Merge branch 'bpf-nfp-map-offload'

Jakub Kicinski says:

====================
This set adds support for creating maps on networking devices.  BPF is
programs+maps, the pure program offload has been around for quite some
time, this patchset adds the map part of the equation.

Maps are allocated on the target device from the start.  There is no
host copy when map is created on the device.  Device maps are represented
by struct bpf_offloaded_map, regardless of type.  Host programs can't
access such maps, access is only possible from a program also loaded
to the same device and/or via the BPF syscall.

Offloaded programs are currently only allowed to perform lookups,
control plane is responsible for populating the maps.

For brevity only infrastructure and basic NFP patches are included.
Target device reporting, netdevsim and tests will follow up as well as
some further optimizations to the NFP code.

v2:
 - leave out the array maps, we will add them trivially later to avoid
   merge conflicts with ongoing spectere&meltdown mitigations.
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

9 files changed, 337 insertions, 105 deletions

diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index ce5b669003b2..192151ec9d12 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -94,13 +94,7 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
 	if (!cmap)
 		return ERR_PTR(-ENOMEM);
 
-	/* mandatory map attributes */
-	cmap->map.map_type = attr->map_type;
-	cmap->map.key_size = attr->key_size;
-	cmap->map.value_size = attr->value_size;
-	cmap->map.max_entries = attr->max_entries;
-	cmap->map.map_flags = attr->map_flags;
-	cmap->map.numa_node = bpf_map_attr_numa_node(attr);
+	bpf_map_init_from_attr(&cmap->map, attr);
 
 	/* Pre-limit array size based on NR_CPUS, not final CPU check */
 	if (cmap->map.max_entries > NR_CPUS) {
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index ebdef54bf7df..565f9ece9115 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -93,13 +93,7 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
 	if (!dtab)
 		return ERR_PTR(-ENOMEM);
 
-	/* mandatory map attributes */
-	dtab->map.map_type = attr->map_type;
-	dtab->map.key_size = attr->key_size;
-	dtab->map.value_size = attr->value_size;
-	dtab->map.max_entries = attr->max_entries;
-	dtab->map.map_flags = attr->map_flags;
-	dtab->map.numa_node = bpf_map_attr_numa_node(attr);
+	bpf_map_init_from_attr(&dtab->map, attr);
 
 	/* make sure page count doesn't overflow */
 	cost = (u64) dtab->map.max_entries * sizeof(struct bpf_dtab_netdev *);
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 3905d4bc5b80..b76828f23b49 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -227,7 +227,7 @@ static int alloc_extra_elems(struct bpf_htab *htab)
 }
 
 /* Called from syscall */
-static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
+static int htab_map_alloc_check(union bpf_attr *attr)
 {
 	bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
 		       attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
@@ -241,9 +241,6 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 	bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
 	bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
 	int numa_node = bpf_map_attr_numa_node(attr);
-	struct bpf_htab *htab;
-	int err, i;
-	u64 cost;
 
 	BUILD_BUG_ON(offsetof(struct htab_elem, htab) !=
 		     offsetof(struct htab_elem, hash_node.pprev));
@@ -254,40 +251,68 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 		/* LRU implementation is much complicated than other
 		 * maps.  Hence, limit to CAP_SYS_ADMIN for now.
 		 */
-		return ERR_PTR(-EPERM);
+		return -EPERM;
 
 	if (attr->map_flags & ~HTAB_CREATE_FLAG_MASK)
 		/* reserved bits should not be used */
-		return ERR_PTR(-EINVAL);
+		return -EINVAL;
 
 	if (!lru && percpu_lru)
-		return ERR_PTR(-EINVAL);
+		return -EINVAL;
 
 	if (lru && !prealloc)
-		return ERR_PTR(-ENOTSUPP);
+		return -ENOTSUPP;
 
