eal/linux/eal_vfio.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2018 Intel Corporation
 */

#include <inttypes.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>

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

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

#define VFIO_MEM_EVENT_CLB_NAME "vfio_mem_event_clb"

/* hot plug/unplug of VFIO groups may cause all DMA maps to be dropped. we can
 * recreate the mappings for DPDK segments, but we cannot do so for memory that
 * was registered by the user themselves, so we need to store the user mappings
 * somewhere, to recreate them later.
 */
#define VFIO_MAX_USER_MEM_MAPS 256
struct user_mem_map {
	uint64_t addr;  /**< start VA */
	uint64_t iova;  /**< start IOVA */
	uint64_t len;   /**< total length of the mapping */
	uint64_t chunk; /**< this mapping can be split in chunks of this size */
};

struct user_mem_maps {
	rte_spinlock_recursive_t lock;
	int n_maps;
	struct user_mem_map maps[VFIO_MAX_USER_MEM_MAPS];
};

struct vfio_config {
	int vfio_enabled;
	int vfio_container_fd;
	int vfio_active_groups;
	const struct vfio_iommu_type *vfio_iommu_type;
	struct vfio_group vfio_groups[VFIO_MAX_GROUPS];
	struct user_mem_maps mem_maps;
};

/* per-process VFIO config */
static struct vfio_config vfio_cfgs[VFIO_MAX_CONTAINERS];
static struct vfio_config *default_vfio_cfg = &vfio_cfgs[0];

static int vfio_type1_dma_map(int);
static int vfio_type1_dma_mem_map(int, uint64_t, uint64_t, uint64_t, int);
static int vfio_spapr_dma_map(int);
static int vfio_spapr_dma_mem_map(int, uint64_t, uint64_t, uint64_t, int);
static int vfio_noiommu_dma_map(int);
static int vfio_noiommu_dma_mem_map(int, uint64_t, uint64_t, uint64_t, int);
static int vfio_dma_mem_map(struct vfio_config *vfio_cfg, uint64_t vaddr,
		uint64_t iova, uint64_t len, int do_map);

/* IOMMU types we support */
static const struct vfio_iommu_type iommu_types[] = {
	/* x86 IOMMU, otherwise known as type 1 */
	{
		.type_id = RTE_VFIO_TYPE1,
		.name = "Type 1",
		.partial_unmap = false,
		.dma_map_func = &vfio_type1_dma_map,
		.dma_user_map_func = &vfio_type1_dma_mem_map
	},
	/* ppc64 IOMMU, otherwise known as spapr */
	{
		.type_id = RTE_VFIO_SPAPR,
		.name = "sPAPR",
		.partial_unmap = true,
		.dma_map_func = &vfio_spapr_dma_map,
		.dma_user_map_func = &vfio_spapr_dma_mem_map
	},
	/* IOMMU-less mode */
	{
		.type_id = RTE_VFIO_NOIOMMU,
		.name = "No-IOMMU",
		.partial_unmap = true,
		.dma_map_func = &vfio_noiommu_dma_map,
		.dma_user_map_func = &vfio_noiommu_dma_mem_map
	},
};

static int
is_null_map(const struct user_mem_map *map)
{
	return map->addr == 0 && map->iova == 0 &&
			map->len == 0 && map->chunk == 0;
}

/* we may need to merge user mem maps together in case of user mapping/unmapping
 * chunks of memory, so we'll need a comparator function to sort segments.
 */
static int
user_mem_map_cmp(const void *a, const void *b)
{
	const struct user_mem_map *umm_a = a;
	const struct user_mem_map *umm_b = b;

	/* move null entries to end */
	if (is_null_map(umm_a))
		return 1;
	if (is_null_map(umm_b))
		return -1;

	/* sort by iova first */
	if (umm_a->iova < umm_b->iova)
		return -1;
	if (umm_a->iova > umm_b->iova)
		return 1;

	if (umm_a->addr < umm_b->addr)
		return -1;
	if (umm_a->addr > umm_b->addr)
		return 1;

	if (umm_a->len < umm_b->len)
		return -1;
	if (umm_a->len > umm_b->len)
		return 1;

	if (umm_a->chunk < umm_b->chunk)
		return -1;
	if (umm_a->chunk > umm_b->chunk)
		return 1;

	return 0;
}

/*
 * Take in an address range and list of current mappings, and produce a list of
 * mappings that will be kept.
 */
static int
process_maps(struct user_mem_map *src, size_t src_len,
		struct user_mem_map newmap[2], uint64_t vaddr, uint64_t len)
{
	struct user_mem_map *src_first = &src[0];
	struct user_mem_map *src_last = &src[src_len - 1];
	struct user_mem_map *dst_first = &newmap[0];
	/* we can get at most two new segments */
	struct user_mem_map *dst_last = &newmap[1];
	uint64_t first_off = vaddr - src_first->addr;
	uint64_t last_off = (src_last->addr + src_last->len) - (vaddr + len);
	int newmap_len = 0;

	if (first_off != 0) {
		dst_first->addr = src_first->addr;
		dst_first->iova = src_first->iova;
		dst_first->len = first_off;
		dst_first->chunk = src_first->chunk;

		newmap_len++;
	}
	if (last_off != 0) {
		/* if we had start offset, we have two segments */
		struct user_mem_map *last =
				first_off == 0 ? dst_first : dst_last;
		last->addr = (src_last->addr + src_last->len) - last_off;
		last->iova = (src_last->iova + src_last->len) - last_off;
		last->len = last_off;
		last->chunk = src_last->chunk;

		newmap_len++;
	}
	return newmap_len;
}

/* erase certain maps from the list */
static void
delete_maps(struct user_mem_maps *user_mem_maps, struct user_mem_map *del_maps,
		size_t n_del)
{
	int i;
	size_t j;

	for (i = 0, j = 0; i < VFIO_MAX_USER_MEM_MAPS && j < n_del; i++) {
		struct user_mem_map *left = &user_mem_maps->maps[i];
		struct user_mem_map *right = &del_maps[j];

		if (user_mem_map_cmp(left, right) == 0) {
			memset(left, 0, sizeof(*left));
			j++;
			user_mem_maps->n_maps--;
		}
	}
}

static void
copy_maps(struct user_mem_maps *user_mem_maps, struct user_mem_map *add_maps,
		size_t n_add)
{
	int i;
	size_t j;

	for (i = 0, j = 0; i < VFIO_MAX_USER_MEM_MAPS && j < n_add; i++) {
		struct user_mem_map *left = &user_mem_maps->maps[i];
		struct user_mem_map *right = &add_maps[j];

		/* insert into empty space */
		if (is_null_map(left)) {
			memcpy(left, right, sizeof(*left));
			j++;
			user_mem_maps->n_maps++;
		}
	}
}

/* try merging two maps into one, return 1 if succeeded */
static int
merge_map(struct user_mem_map *left, struct user_mem_map *right)
{
	/* merge the same maps into one */
	if (memcmp(left, right, sizeof(struct user_mem_map)) == 0)
		goto out;

	if (left->addr + left->len != right->addr)
		return 0;
	if (left->iova + left->len != right->iova)
		return 0;
	if (left->chunk != right->chunk)
		return 0;
	left->len += right->len;

out:
	memset(right, 0, sizeof(*right));

	return 1;
}

static bool
addr_is_chunk_aligned(struct user_mem_map *maps, size_t n_maps,
		uint64_t vaddr, uint64_t iova)
{
	unsigned int i;

	for (i = 0; i < n_maps; i++) {
		struct user_mem_map *map = &maps[i];
		uint64_t map_va_end = map->addr + map->len;
		uint64_t map_iova_end = map->iova + map->len;
		uint64_t map_va_off = vaddr - map->addr;
		uint64_t map_iova_off = iova - map->iova;

