acrn-hypervisor/hypervisor/common/hypercall.c

/*
 * Copyright (C) 2018 Intel Corporation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <hypervisor.h>
#include <hv_lib.h>
#include <acrn_common.h>
#include <hv_arch.h>
#include <schedule.h>
#include <hypercall.h>
#include <acrn_hv_defs.h>
#include <hv_debug.h>
#include <version.h>

#define ACRN_DBG_HYCALL	6

bool is_hypercall_from_ring0(void)
{
	uint64_t cs_sel;

	cs_sel = exec_vmread(VMX_GUEST_CS_SEL);
	/* cs_selector[1:0] is CPL */
	if ((cs_sel & 0x3) == 0)
		return true;

	return false;
}

int64_t hcall_get_api_version(struct vm *vm, uint64_t param)
{
	struct hc_api_version version;

	if (!is_vm0(vm))
		return -1;

	version.major_version = HV_API_MAJOR_VERSION;
	version.minor_version = HV_API_MINOR_VERSION;

	if (copy_to_vm(vm, &version, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}

	return 0;
}

static int handle_vpic_irqline(struct vm *vm, int irq, enum irq_mode mode)
{
	int ret = -1;

	if (!vm)
		return ret;

	switch (mode) {
	case IRQ_ASSERT:
		ret = vpic_assert_irq(vm, irq);
		break;
	case IRQ_DEASSERT:
		ret = vpic_deassert_irq(vm, irq);
		break;
	case IRQ_PULSE:
		ret = vpic_pulse_irq(vm, irq);
	default:
		break;
	}

	return ret;
}

static int
handle_vioapic_irqline(struct vm *vm, int irq, enum irq_mode mode)
{
	int ret = -1;

	if (!vm)
		return ret;

	switch (mode) {
	case IRQ_ASSERT:
		ret = vioapic_assert_irq(vm, irq);
		break;
	case IRQ_DEASSERT:
		ret = vioapic_deassert_irq(vm, irq);
		break;
	case IRQ_PULSE:
		ret = vioapic_pulse_irq(vm, irq);
		break;
	default:
		break;
	}
	return ret;
}

static int handle_virt_irqline(struct vm *vm, uint64_t target_vmid,
		struct acrn_irqline *param, enum irq_mode mode)
{
	int ret = 0;
	long intr_type;
	struct vm *target_vm = get_vm_from_vmid(target_vmid);

	if (!vm || !param)
		return -1;

	intr_type = param->intr_type;

	switch (intr_type) {
	case ACRN_INTR_TYPE_ISA:
		/* Call vpic for pic injection */
		ret = handle_vpic_irqline(target_vm, param->pic_irq, mode);

		/* call vioapic for ioapic injection if ioapic_irq != -1*/
		if (param->ioapic_irq != -1UL) {
			/* handle IOAPIC irqline */
			ret = handle_vioapic_irqline(target_vm,
				param->ioapic_irq, mode);
		}
		break;
	case ACRN_INTR_TYPE_IOAPIC:
		/* handle IOAPIC irqline */
		ret = handle_vioapic_irqline(target_vm,
				param->ioapic_irq, mode);
		break;
	default:
		dev_dbg(ACRN_DBG_HYCALL, "vINTR inject failed. type=%d",
				intr_type);
		ret = -1;
	}
	return ret;
}

int64_t hcall_create_vm(struct vm *vm, uint64_t param)
{
	int64_t ret = 0;
	struct vm *target_vm = NULL;
	/* VM are created from hv_main() directly
	 * Here we just return the vmid for DM
	 */
	struct acrn_create_vm cv;
	struct vm_description vm_desc;

	memset((void *)&cv, 0, sizeof(cv));
	if (copy_from_vm(vm, &cv, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}

	memset(&vm_desc, 0, sizeof(vm_desc));
	vm_desc.sworld_enabled =
		(!!(cv.vm_flag & (SECURE_WORLD_ENABLED)));
	memcpy_s(&vm_desc.GUID[0], 16, &cv.GUID[0], 16);
	ret = create_vm(&vm_desc, &target_vm);

	if (ret != 0) {
		dev_dbg(ACRN_DBG_HYCALL, "HCALL: Create VM failed");
		cv.vmid = ACRN_INVALID_VMID;
		ret = -1;
	} else {
		cv.vmid = target_vm->attr.id;
		ret = 0;
	}

