vfio: fix boundary check in region search
[dpdk.git] / lib / librte_eal / linuxapp / eal / eal_vfio.c
index b32cd09..95cd343 100644 (file)
@@ -1,44 +1,18 @@
-/*-
- *   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.
+/* 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_vfio.h"
 
 #ifdef VFIO_PRESENT
 
+#define VFIO_MEM_EVENT_CLB_NAME "vfio_mem_event_clb"
+
 /* per-process VFIO config */
 static struct vfio_config vfio_cfg;
 
 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(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 */
-       { RTE_VFIO_TYPE1, "Type 1", &vfio_type1_dma_map},
+       {
+               .type_id = RTE_VFIO_TYPE1,
+               .name = "Type 1",
+               .dma_map_func = &vfio_type1_dma_map,
+               .dma_user_map_func = &vfio_type1_dma_mem_map
+       },
        /* ppc64 IOMMU, otherwise known as spapr */
-       { RTE_VFIO_SPAPR, "sPAPR", &vfio_spapr_dma_map},
+       {
+               .type_id = RTE_VFIO_SPAPR,
+               .name = "sPAPR",
+               .dma_map_func = &vfio_spapr_dma_map,
+               .dma_user_map_func = &vfio_spapr_dma_mem_map
+       },
        /* IOMMU-less mode */
-       { RTE_VFIO_NOIOMMU, "No-IOMMU", &vfio_noiommu_dma_map},
+       {
+               .type_id = RTE_VFIO_NOIOMMU,
+               .name = "No-IOMMU",
+               .dma_map_func = &vfio_noiommu_dma_map,
+               .dma_user_map_func = &vfio_noiommu_dma_mem_map
+       },
+};
+
+/* 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;
+       uint64_t iova;
+       uint64_t len;
 };
+static struct {
+       rte_spinlock_recursive_t lock;
+       int n_maps;
+       struct user_mem_map maps[VFIO_MAX_USER_MEM_MAPS];
+} user_mem_maps = {
+       .lock = RTE_SPINLOCK_RECURSIVE_INITIALIZER
+};
+
+/* for sPAPR IOMMU, we will need to walk memseg list, but we cannot use
+ * rte_memseg_walk() because by the time we enter callback we will be holding a
+ * write lock, so regular rte-memseg_walk will deadlock. copying the same
+ * iteration code everywhere is not ideal as well. so, use a lockless copy of
+ * memseg walk here.
+ */
+static int
+memseg_walk_thread_unsafe(rte_memseg_walk_t func, void *arg)
+{
+       struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+       int i, ms_idx, ret = 0;
+
+       for (i = 0; i < RTE_MAX_MEMSEG_LISTS; i++) {
+               struct rte_memseg_list *msl = &mcfg->memsegs[i];
+               const struct rte_memseg *ms;
+               struct rte_fbarray *arr;
+
+               if (msl->memseg_arr.count == 0)
+                       continue;
+
+               arr = &msl->memseg_arr;
+
+               ms_idx = rte_fbarray_find_next_used(arr, 0);
+               while (ms_idx >= 0) {
+                       ms = rte_fbarray_get(arr, ms_idx);
+                       ret = func(msl, ms, arg);
+                       if (ret < 0)
+                               return -1;
+                       if (ret > 0)
+                               return 1;
+                       ms_idx = rte_fbarray_find_next_used(arr, ms_idx + 1);
+               }
+       }
+       return 0;
+}
+
+static int
+is_null_map(const struct user_mem_map *map)
+{
+       return map->addr == 0 && map->iova == 0 && map->len == 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;
+
+       return 0;
+}
+
+/* adjust user map entry. this may result in shortening of existing map, or in
+ * splitting existing map in two pieces.
+ */
+static void
+adjust_map(struct user_mem_map *src, struct user_mem_map *end,
+               uint64_t remove_va_start, uint64_t remove_len)
+{
+       /* if va start is same as start address, we're simply moving start */
+       if (remove_va_start == src->addr) {
+               src->addr += remove_len;
+               src->iova += remove_len;
+               src->len -= remove_len;
+       } else if (remove_va_start + remove_len == src->addr + src->len) {
+               /* we're shrinking mapping from the end */
+               src->len -= remove_len;
+       } else {
+               /* we're blowing a hole in the middle */
+               struct user_mem_map tmp;
+               uint64_t total_len = src->len;
+
+               /* adjust source segment length */
+               src->len = remove_va_start - src->addr;
+
+               /* create temporary segment in the middle */
+               tmp.addr = src->addr + src->len;
+               tmp.iova = src->iova + src->len;
+               tmp.len = remove_len;
+
+               /* populate end segment - this one we will be keeping */
+               end->addr = tmp.addr + tmp.len;
+               end->iova = tmp.iova + tmp.len;
+               end->len = total_len - src->len - tmp.len;
+       }
+}
+
+/* try merging two maps into one, return 1 if succeeded */
+static int
+merge_map(struct user_mem_map *left, struct user_mem_map *right)
+{
+       if (left->addr + left->len != right->addr)
+               return 0;
+       if (left->iova + left->len != right->iova)
+               return 0;
+
+       left->len += right->len;
+
+       memset(right, 0, sizeof(*right));
+
+       return 1;
+}
+
+static struct user_mem_map *
+find_user_mem_map(uint64_t addr, uint64_t iova, uint64_t len)
+{
+       uint64_t va_end = addr + len;
+       uint64_t iova_end = iova + len;
+       int i;
+
+       for (i = 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;
+
+               /* check start VA */
+               if (addr < map->addr || addr >= map_va_end)
+                       continue;
+               /* check if VA end is within boundaries */
+               if (va_end <= map->addr || va_end > map_va_end)
+                       continue;
+
+               /* check start IOVA */
+               if (iova < map->iova || iova >= map_iova_end)
+                       continue;
+               /* check if IOVA end is within boundaries */
+               if (iova_end <= map->iova || iova_end > map_iova_end)
+                       continue;
+
+               /* we've found our map */
+               return map;
+       }
+       return NULL;
+}
+
+/* this will sort all user maps, and merge/compact any adjacent maps */
+static void
+compact_user_maps(void)
+{
+       int i, n_merged, cur_idx;
+
+       qsort(user_mem_maps.maps, user_mem_maps.n_maps,
+                       sizeof(user_mem_maps.maps[0]), user_mem_map_cmp);
+
+       /* we'll go over the list backwards when merging */
+       n_merged = 0;
+       for (i = user_mem_maps.n_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;
+
+               if (merge_map(l, r))
+                       n_merged++;
+       }
+
+       /* the entries are still sorted, but now they have holes in them, so
+        * walk through the list and remove the holes
+        */
+       if (n_merged > 0) {
+               cur_idx = 0;
+               for (i = 0; i < user_mem_maps.n_maps; i++) {
+                       if (!is_null_map(&user_mem_maps.maps[i])) {
+                               struct user_mem_map *src, *dst;
+
+                               src = &user_mem_maps.maps[i];
+                               dst = &user_mem_maps.maps[cur_idx++];
+
+                               if (src != dst) {
+                                       memcpy(dst, src, sizeof(*src));
+                                       memset(src, 0, sizeof(*src));
+                               }
+                       }
+               }
+               user_mem_maps.n_maps = cur_idx;
+       }
+}
 