		/* we include end of the segment in comparison as well */
		bool addr_in_map = (vaddr >= map->addr) && (vaddr <= map_va_end);
		bool iova_in_map = (iova >= map->iova) && (iova <= map_iova_end);
		/* chunk may not be power of two, so use modulo */
		bool addr_is_aligned = (map_va_off % map->chunk) == 0;
		bool iova_is_aligned = (map_iova_off % map->chunk) == 0;

		if (addr_in_map && iova_in_map &&
				addr_is_aligned && iova_is_aligned)
			return true;
	}
	return false;
}

static int
find_user_mem_maps(struct user_mem_maps *user_mem_maps, uint64_t addr,
		uint64_t iova, uint64_t len, struct user_mem_map *dst,
		size_t dst_len)
{
	uint64_t va_end = addr + len;
	uint64_t iova_end = iova + len;
	bool found = false;
	size_t j;
	int i, ret;

	for (i = 0, j = 0; i < user_mem_maps->n_maps; i++) {
		struct user_mem_map *map = &user_mem_maps->maps[i];
		uint64_t map_va_end = map->addr + map->len;
		uint64_t map_iova_end = map->iova + map->len;

		bool start_addr_in_map = (addr >= map->addr) &&
				(addr < map_va_end);
		bool end_addr_in_map = (va_end > map->addr) &&
				(va_end <= map_va_end);
		bool start_iova_in_map = (iova >= map->iova) &&
				(iova < map_iova_end);
		bool end_iova_in_map = (iova_end > map->iova) &&
				(iova_end <= map_iova_end);

		/* do we have space in temporary map? */
		if (j == dst_len) {
			ret = -ENOSPC;
			goto err;
		}
		/* check if current map is start of our segment */
		if (!found && start_addr_in_map && start_iova_in_map)
			found = true;
		/* if we have previously found a segment, add it to the map */
		if (found) {
			/* copy the segment into our temporary map */
			memcpy(&dst[j++], map, sizeof(*map));

			/* if we match end of segment, quit */
			if (end_addr_in_map && end_iova_in_map)
				return j;
		}
	}
	/* we didn't find anything */
	ret = -ENOENT;
err:
	memset(dst, 0, sizeof(*dst) * dst_len);
	return ret;
}

/* this will sort all user maps, and merge/compact any adjacent maps */
static void
compact_user_maps(struct user_mem_maps *user_mem_maps)
{
	int i;

	qsort(user_mem_maps->maps, VFIO_MAX_USER_MEM_MAPS,
			sizeof(user_mem_maps->maps[0]), user_mem_map_cmp);

	/* we'll go over the list backwards when merging */
	for (i = VFIO_MAX_USER_MEM_MAPS - 2; i >= 0; i--) {
		struct user_mem_map *l, *r;

		l = &user_mem_maps->maps[i];
		r = &user_mem_maps->maps[i + 1];

		if (is_null_map(l) || is_null_map(r))
			continue;

		/* try and merge the maps */
		if (merge_map(l, r))
			user_mem_maps->n_maps--;
	}

	/* the entries are still sorted, but now they have holes in them, so
	 * sort the list again.
	 */
	qsort(user_mem_maps->maps, VFIO_MAX_USER_MEM_MAPS,
			sizeof(user_mem_maps->maps[0]), user_mem_map_cmp);
}

static int
vfio_open_group_fd(int iommu_group_num)
{
	int vfio_group_fd;
	char filename[PATH_MAX];
	struct rte_mp_msg mp_req, *mp_rep;
	struct rte_mp_reply mp_reply = {0};
	struct timespec ts = {.tv_sec = 5, .tv_nsec = 0};
	struct vfio_mp_param *p = (struct vfio_mp_param *)mp_req.param;
	const struct internal_config *internal_conf =
		eal_get_internal_configuration();

	/* if primary, try to open the group */
	if (internal_conf->process_type == RTE_PROC_PRIMARY) {
		/* try regular group format */
		snprintf(filename, sizeof(filename),
				 VFIO_GROUP_FMT, iommu_group_num);
		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_num);
			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 -ENOENT;
			}
			/* noiommu group found */
		}

		return vfio_group_fd;
	}
	/* if we're in a secondary process, request group fd from the primary
	 * process via mp channel.
	 */
	p->req = SOCKET_REQ_GROUP;
	p->group_num = iommu_group_num;
	strcpy(mp_req.name, EAL_VFIO_MP);
	mp_req.len_param = sizeof(*p);
	mp_req.num_fds = 0;

	vfio_group_fd = -1;
	if (rte_mp_request_sync(&mp_req, &mp_reply, &ts) == 0 &&
	    mp_reply.nb_received == 1) {
		mp_rep = &mp_reply.msgs[0];
		p = (struct vfio_mp_param *)mp_rep->param;
		if (p->result == SOCKET_OK && mp_rep->num_fds == 1) {
			vfio_group_fd = mp_rep->fds[0];
		} else if (p->result == SOCKET_NO_FD) {
			RTE_LOG(ERR, EAL, "Bad VFIO group fd\n");
			vfio_group_fd = -ENOENT;
		}
	}

	free(mp_reply.msgs);
	if (vfio_group_fd < 0 && vfio_group_fd != -ENOENT)
		RTE_LOG(ERR, EAL, "Cannot request VFIO group fd\n");
	return vfio_group_fd;
}

static struct vfio_config *
get_vfio_cfg_by_group_num(int iommu_group_num)
{
	struct vfio_config *vfio_cfg;
	int i, j;

	for (i = 0; i < VFIO_MAX_CONTAINERS; i++) {
		vfio_cfg = &vfio_cfgs[i];
		for (j = 0; j < VFIO_MAX_GROUPS; j++) {
			if (vfio_cfg->vfio_groups[j].group_num ==
					iommu_group_num)
				return vfio_cfg;
		}
	}

	return NULL;
}

static int
vfio_get_group_fd(struct vfio_config *vfio_cfg,
		int iommu_group_num)
{
	int i;
	int vfio_group_fd;
	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_num == iommu_group_num)
			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_num == -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;
	}

	vfio_group_fd = vfio_open_group_fd(iommu_group_num);
	if (vfio_group_fd < 0) {
		RTE_LOG(ERR, EAL, "Failed to open VFIO group %d\n",
			iommu_group_num);
		return vfio_group_fd;
	}

	cur_grp->group_num = iommu_group_num;
	cur_grp->fd = vfio_group_fd;
	vfio_cfg->vfio_active_groups++;

	return vfio_group_fd;
}

static struct vfio_config *
get_vfio_cfg_by_group_fd(int vfio_group_fd)
{
	struct vfio_config *vfio_cfg;
	int i, j;

	for (i = 0; i < VFIO_MAX_CONTAINERS; i++) {
		vfio_cfg = &vfio_cfgs[i];
		for (j = 0; j < VFIO_MAX_GROUPS; j++)
			if (vfio_cfg->vfio_groups[j].fd == vfio_group_fd)
				return vfio_cfg;
	}

	return NULL;
}

static struct vfio_config *
get_vfio_cfg_by_container_fd(int container_fd)
{
	int i;

	if (container_fd == RTE_VFIO_DEFAULT_CONTAINER_FD)
		return default_vfio_cfg;

	for (i = 0; i < VFIO_MAX_CONTAINERS; i++) {
		if (vfio_cfgs[i].vfio_container_fd == container_fd)
			return &vfio_cfgs[i];
	}

	return NULL;
}

int
rte_vfio_get_group_fd(int iommu_group_num)
{
	struct vfio_config *vfio_cfg;

