[dpdk-dev] [PATCH 3/4] common/mlx5: refactor memory management codes

[Vu Pham <vuhuoong@mellanox.com>]

From: Vu Pham <vuhuong@mellanox.com>

Refactor common memory btree and cache management to common driver.
Replace some input parameters of MR APIs to more common datastructure
like PD, port_id, share_cache,... so that muliptle PMD drivers can
use those MR APIs.

Signed-off-by: Vu Pham <vuhuong@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
---
 drivers/common/mlx5/mlx5_common_mr.c            | 1106 +++++++++++++++++++++++
 drivers/common/mlx5/mlx5_common_mr.h            |  160 ++++
 drivers/common/mlx5/rte_common_mlx5_version.map |   14 +
 3 files changed, 1280 insertions(+)
 create mode 100644 drivers/common/mlx5/mlx5_common_mr.c
 create mode 100644 drivers/common/mlx5/mlx5_common_mr.h

diff --git a/drivers/common/mlx5/mlx5_common_mr.c b/drivers/common/mlx5/mlx5_common_mr.c
new file mode 100644
index 0000000000..46eaf12350
--- /dev/null
+++ b/drivers/common/mlx5/mlx5_common_mr.c
@@ -0,0 +1,1106 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2016 6WIND S.A.
+ * Copyright 2020 Mellanox Technologies, Ltd
+ */
+#include <rte_eal_memconfig.h>
+#include <rte_errno.h>
+#include <rte_mempool.h>
+#include <rte_malloc.h>
+#include <rte_rwlock.h>
+
+#include "mlx5_glue.h"
+#include "mlx5_common_mp.h"
+#include "mlx5_common_mr.h"
+#include "mlx5_common_utils.h"
+
+struct mr_find_contig_memsegs_data {
+	uintptr_t addr;
+	uintptr_t start;
+	uintptr_t end;
+	const struct rte_memseg_list *msl;
+};
+
+/**
+ * Expand B-tree table to a given size. Can't be called with holding
+ * memory_hotplug_lock or share_cache.rwlock due to rte_realloc().
+ *
+ * @param bt
+ *   Pointer to B-tree structure.
+ * @param n
+ *   Number of entries for expansion.
+ *
+ * @return
+ *   0 on success, -1 on failure.
+ */
+static int
+mr_btree_expand(struct mlx5_mr_btree *bt, int n)
+{
+	void *mem;
+	int ret = 0;
+
+	if (n <= bt->size)
+		return ret;
+	/*
+	 * Downside of directly using rte_realloc() is that SOCKET_ID_ANY is
+	 * used inside if there's no room to expand. Because this is a quite
+	 * rare case and a part of very slow path, it is very acceptable.
+	 * Initially cache_bh[] will be given practically enough space and once
+	 * it is expanded, expansion wouldn't be needed again ever.
+	 */
+	mem = rte_realloc(bt->table, n * sizeof(struct mr_cache_entry), 0);
+	if (mem == NULL) {
+		/* Not an error, B-tree search will be skipped. */
+		DRV_LOG(WARNING, "failed to expand MR B-tree (%p) table",
+			(void *)bt);
+		ret = -1;
+	} else {
+		DRV_LOG(DEBUG, "expanded MR B-tree table (size=%u)", n);
+		bt->table = mem;
+		bt->size = n;
+	}
+	return ret;
+}
+
+/**
+ * Look up LKey from given B-tree lookup table, store the last index and return
+ * searched LKey.
+ *
+ * @param bt
+ *   Pointer to B-tree structure.
+ * @param[out] idx
+ *   Pointer to index. Even on search failure, returns index where it stops
+ *   searching so that index can be used when inserting a new entry.
+ * @param addr
+ *   Search key.
+ *
+ * @return
+ *   Searched LKey on success, UINT32_MAX on no match.
+ */
+static uint32_t
+mr_btree_lookup(struct mlx5_mr_btree *bt, uint16_t *idx, uintptr_t addr)
+{
+	struct mr_cache_entry *lkp_tbl;
+	uint16_t n;
+	uint16_t base = 0;
+
+	MLX5_ASSERT(bt != NULL);
+	lkp_tbl = *bt->table;
+	n = bt->len;
+	/* First entry must be NULL for comparison. */
+	MLX5_ASSERT(bt->len > 0 || (lkp_tbl[0].start == 0 &&
+				    lkp_tbl[0].lkey == UINT32_MAX));
+	/* Binary search. */
+	do {
+		register uint16_t delta = n >> 1;
+
+		if (addr < lkp_tbl[base + delta].start) {
+			n = delta;
+		} else {
+			base += delta;
+			n -= delta;
+		}
+	} while (n > 1);
+	MLX5_ASSERT(addr >= lkp_tbl[base].start);
+	*idx = base;
+	if (addr < lkp_tbl[base].end)
+		return lkp_tbl[base].lkey;
+	/* Not found. */
+	return UINT32_MAX;
+}
+
+/**
+ * Insert an entry to B-tree lookup table.
+ *
+ * @param bt
+ *   Pointer to B-tree structure.
+ * @param entry
+ *   Pointer to new entry to insert.
+ *
+ * @return
+ *   0 on success, -1 on failure.
+ */
+static int
+mr_btree_insert(struct mlx5_mr_btree *bt, struct mr_cache_entry *entry)
+{
+	struct mr_cache_entry *lkp_tbl;
+	uint16_t idx = 0;
+	size_t shift;
+
+	MLX5_ASSERT(bt != NULL);
+	MLX5_ASSERT(bt->len <= bt->size);
+	MLX5_ASSERT(bt->len > 0);
+	lkp_tbl = *bt->table;
+	/* Find out the slot for insertion. */
+	if (mr_btree_lookup(bt, &idx, entry->start) != UINT32_MAX) {
+		DRV_LOG(DEBUG,
+			"abort insertion to B-tree(%p): already exist at"
+			" idx=%u [0x%" PRIxPTR ", 0x%" PRIxPTR ") lkey=0x%x",
+			(void *)bt, idx, entry->start, entry->end, entry->lkey);
+		/* Already exist, return. */
+		return 0;
+	}
+	/* If table is full, return error. */
+	if (unlikely(bt->len == bt->size)) {
+		bt->overflow = 1;
+		return -1;
+	}
+	/* Insert entry. */
+	++idx;
+	shift = (bt->len - idx) * sizeof(struct mr_cache_entry);
+	if (shift)
+		memmove(&lkp_tbl[idx + 1], &lkp_tbl[idx], shift);
+	lkp_tbl[idx] = *entry;
+	bt->len++;
+	DRV_LOG(DEBUG,
+		"inserted B-tree(%p)[%u],"
+		" [0x%" PRIxPTR ", 0x%" PRIxPTR ") lkey=0x%x",
+		(void *)bt, idx, entry->start, entry->end, entry->lkey);
+	return 0;
+}
+
+/**
+ * Initialize B-tree and allocate memory for lookup table.