 int
-vfio_get_group_fd(int iommu_group_no)
+rte_vfio_get_group_fd(int iommu_group_num)
 {
        int i;
        int vfio_group_fd;
-       int group_idx = -1;
        char filename[PATH_MAX];
+       struct vfio_group *cur_grp;
+       struct rte_mp_msg mp_req, *mp_rep;
+       struct rte_mp_reply mp_reply;
+       struct timespec ts = {.tv_sec = 5, .tv_nsec = 0};
+       struct vfio_mp_param *p = (struct vfio_mp_param *)mp_req.param;
 
        /* 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)
+               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 */
@@ -84,13 +308,13 @@ vfio_get_group_fd(int iommu_group_no)
 
        /* 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) {
-                       group_idx = i;
+               if (vfio_cfg.vfio_groups[i].group_num == -1) {
+                       cur_grp = &vfio_cfg.vfio_groups[i];
                        break;
                }
 
        /* This should not happen */
-       if (group_idx == -1) {
+       if (i == VFIO_MAX_GROUPS) {
                RTE_LOG(ERR, EAL, "No VFIO group free slot found\n");
                return -1;
        }
@@ -98,7 +322,7 @@ vfio_get_group_fd(int iommu_group_no)
        if (internal_config.process_type == RTE_PROC_PRIMARY) {
                /* try regular group format */
                snprintf(filename, sizeof(filename),
-                                VFIO_GROUP_FMT, iommu_group_no);
+                                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 */
@@ -110,7 +334,8 @@ vfio_get_group_fd(int iommu_group_no)
 
                        /* special case: try no-IOMMU path as well */
                        snprintf(filename, sizeof(filename),
-                                       VFIO_NOIOMMU_GROUP_FMT, iommu_group_no);
+                                       VFIO_NOIOMMU_GROUP_FMT,
+                                       iommu_group_num);
                        vfio_group_fd = open(filename, O_RDWR);
                        if (vfio_group_fd < 0) {
                                if (errno != ENOENT) {
@@ -123,53 +348,40 @@ vfio_get_group_fd(int iommu_group_no)
                        /* noiommu group found */
                }
 
