f-stack/dpdk/lib/librte_eal/linuxapp/eal/eal_vfio.c

/*-
 *   BSD LICENSE
 *
 *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
 *   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 <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>

#include <rte_log.h>
#include <rte_memory.h>
#include <rte_eal_memconfig.h>
#include <rte_vfio.h>

#include "eal_filesystem.h"
#include "eal_vfio.h"
#include "eal_private.h"

#ifdef VFIO_PRESENT

/* per-process VFIO config */
static struct vfio_config vfio_cfg;

static int vfio_type1_dma_map(int);
static int vfio_spapr_dma_map(int);
static int vfio_noiommu_dma_map(int);

/* IOMMU types we support */
static const struct vfio_iommu_type iommu_types[] = {
	/* x86 IOMMU, otherwise known as type 1 */
	{ RTE_VFIO_TYPE1, "Type 1", &vfio_type1_dma_map},
	/* ppc64 IOMMU, otherwise known as spapr */
	{ RTE_VFIO_SPAPR, "sPAPR", &vfio_spapr_dma_map},
	/* IOMMU-less mode */
	{ RTE_VFIO_NOIOMMU, "No-IOMMU", &vfio_noiommu_dma_map},
};

int
vfio_get_group_fd(int iommu_group_no)
{
	int i;
	int vfio_group_fd;
	char filename[PATH_MAX];
	struct vfio_group *cur_grp;

	/* check if we already have the group descriptor open */
	for (i = 0; i < VFIO_MAX_GROUPS; i++)
		if (vfio_cfg.vfio_groups[i].group_no == iommu_group_no)
			return vfio_cfg.vfio_groups[i].fd;

	/* Lets see first if there is room for a new group */
	if (vfio_cfg.vfio_active_groups == VFIO_MAX_GROUPS) {
		RTE_LOG(ERR, EAL, "Maximum number of VFIO groups reached!\n");
		return -1;
	}

	/* Now lets get an index for the new group */
	for (i = 0; i < VFIO_MAX_GROUPS; i++)
		if (vfio_cfg.vfio_groups[i].group_no == -1) {
			cur_grp = &vfio_cfg.vfio_groups[i];
			break;
		}

	/* This should not happen */
	if (i == VFIO_MAX_GROUPS) {
		RTE_LOG(ERR, EAL, "No VFIO group free slot found\n");
		return -1;
	}
	/* if primary, try to open the group */
	if (internal_config.process_type == RTE_PROC_PRIMARY) {
		/* try regular group format */
		snprintf(filename, sizeof(filename),
				 VFIO_GROUP_FMT, iommu_group_no);
		vfio_group_fd = open(filename, O_RDWR);
		if (vfio_group_fd < 0) {
			/* if file not found, it's not an error */
			if (errno != ENOENT) {
				RTE_LOG(ERR, EAL, "Cannot open %s: %s\n", filename,
						strerror(errno));
				return -1;
			}

			/* special case: try no-IOMMU path as well */
			snprintf(filename, sizeof(filename),
					VFIO_NOIOMMU_GROUP_FMT, iommu_group_no);
			vfio_group_fd = open(filename, O_RDWR);
			if (vfio_group_fd < 0) {
				if (errno != ENOENT) {
					RTE_LOG(ERR, EAL, "Cannot open %s: %s\n", filename,
							strerror(errno));
					return -1;
				}
				return 0;
			}
			/* noiommu group found */
		}

		cur_grp->group_no = iommu_group_no;
		cur_grp->fd = vfio_group_fd;
		vfio_cfg.vfio_active_groups++;
		return vfio_group_fd;
	}
	/* if we're in a secondary process, request group fd from the primary
	 * process via our socket
	 */
	else {
		int socket_fd, ret;

		socket_fd = vfio_mp_sync_connect_to_primary();