+ *
+ * @param bt
+ *   Pointer to B-tree structure.
+ * @param n
+ *   Number of entries to allocate.
+ * @param socket
+ *   NUMA socket on which memory must be allocated.
+ *
+ * @return
+ *   0 on success, a negative errno value otherwise and rte_errno is set.
+ */
+int
+mlx5_mr_btree_init(struct mlx5_mr_btree *bt, int n, int socket)
+{
+	if (bt == NULL) {
+		rte_errno = EINVAL;
+		return -rte_errno;
+	}
+	MLX5_ASSERT(!bt->table && !bt->size);
+	memset(bt, 0, sizeof(*bt));
+	bt->table = rte_calloc_socket("B-tree table",
+				      n, sizeof(struct mr_cache_entry),
+				      0, socket);
+	if (bt->table == NULL) {
+		rte_errno = ENOMEM;
+		DEBUG("failed to allocate memory for btree cache on socket %d",
+		      socket);
+		return -rte_errno;
+	}
+	bt->size = n;
+	/* First entry must be NULL for binary search. */
+	(*bt->table)[bt->len++] = (struct mr_cache_entry) {
+		.lkey = UINT32_MAX,
+	};
+	DEBUG("initialized B-tree %p with table %p",
+	      (void *)bt, (void *)bt->table);
+	return 0;
+}
+
+/**
+ * Free B-tree resources.
+ *
+ * @param bt
+ *   Pointer to B-tree structure.
+ */
+void
+mlx5_mr_btree_free(struct mlx5_mr_btree *bt)
+{
+	if (bt == NULL)
+		return;
+	DEBUG("freeing B-tree %p with table %p",
+	      (void *)bt, (void *)bt->table);
+	rte_free(bt->table);
+	memset(bt, 0, sizeof(*bt));
+}
+
+/**
+ * Dump all the entries in a B-tree
+ *
+ * @param bt
+ *   Pointer to B-tree structure.
+ */
+void
+mlx5_mr_btree_dump(struct mlx5_mr_btree *bt __rte_unused)
+{
+#ifdef RTE_LIBRTE_MLX5_DEBUG
+	int idx;
+	struct mr_cache_entry *lkp_tbl;
+
+	if (bt == NULL)
+		return;
+	lkp_tbl = *bt->table;
+	for (idx = 0; idx < bt->len; ++idx) {
+		struct mr_cache_entry *entry = &lkp_tbl[idx];
+
+		DEBUG("B-tree(%p)[%u],"
+		      " [0x%" PRIxPTR ", 0x%" PRIxPTR ") lkey=0x%x",
+		      (void *)bt, idx, entry->start, entry->end, entry->lkey);
+	}
+#endif
+}
+
+/**
+ * Find virtually contiguous memory chunk in a given MR.
+ *
+ * @param dev
+ *   Pointer to MR structure.
+ * @param[out] entry
+ *   Pointer to returning MR cache entry. If not found, this will not be
+ *   updated.
+ * @param start_idx
+ *   Start index of the memseg bitmap.
+ *
+ * @return
+ *   Next index to go on lookup.
+ */
+static int
+mr_find_next_chunk(struct mlx5_mr *mr, struct mr_cache_entry *entry,
+		   int base_idx)
+{
+	uintptr_t start = 0;
+	uintptr_t end = 0;
+	uint32_t idx = 0;
+
+	/* MR for external memory doesn't have memseg list. */
+	if (mr->msl == NULL) {
+		struct ibv_mr *ibv_mr = mr->ibv_mr;
+
+		MLX5_ASSERT(mr->ms_bmp_n == 1);
+		MLX5_ASSERT(mr->ms_n == 1);
+		MLX5_ASSERT(base_idx == 0);
+		/*
+		 * Can't search it from memseg list but get it directly from
+		 * verbs MR as there's only one chunk.
+		 */
+		entry->start = (uintptr_t)ibv_mr->addr;
+		entry->end = (uintptr_t)ibv_mr->addr + mr->ibv_mr->length;
+		entry->lkey = rte_cpu_to_be_32(mr->ibv_mr->lkey);
+		/* Returning 1 ends iteration. */
+		return 1;
+	}
+	for (idx = base_idx; idx < mr->ms_bmp_n; ++idx) {
+		if (rte_bitmap_get(mr->ms_bmp, idx)) {
+			const struct rte_memseg_list *msl;
+			const struct rte_memseg *ms;
+
+			msl = mr->msl;
+			ms = rte_fbarray_get(&msl->memseg_arr,
+					     mr->ms_base_idx + idx);
+			MLX5_ASSERT(msl->page_sz == ms->hugepage_sz);
+			if (!start)
+				start = ms->addr_64;
+			end = ms->addr_64 + ms->hugepage_sz;
+		} else if (start) {
+			/* Passed the end of a fragment. */
+			break;
+		}
+	}
+	if (start) {
+		/* Found one chunk. */
+		entry->start = start;
+		entry->end = end;
+		entry->lkey = rte_cpu_to_be_32(mr->ibv_mr->lkey);
+	}
+	return idx;
+}
+
+/**
+ * Insert a MR to the global B-tree cache. It may fail due to low-on-memory.
+ * Then, this entry will have to be searched by mr_lookup_list() in
+ * mlx5_mr_create() on miss.
+ *
+ * @param share_cache
+ *   Pointer to a global shared MR cache.
+ * @param mr
+ *   Pointer to MR to insert.
+ *
+ * @return
+ *   0 on success, -1 on failure.
+ */
+int
+mlx5_mr_insert_cache(struct mlx5_mr_share_cache *share_cache,
+		     struct mlx5_mr *mr)
+{
+	unsigned int n;
+
+	DRV_LOG(DEBUG, "Inserting MR(%p) to global cache(%p)",
+		(void *)mr, (void *)share_cache);
+	for (n = 0; n < mr->ms_bmp_n; ) {
+		struct mr_cache_entry entry;
+
+		memset(&entry, 0, sizeof(entry));
+		/* Find a contiguous chunk and advance the index. */
+		n = mr_find_next_chunk(mr, &entry, n);
+		if (!entry.end)
+			break;
+		if (mr_btree_insert(&share_cache->cache, &entry) < 0) {
+			/*
+			 * Overflowed, but the global table cannot be expanded
+			 * because of deadlock.
+			 */
+			return -1;
+		}
+	}
+	return 0;
+}
+
+/**
+ * Look up address in the original global MR list.
+ *
+ * @param share_cache
+ *   Pointer to a global shared MR cache.