	/* get the vfio_config it belongs to */
	vfio_cfg = get_vfio_cfg_by_group_num(iommu_group_num);
	vfio_cfg = vfio_cfg ? vfio_cfg : default_vfio_cfg;

	return vfio_get_group_fd(vfio_cfg, iommu_group_num);
}

static int
get_vfio_group_idx(int vfio_group_fd)
{
	struct vfio_config *vfio_cfg;
	int i, j;

	for (i = 0; i < VFIO_MAX_CONTAINERS; i++) {
		vfio_cfg = &vfio_cfgs[i];
		for (j = 0; j < VFIO_MAX_GROUPS; j++)
			if (vfio_cfg->vfio_groups[j].fd == vfio_group_fd)
				return j;
	}

	return -1;
}

static void
vfio_group_device_get(int vfio_group_fd)
{
	struct vfio_config *vfio_cfg;
	int i;

	vfio_cfg = get_vfio_cfg_by_group_fd(vfio_group_fd);
	if (vfio_cfg == NULL) {
		RTE_LOG(ERR, EAL, "Invalid VFIO group fd!\n");
		return;
	}

	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)
{
	struct vfio_config *vfio_cfg;
	int i;

	vfio_cfg = get_vfio_cfg_by_group_fd(vfio_group_fd);
	if (vfio_cfg == NULL) {
		RTE_LOG(ERR, EAL, "Invalid VFIO group fd!\n");
		return;
	}

	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)
{
	struct vfio_config *vfio_cfg;
	int i;

	vfio_cfg = get_vfio_cfg_by_group_fd(vfio_group_fd);
	if (vfio_cfg == NULL) {
		RTE_LOG(ERR, EAL, "Invalid VFIO group fd!\n");
		return -1;
	}

	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;
}

static void
vfio_mem_event_callback(enum rte_mem_event type, const void *addr, size_t len,
		void *arg __rte_unused)
{
	struct rte_memseg_list *msl;
	struct rte_memseg *ms;
	size_t cur_len = 0;

	msl = rte_mem_virt2memseg_list(addr);

	/* for IOVA as VA mode, no need to care for IOVA addresses */
	if (rte_eal_iova_mode() == RTE_IOVA_VA && msl->external == 0) {
		uint64_t vfio_va = (uint64_t)(uintptr_t)addr;
		uint64_t page_sz = msl->page_sz;

		/* Maintain granularity of DMA map/unmap to memseg size */
		for (; cur_len < len; cur_len += page_sz) {
			if (type == RTE_MEM_EVENT_ALLOC)
				vfio_dma_mem_map(default_vfio_cfg, vfio_va,
						 vfio_va, page_sz, 1);
			else
				vfio_dma_mem_map(default_vfio_cfg, vfio_va,
						 vfio_va, page_sz, 0);
			vfio_va += page_sz;
		}

		return;
	}

	/* memsegs are contiguous in memory */
	ms = rte_mem_virt2memseg(addr, msl);
	while (cur_len < len) {
		/* some memory segments may have invalid IOVA */
		if (ms->iova == RTE_BAD_IOVA) {
			RTE_LOG(DEBUG, EAL,
				"Memory segment at %p has bad IOVA, skipping\n",
				ms->addr);
			goto next;
		}
		if (type == RTE_MEM_EVENT_ALLOC)
			vfio_dma_mem_map(default_vfio_cfg, ms->addr_64,
					ms->iova, ms->len, 1);
		else
			vfio_dma_mem_map(default_vfio_cfg, ms->addr_64,
					ms->iova, ms->len, 0);
next:
		cur_len += ms->len;
		++ms;
	}
}

static int
vfio_sync_default_container(void)
{
	struct rte_mp_msg mp_req, *mp_rep;
	struct rte_mp_reply mp_reply = {0};
	struct timespec ts = {.tv_sec = 5, .tv_nsec = 0};
	struct vfio_mp_param *p = (struct vfio_mp_param *)mp_req.param;
	int iommu_type_id;
	unsigned int i;

	/* cannot be called from primary */
	if (rte_eal_process_type() != RTE_PROC_SECONDARY)
		return -1;

	/* default container fd should have been opened in rte_vfio_enable() */
	if (!default_vfio_cfg->vfio_enabled ||
			default_vfio_cfg->vfio_container_fd < 0) {
		RTE_LOG(ERR, EAL, "VFIO support is not initialized\n");
		return -1;
	}

	/* find default container's IOMMU type */
	p->req = SOCKET_REQ_IOMMU_TYPE;
	strcpy(mp_req.name, EAL_VFIO_MP);
	mp_req.len_param = sizeof(*p);
	mp_req.num_fds = 0;

	iommu_type_id = -1;
	if (rte_mp_request_sync(&mp_req, &mp_reply, &ts) == 0 &&
			mp_reply.nb_received == 1) {
		mp_rep = &mp_reply.msgs[0];
		p = (struct vfio_mp_param *)mp_rep->param;
		if (p->result == SOCKET_OK)
			iommu_type_id = p->iommu_type_id;
	}
	free(mp_reply.msgs);
	if (iommu_type_id < 0) {
		RTE_LOG(ERR, EAL,
			"Could not get IOMMU type for default container\n");
		return -1;
	}

	/* we now have an fd for default container, as well as its IOMMU type.
	 * now, set up default VFIO container config to match.
	 */
	for (i = 0; i < RTE_DIM(iommu_types); i++) {
		const struct vfio_iommu_type *t = &iommu_types[i];
		if (t->type_id != iommu_type_id)
			continue;

		/* we found our IOMMU type */
		default_vfio_cfg->vfio_iommu_type = t;

		return 0;
	}
	RTE_LOG(ERR, EAL, "Could not find IOMMU type id (%i)\n",
			iommu_type_id);
	return -1;
}

int
rte_vfio_clear_group(int vfio_group_fd)
{
	int i;
	struct vfio_config *vfio_cfg;

	vfio_cfg = get_vfio_cfg_by_group_fd(vfio_group_fd);
	if (vfio_cfg == NULL) {
		RTE_LOG(ERR, EAL, "Invalid VFIO group fd!\n");
		return -1;
	}

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

	return 0;
}

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)
	};
	struct vfio_config *vfio_cfg;
	struct user_mem_maps *user_mem_maps;
	int vfio_container_fd;
	int vfio_group_fd;
	int iommu_group_num;
	rte_uuid_t vf_token;
	int i, ret;
	const struct internal_config *internal_conf =
		eal_get_internal_configuration();

	/* get group number */
	ret = rte_vfio_get_group_num(sysfs_base, dev_addr, &iommu_group_num);
	if (ret == 0) {
		RTE_LOG(NOTICE, 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 = rte_vfio_get_group_fd(iommu_group_num);
	if (vfio_group_fd < 0 && vfio_group_fd != -ENOENT)
		return -1;

	/*
	 * if vfio_group_fd == -ENOENT, that means the device
	 * isn't managed by VFIO
	 */
	if (vfio_group_fd == -ENOENT) {
		RTE_LOG(NOTICE, 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 VFIO group status, "
			"error %i (%s)\n", dev_addr, errno, strerror(errno));
		close(vfio_group_fd);
		rte_vfio_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! "
			"Not all devices in IOMMU group bound to VFIO or unbound\n",
			dev_addr);
		close(vfio_group_fd);
		rte_vfio_clear_group(vfio_group_fd);
		return -1;
	}

	/* get the vfio_config it belongs to */
	vfio_cfg = get_vfio_cfg_by_group_num(iommu_group_num);
	vfio_cfg = vfio_cfg ? vfio_cfg : default_vfio_cfg;
	vfio_container_fd = vfio_cfg->vfio_container_fd;
	user_mem_maps = &vfio_cfg->mem_maps;