		if (socket_fd < 0) {
			RTE_LOG(ERR, EAL, "  cannot connect to primary process!\n");
			return -1;
		}
		if (vfio_mp_sync_send_request(socket_fd, SOCKET_REQ_GROUP) < 0) {
			RTE_LOG(ERR, EAL, "  cannot request container fd!\n");
			close(socket_fd);
			return -1;
		}
		if (vfio_mp_sync_send_request(socket_fd, iommu_group_no) < 0) {
			RTE_LOG(ERR, EAL, "  cannot send group number!\n");
			close(socket_fd);
			return -1;
		}
		ret = vfio_mp_sync_receive_request(socket_fd);
		switch (ret) {
		case SOCKET_NO_FD:
			close(socket_fd);
			return 0;
		case SOCKET_OK:
			vfio_group_fd = vfio_mp_sync_receive_fd(socket_fd);
			/* if we got the fd, store it and return it */
			if (vfio_group_fd > 0) {
				close(socket_fd);
				cur_grp->group_no = iommu_group_no;
				cur_grp->fd = vfio_group_fd;
				vfio_cfg.vfio_active_groups++;
				return vfio_group_fd;
			}
			/* fall-through on error */
		default:
			RTE_LOG(ERR, EAL, "  cannot get container fd!\n");
			close(socket_fd);
			return -1;
		}
	}
	return -1;
}


static int
get_vfio_group_idx(int vfio_group_fd)
{
	int i;
	for (i = 0; i < VFIO_MAX_GROUPS; i++)
		if (vfio_cfg.vfio_groups[i].fd == vfio_group_fd)
			return i;
	return -1;
}

static void
vfio_group_device_get(int vfio_group_fd)
{
	int i;

	i = get_vfio_group_idx(vfio_group_fd);
	if (i < 0 || i > (VFIO_MAX_GROUPS - 1))
		RTE_LOG(ERR, EAL, "  wrong vfio_group index (%d)\n", i);
	else
		vfio_cfg.vfio_groups[i].devices++;
}

static void
vfio_group_device_put(int vfio_group_fd)
{
	int i;

	i = get_vfio_group_idx(vfio_group_fd);
	if (i < 0 || i > (VFIO_MAX_GROUPS - 1))
		RTE_LOG(ERR, EAL, "  wrong vfio_group index (%d)\n", i);
	else
		vfio_cfg.vfio_groups[i].devices--;
}

static int
vfio_group_device_count(int vfio_group_fd)
{
	int i;

	i = get_vfio_group_idx(vfio_group_fd);
	if (i < 0 || i > (VFIO_MAX_GROUPS - 1)) {
		RTE_LOG(ERR, EAL, "  wrong vfio_group index (%d)\n", i);
		return -1;
	}

	return vfio_cfg.vfio_groups[i].devices;
}

int
clear_group(int vfio_group_fd)
{
	int i;
	int socket_fd, ret;

	if (internal_config.process_type == RTE_PROC_PRIMARY) {

		i = get_vfio_group_idx(vfio_group_fd);
		if (i < 0)
			return -1;
		vfio_cfg.vfio_groups[i].group_no = -1;
		vfio_cfg.vfio_groups[i].fd = -1;
		vfio_cfg.vfio_groups[i].devices = 0;
		vfio_cfg.vfio_active_groups--;
		return 0;
	}

	/* This is just for SECONDARY processes */
	socket_fd = vfio_mp_sync_connect_to_primary();

	if (socket_fd < 0) {
		RTE_LOG(ERR, EAL, "  cannot connect to primary process!\n");
		return -1;
	}

	if (vfio_mp_sync_send_request(socket_fd, SOCKET_CLR_GROUP) < 0) {
		RTE_LOG(ERR, EAL, "  cannot request container fd!\n");
		close(socket_fd);
		return -1;
	}

	if (vfio_mp_sync_send_request(socket_fd, vfio_group_fd) < 0) {
		RTE_LOG(ERR, EAL, "  cannot send group fd!\n");
		close(socket_fd);
		return -1;
	}