+ * @param[out] entry
+ *   Pointer to returning MR cache entry. If no match, this will not be updated.
+ * @param addr
+ *   Search key.
+ *
+ * @return
+ *   Found MR on match, NULL otherwise.
+ */
+struct mlx5_mr *
+mlx5_mr_lookup_list(struct mlx5_mr_share_cache *share_cache,
+		    struct mr_cache_entry *entry, uintptr_t addr)
+{
+	struct mlx5_mr *mr;
+
+	/* Iterate all the existing MRs. */
+	LIST_FOREACH(mr, &share_cache->mr_list, mr) {
+		unsigned int n;
+
+		if (mr->ms_n == 0)
+			continue;
+		for (n = 0; n < mr->ms_bmp_n; ) {
+			struct mr_cache_entry ret;
+
+			memset(&ret, 0, sizeof(ret));
+			n = mr_find_next_chunk(mr, &ret, n);
+			if (addr >= ret.start && addr < ret.end) {
+				/* Found. */
+				*entry = ret;
+				return mr;
+			}
+		}
+	}
+	return NULL;
+}
+
+/**
+ * Look up address on global MR cache.
+ *
+ * @param share_cache
+ *   Pointer to a global shared MR cache.
+ * @param[out] entry
+ *   Pointer to returning MR cache entry. If no match, this will not be updated.
+ * @param addr
+ *   Search key.
+ *
+ * @return
+ *   Searched LKey on success, UINT32_MAX on failure and rte_errno is set.
+ */
+uint32_t
+mlx5_mr_lookup_cache(struct mlx5_mr_share_cache *share_cache,
+		     struct mr_cache_entry *entry, uintptr_t addr)
+{
+	uint16_t idx;
+	uint32_t lkey = UINT32_MAX;
+	struct mlx5_mr *mr;
+
+	/*
+	 * If the global cache has overflowed since it failed to expand the
+	 * B-tree table, it can't have all the existing MRs. Then, the address
+	 * has to be searched by traversing the original MR list instead, which
+	 * is very slow path. Otherwise, the global cache is all inclusive.
+	 */
+	if (!unlikely(share_cache->cache.overflow)) {
+		lkey = mr_btree_lookup(&share_cache->cache, &idx, addr);
+		if (lkey != UINT32_MAX)
+			*entry = (*share_cache->cache.table)[idx];
+	} else {
+		/* Falling back to the slowest path. */
+		mr = mlx5_mr_lookup_list(share_cache, entry, addr);
+		if (mr != NULL)
+			lkey = entry->lkey;
+	}
+	MLX5_ASSERT(lkey == UINT32_MAX || (addr >= entry->start &&
+					   addr < entry->end));
+	return lkey;
+}
+
+/**
+ * Free MR resources. MR lock must not be held to avoid a deadlock. rte_free()
+ * can raise memory free event and the callback function will spin on the lock.
+ *
+ * @param mr
+ *   Pointer to MR to free.
+ */
+static void
+mr_free(struct mlx5_mr *mr)
+{
+	if (mr == NULL)
+		return;
+	DRV_LOG(DEBUG, "freeing MR(%p):", (void *)mr);
+	if (mr->ibv_mr != NULL)
+		claim_zero(mlx5_glue->dereg_mr(mr->ibv_mr));
+	if (mr->ms_bmp != NULL)
+		rte_bitmap_free(mr->ms_bmp);
+	rte_free(mr);
+}
+
+void
+mlx5_mr_rebuild_cache(struct mlx5_mr_share_cache *share_cache)
+{
+	struct mlx5_mr *mr;
+
+	DRV_LOG(DEBUG, "Rebuild dev cache[] %p", (void *)share_cache);
+	/* Flush cache to rebuild. */
+	share_cache->cache.len = 1;
+	share_cache->cache.overflow = 0;
+	/* Iterate all the existing MRs. */
+	LIST_FOREACH(mr, &share_cache->mr_list, mr)
+		if (mlx5_mr_insert_cache(share_cache, mr) < 0)
+			return;
+}
+
+/**
+ * Release resources of detached MR having no online entry.
+ *
+ * @param share_cache
+ *   Pointer to a global shared MR cache.
+ */
+static void
+mlx5_mr_garbage_collect(struct mlx5_mr_share_cache *share_cache)
+{
+	struct mlx5_mr *mr_next;
+	struct mlx5_mr_list free_list = LIST_HEAD_INITIALIZER(free_list);
+
+	/* Must be called from the primary process. */
+	MLX5_ASSERT(rte_eal_process_type() == RTE_PROC_PRIMARY);
+	/*
+	 * MR can't be freed with holding the lock because rte_free() could call
+	 * memory free callback function. This will be a deadlock situation.
+	 */
+	rte_rwlock_write_lock(&share_cache->rwlock);
+	/* Detach the whole free list and release it after unlocking. */
+	free_list = share_cache->mr_free_list;
+	LIST_INIT(&share_cache->mr_free_list);
+	rte_rwlock_write_unlock(&share_cache->rwlock);
+	/* Release resources. */
+	mr_next = LIST_FIRST(&free_list);
+	while (mr_next != NULL) {
+		struct mlx5_mr *mr = mr_next;
+
+		mr_next = LIST_NEXT(mr, mr);
+		mr_free(mr);
+	}
+}
+
+/* Called during rte_memseg_contig_walk() by mlx5_mr_create(). */
+static int
+mr_find_contig_memsegs_cb(const struct rte_memseg_list *msl,
+			  const struct rte_memseg *ms, size_t len, void *arg)
+{
+	struct mr_find_contig_memsegs_data *data = arg;
+
+	if (data->addr < ms->addr_64 || data->addr >= ms->addr_64 + len)
+		return 0;
+	/* Found, save it and stop walking. */
+	data->start = ms->addr_64;
+	data->end = ms->addr_64 + len;
+	data->msl = msl;
+	return 1;
+}
+
+/**
+ * Create a new global Memory Region (MR) for a missing virtual address.
+ * This API should be called on a secondary process, then a request is sent to
+ * the primary process in order to create a MR for the address. As the global MR
+ * list is on the shared memory, following LKey lookup should succeed unless the
+ * request fails.
+ *
+ * @param pd
+ *   Pointer to ibv_pd of a device (net, regex, vdpa,...).
+ * @param share_cache
+ *   Pointer to a global shared MR cache.
+ * @param[out] entry
+ *   Pointer to returning MR cache entry, found in the global cache or newly
+ *   created. If failed to create one, this will not be updated.
+ * @param addr
+ *   Target virtual address to register.
+ * @param mr_ext_memseg_en
+ *   Configurable flag about external memory segment enable or not.
+ *
+ * @return
+ *   Searched LKey on success, UINT32_MAX on failure and rte_errno is set.
