_dbg(DBG_LEVEL_IRQ,
								"IOAPIC gsi=%hhu pirq=%u vgsi=%d switch from %s to %s for vm%d",
								entry->phys_sid.intx_id.gsi,
								entry->allocated_pirq, entry->virt_sid.intx_id.gsi,
								(vgsi_ctlr == INTX_CTLR_IOAPIC) ? "vPIC" : "vIOAPIC",
								(vgsi_ctlr == INTX_CTLR_IOAPIC) ? "vIOPIC" : "vPIC",
								entry->vm->vm_id);
					}
				}

				/* entry could be updated by above switch check */
				if (entry == NULL) {
					uint32_t phys_gsi = virt_gsi;

					entry = add_intx_remapping(vm, virt_gsi, phys_gsi, vgsi_ctlr);
					if (entry == NULL) {
						pr_err("%s, add intx remapping failed",
								__func__);
						status = -ENODEV;
					}
				}
			} else {
				/* ptirq_intx_pin_remap is triggered by vPIC/vIOAPIC
				 * everytime a pin get unmask, here filter out pins
				 * not get mapped.
				 */
				status = -ENODEV;
			}
		}
		spinlock_release(&ptdev_lock);
	} else {
		status = -EINVAL;
	}

	if (status == 0) {
		activate_physical_ioapic(vm, entry);
	}

	return status;
}

/* @pre vm != NULL
 * except sos_vm, Device Model should call this function to pre-hold ptdev intx
 * entries:
 * - the entry is identified by phys_pin:
 *   one entry vs. one phys_pin
 * - currently, one phys_pin can only be held by one pin source (vPIC or
 *   vIOAPIC)
 */
int32_t ptirq_add_intx_remapping(struct acrn_vm *vm, uint32_t virt_gsi, uint32_t phys_gsi, bool pic_pin)
{
	struct ptirq_remapping_info *entry;
	enum intx_ctlr vgsi_ctlr = pic_pin ? INTX_CTLR_PIC : INTX_CTLR_IOAPIC;

	spinlock_obtain(&ptdev_lock);
	entry = add_intx_remapping(vm, virt_gsi, phys_gsi, vgsi_ctlr);
	spinlock_release(&ptdev_lock);

	return (entry != NULL) ? 0 : -ENODEV;
}

/*
 * @pre vm != NULL
 */
void ptirq_remove_intx_remapping(const struct acrn_vm *vm, uint32_t virt_gsi, bool pic_pin)
{
	enum intx_ctlr vgsi_ctlr = pic_pin ? INTX_CTLR_PIC : INTX_CTLR_IOAPIC;

	spinlock_obtain(&ptdev_lock);
	remove_intx_remapping(vm, virt_gsi, vgsi_ctlr);
	spinlock_release(&ptdev_lock);
}

/*
 * @pre vm != NULL
 */
void ptirq_remove_msix_remapping(const struct acrn_vm *vm, uint16_t virt_bdf,
		uint32_t vector_count)
{
	uint32_t i;

	for (i = 0U; i < vector_count; i++) {
		spinlock_obtain(&ptdev_lock);
		remove_msix_remapping(vm, virt_bdf, i);
		spinlock_release(&ptdev_lock);
	}
}