-               vfio_cfg.vfio_groups[group_idx].group_no = iommu_group_no;
-               vfio_cfg.vfio_groups[group_idx].fd = 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;
        }
        /* if we're in a secondary process, request group fd from the primary
-        * process via our socket
+        * process via mp channel.
         */
-       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, return it */
-                       if (vfio_group_fd > 0) {
-                               close(socket_fd);
-                               return vfio_group_fd;
-                       }
-                       /* fall-through on error */
-               default:
-                       RTE_LOG(ERR, EAL, "  cannot get container fd!\n");
-                       close(socket_fd);
-                       return -1;
+       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) {
+                       cur_grp->group_num = iommu_group_num;
+                       vfio_group_fd = mp_rep->fds[0];
+                       cur_grp->fd = vfio_group_fd;
+                       vfio_cfg.vfio_active_groups++;
+               } else if (p->result == SOCKET_NO_FD) {
+                       RTE_LOG(ERR, EAL, "  bad VFIO group fd\n");
+                       vfio_group_fd = 0;
                }
+               free(mp_reply.msgs);
        }
-       return -1;
+
+       if (vfio_group_fd < 0)
+               RTE_LOG(ERR, EAL, "  cannot request group fd\n");
+       return vfio_group_fd;
 }
 
 
@@ -221,77 +433,98 @@ vfio_group_device_count(int vfio_group_fd)
        return vfio_cfg.vfio_groups[i].devices;
 }
 
+static void
+vfio_mem_event_callback(enum rte_mem_event type, const void *addr, size_t len)
+{
+       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) {
+               uint64_t vfio_va = (uint64_t)(uintptr_t)addr;
+               if (type == RTE_MEM_EVENT_ALLOC)
+                       vfio_dma_mem_map(vfio_va, vfio_va, len, 1);
+               else
+                       vfio_dma_mem_map(vfio_va, vfio_va, len, 0);
+               return;
+       }
+
+       /* memsegs are contiguous in memory */
+       ms = rte_mem_virt2memseg(addr, msl);
+       while (cur_len < len) {
+               if (type == RTE_MEM_EVENT_ALLOC)
+                       vfio_dma_mem_map(ms->addr_64, ms->iova, ms->len, 1);
+               else
+                       vfio_dma_mem_map(ms->addr_64, ms->iova, ms->len, 0);
+
+               cur_len += ms->len;
+               ++ms;
+       }
+}
+
 int
-clear_group(int vfio_group_fd)
+rte_vfio_clear_group(int vfio_group_fd)
 {
        int i;
-       int socket_fd, ret;
+       struct rte_mp_msg mp_req, *mp_rep;
+       struct rte_mp_reply mp_reply;
+       struct timespec ts = {.tv_sec = 5, .tv_nsec = 0};
+       struct vfio_mp_param *p = (struct vfio_mp_param *)mp_req.param;
 
        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].group_num = -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;
-       }
+       p->req = SOCKET_CLR_GROUP;
+       p->group_num = vfio_group_fd;
+       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) {
+                       free(mp_reply.msgs);
+                       return 0;
+               } else if (p->result == SOCKET_NO_FD)
+                       RTE_LOG(ERR, EAL, "  BAD VFIO group fd!\n");
+               else
+                       RTE_LOG(ERR, EAL, "  no such VFIO group fd!\n");
 
-       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;
+               free(mp_reply.msgs);
        }
 
-       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
-vfio_setup_device(const char *sysfs_base, const char *dev_addr,
+rte_vfio_setup_device(const char *sysfs_base, const char *dev_addr,
                int *vfio_dev_fd, struct vfio_device_info *device_info)
 {
+       struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+       rte_rwlock_t *mem_lock = &mcfg->memory_hotplug_lock;
        struct vfio_group_status group_status = {
                        .argsz = sizeof(group_status)
        };
        int vfio_group_fd;
-       int iommu_group_no;
-       int ret;
+       int iommu_group_num;
+       int i, ret;
 
        /* get group number */
-       ret = vfio_get_group_no(sysfs_base, dev_addr, &iommu_group_no);
+       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, skipping\n",
                        dev_addr);
@@ -303,7 +536,7 @@ vfio_setup_device(const char *sysfs_base, const char *dev_addr,
                return -1;
 
        /* get the actual group fd */
-       vfio_group_fd = vfio_get_group_fd(iommu_group_no);
+       vfio_group_fd = rte_vfio_get_group_fd(iommu_group_num);
        if (vfio_group_fd < 0)
                return -1;
 