+ */
+static uint32_t
+mlx5_mr_create_secondary(struct ibv_pd *pd __rte_unused,
+			 struct mlx5_mp_id *mp_id,
+			 struct mlx5_mr_share_cache *share_cache,
+			 struct mr_cache_entry *entry, uintptr_t addr,
+			 unsigned int mr_ext_memseg_en __rte_unused)
+{
+	int ret;
+
+	DEBUG("port %u requesting MR creation for address (%p)",
+	      mp_id->port_id, (void *)addr);
+	ret = mlx5_mp_req_mr_create(mp_id, addr);
+	if (ret) {
+		DEBUG("Fail to request MR creation for address (%p)",
+		      (void *)addr);
+		return UINT32_MAX;
+	}
+	rte_rwlock_read_lock(&share_cache->rwlock);
+	/* Fill in output data. */
+	mlx5_mr_lookup_cache(share_cache, entry, addr);
+	/* Lookup can't fail. */
+	MLX5_ASSERT(entry->lkey != UINT32_MAX);
+	rte_rwlock_read_unlock(&share_cache->rwlock);
+	DEBUG("MR CREATED by primary process for %p:\n"
+	      "  [0x%" PRIxPTR ", 0x%" PRIxPTR "), lkey=0x%x",
+	      (void *)addr, entry->start, entry->end, entry->lkey);
+	return entry->lkey;
+}
+
+/**
+ * Create a new global Memory Region (MR) for a missing virtual address.
+ * Register entire virtually contiguous memory chunk around the address.
+ *
+ * @param pd
+ *   Pointer to ibv_pd of a device (net, regex, vdpa,...).
+ * @param share_cache
+ *   Pointer to a global shared MR cache.
+ * @param[out] entry
+ *   Pointer to returning MR cache entry, found in the global cache or newly
+ *   created. If failed to create one, this will not be updated.
+ * @param addr
+ *   Target virtual address to register.
+ * @param mr_ext_memseg_en
+ *   Configurable flag about external memory segment enable or not.
+ *
+ * @return
+ *   Searched LKey on success, UINT32_MAX on failure and rte_errno is set.
+ */
+uint32_t
+mlx5_mr_create_primary(struct ibv_pd *pd,
+		       struct mlx5_mr_share_cache *share_cache,
+		       struct mr_cache_entry *entry, uintptr_t addr,
+		       unsigned int mr_ext_memseg_en)
+{
+	struct mr_find_contig_memsegs_data data = {.addr = addr, };
+	struct mr_find_contig_memsegs_data data_re;
+	const struct rte_memseg_list *msl;
+	const struct rte_memseg *ms;
+	struct mlx5_mr *mr = NULL;
+	int ms_idx_shift = -1;
+	uint32_t bmp_size;
+	void *bmp_mem;
+	uint32_t ms_n;
+	uint32_t n;
+	size_t len;
+
+	DRV_LOG(DEBUG, "Creating a MR using address (%p)", (void *)addr);
+	/*
+	 * Release detached MRs if any. This can't be called with holding either
+	 * memory_hotplug_lock or share_cache->rwlock. MRs on the free list have
+	 * been detached by the memory free event but it couldn't be released
+	 * inside the callback due to deadlock. As a result, releasing resources
+	 * is quite opportunistic.
+	 */
+	mlx5_mr_garbage_collect(share_cache);
+	/*
+	 * If enabled, find out a contiguous virtual address chunk in use, to
+	 * which the given address belongs, in order to register maximum range.
+	 * In the best case where mempools are not dynamically recreated and
+	 * '--socket-mem' is specified as an EAL option, it is very likely to
+	 * have only one MR(LKey) per a socket and per a hugepage-size even
+	 * though the system memory is highly fragmented. As the whole memory
+	 * chunk will be pinned by kernel, it can't be reused unless entire
+	 * chunk is freed from EAL.
+	 *
+	 * If disabled, just register one memseg (page). Then, memory
+	 * consumption will be minimized but it may drop performance if there
+	 * are many MRs to lookup on the datapath.
+	 */
+	if (!mr_ext_memseg_en) {
+		data.msl = rte_mem_virt2memseg_list((void *)addr);
+		data.start = RTE_ALIGN_FLOOR(addr, data.msl->page_sz);
+		data.end = data.start + data.msl->page_sz;
+	} else if (!rte_memseg_contig_walk(mr_find_contig_memsegs_cb, &data)) {
+		DRV_LOG(WARNING,
+			"Unable to find virtually contiguous"
+			" chunk for address (%p)."
+			" rte_memseg_contig_walk() failed.", (void *)addr);
+		rte_errno = ENXIO;
+		goto err_nolock;
+	}
+alloc_resources:
+	/* Addresses must be page-aligned. */
+	MLX5_ASSERT(data.msl);
+	MLX5_ASSERT(rte_is_aligned((void *)data.start, data.msl->page_sz));
+	MLX5_ASSERT(rte_is_aligned((void *)data.end, data.msl->page_sz));
+	msl = data.msl;
+	ms = rte_mem_virt2memseg((void *)data.start, msl);
+	len = data.end - data.start;
+	MLX5_ASSERT(ms);
+	MLX5_ASSERT(msl->page_sz == ms->hugepage_sz);
+	/* Number of memsegs in the range. */
+	ms_n = len / msl->page_sz;
+	DEBUG("Extending %p to [0x%" PRIxPTR ", 0x%" PRIxPTR "),"
+	      " page_sz=0x%" PRIx64 ", ms_n=%u",
+	      (void *)addr, data.start, data.end, msl->page_sz, ms_n);
+	/* Size of memory for bitmap. */
+	bmp_size = rte_bitmap_get_memory_footprint(ms_n);
+	mr = rte_zmalloc_socket(NULL,
+				RTE_ALIGN_CEIL(sizeof(*mr),
+					       RTE_CACHE_LINE_SIZE) +
+				bmp_size,
+				RTE_CACHE_LINE_SIZE, msl->socket_id);
+	if (mr == NULL) {
+		DEBUG("Unable to allocate memory for a new MR of"
+		      " address (%p).", (void *)addr);
+		rte_errno = ENOMEM;
+		goto err_nolock;
+	}
+	mr->msl = msl;
+	/*
+	 * Save the index of the first memseg and initialize memseg bitmap. To
+	 * see if a memseg of ms_idx in the memseg-list is still valid, check:
+	 *	rte_bitmap_get(mr->bmp, ms_idx - mr->ms_base_idx)
+	 */
+	mr->ms_base_idx = rte_fbarray_find_idx(&msl->memseg_arr, ms);
+	bmp_mem = RTE_PTR_ALIGN_CEIL(mr + 1, RTE_CACHE_LINE_SIZE);
+	mr->ms_bmp = rte_bitmap_init(ms_n, bmp_mem, bmp_size);
+	if (mr->ms_bmp == NULL) {
+		DEBUG("Unable to initialize bitmap for a new MR of"
+		      " address (%p).", (void *)addr);
+		rte_errno = EINVAL;
+		goto err_nolock;
+	}
+	/*
+	 * Should recheck whether the extended contiguous chunk is still valid.