	/* 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_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);
			rte_vfio_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_conf->process_type == RTE_PROC_PRIMARY &&
				vfio_cfg->vfio_active_groups == 1 &&
				vfio_group_device_count(vfio_group_fd) == 0) {
			const struct vfio_iommu_type *t;

			/* select an IOMMU type which we will be using */
			t = vfio_set_iommu_type(vfio_container_fd);
			if (!t) {
				RTE_LOG(ERR, EAL,
					"%s failed to select IOMMU type\n",
					dev_addr);
				close(vfio_group_fd);
				rte_vfio_clear_group(vfio_group_fd);
				return -1;
			}
			/* lock memory hotplug before mapping and release it
			 * after registering callback, to prevent races
			 */
			rte_mcfg_mem_read_lock();
			if (vfio_cfg == default_vfio_cfg)
				ret = t->dma_map_func(vfio_container_fd);
			else
				ret = 0;
			if (ret) {
				RTE_LOG(ERR, EAL,
					"%s DMA remapping failed, error "
					"%i (%s)\n",
					dev_addr, errno, strerror(errno));
				close(vfio_group_fd);
				rte_vfio_clear_group(vfio_group_fd);
				rte_mcfg_mem_read_unlock();
				return -1;
			}

			vfio_cfg->vfio_iommu_type = t;

			/* re-map all user-mapped segments */
			rte_spinlock_recursive_lock(&user_mem_maps->lock);

			/* this IOMMU type may not support DMA mapping, but
			 * if we have mappings in the list - that means we have
			 * previously mapped something successfully, so we can
			 * be sure that DMA mapping is supported.
			 */
			for (i = 0; i < user_mem_maps->n_maps; i++) {
				struct user_mem_map *map;
				map = &user_mem_maps->maps[i];

				ret = t->dma_user_map_func(
						vfio_container_fd,
						map->addr, map->iova, map->len,
						1);
				if (ret) {
					RTE_LOG(ERR, EAL, "Couldn't map user memory for DMA: "
							"va: 0x%" PRIx64 " "
							"iova: 0x%" PRIx64 " "
							"len: 0x%" PRIu64 "\n",
							map->addr, map->iova,
							map->len);
					rte_spinlock_recursive_unlock(
							&user_mem_maps->lock);
					rte_mcfg_mem_read_unlock();
					return -1;
				}
			}
			rte_spinlock_recursive_unlock(&user_mem_maps->lock);

			/* register callback for mem events */
			if (vfio_cfg == default_vfio_cfg)
				ret = rte_mem_event_callback_register(
					VFIO_MEM_EVENT_CLB_NAME,
					vfio_mem_event_callback, NULL);
			else
				ret = 0;
			/* unlock memory hotplug */
			rte_mcfg_mem_read_unlock();

			if (ret && rte_errno != ENOTSUP) {
				RTE_LOG(ERR, EAL, "Could not install memory event callback for VFIO\n");
				return -1;
			}
			if (ret)
				RTE_LOG(DEBUG, EAL, "Memory event callbacks not supported\n");
			else
				RTE_LOG(DEBUG, EAL, "Installed memory event callback for VFIO\n");
		}
	} else if (rte_eal_process_type() != RTE_PROC_PRIMARY &&
			vfio_cfg == default_vfio_cfg &&
			vfio_cfg->vfio_iommu_type == NULL) {
		/* if we're not a primary process, we do not set up the VFIO
		 * container because it's already been set up by the primary
		 * process. instead, we simply ask the primary about VFIO type
		 * we are using, and set the VFIO config up appropriately.
		 */
		ret = vfio_sync_default_container();
		if (ret < 0) {
			RTE_LOG(ERR, EAL, "Could not sync default VFIO container\n");
			close(vfio_group_fd);
			rte_vfio_clear_group(vfio_group_fd);
			return -1;
		}
		/* we have successfully initialized VFIO, notify user */
		const struct vfio_iommu_type *t =
				default_vfio_cfg->vfio_iommu_type;
		RTE_LOG(INFO, EAL, "Using IOMMU type %d (%s)\n",
				t->type_id, t->name);
	}

	rte_eal_vfio_get_vf_token(vf_token);

	/* get a file descriptor for the device with VF token firstly */
	if (!rte_uuid_is_null(vf_token)) {
		char vf_token_str[RTE_UUID_STRLEN];
		char dev[PATH_MAX];

		rte_uuid_unparse(vf_token, vf_token_str, sizeof(vf_token_str));
		snprintf(dev, sizeof(dev),
			 "%s vf_token=%s", dev_addr, vf_token_str);

		*vfio_dev_fd = ioctl(vfio_group_fd, VFIO_GROUP_GET_DEVICE_FD,
				     dev);
		if (*vfio_dev_fd >= 0)
			goto dev_get_info;
	}

	/* 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);
		rte_vfio_clear_group(vfio_group_fd);
		return -1;
	}

	/* test and setup the device */
dev_get_info:
	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);
		rte_vfio_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_config *vfio_cfg;
	int vfio_group_fd;
	int iommu_group_num;
	int ret;

	/* we don't want any DMA mapping messages to come while we're detaching
	 * VFIO device, because this might be the last device and we might need
	 * to unregister the callback.
	 */
	rte_mcfg_mem_read_lock();

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

	/* get the actual group fd */
	vfio_group_fd = rte_vfio_get_group_fd(iommu_group_num);
	if (vfio_group_fd < 0) {
		RTE_LOG(INFO, EAL, "rte_vfio_get_group_fd failed for %s\n",
				   dev_addr);
		ret = vfio_group_fd;
		goto out;
	}

	/* get the vfio_config it belongs to */
	vfio_cfg = get_vfio_cfg_by_group_num(iommu_group_num);
	vfio_cfg = vfio_cfg ? vfio_cfg : default_vfio_cfg;

	/* 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);
		ret = -1;
		goto out;
	}

	/* 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);
			ret = -1;
			goto out;
		}

		if (rte_vfio_clear_group(vfio_group_fd) < 0) {
			RTE_LOG(INFO, EAL, "Error when clearing group for %s\n",
					   dev_addr);
			ret = -1;
			goto out;
		}
	}

	/* if there are no active device groups, unregister the callback to
	 * avoid spurious attempts to map/unmap memory from VFIO.
	 */
	if (vfio_cfg == default_vfio_cfg && vfio_cfg->vfio_active_groups == 0 &&
			rte_eal_process_type() != RTE_PROC_SECONDARY)
		rte_mem_event_callback_unregister(VFIO_MEM_EVENT_CLB_NAME,
				NULL);

	/* success */
	ret = 0;

out:
	rte_mcfg_mem_read_unlock();
	return ret;
}

int
rte_vfio_enable(const char *modname)
{
	/* initialize group list */
	int i, j;
	int vfio_available;
	const struct internal_config *internal_conf =
		eal_get_internal_configuration();

	rte_spinlock_recursive_t lock = RTE_SPINLOCK_RECURSIVE_INITIALIZER;

	for (i = 0; i < VFIO_MAX_CONTAINERS; i++) {
		vfio_cfgs[i].vfio_container_fd = -1;
		vfio_cfgs[i].vfio_active_groups = 0;
		vfio_cfgs[i].vfio_iommu_type = NULL;
		vfio_cfgs[i].mem_maps.lock = lock;

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

	RTE_LOG(DEBUG, 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;
	}

	if (internal_conf->process_type == RTE_PROC_PRIMARY) {
		/* open a new container */
		default_vfio_cfg->vfio_container_fd =
				rte_vfio_get_container_fd();
	} else {
		/* get the default container from the primary process */
		default_vfio_cfg->vfio_container_fd =
				vfio_get_default_container_fd();
	}