	if (copy_to_vm(vm, &cv.vmid, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}

	return ret;
}

int64_t hcall_destroy_vm(uint64_t vmid)
{
	int64_t ret = 0;
	struct vm *target_vm = get_vm_from_vmid(vmid);

	if (target_vm == NULL)
		return -1;

	ret = shutdown_vm(target_vm);
	return ret;
}

int64_t hcall_resume_vm(uint64_t vmid)
{
	int64_t ret = 0;
	struct vm *target_vm = get_vm_from_vmid(vmid);

	if (target_vm == NULL)
		return -1;
	if (target_vm->sw.req_buf == 0)
		ret = -1;
	else
		ret = start_vm(target_vm);

	return ret;
}

int64_t hcall_pause_vm(uint64_t vmid)
{
	struct vm *target_vm = get_vm_from_vmid(vmid);

	if (target_vm == NULL)
		return -1;

	pause_vm(target_vm);

	return 0;
}

int64_t hcall_create_vcpu(struct vm *vm, uint64_t vmid, uint64_t param)
{
	int ret, pcpu_id;
	struct acrn_create_vcpu cv;

	struct vm *target_vm = get_vm_from_vmid(vmid);

	if (!target_vm || !param)
		return -1;

	if (copy_from_vm(vm, &cv, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}

	pcpu_id = allocate_pcpu();
	if (-1 == pcpu_id) {
		pr_err("%s: No physical available\n", __func__);
		return -1;
	}

	ret = prepare_vcpu(target_vm, pcpu_id);

	return ret;
}

int64_t hcall_assert_irqline(struct vm *vm, uint64_t vmid, uint64_t param)
{
	int64_t ret = 0;
	struct acrn_irqline irqline;

	if (copy_from_vm(vm, &irqline, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}
	ret = handle_virt_irqline(vm, vmid, &irqline, IRQ_ASSERT);

	return ret;
}

int64_t hcall_deassert_irqline(struct vm *vm, uint64_t vmid, uint64_t param)
{
	int64_t ret = 0;
	struct acrn_irqline irqline;

	if (copy_from_vm(vm, &irqline, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}
	ret = handle_virt_irqline(vm, vmid, &irqline, IRQ_DEASSERT);

	return ret;
}

int64_t hcall_pulse_irqline(struct vm *vm, uint64_t vmid, uint64_t param)
{
	int64_t ret = 0;
	struct acrn_irqline irqline;

	if (copy_from_vm(vm, &irqline, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}
	ret = handle_virt_irqline(vm, vmid, &irqline, IRQ_PULSE);

	return ret;
}

int64_t hcall_inject_msi(struct vm *vm, uint64_t vmid, uint64_t param)
{
	int ret = 0;
	struct acrn_msi_entry msi;
	struct vm *target_vm = get_vm_from_vmid(vmid);

	if (target_vm == NULL)
		return -1;

	memset((void *)&msi, 0, sizeof(msi));
	if (copy_from_vm(vm, &msi, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}
	ret = vlapic_intr_msi(target_vm, msi.msi_addr, msi.msi_data);

	return ret;
}

int64_t hcall_set_ioreq_buffer(struct vm *vm, uint64_t vmid, uint64_t param)
{
	int64_t ret = 0;
	struct acrn_set_ioreq_buffer iobuf;
	struct vm *target_vm = get_vm_from_vmid(vmid);

	if (target_vm == NULL)
		return -1;

	memset((void *)&iobuf, 0, sizeof(iobuf));

	if (copy_from_vm(vm, &iobuf, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}

	dev_dbg(ACRN_DBG_HYCALL, "[%d] SET BUFFER=0x%x",
			vmid, iobuf.req_buf);