+	 * Because memory_hotplug_lock can't be held if there's any memory
+	 * related calls in a critical path, resource allocation above can't be
+	 * locked. If the memory has been changed at this point, try again with
+	 * just single page. If not, go on with the big chunk atomically from
+	 * here.
+	 */
+	rte_mcfg_mem_read_lock();
+	data_re = data;
+	if (len > msl->page_sz &&
+	    !rte_memseg_contig_walk(mr_find_contig_memsegs_cb, &data_re)) {
+		DEBUG("Unable to find virtually contiguous"
+		      " chunk for address (%p)."
+		      " rte_memseg_contig_walk() failed.", (void *)addr);
+		rte_errno = ENXIO;
+		goto err_memlock;
+	}
+	if (data.start != data_re.start || data.end != data_re.end) {
+		/*
+		 * The extended contiguous chunk has been changed. Try again
+		 * with single memseg instead.
+		 */
+		data.start = RTE_ALIGN_FLOOR(addr, msl->page_sz);
+		data.end = data.start + msl->page_sz;
+		rte_mcfg_mem_read_unlock();
+		mr_free(mr);
+		goto alloc_resources;
+	}
+	MLX5_ASSERT(data.msl == data_re.msl);
+	rte_rwlock_write_lock(&share_cache->rwlock);
+	/*
+	 * Check the address is really missing. If other thread already created
+	 * one or it is not found due to overflow, abort and return.
+	 */
+	if (mlx5_mr_lookup_cache(share_cache, entry, addr) != UINT32_MAX) {
+		/*
+		 * Insert to the global cache table. It may fail due to
+		 * low-on-memory. Then, this entry will have to be searched
+		 * here again.
+		 */
+		mr_btree_insert(&share_cache->cache, entry);
+		DEBUG("Found MR for %p on final lookup, abort", (void *)addr);
+		rte_rwlock_write_unlock(&share_cache->rwlock);
+		rte_mcfg_mem_read_unlock();
+		/*
+		 * Must be unlocked before calling rte_free() because
+		 * mlx5_mr_mem_event_free_cb() can be called inside.
+		 */
+		mr_free(mr);
+		return entry->lkey;
+	}
+	/*
+	 * Trim start and end addresses for verbs MR. Set bits for registering
+	 * memsegs but exclude already registered ones. Bitmap can be
+	 * fragmented.
+	 */
+	for (n = 0; n < ms_n; ++n) {
+		uintptr_t start;
+		struct mr_cache_entry ret;
+
+		memset(&ret, 0, sizeof(ret));
+		start = data_re.start + n * msl->page_sz;
+		/* Exclude memsegs already registered by other MRs. */
+		if (mlx5_mr_lookup_cache(share_cache, &ret, start) ==
+		    UINT32_MAX) {
+			/*
+			 * Start from the first unregistered memseg in the
+			 * extended range.
+			 */
+			if (ms_idx_shift == -1) {
+				mr->ms_base_idx += n;
+				data.start = start;
+				ms_idx_shift = n;
+			}
+			data.end = start + msl->page_sz;
+			rte_bitmap_set(mr->ms_bmp, n - ms_idx_shift);
+			++mr->ms_n;
+		}
+	}
+	len = data.end - data.start;
+	mr->ms_bmp_n = len / msl->page_sz;
+	MLX5_ASSERT(ms_idx_shift + mr->ms_bmp_n <= ms_n);
+	/*
+	 * Finally create a verbs MR for the memory chunk. ibv_reg_mr() can be
+	 * called with holding the memory lock because it doesn't use
+	 * mlx5_alloc_buf_extern() which eventually calls rte_malloc_socket()
+	 * through mlx5_alloc_verbs_buf().
+	 */
+	mr->ibv_mr = mlx5_glue->reg_mr(pd, (void *)data.start, len,
+				       IBV_ACCESS_LOCAL_WRITE);
+	if (mr->ibv_mr == NULL) {
+		DEBUG("Fail to create a verbs MR for address (%p)",
+		      (void *)addr);
+		rte_errno = EINVAL;
+		goto err_mrlock;
+	}
+	MLX5_ASSERT((uintptr_t)mr->ibv_mr->addr == data.start);
+	MLX5_ASSERT(mr->ibv_mr->length == len);
+	LIST_INSERT_HEAD(&share_cache->mr_list, mr, mr);
+	DEBUG("MR CREATED (%p) for %p:\n"
+	      "  [0x%" PRIxPTR ", 0x%" PRIxPTR "),"
+	      " lkey=0x%x base_idx=%u ms_n=%u, ms_bmp_n=%u",
+	      (void *)mr, (void *)addr, data.start, data.end,
+	      rte_cpu_to_be_32(mr->ibv_mr->lkey),
+	      mr->ms_base_idx, mr->ms_n, mr->ms_bmp_n);
+	/* Insert to the global cache table. */
+	mlx5_mr_insert_cache(share_cache, mr);
+	/* Fill in output data. */
+	mlx5_mr_lookup_cache(share_cache, entry, addr);
+	/* Lookup can't fail. */
+	MLX5_ASSERT(entry->lkey != UINT32_MAX);
+	rte_rwlock_write_unlock(&share_cache->rwlock);
+	rte_mcfg_mem_read_unlock();
+	return entry->lkey;
+err_mrlock:
+	rte_rwlock_write_unlock(&share_cache->rwlock);
+err_memlock:
+	rte_mcfg_mem_read_unlock();
+err_nolock:
+	/*
+	 * In case of error, as this can be called in a datapath, a warning
+	 * message per an error is preferable instead. Must be unlocked before
+	 * calling rte_free() because mlx5_mr_mem_event_free_cb() can be called
+	 * inside.
+	 */
+	mr_free(mr);
+	return UINT32_MAX;
+}
+
+/**
+ * Create a new global Memory Region (MR) for a missing virtual address.
+ * This can be called from primary and secondary process.
+ *
+ * @param pd
+ *   Pointer to ibv_pd of a device (net, regex, vdpa,...).
+ * @param share_cache
+ *   Pointer to a global shared MR cache.
+ * @param[out] entry
+ *   Pointer to returning MR cache entry, found in the global cache or newly
+ *   created. If failed to create one, this will not be updated.
+ * @param addr
+ *   Target virtual address to register.