	ret = vfio_mp_sync_receive_request(socket_fd);
	switch (ret) {
	case SOCKET_NO_FD:
		RTE_LOG(ERR, EAL, "  BAD VFIO group fd!\n");
		close(socket_fd);
		break;
	case SOCKET_OK:
		close(socket_fd);
		return 0;
	case SOCKET_ERR:
		RTE_LOG(ERR, EAL, "  Socket error\n");
		close(socket_fd);
		break;
	default:
		RTE_LOG(ERR, EAL, "  UNKNOWN reply, %d\n", ret);
		close(socket_fd);
	}
	return -1;
}

int
rte_vfio_setup_device(const char *sysfs_base, const char *dev_addr,
		int *vfio_dev_fd, struct vfio_device_info *device_info)
{
	struct vfio_group_status group_status = {
			.argsz = sizeof(group_status)
	};
	int vfio_group_fd;
	int iommu_group_no;
	int ret;

	/* get group number */
	ret = vfio_get_group_no(sysfs_base, dev_addr, &iommu_group_no);
	if (ret == 0) {
		RTE_LOG(WARNING, EAL, "  %s not managed by VFIO driver, skipping\n",
			dev_addr);
		return 1;
	}

	/* if negative, something failed */
	if (ret < 0)
		return -1;

	/* get the actual group fd */
	vfio_group_fd = vfio_get_group_fd(iommu_group_no);
	if (vfio_group_fd < 0)
		return -1;

	/* if group_fd == 0, that means the device isn't managed by VFIO */
	if (vfio_group_fd == 0) {
		RTE_LOG(WARNING, EAL, " %s not managed by VFIO driver, skipping\n",
				dev_addr);
		return 1;
	}

	/*
	 * at this point, we know that this group is viable (meaning, all devices
	 * are either bound to VFIO or not bound to anything)
	 */

	/* check if the group is viable */
	ret = ioctl(vfio_group_fd, VFIO_GROUP_GET_STATUS, &group_status);
	if (ret) {
		RTE_LOG(ERR, EAL, "  %s cannot get group status, "
				"error %i (%s)\n", dev_addr, errno, strerror(errno));
		close(vfio_group_fd);
		clear_group(vfio_group_fd);
		return -1;
	} else if (!(group_status.flags & VFIO_GROUP_FLAGS_VIABLE)) {
		RTE_LOG(ERR, EAL, "  %s VFIO group is not viable!\n", dev_addr);
		close(vfio_group_fd);
		clear_group(vfio_group_fd);
		return -1;
	}

	/* check if group does not have a container yet */
	if (!(group_status.flags & VFIO_GROUP_FLAGS_CONTAINER_SET)) {

		/* add group to a container */
		ret = ioctl(vfio_group_fd, VFIO_GROUP_SET_CONTAINER,
				&vfio_cfg.vfio_container_fd);
		if (ret) {
			RTE_LOG(ERR, EAL, "  %s cannot add VFIO group to container, "
					"error %i (%s)\n", dev_addr, errno, strerror(errno));
			close(vfio_group_fd);
			clear_group(vfio_group_fd);
			return -1;
		}

		/*
		 * pick an IOMMU type and set up DMA mappings for container
		 *
		 * needs to be done only once, only when first group is
		 * assigned to a container and only in primary process.
		 * Note this can happen several times with the hotplug
		 * functionality.
		 */
		if (internal_config.process_type == RTE_PROC_PRIMARY &&
				vfio_cfg.vfio_active_groups == 1) {
			/* select an IOMMU type which we will be using */
			const struct vfio_iommu_type *t =
				vfio_set_iommu_type(vfio_cfg.vfio_container_fd);
			if (!t) {
				RTE_LOG(ERR, EAL,
					"  %s failed to select IOMMU type\n",
					dev_addr);
				close(vfio_group_fd);
				clear_group(vfio_group_fd);
				return -1;
			}
			ret = t->dma_map_func(vfio_cfg.vfio_container_fd);
			if (ret) {
				RTE_LOG(ERR, EAL,
					"  %s DMA remapping failed, error %i (%s)\n",
					dev_addr, errno, strerror(errno));
				close(vfio_group_fd);
				clear_group(vfio_group_fd);
				return -1;
			}
		}
	}