	/* check if we have VFIO driver enabled */
	if (default_vfio_cfg->vfio_container_fd != -1) {
		RTE_LOG(INFO, EAL, "VFIO support initialized\n");
		default_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 default_vfio_cfg->vfio_enabled && mod_available;
}

int
vfio_get_default_container_fd(void)
{
	struct rte_mp_msg mp_req, *mp_rep;
	struct rte_mp_reply mp_reply = {0};
	struct timespec ts = {.tv_sec = 5, .tv_nsec = 0};
	struct vfio_mp_param *p = (struct vfio_mp_param *)mp_req.param;
	int container_fd;
	const struct internal_config *internal_conf =
		eal_get_internal_configuration();

	if (default_vfio_cfg->vfio_enabled)
		return default_vfio_cfg->vfio_container_fd;

	if (internal_conf->process_type == RTE_PROC_PRIMARY) {
		/* if we were secondary process we would try requesting
		 * container fd from the primary, but we're the primary
		 * process so just exit here
		 */
		return -1;
	}

	p->req = SOCKET_REQ_DEFAULT_CONTAINER;
	strcpy(mp_req.name, EAL_VFIO_MP);
	mp_req.len_param = sizeof(*p);
	mp_req.num_fds = 0;

	if (rte_mp_request_sync(&mp_req, &mp_reply, &ts) == 0 &&
	    mp_reply.nb_received == 1) {
		mp_rep = &mp_reply.msgs[0];
		p = (struct vfio_mp_param *)mp_rep->param;
		if (p->result == SOCKET_OK && mp_rep->num_fds == 1) {
			container_fd = mp_rep->fds[0];
			free(mp_reply.msgs);
			return container_fd;
		}
	}

	free(mp_reply.msgs);
	RTE_LOG(ERR, EAL, "Cannot request default VFIO container fd\n");
	return -1;
}

int
vfio_get_iommu_type(void)
{
	if (default_vfio_cfg->vfio_iommu_type == NULL)
		return -1;

	return default_vfio_cfg->vfio_iommu_type->type_id;
}

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(INFO, 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
rte_vfio_get_container_fd(void)
{
	int ret, vfio_container_fd;
	struct rte_mp_msg mp_req, *mp_rep;
	struct rte_mp_reply mp_reply = {0};
	struct timespec ts = {.tv_sec = 5, .tv_nsec = 0};
	struct vfio_mp_param *p = (struct vfio_mp_param *)mp_req.param;
	const struct internal_config *internal_conf =
		eal_get_internal_configuration();


	/* if we're in a primary process, try to open the container */
	if (internal_conf->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 %s, error "
					"%i (%s)\n", VFIO_CONTAINER_PATH,
					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;
	}
	/*
	 * if we're in a secondary process, request container fd from the
	 * primary process via mp channel
	 */
	p->req = SOCKET_REQ_CONTAINER;
	strcpy(mp_req.name, EAL_VFIO_MP);
	mp_req.len_param = sizeof(*p);
	mp_req.num_fds = 0;

	vfio_container_fd = -1;
	if (rte_mp_request_sync(&mp_req, &mp_reply, &ts) == 0 &&
	    mp_reply.nb_received == 1) {
		mp_rep = &mp_reply.msgs[0];
		p = (struct vfio_mp_param *)mp_rep->param;
		if (p->result == SOCKET_OK && mp_rep->num_fds == 1) {
			vfio_container_fd = mp_rep->fds[0];
			free(mp_reply.msgs);
			return vfio_container_fd;
		}
	}

	free(mp_reply.msgs);
	RTE_LOG(ERR, EAL, "Cannot request VFIO container fd\n");
	return -1;
}

int
rte_vfio_get_group_num(const char *sysfs_base,
		const char *dev_addr, int *iommu_group_num)
{
	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_num = 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
type1_map_contig(const struct rte_memseg_list *msl, const struct rte_memseg *ms,
		size_t len, void *arg)
{
	int *vfio_container_fd = arg;

	if (msl->external)
		return 0;

	return vfio_type1_dma_mem_map(*vfio_container_fd, ms->addr_64, ms->iova,
			len, 1);
}

static int
type1_map(const struct rte_memseg_list *msl, const struct rte_memseg *ms,
		void *arg)
{
	int *vfio_container_fd = arg;

	/* skip external memory that isn't a heap */
	if (msl->external && !msl->heap)
		return 0;

	/* skip any segments with invalid IOVA addresses */
	if (ms->iova == RTE_BAD_IOVA)
		return 0;

	/* if IOVA mode is VA, we've already mapped the internal segments */
	if (!msl->external && rte_eal_iova_mode() == RTE_IOVA_VA)
		return 0;

	return vfio_type1_dma_mem_map(*vfio_container_fd, ms->addr_64, ms->iova,
			ms->len, 1);
}

static int
vfio_type1_dma_mem_map(int vfio_container_fd, uint64_t vaddr, uint64_t iova,
		uint64_t len, int do_map)
{
	struct vfio_iommu_type1_dma_map dma_map;
	struct vfio_iommu_type1_dma_unmap dma_unmap;
	int ret;

	if (do_map != 0) {
		memset(&dma_map, 0, sizeof(dma_map));
		dma_map.argsz = sizeof(struct vfio_iommu_type1_dma_map);
		dma_map.vaddr = vaddr;
		dma_map.size = len;
		dma_map.iova = 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) {
			/**
			 * In case the mapping was already done EEXIST will be
			 * returned from kernel.
			 */
			if (errno == EEXIST) {
				RTE_LOG(DEBUG, EAL,
					"Memory segment is already mapped, skipping");
			} else {
				RTE_LOG(ERR, EAL,
					"Cannot set up DMA remapping, error "
					"%i (%s)\n", errno, strerror(errno));
				return -1;
			}
		}
	} else {
		memset(&dma_unmap, 0, sizeof(dma_unmap));
		dma_unmap.argsz = sizeof(struct vfio_iommu_type1_dma_unmap);
		dma_unmap.size = len;
		dma_unmap.iova = iova;

		ret = ioctl(vfio_container_fd, VFIO_IOMMU_UNMAP_DMA,
				&dma_unmap);
		if (ret) {
			RTE_LOG(ERR, EAL, "Cannot clear DMA remapping, error "
					"%i (%s)\n", errno, strerror(errno));
			return -1;
		} else if (dma_unmap.size != len) {
			RTE_LOG(ERR, EAL, "Unexpected size %"PRIu64
				" of DMA remapping cleared instead of %"PRIu64"\n",
				(uint64_t)dma_unmap.size, len);
			rte_errno = EIO;
			return -1;
		}
	}

	return 0;
}

static int
vfio_type1_dma_map(int vfio_container_fd)
{
	if (rte_eal_iova_mode() == RTE_IOVA_VA) {
		/* with IOVA as VA mode, we can get away with mapping contiguous
		 * chunks rather than going page-by-page.
		 */
		int ret = rte_memseg_contig_walk(type1_map_contig,
				&vfio_container_fd);
		if (ret)
			return ret;
		/* we have to continue the walk because we've skipped the
		 * external segments during the config walk.
		 */
	}
	return rte_memseg_walk(type1_map, &vfio_container_fd);
}