+ *
+ * @return
+ *   Searched LKey on success, UINT32_MAX on failure and rte_errno is set.
+ */
+static uint32_t
+mlx5_mr_create(struct ibv_pd *pd, struct mlx5_mp_id *mp_id,
+	       struct mlx5_mr_share_cache *share_cache,
+	       struct mr_cache_entry *entry, uintptr_t addr,
+	       unsigned int mr_ext_memseg_en)
+{
+	uint32_t ret = 0;
+
+	switch (rte_eal_process_type()) {
+	case RTE_PROC_PRIMARY:
+		ret = mlx5_mr_create_primary(pd, share_cache, entry,
+					     addr, mr_ext_memseg_en);
+		break;
+	case RTE_PROC_SECONDARY:
+		ret = mlx5_mr_create_secondary(pd, mp_id, share_cache, entry,
+					       addr, mr_ext_memseg_en);
+		break;
+	default:
+		break;
+	}
+	return ret;
+}
+
+/**
+ * Look up address in the global MR cache table. If not found, create a new MR.
+ * Insert the found/created entry to local bottom-half cache table.
+ *
+ * @param pd
+ *   Pointer to ibv_pd of a device (net, regex, vdpa,...).
+ * @param share_cache
+ *   Pointer to a global shared MR cache.
+ * @param mr_ctrl
+ *   Pointer to per-queue MR control structure.
+ * @param[out] entry
+ *   Pointer to returning MR cache entry, found in the global cache or newly
+ *   created. If failed to create one, this is not written.
+ * @param addr
+ *   Search key.
+ *
+ * @return
+ *   Searched LKey on success, UINT32_MAX on no match.
+ */
+static uint32_t
+mr_lookup_caches(struct ibv_pd *pd, struct mlx5_mp_id *mp_id,
+		 struct mlx5_mr_share_cache *share_cache,
+		 struct mlx5_mr_ctrl *mr_ctrl,
+		 struct mr_cache_entry *entry, uintptr_t addr,
+		 unsigned int mr_ext_memseg_en)
+{
+	struct mlx5_mr_btree *bt = &mr_ctrl->cache_bh;
+	uint32_t lkey;
+	uint16_t idx;
+
+	/* If local cache table is full, try to double it. */
+	if (unlikely(bt->len == bt->size))
+		mr_btree_expand(bt, bt->size << 1);
+	/* Look up in the global cache. */
+	rte_rwlock_read_lock(&share_cache->rwlock);
+	lkey = mr_btree_lookup(&share_cache->cache, &idx, addr);
+	if (lkey != UINT32_MAX) {
+		/* Found. */
+		*entry = (*share_cache->cache.table)[idx];
+		rte_rwlock_read_unlock(&share_cache->rwlock);
+		/*
+		 * Update local cache. Even if it fails, return the found entry
+		 * to update top-half cache. Next time, this entry will be found
+		 * in the global cache.
+		 */
+		mr_btree_insert(bt, entry);
+		return lkey;
+	}
+	rte_rwlock_read_unlock(&share_cache->rwlock);
+	/* First time to see the address? Create a new MR. */
+	lkey = mlx5_mr_create(pd, mp_id, share_cache, entry, addr,
+			      mr_ext_memseg_en);
+	/*
+	 * Update the local cache if successfully created a new global MR. Even
+	 * if failed to create one, there's no action to take in this datapath
+	 * code. As returning LKey is invalid, this will eventually make HW
+	 * fail.
+	 */
+	if (lkey != UINT32_MAX)
+		mr_btree_insert(bt, entry);
+	return lkey;
+}
+
+/**
+ * Bottom-half of LKey search on datapath. First search in cache_bh[] and if
+ * misses, search in the global MR cache table and update the new entry to
+ * per-queue local caches.
+ *
+ * @param pd
+ *   Pointer to ibv_pd of a device (net, regex, vdpa,...).
+ * @param share_cache
+ *   Pointer to a global shared MR cache.
+ * @param mr_ctrl
+ *   Pointer to per-queue MR control structure.
+ * @param addr
+ *   Search key.
+ *
+ * @return
+ *   Searched LKey on success, UINT32_MAX on no match.
+ */
+uint32_t mlx5_mr_addr2mr_bh(struct ibv_pd *pd, struct mlx5_mp_id *mp_id,
+			    struct mlx5_mr_share_cache *share_cache,
+			    struct mlx5_mr_ctrl *mr_ctrl,
+			    uintptr_t addr, unsigned int mr_ext_memseg_en)
+{
+	uint32_t lkey;
+	uint16_t bh_idx = 0;
+	/* Victim in top-half cache to replace with new entry. */
+	struct mr_cache_entry *repl = &mr_ctrl->cache[mr_ctrl->head];
+
+	/* Binary-search MR translation table. */
+	lkey = mr_btree_lookup(&mr_ctrl->cache_bh, &bh_idx, addr);
+	/* Update top-half cache. */
+	if (likely(lkey != UINT32_MAX)) {
+		*repl = (*mr_ctrl->cache_bh.table)[bh_idx];
+	} else {
+		/*
+		 * If missed in local lookup table, search in the global cache
+		 * and local cache_bh[] will be updated inside if possible.
+		 * Top-half cache entry will also be updated.
+		 */
+		lkey = mr_lookup_caches(pd, mp_id, share_cache, mr_ctrl,
+					repl, addr, mr_ext_memseg_en);
+		if (unlikely(lkey == UINT32_MAX))
+			return UINT32_MAX;
+	}
+	/* Update the most recently used entry. */
+	mr_ctrl->mru = mr_ctrl->head;
+	/* Point to the next victim, the oldest. */
+	mr_ctrl->head = (mr_ctrl->head + 1) % MLX5_MR_CACHE_N;
+	return lkey;
+}
+
+/**
+ * Release all the created MRs and resources on global MR cache of a device.
+ * list.
+ *
+ * @param share_cache
+ *   Pointer to a global shared MR cache.
+ */
+void
+mlx5_mr_release_cache(struct mlx5_mr_share_cache *share_cache)
+{
+	struct mlx5_mr *mr_next;
+
+	rte_rwlock_write_lock(&share_cache->rwlock);
+	/* Detach from MR list and move to free list. */
+	mr_next = LIST_FIRST(&share_cache->mr_list);
+	while (mr_next != NULL) {
+		struct mlx5_mr *mr = mr_next;
+
+		mr_next = LIST_NEXT(mr, mr);
+		LIST_REMOVE(mr, mr);
+		LIST_INSERT_HEAD(&share_cache->mr_free_list, mr, mr);
+	}
+	LIST_INIT(&share_cache->mr_list);
+	/* Free global cache. */
+	mlx5_mr_btree_free(&share_cache->cache);
+	rte_rwlock_write_unlock(&share_cache->rwlock);
+	/* Free all remaining MRs. */
+	mlx5_mr_garbage_collect(share_cache);
+}
+
+/**
+ * Flush all of the local cache entries.