	/* get a file descriptor for the device */
	*vfio_dev_fd = ioctl(vfio_group_fd, VFIO_GROUP_GET_DEVICE_FD, dev_addr);
	if (*vfio_dev_fd < 0) {
		/* if we cannot get a device fd, this implies a problem with
		 * the VFIO group or the container not having IOMMU configured.
		 */

		RTE_LOG(WARNING, EAL, "Getting a vfio_dev_fd for %s failed\n",
				dev_addr);
		close(vfio_group_fd);
		clear_group(vfio_group_fd);
		return -1;
	}

	/* test and setup the device */
	ret = ioctl(*vfio_dev_fd, VFIO_DEVICE_GET_INFO, device_info);
	if (ret) {
		RTE_LOG(ERR, EAL, "  %s cannot get device info, "
				"error %i (%s)\n", dev_addr, errno,
				strerror(errno));
		close(*vfio_dev_fd);
		close(vfio_group_fd);
		clear_group(vfio_group_fd);
		return -1;
	}
	vfio_group_device_get(vfio_group_fd);

	return 0;
}

int
rte_vfio_release_device(const char *sysfs_base, const char *dev_addr,
		    int vfio_dev_fd)
{
	struct vfio_group_status group_status = {
			.argsz = sizeof(group_status)
	};
	int vfio_group_fd;
	int iommu_group_no;
	int ret;

	/* get group number */
	ret = vfio_get_group_no(sysfs_base, dev_addr, &iommu_group_no);
	if (ret <= 0) {
		RTE_LOG(WARNING, EAL, "  %s not managed by VFIO driver\n",
			dev_addr);
		/* This is an error at this point. */
		return -1;
	}

	/* get the actual group fd */
	vfio_group_fd = vfio_get_group_fd(iommu_group_no);
	if (vfio_group_fd <= 0) {
		RTE_LOG(INFO, EAL, "vfio_get_group_fd failed for %s\n",
				   dev_addr);
		return -1;
	}

	/* At this point we got an active group. Closing it will make the
	 * container detachment. If this is the last active group, VFIO kernel
	 * code will unset the container and the IOMMU mappings.
	 */

	/* Closing a device */
	if (close(vfio_dev_fd) < 0) {
		RTE_LOG(INFO, EAL, "Error when closing vfio_dev_fd for %s\n",
				   dev_addr);
		return -1;
	}

	/* An VFIO group can have several devices attached. Just when there is
	 * no devices remaining should the group be closed.
	 */
	vfio_group_device_put(vfio_group_fd);
	if (!vfio_group_device_count(vfio_group_fd)) {

		if (close(vfio_group_fd) < 0) {
			RTE_LOG(INFO, EAL, "Error when closing vfio_group_fd for %s\n",
				dev_addr);
			return -1;
		}

		if (clear_group(vfio_group_fd) < 0) {
			RTE_LOG(INFO, EAL, "Error when clearing group for %s\n",
					   dev_addr);
			return -1;
		}
	}

	return 0;
}

int
rte_vfio_enable(const char *modname)
{
	/* initialize group list */
	int i;
	int vfio_available;

	for (i = 0; i < VFIO_MAX_GROUPS; i++) {
		vfio_cfg.vfio_groups[i].fd = -1;
		vfio_cfg.vfio_groups[i].group_no = -1;
		vfio_cfg.vfio_groups[i].devices = 0;
	}

	/* inform the user that we are probing for VFIO */
	RTE_LOG(INFO, EAL, "Probing VFIO support...\n");

	/* check if vfio module is loaded */
	vfio_available = rte_eal_check_module(modname);