	/* store gpa of guest request_buffer */
	target_vm->sw.req_buf = gpa2hpa(vm, iobuf.req_buf);

	return ret;
}

static void complete_request(struct vcpu *vcpu)
{
	/*
	 * If vcpu is in Zombie state and will be destroyed soon. Just
	 * mark ioreq done and don't resume vcpu.
	 */
	if (vcpu->state == VCPU_ZOMBIE) {
		struct vhm_request_buffer *req_buf;

		req_buf = (struct vhm_request_buffer *)vcpu->vm->sw.req_buf;
		req_buf->req_queue[vcpu->vcpu_id].valid = false;
		atomic_store_rel_32(&vcpu->ioreq_pending, 0);

		return;
	}

	switch (vcpu->req.type) {
	case REQ_MMIO:
		request_vcpu_pre_work(vcpu, ACRN_VCPU_MMIO_COMPLETE);
		break;

	case REQ_PORTIO:
		dm_emulate_pio_post(vcpu);
		break;

	default:
		break;
	}

	resume_vcpu(vcpu);
}

int64_t hcall_notify_req_finish(uint64_t vmid, uint64_t vcpu_id)
{
	int64_t ret = 0;
	struct vhm_request_buffer *req_buf;
	struct vhm_request *req;
	struct vcpu *vcpu;
	struct vm *target_vm = get_vm_from_vmid(vmid);

	/* make sure we have set req_buf */
	if (!target_vm || target_vm->sw.req_buf == 0)
		return -1;

	dev_dbg(ACRN_DBG_HYCALL, "[%d] NOTIFY_FINISH for vcpu %d",
			vmid, vcpu_id);

	vcpu = vcpu_from_vid(target_vm, vcpu_id);
	ASSERT(vcpu != NULL, "Failed to get VCPU context.");

	req_buf = (struct vhm_request_buffer *)target_vm->sw.req_buf;
	req = req_buf->req_queue + vcpu_id;

	if (req->valid &&
		((req->processed == REQ_STATE_SUCCESS) ||
		 (req->processed == REQ_STATE_FAILED)))
		complete_request(vcpu);

	return ret;
}

int64_t hcall_set_vm_memmap(struct vm *vm, uint64_t vmid, uint64_t param)
{
	int64_t ret = 0;
	uint64_t hpa;
	uint32_t attr, prot;
	struct vm_set_memmap memmap;
	struct vm *target_vm = get_vm_from_vmid(vmid);

	if (!vm || !target_vm)
		return -1;

	memset((void *)&memmap, 0, sizeof(memmap));

	if (copy_from_vm(vm, &memmap, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}

	if (!is_vm0(vm)) {
		pr_err("%s: ERROR! Not coming from service vm", __func__);
		return -1;
	}

	if (is_vm0(target_vm)) {
		pr_err("%s: ERROR! Targeting to service vm", __func__);
		return -1;
	}

	if ((memmap.length & 0xFFF) != 0) {
		pr_err("%s: ERROR! [vm%d] map size 0x%x is not page aligned",
				__func__, vmid, memmap.length);
		return -1;
	}

	hpa = gpa2hpa(vm, memmap.vm0_gpa);
	dev_dbg(ACRN_DBG_HYCALL, "[vm%d] gpa=0x%x hpa=0x%x size=0x%x",
			vmid, memmap.remote_gpa, hpa, memmap.length);

	/* Check prot */
	attr = 0;
	if (memmap.type != MAP_UNMAP) {
		prot = memmap.prot;
		if (prot & MEM_ACCESS_READ)
			attr |= MMU_MEM_ATTR_READ;
		if (prot & MEM_ACCESS_WRITE)
			attr |= MMU_MEM_ATTR_WRITE;
		if (prot & MEM_ACCESS_EXEC)
			attr |= MMU_MEM_ATTR_EXECUTE;
		if (prot & MEM_TYPE_WB)
			attr |= MMU_MEM_ATTR_WB_CACHE;
		else if (prot & MEM_TYPE_WT)
			attr |= MMU_MEM_ATTR_WT_CACHE;
		else if (prot & MEM_TYPE_UC)
			attr |= MMU_MEM_ATTR_UNCACHED;
		else if (prot & MEM_TYPE_WC)
			attr |= MMU_MEM_ATTR_WC;
		else if (prot & MEM_TYPE_WP)
			attr |= MMU_MEM_ATTR_WP;
		else
			attr |= MMU_MEM_ATTR_UNCACHED;
	}