+ *
+ * @param mr_ctrl
+ *   Pointer to per-queue MR local cache.
+ */
+void
+mlx5_mr_flush_local_cache(struct mlx5_mr_ctrl *mr_ctrl)
+{
+	/* Reset the most-recently-used index. */
+	mr_ctrl->mru = 0;
+	/* Reset the linear search array. */
+	mr_ctrl->head = 0;
+	memset(mr_ctrl->cache, 0, sizeof(mr_ctrl->cache));
+	/* Reset the B-tree table. */
+	mr_ctrl->cache_bh.len = 1;
+	mr_ctrl->cache_bh.overflow = 0;
+	/* Update the generation number. */
+	mr_ctrl->cur_gen = *mr_ctrl->dev_gen_ptr;
+	DRV_LOG(DEBUG, "mr_ctrl(%p): flushed, cur_gen=%d",
+		(void *)mr_ctrl, mr_ctrl->cur_gen);
+}
+
+/**
+ * Creates a memory region for external memory, that is memory which is not
+ * part of the DPDK memory segments.
+ *
+ * @param pd
+ *   Pointer to ibv_pd of a device (net, regex, vdpa,...).
+ * @param addr
+ *   Starting virtual address of memory.
+ * @param len
+ *   Length of memory segment being mapped.
+ * @param socked_id
+ *   Socket to allocate heap memory for the control structures.
+ *
+ * @return
+ *   Pointer to MR structure on success, NULL otherwise.
+ */
+struct mlx5_mr *
+mlx5_create_mr_ext(struct ibv_pd *pd, uintptr_t addr, size_t len, int socket_id)
+{
+	struct mlx5_mr *mr = NULL;
+
+	mr = rte_zmalloc_socket(NULL,
+				RTE_ALIGN_CEIL(sizeof(*mr),
+					       RTE_CACHE_LINE_SIZE),
+				RTE_CACHE_LINE_SIZE, socket_id);
+	if (mr == NULL)
+		return NULL;
+	mr->ibv_mr = mlx5_glue->reg_mr(pd, (void *)addr, len,
+				       IBV_ACCESS_LOCAL_WRITE);
+	if (mr->ibv_mr == NULL) {
+		DRV_LOG(WARNING,
+			"Fail to create a verbs MR for address (%p)",
+			(void *)addr);
+		rte_free(mr);
+		return NULL;
+	}
+	mr->msl = NULL; /* Mark it is external memory. */
+	mr->ms_bmp = NULL;
+	mr->ms_n = 1;
+	mr->ms_bmp_n = 1;
+	DRV_LOG(DEBUG,
+		"MR CREATED (%p) for external memory %p:\n"
+		"  [0x%" PRIxPTR ", 0x%" PRIxPTR "),"
+		" lkey=0x%x base_idx=%u ms_n=%u, ms_bmp_n=%u",
+		(void *)mr, (void *)addr,
+		addr, addr + len, rte_cpu_to_be_32(mr->ibv_mr->lkey),
+		mr->ms_base_idx, mr->ms_n, mr->ms_bmp_n);
+	return mr;
+}
+
+/**
+ * Dump all the created MRs and the global cache entries.
+ *
+ * @param sh
+ *   Pointer to Ethernet device shared context.
+ */
+void
+mlx5_mr_dump_cache(struct mlx5_mr_share_cache *share_cache __rte_unused)
+{
+#ifdef RTE_LIBRTE_MLX5_DEBUG
+	struct mlx5_mr *mr;
+	int mr_n = 0;
+	int chunk_n = 0;
+
+	rte_rwlock_read_lock(&share_cache->rwlock);
+	/* Iterate all the existing MRs. */
+	LIST_FOREACH(mr, &share_cache->mr_list, mr) {
+		unsigned int n;
+
+		DEBUG("MR[%u], LKey = 0x%x, ms_n = %u, ms_bmp_n = %u",
+		      mr_n++, rte_cpu_to_be_32(mr->ibv_mr->lkey),
+		      mr->ms_n, mr->ms_bmp_n);
+		if (mr->ms_n == 0)
+			continue;
+		for (n = 0; n < mr->ms_bmp_n; ) {
+			struct mr_cache_entry ret = { 0, };
+
+			n = mr_find_next_chunk(mr, &ret, n);
+			if (!ret.end)
+				break;
+			DEBUG("  chunk[%u], [0x%" PRIxPTR ", 0x%" PRIxPTR ")",
+			      chunk_n++, ret.start, ret.end);
+		}
+	}
+	DEBUG("Dumping global cache %p", (void *)share_cache);
+	mlx5_mr_btree_dump(&share_cache->cache);
+	rte_rwlock_read_unlock(&share_cache->rwlock);
+#endif
+}
diff --git a/drivers/common/mlx5/mlx5_common_mr.h b/drivers/common/mlx5/mlx5_common_mr.h
new file mode 100644
index 0000000000..e805f96375
--- /dev/null
+++ b/drivers/common/mlx5/mlx5_common_mr.h
@@ -0,0 +1,160 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2018 6WIND S.A.