	/* return error directly */
	if (vfio_available == -1) {
		RTE_LOG(INFO, EAL, "Could not get loaded module details!\n");
		return -1;
	}

	/* return 0 if VFIO modules not loaded */
	if (vfio_available == 0) {
		RTE_LOG(DEBUG, EAL, "VFIO modules not loaded, "
			"skipping VFIO support...\n");
		return 0;
	}

	vfio_cfg.vfio_container_fd = vfio_get_container_fd();

	/* check if we have VFIO driver enabled */
	if (vfio_cfg.vfio_container_fd != -1) {
		RTE_LOG(NOTICE, EAL, "VFIO support initialized\n");
		vfio_cfg.vfio_enabled = 1;
	} else {
		RTE_LOG(NOTICE, EAL, "VFIO support could not be initialized\n");
	}

	return 0;
}

int
rte_vfio_is_enabled(const char *modname)
{
	const int mod_available = rte_eal_check_module(modname) > 0;
	return vfio_cfg.vfio_enabled && mod_available;
}

const struct vfio_iommu_type *
vfio_set_iommu_type(int vfio_container_fd)
{
	unsigned idx;
	for (idx = 0; idx < RTE_DIM(iommu_types); idx++) {
		const struct vfio_iommu_type *t = &iommu_types[idx];

		int ret = ioctl(vfio_container_fd, VFIO_SET_IOMMU,
				t->type_id);
		if (!ret) {
			RTE_LOG(NOTICE, EAL, "  using IOMMU type %d (%s)\n",
					t->type_id, t->name);
			return t;
		}
		/* not an error, there may be more supported IOMMU types */
		RTE_LOG(DEBUG, EAL, "  set IOMMU type %d (%s) failed, "
				"error %i (%s)\n", t->type_id, t->name, errno,
				strerror(errno));
	}
	/* if we didn't find a suitable IOMMU type, fail */
	return NULL;
}

int
vfio_has_supported_extensions(int vfio_container_fd)
{
	int ret;
	unsigned idx, n_extensions = 0;
	for (idx = 0; idx < RTE_DIM(iommu_types); idx++) {
		const struct vfio_iommu_type *t = &iommu_types[idx];

		ret = ioctl(vfio_container_fd, VFIO_CHECK_EXTENSION,
				t->type_id);
		if (ret < 0) {
			RTE_LOG(ERR, EAL, "  could not get IOMMU type, "
				"error %i (%s)\n", errno,
				strerror(errno));
			close(vfio_container_fd);
			return -1;
		} else if (ret == 1) {
			/* we found a supported extension */
			n_extensions++;
		}
		RTE_LOG(DEBUG, EAL, "  IOMMU type %d (%s) is %s\n",
				t->type_id, t->name,
				ret ? "supported" : "not supported");
	}

	/* if we didn't find any supported IOMMU types, fail */
	if (!n_extensions) {
		close(vfio_container_fd);
		return -1;
	}

	return 0;
}

int
vfio_get_container_fd(void)
{
	int ret, vfio_container_fd;

	/* if we're in a primary process, try to open the container */
	if (internal_config.process_type == RTE_PROC_PRIMARY) {
		vfio_container_fd = open(VFIO_CONTAINER_PATH, O_RDWR);
		if (vfio_container_fd < 0) {
			RTE_LOG(ERR, EAL, "  cannot open VFIO container, "
					"error %i (%s)\n", errno, strerror(errno));
			return -1;
		}