	/* create gpa to hpa EPT mapping */
	ret = ept_mmap(target_vm, hpa,
			memmap.remote_gpa, memmap.length, memmap.type, attr);

	return ret;
}

int64_t hcall_remap_pci_msix(struct vm *vm, uint64_t vmid, uint64_t param)
{
	int64_t ret = 0;
	struct acrn_vm_pci_msix_remap remap;
	struct ptdev_msi_info info;
	struct vm *target_vm = get_vm_from_vmid(vmid);

	if (target_vm == NULL)
		return -1;

	memset((void *)&remap, 0, sizeof(remap));

	if (copy_from_vm(vm, &remap, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}

	if (!is_vm0(vm))
		ret = -1;
	else {
		info.msix = remap.msix;
		info.msix_entry_index = remap.msix_entry_index;
		info.vmsi_ctl = remap.msi_ctl;
		info.vmsi_addr = remap.msi_addr;
		info.vmsi_data = remap.msi_data;

		ret = ptdev_msix_remap(target_vm,
				remap.virt_bdf, &info);
		remap.msi_data = info.pmsi_data;
		remap.msi_addr = info.pmsi_addr;

		if (copy_to_vm(vm, &remap, param)) {
			pr_err("%s: Unable copy param to vm\n", __func__);
			return -1;
		}
	}

	return ret;
}

int64_t hcall_gpa_to_hpa(struct vm *vm, uint64_t vmid, uint64_t param)
{
	int64_t ret = 0;
	struct vm_gpa2hpa v_gpa2hpa;
	struct vm *target_vm = get_vm_from_vmid(vmid);

	if (target_vm == NULL)
		return -1;

	memset((void *)&v_gpa2hpa, 0, sizeof(v_gpa2hpa));

	if (copy_from_vm(vm, &v_gpa2hpa, param)) {
		pr_err("HCALL gpa2hpa: Unable copy param from vm\n");
		return -1;
	}
	v_gpa2hpa.hpa = gpa2hpa(target_vm, v_gpa2hpa.gpa);
	if (copy_to_vm(vm, &v_gpa2hpa, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}

	return ret;
}

int64_t hcall_assign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param)
{
	int64_t ret = 0;
	uint16_t bdf;
	struct vm *target_vm = get_vm_from_vmid(vmid);

	if (target_vm == NULL)
		return -1;

	if (copy_from_vm(vm, &bdf, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}

	/* create a iommu domain for target VM if not created */
	if (!target_vm->iommu_domain) {
		ASSERT(target_vm->arch_vm.nworld_eptp, "EPT of VM not set!");
		/* TODO: how to get vm's address width? */
		target_vm->iommu_domain = create_iommu_domain(vmid,
				target_vm->arch_vm.nworld_eptp, 48);
		ASSERT(target_vm->iommu_domain,
				"failed to created iommu domain!");
	}
	ret = assign_iommu_device(target_vm->iommu_domain,
			(uint8_t)(bdf >> 8), (uint8_t)(bdf & 0xff));

	return ret;
}

int64_t hcall_deassign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param)
{
	int64_t ret = 0;
	uint16_t bdf;
	struct vm *target_vm = get_vm_from_vmid(vmid);

	if (target_vm == NULL)
		return -1;

	if (copy_from_vm(vm, &bdf, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}
	ret = unassign_iommu_device(target_vm->iommu_domain,
			(uint8_t)(bdf >> 8), (uint8_t)(bdf & 0xff));

	return ret;
}

int64_t hcall_set_ptdev_intr_info(struct vm *vm, uint64_t vmid, uint64_t param)
{
	int64_t ret = 0;
	struct hc_ptdev_irq irq;
	struct vm *target_vm = get_vm_from_vmid(vmid);

	if (target_vm == NULL)
		return -1;

	memset((void *)&irq, 0, sizeof(irq));

	if (copy_from_vm(vm, &irq, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}

	if (irq.type == IRQ_INTX)
		ptdev_add_intx_remapping(target_vm,
				irq.virt_bdf, irq.phys_bdf,
				irq.is.intx.virt_pin, irq.is.intx.phys_pin,
				irq.is.intx.pic_pin);
	else if (irq.type == IRQ_MSI || irq.type == IRQ_MSIX)
		ptdev_add_msix_remapping(target_vm,
				irq.virt_bdf, irq.phys_bdf,
				irq.is.msix.vector_cnt);