+ * Copyright 2018 Mellanox Technologies, Ltd
+ */
+
+#ifndef RTE_PMD_MLX5_COMMON_MR_H_
+#define RTE_PMD_MLX5_COMMON_MR_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include <sys/queue.h>
+
+/* Verbs header. */
+/* ISO C doesn't support unnamed structs/unions, disabling -pedantic. */
+#ifdef PEDANTIC
+#pragma GCC diagnostic ignored "-Wpedantic"
+#endif
+#include <infiniband/verbs.h>
+#include <infiniband/mlx5dv.h>
+#ifdef PEDANTIC
+#pragma GCC diagnostic error "-Wpedantic"
+#endif
+
+#include <rte_rwlock.h>
+#include <rte_bitmap.h>
+#include <rte_memory.h>
+
+#include "mlx5_common_mp.h"
+
+/* Size of per-queue MR cache array for linear search. */
+#define MLX5_MR_CACHE_N 8
+#define MLX5_MR_BTREE_CACHE_N 256
+
+/* Memory Region object. */
+struct mlx5_mr {
+	LIST_ENTRY(mlx5_mr) mr; /**< Pointer to the prev/next entry. */
+	struct ibv_mr *ibv_mr; /* Verbs Memory Region. */
+	const struct rte_memseg_list *msl;
+	int ms_base_idx; /* Start index of msl->memseg_arr[]. */
+	int ms_n; /* Number of memsegs in use. */
+	uint32_t ms_bmp_n; /* Number of bits in memsegs bit-mask. */
+	struct rte_bitmap *ms_bmp; /* Bit-mask of memsegs belonged to MR. */
+};
+
+/* Cache entry for Memory Region. */
+struct mr_cache_entry {
+	uintptr_t start; /* Start address of MR. */
+	uintptr_t end; /* End address of MR. */
+	uint32_t lkey; /* rte_cpu_to_be_32(ibv_mr->lkey). */
+} __rte_packed;
+
+/* MR Cache table for Binary search. */
+struct mlx5_mr_btree {
+	uint16_t len; /* Number of entries. */
+	uint16_t size; /* Total number of entries. */
+	int overflow; /* Mark failure of table expansion. */
+	struct mr_cache_entry (*table)[];
+} __rte_packed;
+
+/* Per-queue MR control descriptor. */
+struct mlx5_mr_ctrl {
+	uint32_t *dev_gen_ptr; /* Generation number of device to poll. */
+	uint32_t cur_gen; /* Generation number saved to flush caches. */
+	uint16_t mru; /* Index of last hit entry in top-half cache. */
+	uint16_t head; /* Index of the oldest entry in top-half cache. */
+	struct mr_cache_entry cache[MLX5_MR_CACHE_N]; /* Cache for top-half. */
+	struct mlx5_mr_btree cache_bh; /* Cache for bottom-half. */
+} __rte_packed;
+
+LIST_HEAD(mlx5_mr_list, mlx5_mr);
+
+/* Global per-device MR cache. */
+struct mlx5_mr_share_cache {
+	uint32_t dev_gen; /* Generation number to flush local caches. */
+	rte_rwlock_t rwlock; /* MR cache Lock. */
+	struct mlx5_mr_btree cache; /* Global MR cache table. */
+	struct mlx5_mr_list mr_list; /* Registered MR list. */
+	struct mlx5_mr_list mr_free_list; /* Freed MR list. */
+} __rte_packed;
+
+/**
+ * Look up LKey from given lookup table by linear search. Firstly look up the
+ * last-hit entry. If miss, the entire array is searched. If found, update the
+ * last-hit index and return LKey.
+ *
+ * @param lkp_tbl
+ *   Pointer to lookup table.
+ * @param[in,out] cached_idx
+ *   Pointer to last-hit index.
+ * @param n
+ *   Size of lookup table.
+ * @param addr
+ *   Search key.
+ *
+ * @return
+ *   Searched LKey on success, UINT32_MAX on no match.
+ */
+static __rte_always_inline uint32_t
+mlx5_mr_lookup_lkey(struct mr_cache_entry *lkp_tbl, uint16_t *cached_idx,
+		    uint16_t n, uintptr_t addr)
+{
+	uint16_t idx;
+
+	if (likely(addr >= lkp_tbl[*cached_idx].start &&
+		   addr < lkp_tbl[*cached_idx].end))
+		return lkp_tbl[*cached_idx].lkey;
+	for (idx = 0; idx < n && lkp_tbl[idx].start != 0; ++idx) {
+		if (addr >= lkp_tbl[idx].start &&
+		    addr < lkp_tbl[idx].end) {
+			/* Found. */
+			*cached_idx = idx;
+			return lkp_tbl[idx].lkey;
+		}
+	}
+	return UINT32_MAX;
+}
+
+__rte_experimental
+int mlx5_mr_btree_init(struct mlx5_mr_btree *bt, int n, int socket);
+__rte_experimental
+void mlx5_mr_btree_free(struct mlx5_mr_btree *bt);
+__rte_experimental
+void mlx5_mr_btree_dump(struct mlx5_mr_btree *bt __rte_unused);
+__rte_experimental
+uint32_t mlx5_mr_addr2mr_bh(struct ibv_pd *pd, struct mlx5_mp_id *mp_id,
+			    struct mlx5_mr_share_cache *share_cache,
+			    struct mlx5_mr_ctrl *mr_ctrl,
+			    uintptr_t addr, unsigned int mr_ext_memseg_en);
+__rte_experimental
+void mlx5_mr_release_cache(struct mlx5_mr_share_cache *mr_cache);
+__rte_experimental
+void mlx5_mr_dump_cache(struct mlx5_mr_share_cache *share_cache __rte_unused);
+__rte_experimental
+void mlx5_mr_rebuild_cache(struct mlx5_mr_share_cache *share_cache);
+__rte_experimental
+void mlx5_mr_flush_local_cache(struct mlx5_mr_ctrl *mr_ctrl);
+__rte_experimental
+int
+mlx5_mr_insert_cache(struct mlx5_mr_share_cache *share_cache,
+		     struct mlx5_mr *mr);
+__rte_experimental
+uint32_t
+mlx5_mr_lookup_cache(struct mlx5_mr_share_cache *share_cache,
+		     struct mr_cache_entry *entry, uintptr_t addr);
+__rte_experimental
+struct mlx5_mr *
+mlx5_mr_lookup_list(struct mlx5_mr_share_cache *share_cache,
+		    struct mr_cache_entry *entry, uintptr_t addr);
+__rte_experimental
+struct mlx5_mr *
+mlx5_create_mr_ext(struct ibv_pd *pd, uintptr_t addr, size_t len,
+		   int socket_id);
+__rte_experimental
+uint32_t
+mlx5_mr_create_primary(struct ibv_pd *pd,
+		       struct mlx5_mr_share_cache *share_cache,
+		       struct mr_cache_entry *entry, uintptr_t addr,
+		       unsigned int mr_ext_memseg_en);
+
+#endif /* RTE_PMD_MLX5_COMMON_MR_H_ */
diff --git a/drivers/common/mlx5/rte_common_mlx5_version.map b/drivers/common/mlx5/rte_common_mlx5_version.map
index 265703d1c9..b58a378278 100644
--- a/drivers/common/mlx5/rte_common_mlx5_version.map
+++ b/drivers/common/mlx5/rte_common_mlx5_version.map
@@ -61,4 +61,18 @@ EXPERIMENTAL {
 	mlx5_mp_req_mr_create;
 	mlx5_mp_req_queue_state_modify;
 	mlx5_mp_req_verbs_cmd_fd;
+
+	mlx5_mr_btree_init;
+	mlx5_mr_btree_free;
+	mlx5_mr_btree_dump;
+	mlx5_mr_addr2mr_bh;
+	mlx5_mr_release_cache;
+	mlx5_mr_dump_cache;
+	mlx5_mr_rebuild_cache;
+	mlx5_mr_insert_cache;
+	mlx5_mr_lookup_cache;
+	mlx5_mr_lookup_list;
+	mlx5_create_mr_ext;
+	mlx5_mr_create_primary;
+	mlx5_mr_flush_local_cache;
 };
-- 
2.16.6