@@ -325,12 +558,12 @@ vfio_setup_device(const char *sysfs_base, const char *dev_addr,
                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);
+               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!\n", dev_addr);
                close(vfio_group_fd);
-               clear_group(vfio_group_fd);
+               rte_vfio_clear_group(vfio_group_fd);
                return -1;
        }
 
@@ -344,7 +577,7 @@ vfio_setup_device(const char *sysfs_base, const char *dev_addr,
                        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);
+                       rte_vfio_clear_group(vfio_group_fd);
                        return -1;
                }
 
@@ -357,27 +590,83 @@ vfio_setup_device(const char *sysfs_base, const char *dev_addr,
                 * functionality.
                 */
                if (internal_config.process_type == RTE_PROC_PRIMARY &&
-                               vfio_cfg.vfio_active_groups == 1) {
+                               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 */
-                       const struct vfio_iommu_type *t =
-                               vfio_set_iommu_type(vfio_cfg.vfio_container_fd);
+                       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);
+                               rte_vfio_clear_group(vfio_group_fd);
                                return -1;
                        }
+                       /* lock memory hotplug before mapping and release it
+                        * after registering callback, to prevent races
+                        */
+                       rte_rwlock_read_lock(mem_lock);
                        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);
+                               rte_vfio_clear_group(vfio_group_fd);
+                               rte_rwlock_read_unlock(mem_lock);
+                               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_cfg.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_rwlock_read_unlock(mem_lock);
+                                       return -1;
+                               }
+                       }
+                       rte_spinlock_recursive_unlock(&user_mem_maps.lock);
+
+                       /* register callback for mem events */
+                       ret = rte_mem_event_callback_register(
+                                       VFIO_MEM_EVENT_CLB_NAME,
+                                       vfio_mem_event_callback);
+                       /* unlock memory hotplug */
+                       rte_rwlock_read_unlock(mem_lock);
+
+                       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");
                }
        }
 
@@ -391,7 +680,7 @@ vfio_setup_device(const char *sysfs_base, const char *dev_addr,
                RTE_LOG(WARNING, EAL, "Getting a vfio_dev_fd for %s failed\n",
                                dev_addr);
                close(vfio_group_fd);
-               clear_group(vfio_group_fd);
+               rte_vfio_clear_group(vfio_group_fd);
                return -1;
        }
 
@@ -403,7 +692,7 @@ vfio_setup_device(const char *sysfs_base, const char *dev_addr,
                                strerror(errno));
                close(*vfio_dev_fd);
                close(vfio_group_fd);
-               clear_group(vfio_group_fd);
+               rte_vfio_clear_group(vfio_group_fd);
                return -1;
        }
        vfio_group_device_get(vfio_group_fd);
@@ -412,31 +701,41 @@ vfio_setup_device(const char *sysfs_base, const char *dev_addr,
 }
 
 int
-vfio_release_device(const char *sysfs_base, const char *dev_addr,
+rte_vfio_release_device(const char *sysfs_base, const char *dev_addr,
                    int vfio_dev_fd)
 {
+       struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+       rte_rwlock_t *mem_lock = &mcfg->memory_hotplug_lock;
        struct vfio_group_status group_status = {
                        .argsz = sizeof(group_status)
        };
        int vfio_group_fd;
-       int iommu_group_no;
+       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_rwlock_read_lock(mem_lock);
+
        /* get group number */
-       ret = vfio_get_group_no(sysfs_base, dev_addr, &iommu_group_no);
+       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. */
-               return -1;
+               ret = -1;
+               goto out;
        }
 
        /* get the actual group fd */
-       vfio_group_fd = vfio_get_group_fd(iommu_group_no);
+       vfio_group_fd = rte_vfio_get_group_fd(iommu_group_num);
        if (vfio_group_fd <= 0) {
-               RTE_LOG(INFO, EAL, "vfio_get_group_fd failed for %s\n",
+               RTE_LOG(INFO, EAL, "rte_vfio_get_group_fd failed for %s\n",
                                   dev_addr);
-               return -1;
+               ret = -1;
+               goto out;
        }
 
        /* At this point we got an active group. Closing it will make the
@@ -448,7 +747,8 @@ vfio_release_device(const char *sysfs_base, const char *dev_addr,
        if (close(vfio_dev_fd) < 0) {
                RTE_LOG(INFO, EAL, "Error when closing vfio_dev_fd for %s\n",
                                   dev_addr);
-               return -1;
+               ret = -1;
+               goto out;
        }
 