	return ret;
}

int64_t
hcall_reset_ptdev_intr_info(struct vm *vm, uint64_t vmid, uint64_t param)
{
	int64_t ret = 0;
	struct hc_ptdev_irq irq;
	struct vm *target_vm = get_vm_from_vmid(vmid);

	if (target_vm == NULL)
		return -1;

	memset((void *)&irq, 0, sizeof(irq));

	if (copy_from_vm(vm, &irq, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}

	if (irq.type == IRQ_INTX)
		ptdev_remove_intx_remapping(target_vm,
				irq.is.intx.virt_pin,
				irq.is.intx.pic_pin);
	else if (irq.type == IRQ_MSI || irq.type == IRQ_MSIX)
		ptdev_remove_msix_remapping(target_vm,
				irq.virt_bdf,
				irq.is.msix.vector_cnt);

	return ret;
}

int64_t hcall_setup_sbuf(struct vm *vm, uint64_t param)
{
	struct sbuf_setup_param ssp;
	uint64_t *hva;

	memset((void *)&ssp, 0, sizeof(ssp));

	if (copy_from_vm(vm, &ssp, param)) {
		pr_err("%s: Unable copy param to vm\n", __func__);
		return -1;
	}

	if (ssp.gpa)
		hva = (uint64_t *)GPA2HVA(vm, ssp.gpa);
	else
		hva = (uint64_t *)NULL;

	return sbuf_share_setup(ssp.pcpu_id, ssp.sbuf_id, hva);
}

static void fire_vhm_interrupt(void)
{
	/*
	 * use vLAPIC to inject vector to SOS vcpu 0 if vlapic is enabled
	 * otherwise, send IPI hardcoded to CPU_BOOT_ID
	 */
	struct vm *vm0;
	struct vcpu *vcpu;

	vm0 = get_vm_from_vmid(0);
	ASSERT(vm0, "VM Pointer is NULL");

	vcpu = vcpu_from_vid(vm0, 0);
	ASSERT(vcpu, "vcpu_from_vid failed");

	vlapic_intr_edge(vcpu, VECTOR_VIRT_IRQ_VHM);
}

static void acrn_print_request(int vcpu_id, struct vhm_request *req)
{
	switch (req->type) {
	case REQ_MMIO:
		dev_dbg(ACRN_DBG_HYCALL, "[vcpu_id=%d type=MMIO]", vcpu_id);
		dev_dbg(ACRN_DBG_HYCALL,
			"gpa=0x%lx, R/W=%d, size=%ld value=0x%lx processed=%lx",
			req->reqs.mmio_request.address,
			req->reqs.mmio_request.direction,
			req->reqs.mmio_request.size,
			req->reqs.mmio_request.value,
			req->processed);
		break;
	case REQ_PORTIO:
		dev_dbg(ACRN_DBG_HYCALL, "[vcpu_id=%d type=PORTIO]", vcpu_id);
		dev_dbg(ACRN_DBG_HYCALL,
			"IO=0x%lx, R/W=%d, size=%ld value=0x%lx processed=%lx",
			req->reqs.pio_request.address,
			req->reqs.pio_request.direction,
			req->reqs.pio_request.size,
			req->reqs.pio_request.value,
			req->processed);
		break;
	default:
		dev_dbg(ACRN_DBG_HYCALL, "[vcpu_id=%d type=%d] NOT support type",
			vcpu_id, req->type);
		break;
	}
}

int acrn_insert_request_wait(struct vcpu *vcpu, struct vhm_request *req)
{
	struct vhm_request_buffer *req_buf =
		(void *)HPA2HVA(vcpu->vm->sw.req_buf);
	long cur;

	ASSERT(sizeof(*req) == (4096/VHM_REQUEST_MAX),
			"vhm_request page broken!");


	if (!vcpu || !req || vcpu->vm->sw.req_buf == 0)
		return -1;

	/* ACRN insert request to VHM and inject upcall */
	cur = vcpu->vcpu_id;
	memcpy_s(&req_buf->req_queue[cur], sizeof(struct vhm_request),
		 req, sizeof(struct vhm_request));