		/* check VFIO API version */
		ret = ioctl(vfio_container_fd, VFIO_GET_API_VERSION);
		if (ret != VFIO_API_VERSION) {
			if (ret < 0)
				RTE_LOG(ERR, EAL, "  could not get VFIO API version, "
						"error %i (%s)\n", errno, strerror(errno));
			else
				RTE_LOG(ERR, EAL, "  unsupported VFIO API version!\n");
			close(vfio_container_fd);
			return -1;
		}

		ret = vfio_has_supported_extensions(vfio_container_fd);
		if (ret) {
			RTE_LOG(ERR, EAL, "  no supported IOMMU "
					"extensions found!\n");
			return -1;
		}

		return vfio_container_fd;
	} else {
		/*
		 * if we're in a secondary process, request container fd from the
		 * primary process via our socket
		 */
		int socket_fd;

		socket_fd = vfio_mp_sync_connect_to_primary();
		if (socket_fd < 0) {
			RTE_LOG(ERR, EAL, "  cannot connect to primary process!\n");
			return -1;
		}
		if (vfio_mp_sync_send_request(socket_fd, SOCKET_REQ_CONTAINER) < 0) {
			RTE_LOG(ERR, EAL, "  cannot request container fd!\n");
			close(socket_fd);
			return -1;
		}
		vfio_container_fd = vfio_mp_sync_receive_fd(socket_fd);
		if (vfio_container_fd < 0) {
			RTE_LOG(ERR, EAL, "  cannot get container fd!\n");
			close(socket_fd);
			return -1;
		}
		close(socket_fd);
		return vfio_container_fd;
	}

	return -1;
}

int
vfio_get_group_no(const char *sysfs_base,
		const char *dev_addr, int *iommu_group_no)
{
	char linkname[PATH_MAX];
	char filename[PATH_MAX];
	char *tok[16], *group_tok, *end;
	int ret;

	memset(linkname, 0, sizeof(linkname));
	memset(filename, 0, sizeof(filename));

	/* try to find out IOMMU group for this device */
	snprintf(linkname, sizeof(linkname),
			 "%s/%s/iommu_group", sysfs_base, dev_addr);

	ret = readlink(linkname, filename, sizeof(filename));

	/* if the link doesn't exist, no VFIO for us */
	if (ret < 0)
		return 0;

	ret = rte_strsplit(filename, sizeof(filename),
			tok, RTE_DIM(tok), '/');

	if (ret <= 0) {
		RTE_LOG(ERR, EAL, "  %s cannot get IOMMU group\n", dev_addr);
		return -1;
	}

	/* IOMMU group is always the last token */
	errno = 0;
	group_tok = tok[ret - 1];
	end = group_tok;
	*iommu_group_no = strtol(group_tok, &end, 10);
	if ((end != group_tok && *end != '\0') || errno != 0) {
		RTE_LOG(ERR, EAL, "  %s error parsing IOMMU number!\n", dev_addr);
		return -1;
	}

	return 1;
}

static int
vfio_type1_dma_map(int vfio_container_fd)
{
	const struct rte_memseg *ms = rte_eal_get_physmem_layout();
	int i, ret;

	/* map all DPDK segments for DMA. use 1:1 PA to IOVA mapping */
	for (i = 0; i < RTE_MAX_MEMSEG; i++) {
		struct vfio_iommu_type1_dma_map dma_map;

		if (ms[i].addr == NULL)
			break;

		memset(&dma_map, 0, sizeof(dma_map));
		dma_map.argsz = sizeof(struct vfio_iommu_type1_dma_map);
		dma_map.vaddr = ms[i].addr_64;
		dma_map.size = ms[i].len;
		dma_map.iova = ms[i].iova;
		dma_map.flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE;

		ret = ioctl(vfio_container_fd, VFIO_IOMMU_MAP_DMA, &dma_map);

		if (ret) {
			RTE_LOG(ERR, EAL, "  cannot set up DMA remapping, "
					  "error %i (%s)\n", errno,
					  strerror(errno));
			return -1;
		}
	}

	return 0;
}

static int
vfio_spapr_dma_map(int vfio_container_fd)
{
	const struct rte_memseg *ms = rte_eal_get_physmem_layout();
	int i, ret;

	struct vfio_iommu_spapr_register_memory reg = {
		.argsz = sizeof(reg),
		.flags = 0
	};
	struct vfio_iommu_spapr_tce_info info = {
		.argsz = sizeof(info),
	};
	struct vfio_iommu_spapr_tce_create create = {
		.argsz = sizeof(create),
	};
	struct vfio_iommu_spapr_tce_remove remove = {
		.argsz = sizeof(remove),
	};