        /* An VFIO group can have several devices attached. Just when there is
@@ -460,21 +760,34 @@ vfio_release_device(const char *sysfs_base, const char *dev_addr,
                if (close(vfio_group_fd) < 0) {
                        RTE_LOG(INFO, EAL, "Error when closing vfio_group_fd for %s\n",
                                dev_addr);
-                       return -1;
+                       ret = -1;
+                       goto out;
                }
 
-               if (clear_group(vfio_group_fd) < 0) {
+               if (rte_vfio_clear_group(vfio_group_fd) < 0) {
                        RTE_LOG(INFO, EAL, "Error when clearing group for %s\n",
                                           dev_addr);
-                       return -1;
+                       ret = -1;
+                       goto out;
                }
        }
 
-       return 0;
+       /* if there are no active device groups, unregister the callback to
+        * avoid spurious attempts to map/unmap memory from VFIO.
+        */
+       if (vfio_cfg.vfio_active_groups == 0)
+               rte_mem_event_callback_unregister(VFIO_MEM_EVENT_CLB_NAME);
+
+       /* success */
+       ret = 0;
+
+out:
+       rte_rwlock_read_unlock(mem_lock);
+       return ret;
 }
 
 int
-vfio_enable(const char *modname)
+rte_vfio_enable(const char *modname)
 {
        /* initialize group list */
        int i;
@@ -482,14 +795,14 @@ vfio_enable(const char *modname)
 
        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].group_num = -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-pci module is loaded */
+       /* check if vfio module is loaded */
        vfio_available = rte_eal_check_module(modname);
 
        /* return error directly */
@@ -505,7 +818,7 @@ vfio_enable(const char *modname)
                return 0;
        }
 
-       vfio_cfg.vfio_container_fd = vfio_get_container_fd();
+       vfio_cfg.vfio_container_fd = rte_vfio_get_container_fd();
 
        /* check if we have VFIO driver enabled */
        if (vfio_cfg.vfio_container_fd != -1) {
@@ -519,9 +832,9 @@ vfio_enable(const char *modname)
 }
 
 int
-vfio_is_enabled(const char *modname)
+rte_vfio_is_enabled(const char *modname)
 {
-       const int mod_available = rte_eal_check_module(modname);
+       const int mod_available = rte_eal_check_module(modname) > 0;
        return vfio_cfg.vfio_enabled && mod_available;
 }
 
@@ -583,9 +896,14 @@ vfio_has_supported_extensions(int vfio_container_fd)
 }
 
 int
-vfio_get_container_fd(void)
+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;
+       struct timespec ts = {.tv_sec = 5, .tv_nsec = 0};
+       struct vfio_mp_param *p = (struct vfio_mp_param *)mp_req.param;
+
 
        /* if we're in a primary process, try to open the container */
        if (internal_config.process_type == RTE_PROC_PRIMARY) {
@@ -616,39 +934,35 @@ vfio_get_container_fd(void)
                }
 
                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;
+       }
+       /*
+        * 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) {
+                       free(mp_reply.msgs);
+                       return mp_rep->fds[0];
                }
-               close(socket_fd);
-               return vfio_container_fd;
+               free(mp_reply.msgs);
        }
 
+       RTE_LOG(ERR, EAL, "  cannot request container fd\n");
        return -1;
 }
 
 int
-vfio_get_group_no(const char *sysfs_base,
-               const char *dev_addr, int *iommu_group_no)
+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];
@@ -680,7 +994,7 @@ vfio_get_group_no(const char *sysfs_base,
        errno = 0;
        group_tok = tok[ret - 1];
        end = group_tok;
-       *iommu_group_no = strtol(group_tok, &end, 10);
+       *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;
@@ -690,34 +1004,49 @@ vfio_get_group_no(const char *sysfs_base,
 }
 
 static int
-vfio_type1_dma_map(int vfio_container_fd)
+type1_map(const struct rte_memseg_list *msl __rte_unused,
+               const struct rte_memseg *ms, void *arg)
 {
-       const struct rte_memseg *ms = rte_eal_get_physmem_layout();
-       int i, ret;
+       int *vfio_container_fd = arg;
 
-       /* 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;
+       return vfio_type1_dma_mem_map(*vfio_container_fd, ms->addr_64, ms->iova,
+                       ms->len, 1);
+}
 
-               if (ms[i].addr == NULL)
-                       break;
+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 = ms[i].addr_64;
-               dma_map.size = ms[i].len;
-               if (rte_eal_iova_mode() == RTE_IOVA_VA)
-                       dma_map.iova = dma_map.vaddr;
-               else
-                       dma_map.iova = ms[i].phys_addr;
-               dma_map.flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE;
+               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 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 set up DMA remapping, "
-                                         "error %i (%s)\n", errno,
-                                         strerror(errno));
+                       RTE_LOG(ERR, EAL, "  cannot clear DMA remapping, error %i (%s)\n",
+                                       errno, strerror(errno));
                        return -1;
                }
        }
@@ -726,24 +1055,107 @@ vfio_type1_dma_map(int vfio_container_fd)
 }
 
 static int
-vfio_spapr_dma_map(int vfio_container_fd)
+vfio_type1_dma_map(int vfio_container_fd)
 {
-       const struct rte_memseg *ms = rte_eal_get_physmem_layout();
-       int i, ret;
+       return rte_memseg_walk(type1_map, &vfio_container_fd);
+}
 