/* Track the size of the statically allocated DMA window for SPAPR */
uint64_t spapr_dma_win_len;
uint64_t spapr_dma_win_page_sz;

static int
vfio_spapr_dma_do_map(int vfio_container_fd, uint64_t vaddr, uint64_t iova,
		uint64_t len, int do_map)
{
	struct vfio_iommu_spapr_register_memory reg = {
		.argsz = sizeof(reg),
		.vaddr = (uintptr_t) vaddr,
		.size = len,
		.flags = 0
	};
	int ret;

	if (do_map != 0) {
		struct vfio_iommu_type1_dma_map dma_map;

		if (iova + len > spapr_dma_win_len) {
			RTE_LOG(ERR, EAL, "DMA map attempt outside DMA window\n");
			return -1;
		}

		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 = vaddr;
		dma_map.size = len;
		dma_map.iova = 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 map vaddr for IOMMU, error "
					"%i (%s)\n", errno, strerror(errno));
			return -1;
		}

	} else {
		struct vfio_iommu_type1_dma_map dma_unmap;

		memset(&dma_unmap, 0, sizeof(dma_unmap));
		dma_unmap.argsz = sizeof(struct vfio_iommu_type1_dma_unmap);
		dma_unmap.size = len;
		dma_unmap.iova = iova;

		ret = ioctl(vfio_container_fd, VFIO_IOMMU_UNMAP_DMA,
				&dma_unmap);
		if (ret) {
			RTE_LOG(ERR, EAL, "Cannot unmap vaddr for IOMMU, error "
					"%i (%s)\n", errno, strerror(errno));
			return -1;
		}

		ret = ioctl(vfio_container_fd,
				VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY, &reg);
		if (ret) {
			RTE_LOG(ERR, EAL,
				"Cannot unregister vaddr for IOMMU, error "
				"%i (%s)\n", errno, strerror(errno));
			return -1;
		}
	}

	return ret;
}

static int
vfio_spapr_map_walk(const struct rte_memseg_list *msl,
		const struct rte_memseg *ms, void *arg)
{
	int *vfio_container_fd = arg;

	/* skip external memory that isn't a heap */
	if (msl->external && !msl->heap)
		return 0;

	/* skip any segments with invalid IOVA addresses */
	if (ms->iova == RTE_BAD_IOVA)
		return 0;

	return vfio_spapr_dma_do_map(*vfio_container_fd,
		ms->addr_64, ms->iova, ms->len, 1);
}

struct spapr_size_walk_param {
	uint64_t max_va;
	uint64_t page_sz;
	bool is_user_managed;
};

/*
 * In order to set the DMA window size required for the SPAPR IOMMU
 * we need to walk the existing virtual memory allocations as well as
 * find the hugepage size used.
 */
static int
vfio_spapr_size_walk(const struct rte_memseg_list *msl, void *arg)
{
	struct spapr_size_walk_param *param = arg;
	uint64_t max = (uint64_t) msl->base_va + (uint64_t) msl->len;

	if (msl->external && !msl->heap) {
		/* ignore user managed external memory */
		param->is_user_managed = true;
		return 0;
	}

	if (max > param->max_va) {
		param->page_sz = msl->page_sz;
		param->max_va = max;
	}

	return 0;
}

/*
 * Find the highest memory address used in physical or virtual address
 * space and use that as the top of the DMA window.
 */
static int
find_highest_mem_addr(struct spapr_size_walk_param *param)
{
	/* find the maximum IOVA address for setting the DMA window size */
	if (rte_eal_iova_mode() == RTE_IOVA_PA) {
		static const char proc_iomem[] = "/proc/iomem";
		static const char str_sysram[] = "System RAM";
		uint64_t start, end, max = 0;
		char *line = NULL;
		char *dash, *space;
		size_t line_len;

		/*
		 * Example "System RAM" in /proc/iomem:
		 * 00000000-1fffffffff : System RAM
		 * 200000000000-201fffffffff : System RAM
		 */
		FILE *fd = fopen(proc_iomem, "r");
		if (fd == NULL) {
			RTE_LOG(ERR, EAL, "Cannot open %s\n", proc_iomem);
			return -1;
		}
		/* Scan /proc/iomem for the highest PA in the system */
		while (getline(&line, &line_len, fd) != -1) {
			if (strstr(line, str_sysram) == NULL)
				continue;

			space = strstr(line, " ");
			dash = strstr(line, "-");

			/* Validate the format of the memory string */
			if (space == NULL || dash == NULL || space < dash) {
				RTE_LOG(ERR, EAL, "Can't parse line \"%s\" in file %s\n",
					line, proc_iomem);
				continue;
			}

			start = strtoull(line, NULL, 16);
			end   = strtoull(dash + 1, NULL, 16);
			RTE_LOG(DEBUG, EAL, "Found system RAM from 0x%" PRIx64
				" to 0x%" PRIx64 "\n", start, end);
			if (end > max)
				max = end;
		}
		free(line);
		fclose(fd);

		if (max == 0) {
			RTE_LOG(ERR, EAL, "Failed to find valid \"System RAM\" "
				"entry in file %s\n", proc_iomem);
			return -1;
		}

		spapr_dma_win_len = rte_align64pow2(max + 1);
		return 0;
	} else if (rte_eal_iova_mode() == RTE_IOVA_VA) {
		RTE_LOG(DEBUG, EAL, "Highest VA address in memseg list is 0x%"
			PRIx64 "\n", param->max_va);
		spapr_dma_win_len = rte_align64pow2(param->max_va);
		return 0;
	}

	spapr_dma_win_len = 0;
	RTE_LOG(ERR, EAL, "Unsupported IOVA mode\n");
	return -1;
}


/*
 * The SPAPRv2 IOMMU supports 2 DMA windows with starting
 * address at 0 or 1<<59.  By default, a DMA window is set
 * at address 0, 2GB long, with a 4KB page.  For DPDK we
 * must remove the default window and setup a new DMA window
 * based on the hugepage size and memory requirements of
 * the application before we can map memory for DMA.
 */
static int
spapr_dma_win_size(void)
{
	struct spapr_size_walk_param param;

	/* only create DMA window once */
	if (spapr_dma_win_len > 0)
		return 0;

	/* walk the memseg list to find the page size/max VA address */
	memset(&param, 0, sizeof(param));
	if (rte_memseg_list_walk(vfio_spapr_size_walk, &param) < 0) {
		RTE_LOG(ERR, EAL, "Failed to walk memseg list for DMA window size\n");
		return -1;
	}

	/* we can't be sure if DMA window covers external memory */
	if (param.is_user_managed)
		RTE_LOG(WARNING, EAL, "Detected user managed external memory which may not be managed by the IOMMU\n");

	/* check physical/virtual memory size */
	if (find_highest_mem_addr(&param) < 0)
		return -1;
	RTE_LOG(DEBUG, EAL, "Setting DMA window size to 0x%" PRIx64 "\n",
		spapr_dma_win_len);
	spapr_dma_win_page_sz = param.page_sz;
	rte_mem_set_dma_mask(__builtin_ctzll(spapr_dma_win_len));
	return 0;
}

static int
vfio_spapr_create_dma_window(int vfio_container_fd)
{
	struct vfio_iommu_spapr_tce_create create = {
		.argsz = sizeof(create), };
	struct vfio_iommu_spapr_tce_remove remove = {
		.argsz = sizeof(remove), };
	struct vfio_iommu_spapr_tce_info info = {
		.argsz = sizeof(info), };
	int ret;

	ret = spapr_dma_win_size();
	if (ret < 0)
		return ret;

	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;
	}

	/*
	 * sPAPR v1/v2 IOMMU always has a default 1G DMA window set.  The window
	 * can't be changed for v1 but it can be changed for v2. Since DPDK only
	 * supports v2, remove the default DMA window so it can be resized.
	 */
	remove.start_addr = info.dma32_window_start;
	ret = ioctl(vfio_container_fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove);
	if (ret)
		return -1;