	/* query spapr iommu info */
	ret = ioctl(vfio_container_fd, VFIO_IOMMU_SPAPR_TCE_GET_INFO, &info);
	if (ret) {
		RTE_LOG(ERR, EAL, "  cannot get iommu info, "
				"error %i (%s)\n", errno, strerror(errno));
		return -1;
	}

	/* remove default DMA of 32 bit window */
	remove.start_addr = info.dma32_window_start;
	ret = ioctl(vfio_container_fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove);
	if (ret) {
		RTE_LOG(ERR, EAL, "  cannot remove default DMA window, "
				"error %i (%s)\n", errno, strerror(errno));
		return -1;
	}

	/* create DMA window from 0 to max(phys_addr + len) */
	for (i = 0; i < RTE_MAX_MEMSEG; i++) {
		if (ms[i].addr == NULL)
			break;

		create.window_size = RTE_MAX(create.window_size,
				ms[i].iova + ms[i].len);
	}

	/* sPAPR requires window size to be a power of 2 */
	create.window_size = rte_align64pow2(create.window_size);
	create.page_shift = __builtin_ctzll(ms->hugepage_sz);
	create.levels = 1;

	ret = ioctl(vfio_container_fd, VFIO_IOMMU_SPAPR_TCE_CREATE, &create);
	if (ret) {
		RTE_LOG(ERR, EAL, "  cannot create new DMA window, "
				"error %i (%s)\n", errno, strerror(errno));
		return -1;
	}

	if (create.start_addr != 0) {
		RTE_LOG(ERR, EAL, "  DMA window start address != 0\n");
		return -1;
	}

	/* map all DPDK segments for DMA. use 1:1 PA to IOVA mapping */
	for (i = 0; i < RTE_MAX_MEMSEG; i++) {
		struct vfio_iommu_type1_dma_map dma_map;

		if (ms[i].addr == NULL)
			break;

		reg.vaddr = (uintptr_t) ms[i].addr;
		reg.size = ms[i].len;
		ret = ioctl(vfio_container_fd,
			VFIO_IOMMU_SPAPR_REGISTER_MEMORY, &reg);
		if (ret) {
			RTE_LOG(ERR, EAL, "  cannot register vaddr for IOMMU, "
				"error %i (%s)\n", errno, strerror(errno));
			return -1;
		}

		memset(&dma_map, 0, sizeof(dma_map));
		dma_map.argsz = sizeof(struct vfio_iommu_type1_dma_map);
		dma_map.vaddr = ms[i].addr_64;
		dma_map.size = ms[i].len;
		dma_map.iova = ms[i].iova;
		dma_map.flags = VFIO_DMA_MAP_FLAG_READ |
				 VFIO_DMA_MAP_FLAG_WRITE;

		ret = ioctl(vfio_container_fd, VFIO_IOMMU_MAP_DMA, &dma_map);

		if (ret) {
			RTE_LOG(ERR, EAL, "  cannot set up DMA remapping, "
				"error %i (%s)\n", errno, strerror(errno));
			return -1;
		}

	}

	return 0;
}

static int
vfio_noiommu_dma_map(int __rte_unused vfio_container_fd)
{
	/* No-IOMMU mode does not need DMA mapping */
	return 0;
}

int
rte_vfio_noiommu_is_enabled(void)
{
	int fd, ret, cnt __rte_unused;
	char c;

	ret = -1;
	fd = open(VFIO_NOIOMMU_MODE, O_RDONLY);
	if (fd < 0)
		return -1;

	cnt = read(fd, &c, 1);
	if (c == 'Y')
		ret = 1;

	close(fd);
	return ret;
}

#endif