-       struct vfio_iommu_spapr_register_memory reg = {
-               .argsz = sizeof(reg),
-               .flags = 0
+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_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) {
+                       RTE_LOG(ERR, EAL, "  cannot set up DMA remapping, error %i (%s)\n",
+                               errno, strerror(errno));
+                               return -1;
+               }
+
+       } else {
+               struct vfio_iommu_spapr_register_memory reg = {
+                       .argsz = sizeof(reg),
+                       .flags = 0
+               };
+               reg.vaddr = (uintptr_t) vaddr;
+               reg.size = len;
+
+               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;
+               }
+
+               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;
+               }
+       }
+
+       return 0;
+}
+
+static int
+vfio_spapr_map_walk(const struct rte_memseg_list *msl __rte_unused,
+               const struct rte_memseg *ms, void *arg)
+{
+       int *vfio_container_fd = arg;
+
+       return vfio_spapr_dma_mem_map(*vfio_container_fd, ms->addr_64, ms->iova,
+                       ms->len, 1);
+}
+
+struct spapr_walk_param {
+       uint64_t window_size;
+       uint64_t hugepage_sz;
+};
+static int
+vfio_spapr_window_size_walk(const struct rte_memseg_list *msl __rte_unused,
+               const struct rte_memseg *ms, void *arg)
+{
+       struct spapr_walk_param *param = arg;
+       uint64_t max = ms->iova + ms->len;
+
+       if (max > param->window_size) {
+               param->hugepage_sz = ms->hugepage_sz;
+               param->window_size = max;
+       }
+
+       return 0;
+}
+
+static int
+vfio_spapr_create_new_dma_window(int vfio_container_fd,
+               struct vfio_iommu_spapr_tce_create *create) {
+       struct vfio_iommu_spapr_tce_remove remove = {
+               .argsz = sizeof(remove),
        };
        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),
-       };
+       int ret;
 
        /* query spapr iommu info */
        ret = ioctl(vfio_container_fd, VFIO_IOMMU_SPAPR_TCE_GET_INFO, &info);
@@ -762,56 +1174,147 @@ vfio_spapr_dma_map(int vfio_container_fd)
                return -1;
        }
 
-       /* calculate window size based on number of hugepages configured */
-       create.window_size = rte_eal_get_physmem_size();
-       create.page_shift = __builtin_ctzll(ms->hugepage_sz);
-       create.levels = 2;
-
-       ret = ioctl(vfio_container_fd, VFIO_IOMMU_SPAPR_TCE_CREATE, &create);
+       /* create new DMA window */
+       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;
        }
 
-       /* 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 (create->start_addr != 0) {
+               RTE_LOG(ERR, EAL, "  DMA window start address != 0\n");
+               return -1;
+       }
 
-               if (ms[i].addr == NULL)
-                       break;
+       return 0;
+}
 
-               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;
-               }
+static int
+vfio_spapr_dma_mem_map(int vfio_container_fd, uint64_t vaddr, uint64_t iova,
+               uint64_t len, int do_map)
+{
+       struct spapr_walk_param param;
+       struct vfio_iommu_spapr_tce_create create = {
+               .argsz = sizeof(create),
+       };
+       int i, ret = 0;
 
-               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;
-               if (rte_eal_iova_mode() == RTE_IOVA_VA)
-                       dma_map.iova = dma_map.vaddr;
-               else
-                       dma_map.iova = ms[i].phys_addr;
-               dma_map.flags = VFIO_DMA_MAP_FLAG_READ |
-                                VFIO_DMA_MAP_FLAG_WRITE;
+       rte_spinlock_recursive_lock(&user_mem_maps.lock);
 
-               ret = ioctl(vfio_container_fd, VFIO_IOMMU_MAP_DMA, &dma_map);
+       /* check if window size needs to be adjusted */
+       memset(&param, 0, sizeof(param));
 