	/* create a new DMA window (start address is not selectable) */
	create.window_size = spapr_dma_win_len;
	create.page_shift  = __builtin_ctzll(spapr_dma_win_page_sz);
	create.levels = 1;
	ret = ioctl(vfio_container_fd, VFIO_IOMMU_SPAPR_TCE_CREATE, &create);
#ifdef VFIO_IOMMU_SPAPR_INFO_DDW
	/*
	 * The vfio_iommu_spapr_tce_info structure was modified in
	 * Linux kernel 4.2.0 to add support for the
	 * vfio_iommu_spapr_tce_ddw_info structure needed to try
	 * multiple table levels.  Skip the attempt if running with
	 * an older kernel.
	 */
	if (ret) {
		/* if at first we don't succeed, try more levels */
		uint32_t levels;

		for (levels = create.levels + 1;
			ret && levels <= info.ddw.levels; levels++) {
			create.levels = levels;
			ret = ioctl(vfio_container_fd,
				VFIO_IOMMU_SPAPR_TCE_CREATE, &create);
		}
	}
#endif /* VFIO_IOMMU_SPAPR_INFO_DDW */
	if (ret) {
		RTE_LOG(ERR, EAL, "Cannot create new DMA window, error "
				"%i (%s)\n", errno, strerror(errno));
		RTE_LOG(ERR, EAL,
			"Consider using a larger hugepage size if supported by the system\n");
		return -1;
	}

	/* verify the start address  */
	if (create.start_addr != 0) {
		RTE_LOG(ERR, EAL, "Received unsupported start address 0x%"
			PRIx64 "\n", (uint64_t)create.start_addr);
		return -1;
	}
	return ret;
}

static int
vfio_spapr_dma_mem_map(int vfio_container_fd, uint64_t vaddr,
		uint64_t iova, uint64_t len, int do_map)
{
	int ret = 0;

	if (do_map) {
		if (vfio_spapr_dma_do_map(vfio_container_fd,
			vaddr, iova, len, 1)) {
			RTE_LOG(ERR, EAL, "Failed to map DMA\n");
			ret = -1;
		}
	} else {
		if (vfio_spapr_dma_do_map(vfio_container_fd,
			vaddr, iova, len, 0)) {
			RTE_LOG(ERR, EAL, "Failed to unmap DMA\n");
			ret = -1;
		}
	}

	return ret;
}

static int
vfio_spapr_dma_map(int vfio_container_fd)
{
	if (vfio_spapr_create_dma_window(vfio_container_fd) < 0) {
		RTE_LOG(ERR, EAL, "Could not create new DMA window!\n");
		return -1;
	}

	/* map all existing DPDK segments for DMA */
	if (rte_memseg_walk(vfio_spapr_map_walk, &vfio_container_fd) < 0)
		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;
}

static int
vfio_noiommu_dma_mem_map(int __rte_unused vfio_container_fd,
			 uint64_t __rte_unused vaddr,
			 uint64_t __rte_unused iova, uint64_t __rte_unused len,
			 int __rte_unused do_map)
{
	/* No-IOMMU mode does not need DMA mapping */
	return 0;
}

static int
vfio_dma_mem_map(struct vfio_config *vfio_cfg, uint64_t vaddr, uint64_t iova,
		uint64_t len, int do_map)
{
	const struct vfio_iommu_type *t = vfio_cfg->vfio_iommu_type;

	if (!t) {
		RTE_LOG(ERR, EAL, "VFIO support not initialized\n");
		rte_errno = ENODEV;
		return -1;
	}

	if (!t->dma_user_map_func) {
		RTE_LOG(ERR, EAL,
			"VFIO custom DMA region mapping not supported by IOMMU %s\n",
			t->name);
		rte_errno = ENOTSUP;
		return -1;
	}

	return t->dma_user_map_func(vfio_cfg->vfio_container_fd, vaddr, iova,
			len, do_map);
}

static int
container_dma_map(struct vfio_config *vfio_cfg, uint64_t vaddr, uint64_t iova,
		uint64_t len)
{
	struct user_mem_map *new_map;
	struct user_mem_maps *user_mem_maps;
	bool has_partial_unmap;
	int ret = 0;

	user_mem_maps = &vfio_cfg->mem_maps;
	rte_spinlock_recursive_lock(&user_mem_maps->lock);
	if (user_mem_maps->n_maps == VFIO_MAX_USER_MEM_MAPS) {
		RTE_LOG(ERR, EAL, "No more space for user mem maps\n");
		rte_errno = ENOMEM;
		ret = -1;
		goto out;
	}
	/* map the entry */
	if (vfio_dma_mem_map(vfio_cfg, vaddr, iova, len, 1)) {
		/* technically, this will fail if there are currently no devices
		 * plugged in, even if a device were added later, this mapping
		 * might have succeeded. however, since we cannot verify if this
		 * is a valid mapping without having a device attached, consider
		 * this to be unsupported, because we can't just store any old
		 * mapping and pollute list of active mappings willy-nilly.
		 */
		RTE_LOG(ERR, EAL, "Couldn't map new region for DMA\n");
		ret = -1;
		goto out;
	}
	/* do we have partial unmap support? */
	has_partial_unmap = vfio_cfg->vfio_iommu_type->partial_unmap;

	/* create new user mem map entry */
	new_map = &user_mem_maps->maps[user_mem_maps->n_maps++];
	new_map->addr = vaddr;
	new_map->iova = iova;
	new_map->len = len;
	/* for IOMMU types supporting partial unmap, we don't need chunking */
	new_map->chunk = has_partial_unmap ? 0 : len;

	compact_user_maps(user_mem_maps);
out:
	rte_spinlock_recursive_unlock(&user_mem_maps->lock);
	return ret;
}

static int
container_dma_unmap(struct vfio_config *vfio_cfg, uint64_t vaddr, uint64_t iova,
		uint64_t len)
{
	struct user_mem_map orig_maps[VFIO_MAX_USER_MEM_MAPS];
	struct user_mem_map new_maps[2]; /* can be at most 2 */
	struct user_mem_maps *user_mem_maps;
	int n_orig, n_new, newlen, ret = 0;
	bool has_partial_unmap;

	user_mem_maps = &vfio_cfg->mem_maps;
	rte_spinlock_recursive_lock(&user_mem_maps->lock);

	/*
	 * Previously, we had adjacent mappings entirely contained within one
	 * mapping entry. Since we now store original mapping length in some
	 * cases, this is no longer the case, so unmapping can potentially go
	 * over multiple segments and split them in any number of ways.
	 *
	 * To complicate things further, some IOMMU types support arbitrary
	 * partial unmapping, while others will only support unmapping along the
	 * chunk size, so there are a lot of cases we need to handle. To make
	 * things easier code wise, instead of trying to adjust existing
	 * mappings, let's just rebuild them using information we have.
	 */

	/*
	 * first thing to do is check if there exists a mapping that includes
	 * the start and the end of our requested unmap. We need to collect all
	 * maps that include our unmapped region.
	 */
	n_orig = find_user_mem_maps(user_mem_maps, vaddr, iova, len,
			orig_maps, RTE_DIM(orig_maps));
	/* did we find anything? */
	if (n_orig < 0) {
		RTE_LOG(ERR, EAL, "Couldn't find previously mapped region\n");
		rte_errno = EINVAL;
		ret = -1;
		goto out;
	}

	/* do we have partial unmap capability? */
	has_partial_unmap = vfio_cfg->vfio_iommu_type->partial_unmap;