	/* Must clear the signal before we mark req valid
	 * Once we mark to valid, VHM may process req and signal us
	 * before we perform upcall.
	 * because VHM can work in pulling mode without wait for upcall
	 */
	req_buf->req_queue[cur].valid = true;

	acrn_print_request(vcpu->vcpu_id, req_buf->req_queue + cur);

	/* signal VHM */
	fire_vhm_interrupt();

	/* pause vcpu, wait for VHM to handle the MMIO request */
	atomic_store_rel_32(&vcpu->ioreq_pending, 1);
	pause_vcpu(vcpu, VCPU_PAUSED);

	return 0;
}

int acrn_insert_request_nowait(struct vcpu *vcpu, struct vhm_request *req)
{
	struct vhm_request_buffer *req_buf;
	long cur;

	if (!vcpu || !req || !vcpu->vm->sw.req_buf)
		return -1;

	req_buf = (void *)gpa2hpa(vcpu->vm, vcpu->vm->sw.req_buf);

	/* ACRN insert request to VHM and inject upcall */
	cur = vcpu->vcpu_id;
	req_buf->req_queue[cur] = *req;
	req_buf->req_queue[cur].valid = true;

	/* signal VHM and yield CPU */
	fire_vhm_interrupt();

	return 0;
}

static void _get_req_info_(struct vhm_request *req, int *id, char *type,
	char *state, char *dir, long *addr, long *val)
{
	strcpy_s(dir, 16, "NONE");
	*addr = *val = 0;
	*id = req->client;

	switch (req->type) {
	case REQ_PORTIO:
		strcpy_s(type, 16, "PORTIO");
		if (req->reqs.pio_request.direction == REQUEST_READ)
			strcpy_s(dir, 16, "READ");
		else
			strcpy_s(dir, 16, "WRITE");
		*addr = req->reqs.pio_request.address;
		*val = req->reqs.pio_request.value;
		break;
	case REQ_MMIO:
	case REQ_WP:
		strcpy_s(type, 16, "MMIO/WP");
		if (req->reqs.mmio_request.direction == REQUEST_READ)
			strcpy_s(dir, 16, "READ");
		else
			strcpy_s(dir, 16, "WRITE");
		*addr = req->reqs.mmio_request.address;
		*val = req->reqs.mmio_request.value;
		break;
		break;
	default:
		strcpy_s(type, 16, "UNKNOWN");
	}

	switch (req->processed) {
	case REQ_STATE_SUCCESS:
		strcpy_s(state, 16, "SUCCESS");
		break;
	case REQ_STATE_PENDING:
		strcpy_s(state, 16, "PENDING");
		break;
	case REQ_STATE_PROCESSING:
		strcpy_s(state, 16, "PROCESS");
		break;
	case REQ_STATE_FAILED:
		strcpy_s(state, 16, "FAILED");
		break;
	default:
		strcpy_s(state, 16,  "UNKNOWN");
	}
}

int get_req_info(char *str, int str_max)
{
	int i, len, size = str_max, client_id;
	struct vhm_request_buffer *req_buf;
	struct vhm_request *req;
	char type[16], state[16], dir[16];
	long addr, val;
	struct list_head *pos;
	struct vm *vm;

	len = snprintf(str, size,
		"\r\nVM\tVCPU\tCID\tTYPE\tSTATE\tDIR\tADDR\t\t\tVAL");
	size -= len;
	str += len;

	spinlock_obtain(&vm_list_lock);
	list_for_each(pos, &vm_list) {
		vm = list_entry(pos, struct vm, list);
		req_buf = (struct vhm_request_buffer *)vm->sw.req_buf;
		if (req_buf) {
			for (i = 0; i < VHM_REQUEST_MAX; i++) {
				req = req_buf->req_queue + i;
				if (req->valid) {
					_get_req_info_(req, &client_id, type,
						state, dir, &addr, &val);
					len = snprintf(str, size,
						"\r\n%d\t%d\t%d\t%s\t%s\t%s",
						vm->attr.id, i, client_id, type,
						state, dir);
					size -= len;
					str += len;

					len = snprintf(str, size,
						"\t0x%016llx\t0x%016llx",
						addr, val);
					size -= len;
					str += len;
				}
			}
		}
	}
	spinlock_release(&vm_list_lock);
	snprintf(str, size, "\r\n");
	return 0;
}