-               if (ret) {
-                       RTE_LOG(ERR, EAL, "  cannot set up DMA remapping, "
-                               "error %i (%s)\n", errno, strerror(errno));
-                       return -1;
+       if (memseg_walk_thread_unsafe(vfio_spapr_window_size_walk,
+                               &param) < 0) {
+               RTE_LOG(ERR, EAL, "Could not get window size\n");
+               ret = -1;
+               goto out;
+       }
+
+       /* also check user maps */
+       for (i = 0; i < user_mem_maps.n_maps; i++) {
+               uint64_t max = user_mem_maps.maps[i].iova +
+                               user_mem_maps.maps[i].len;
+               create.window_size = RTE_MAX(create.window_size, max);
+       }
+
+       /* sPAPR requires window size to be a power of 2 */
+       create.window_size = rte_align64pow2(param.window_size);
+       create.page_shift = __builtin_ctzll(param.hugepage_sz);
+       create.levels = 1;
+
+       if (do_map) {
+               void *addr;
+               /* re-create window and remap the entire memory */
+               if (iova > create.window_size) {
+                       if (vfio_spapr_create_new_dma_window(vfio_container_fd,
+                                       &create) < 0) {
+                               RTE_LOG(ERR, EAL, "Could not create new DMA window\n");
+                               ret = -1;
+                               goto out;
+                       }
+                       if (memseg_walk_thread_unsafe(vfio_spapr_map_walk,
+                                       &vfio_container_fd) < 0) {
+                               RTE_LOG(ERR, EAL, "Could not recreate DMA maps\n");
+                               ret = -1;
+                               goto out;
+                       }
+                       /* remap all user maps */
+                       for (i = 0; i < user_mem_maps.n_maps; i++) {
+                               struct user_mem_map *map =
+                                               &user_mem_maps.maps[i];
+                               if (vfio_spapr_dma_do_map(vfio_container_fd,
+                                               map->addr, map->iova, map->len,
+                                               1)) {
+                                       RTE_LOG(ERR, EAL, "Could not recreate user DMA maps\n");
+                                       ret = -1;
+                                       goto out;
+                               }
+                       }
                }
 
+               /* now that we've remapped all of the memory that was present
+                * before, map the segment that we were requested to map.
+                *
+                * however, if we were called by the callback, the memory we
+                * were called with was already in the memseg list, so previous
+                * mapping should've mapped that segment already.
+                *
+                * virt2memseg_list is a relatively cheap check, so use that. if
+                * memory is within any memseg list, it's a memseg, so it's
+                * already mapped.
+                */
+               addr = (void *)(uintptr_t)vaddr;
+               if (rte_mem_virt2memseg_list(addr) == NULL &&
+                               vfio_spapr_dma_do_map(vfio_container_fd,
+                                       vaddr, iova, len, 1) < 0) {
+                       RTE_LOG(ERR, EAL, "Could not map segment\n");
+                       ret = -1;
+                       goto out;
+               }
+       } else {
+               /* for unmap, check if iova within DMA window */
+               if (iova > create.window_size) {
+                       RTE_LOG(ERR, EAL, "iova beyond DMA window for unmap");
+                       ret = -1;
+                       goto out;
+               }
+
+               vfio_spapr_dma_do_map(vfio_container_fd, vaddr, iova, len, 0);
+       }
+out:
+       rte_spinlock_recursive_unlock(&user_mem_maps.lock);
+       return ret;
+}
+
+static int
+vfio_spapr_dma_map(int vfio_container_fd)
+{
+       struct vfio_iommu_spapr_tce_create create = {
+               .argsz = sizeof(create),
+       };
+       struct spapr_walk_param param;
+
+       memset(&param, 0, sizeof(param));
+
+       /* create DMA window from 0 to max(phys_addr + len) */
+       rte_memseg_walk(vfio_spapr_window_size_walk, &param);
+
+       /* sPAPR requires window size to be a power of 2 */
+       create.window_size = rte_align64pow2(param.window_size);
+       create.page_shift = __builtin_ctzll(param.hugepage_sz);
+       create.levels = 1;
+
+       if (vfio_spapr_create_new_dma_window(vfio_container_fd, &create) < 0) {
+               RTE_LOG(ERR, EAL, "Could not create new DMA window\n");
+               return -1;
        }
 
+       /* map all DPDK segments for DMA. use 1:1 PA to IOVA mapping */
+       if (rte_memseg_walk(vfio_spapr_map_walk, &vfio_container_fd) < 0)
+               return -1;
+
        return 0;
 }
 