	/*
	 * if we don't support partial unmap, we must check if start and end of
	 * current unmap region are chunk-aligned.
	 */
	if (!has_partial_unmap) {
		bool start_aligned, end_aligned;

		start_aligned = addr_is_chunk_aligned(orig_maps, n_orig,
				vaddr, iova);
		end_aligned = addr_is_chunk_aligned(orig_maps, n_orig,
				vaddr + len, iova + len);

		if (!start_aligned || !end_aligned) {
			RTE_LOG(DEBUG, EAL, "DMA partial unmap unsupported\n");
			rte_errno = ENOTSUP;
			ret = -1;
			goto out;
		}
	}

	/*
	 * now we know we can potentially unmap the region, but we still have to
	 * figure out if there is enough space in our list to store remaining
	 * maps. for this, we will figure out how many segments we are going to
	 * remove, and how many new segments we are going to create.
	 */
	n_new = process_maps(orig_maps, n_orig, new_maps, vaddr, len);

	/* can we store the new maps in our list? */
	newlen = (user_mem_maps->n_maps - n_orig) + n_new;
	if (newlen >= VFIO_MAX_USER_MEM_MAPS) {
		RTE_LOG(ERR, EAL, "Not enough space to store partial mapping\n");
		rte_errno = ENOMEM;
		ret = -1;
		goto out;
	}

	/* unmap the entry */
	if (vfio_dma_mem_map(vfio_cfg, vaddr, iova, len, 0)) {
		/* there may not be any devices plugged in, so unmapping will
		 * fail with ENODEV/ENOTSUP rte_errno values, but that doesn't
		 * stop us from removing the mapping, as the assumption is we
		 * won't be needing this memory any more and thus will want to
		 * prevent it from being remapped again on hotplug. so, only
		 * fail if we indeed failed to unmap (e.g. if the mapping was
		 * within our mapped range but had invalid alignment).
		 */
		if (rte_errno != ENODEV && rte_errno != ENOTSUP) {
			RTE_LOG(ERR, EAL, "Couldn't unmap region for DMA\n");
			ret = -1;
			goto out;
		} else {
			RTE_LOG(DEBUG, EAL, "DMA unmapping failed, but removing mappings anyway\n");
		}
	}

	/* we have unmapped the region, so now update the maps */
	delete_maps(user_mem_maps, orig_maps, n_orig);
	copy_maps(user_mem_maps, new_maps, n_new);
	compact_user_maps(user_mem_maps);
out:
	rte_spinlock_recursive_unlock(&user_mem_maps->lock);
	return ret;
}

int
rte_vfio_noiommu_is_enabled(void)
{
	int fd;
	ssize_t cnt;
	char c;

	fd = open(VFIO_NOIOMMU_MODE, O_RDONLY);
	if (fd < 0) {
		if (errno != ENOENT) {
			RTE_LOG(ERR, EAL, "Cannot open VFIO noiommu file "
					"%i (%s)\n", errno, strerror(errno));
			return -1;
		}
		/*
		 * else the file does not exists
		 * i.e. noiommu is not enabled
		 */
		return 0;
	}

	cnt = read(fd, &c, 1);
	close(fd);
	if (cnt != 1) {
		RTE_LOG(ERR, EAL, "Unable to read from VFIO noiommu file "
				"%i (%s)\n", errno, strerror(errno));
		return -1;
	}

	return c == 'Y';
}

int
rte_vfio_container_create(void)
{
	int i;

	/* Find an empty slot to store new vfio config */
	for (i = 1; i < VFIO_MAX_CONTAINERS; i++) {
		if (vfio_cfgs[i].vfio_container_fd == -1)
			break;
	}

	if (i == VFIO_MAX_CONTAINERS) {
		RTE_LOG(ERR, EAL, "Exceed max VFIO container limit\n");
		return -1;
	}

	vfio_cfgs[i].vfio_container_fd = rte_vfio_get_container_fd();
	if (vfio_cfgs[i].vfio_container_fd < 0) {
		RTE_LOG(NOTICE, EAL, "Fail to create a new VFIO container\n");
		return -1;
	}

	return vfio_cfgs[i].vfio_container_fd;
}

int
rte_vfio_container_destroy(int container_fd)
{
	struct vfio_config *vfio_cfg;
	int i;

	vfio_cfg = get_vfio_cfg_by_container_fd(container_fd);
	if (vfio_cfg == NULL) {
		RTE_LOG(ERR, EAL, "Invalid VFIO container fd\n");
		return -1;
	}

	for (i = 0; i < VFIO_MAX_GROUPS; i++)
		if (vfio_cfg->vfio_groups[i].group_num != -1)
			rte_vfio_container_group_unbind(container_fd,
				vfio_cfg->vfio_groups[i].group_num);

	close(container_fd);
	vfio_cfg->vfio_container_fd = -1;
	vfio_cfg->vfio_active_groups = 0;
	vfio_cfg->vfio_iommu_type = NULL;

	return 0;
}

int
rte_vfio_container_group_bind(int container_fd, int iommu_group_num)
{
	struct vfio_config *vfio_cfg;

	vfio_cfg = get_vfio_cfg_by_container_fd(container_fd);
	if (vfio_cfg == NULL) {
		RTE_LOG(ERR, EAL, "Invalid VFIO container fd\n");
		return -1;
	}

	return vfio_get_group_fd(vfio_cfg, iommu_group_num);
}

int
rte_vfio_container_group_unbind(int container_fd, int iommu_group_num)
{
	struct vfio_config *vfio_cfg;
	struct vfio_group *cur_grp = NULL;
	int i;

	vfio_cfg = get_vfio_cfg_by_container_fd(container_fd);
	if (vfio_cfg == NULL) {
		RTE_LOG(ERR, EAL, "Invalid VFIO container fd\n");
		return -1;
	}

	for (i = 0; i < VFIO_MAX_GROUPS; i++) {
		if (vfio_cfg->vfio_groups[i].group_num == iommu_group_num) {
			cur_grp = &vfio_cfg->vfio_groups[i];
			break;
		}
	}

	/* This should not happen */
	if (i == VFIO_MAX_GROUPS || cur_grp == NULL) {
		RTE_LOG(ERR, EAL, "Specified VFIO group number not found\n");
		return -1;
	}

	if (cur_grp->fd >= 0 && close(cur_grp->fd) < 0) {
		RTE_LOG(ERR, EAL,
			"Error when closing vfio_group_fd for iommu_group_num "
			"%d\n", iommu_group_num);
		return -1;
	}
	cur_grp->group_num = -1;
	cur_grp->fd = -1;
	cur_grp->devices = 0;
	vfio_cfg->vfio_active_groups--;

	return 0;
}

int
rte_vfio_container_dma_map(int container_fd, uint64_t vaddr, uint64_t iova,
		uint64_t len)
{
	struct vfio_config *vfio_cfg;

	if (len == 0) {
		rte_errno = EINVAL;
		return -1;
	}

	vfio_cfg = get_vfio_cfg_by_container_fd(container_fd);
	if (vfio_cfg == NULL) {
		RTE_LOG(ERR, EAL, "Invalid VFIO container fd\n");
		return -1;
	}

	return container_dma_map(vfio_cfg, vaddr, iova, len);
}

int
rte_vfio_container_dma_unmap(int container_fd, uint64_t vaddr, uint64_t iova,
		uint64_t len)
{
	struct vfio_config *vfio_cfg;

	if (len == 0) {
		rte_errno = EINVAL;
		return -1;
	}

	vfio_cfg = get_vfio_cfg_by_container_fd(container_fd);
	if (vfio_cfg == NULL) {
		RTE_LOG(ERR, EAL, "Invalid VFIO container fd\n");
		return -1;
	}

	return container_dma_unmap(vfio_cfg, vaddr, iova, len);
}