@@ -822,23 +1325,262 @@ vfio_noiommu_dma_map(int __rte_unused vfio_container_fd)
        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(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 maping 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);
+}
+
+int __rte_experimental
+rte_vfio_dma_map(uint64_t vaddr, uint64_t iova, uint64_t len)
+{
+       struct user_mem_map *new_map;
+       int ret = 0;
+
+       if (len == 0) {
+               rte_errno = EINVAL;
+               return -1;
+       }
+
+       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(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;
+       }
+       /* 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;
+
+       compact_user_maps();
+out:
+       rte_spinlock_recursive_unlock(&user_mem_maps.lock);
+       return ret;
+}
+
+int __rte_experimental
+rte_vfio_dma_unmap(uint64_t vaddr, uint64_t iova, uint64_t len)
+{
+       struct user_mem_map *map, *new_map = NULL;
+       int ret = 0;
+
+       if (len == 0) {
+               rte_errno = EINVAL;
+               return -1;
+       }
+
+       rte_spinlock_recursive_lock(&user_mem_maps.lock);
+
+       /* find our mapping */
+       map = find_user_mem_map(vaddr, iova, len);
+       if (!map) {
+               RTE_LOG(ERR, EAL, "Couldn't find previously mapped region\n");
+               rte_errno = EINVAL;
+               ret = -1;
+               goto out;
+       }
+       if (map->addr != vaddr || map->iova != iova || map->len != len) {
+               /* we're partially unmapping a previously mapped region, so we
+                * need to split entry into two.
+                */
+               if (user_mem_maps.n_maps == VFIO_MAX_USER_MEM_MAPS) {
+                       RTE_LOG(ERR, EAL, "Not enough space to store partial mapping\n");
+                       rte_errno = ENOMEM;
+                       ret = -1;
+                       goto out;
+               }
+               new_map = &user_mem_maps.maps[user_mem_maps.n_maps++];
+       }
+
+       /* unmap the entry */
+       if (vfio_dma_mem_map(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");
+               }
+       }
+       /* remove map from the list of active mappings */
+       if (new_map != NULL) {
+               adjust_map(map, new_map, vaddr, len);
+
+               /* if we've created a new map by splitting, sort everything */
+               if (!is_null_map(new_map)) {
+                       compact_user_maps();
+               } else {
+                       /* we've created a new mapping, but it was unused */
+                       user_mem_maps.n_maps--;
+               }
+       } else {
+               memset(map, 0, sizeof(*map));
+               compact_user_maps();
+               user_mem_maps.n_maps--;
+       }
+
+out:
+       rte_spinlock_recursive_unlock(&user_mem_maps.lock);
+       return ret;
+}
+
 int
-vfio_noiommu_is_enabled(void)
+rte_vfio_noiommu_is_enabled(void)
 {
-       int fd, ret, cnt __rte_unused;
+       int fd;
+       ssize_t cnt;
        char c;
 
-       ret = -1;
        fd = open(VFIO_NOIOMMU_MODE, O_RDONLY);
-       if (fd < 0)
-               return -1;
+       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);
-       if (c == 'Y')
-               ret = 1;
-
        close(fd);
-       return ret;
+       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';
+}
+
+#else
+
+int __rte_experimental
+rte_vfio_dma_map(uint64_t __rte_unused vaddr, __rte_unused uint64_t iova,
+                 __rte_unused uint64_t len)
+{
+       return -1;
+}
+
+int __rte_experimental
+rte_vfio_dma_unmap(uint64_t __rte_unused vaddr, uint64_t __rte_unused iova,
+                   __rte_unused uint64_t len)
+{
+       return -1;
+}
+
+int
+rte_vfio_setup_device(__rte_unused const char *sysfs_base,
+               __rte_unused const char *dev_addr,
+               __rte_unused int *vfio_dev_fd,
+               __rte_unused struct vfio_device_info *device_info)
+{
+       return -1;
+}
+
+int
+rte_vfio_release_device(__rte_unused const char *sysfs_base,
+               __rte_unused const char *dev_addr, __rte_unused int fd)
+{
+       return -1;
+}
+
+int
+rte_vfio_enable(__rte_unused const char *modname)
+{
+       return -1;
+}
+
+int
+rte_vfio_is_enabled(__rte_unused const char *modname)
+{
+       return -1;
+}
+
+int
+rte_vfio_noiommu_is_enabled(void)
+{
+       return -1;
+}
+
+int
+rte_vfio_clear_group(__rte_unused int vfio_group_fd)
+{
+       return -1;
+}
+
+int __rte_experimental
+rte_vfio_get_group_num(__rte_unused const char *sysfs_base,
+               __rte_unused const char *dev_addr,
+               __rte_unused int *iommu_group_num)
+{
+       return -1;
+}
+
+int __rte_experimental
+rte_vfio_get_container_fd(void)
+{
+       return -1;
+}
+
+int __rte_experimental
+rte_vfio_get_group_fd(__rte_unused int iommu_group_num)
+{
+       return -1;
 }
 
-#endif
+#endif /* VFIO_PRESENT */