 	if (numa_node != NUMA_NO_NODE && (percpu || percpu_lru))
-		return ERR_PTR(-EINVAL);
+		return -EINVAL;
+
+	/* check sanity of attributes.
+	 * value_size == 0 may be allowed in the future to use map as a set
+	 */
+	if (attr->max_entries == 0 || attr->key_size == 0 ||
+	    attr->value_size == 0)
+		return -EINVAL;
+
+	if (attr->key_size > MAX_BPF_STACK)
+		/* eBPF programs initialize keys on stack, so they cannot be
+		 * larger than max stack size
+		 */
+		return -E2BIG;
+
+	if (attr->value_size >= KMALLOC_MAX_SIZE -
+	    MAX_BPF_STACK - sizeof(struct htab_elem))
+		/* if value_size is bigger, the user space won't be able to
+		 * access the elements via bpf syscall. This check also makes
+		 * sure that the elem_size doesn't overflow and it's
+		 * kmalloc-able later in htab_map_update_elem()
+		 */
+		return -E2BIG;
+
+	return 0;
+}
+
+static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
+{
+	bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+		       attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
+	bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH ||
+		    attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
+	/* percpu_lru means each cpu has its own LRU list.
+	 * it is different from BPF_MAP_TYPE_PERCPU_HASH where
+	 * the map's value itself is percpu.  percpu_lru has
+	 * nothing to do with the map's value.
+	 */
+	bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
+	bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
+	struct bpf_htab *htab;
+	int err, i;
+	u64 cost;
 
 	htab = kzalloc(sizeof(*htab), GFP_USER);
 	if (!htab)
 		return ERR_PTR(-ENOMEM);
 
-	/* mandatory map attributes */
-	htab->map.map_type = attr->map_type;
-	htab->map.key_size = attr->key_size;
-	htab->map.value_size = attr->value_size;
-	htab->map.max_entries = attr->max_entries;
-	htab->map.map_flags = attr->map_flags;
-	htab->map.numa_node = numa_node;
-
-	/* check sanity of attributes.
-	 * value_size == 0 may be allowed in the future to use map as a set
-	 */
-	err = -EINVAL;
-	if (htab->map.max_entries == 0 || htab->map.key_size == 0 ||
-	    htab->map.value_size == 0)
-		goto free_htab;
+	bpf_map_init_from_attr(&htab->map, attr);
 
 	if (percpu_lru) {
 		/* ensure each CPU's lru list has >=1 elements.
@@ -304,22 +329,6 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 	/* hash table size must be power of 2 */
 	htab->n_buckets = roundup_pow_of_two(htab->map.max_entries);
 
-	err = -E2BIG;
-	if (htab->map.key_size > MAX_BPF_STACK)
-		/* eBPF programs initialize keys on stack, so they cannot be
-		 * larger than max stack size
-		 */
-		goto free_htab;
-
-	if (htab->map.value_size >= KMALLOC_MAX_SIZE -
-	    MAX_BPF_STACK - sizeof(struct htab_elem))
-		/* if value_size is bigger, the user space won't be able to
-		 * access the elements via bpf syscall. This check also makes
-		 * sure that the elem_size doesn't overflow and it's
-		 * kmalloc-able later in htab_map_update_elem()
-		 */
-		goto free_htab;
-
 	htab->elem_size = sizeof(struct htab_elem) +
 			  round_up(htab->map.key_size, 8);
 	if (percpu)
@@ -327,6 +336,7 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 	else
 		htab->elem_size += round_up(htab->map.value_size, 8);
 
+	err = -E2BIG;
 	/* prevent zero size kmalloc and check for u32 overflow */
 	if (htab->n_buckets == 0 ||
 	    htab->n_buckets > U32_MAX / sizeof(struct bucket))
@@ -1143,6 +1153,7 @@ static void htab_map_free(struct bpf_map *map)
 }
 
 const struct bpf_map_ops htab_map_ops = {
+	.map_alloc_check = htab_map_alloc_check,
 	.map_alloc = htab_map_alloc,
 	.map_free = htab_map_free,
 	.map_get_next_key = htab_map_get_next_key,
@@ -1153,6 +1164,7 @@ const struct bpf_map_ops htab_map_ops = {
 };
 
 const struct bpf_map_ops htab_lru_map_ops = {
+	.map_alloc_check = htab_map_alloc_check,
 	.map_alloc = htab_map_alloc,
 	.map_free = htab_map_free,
 	.map_get_next_key = htab_map_get_next_key,
@@ -1236,6 +1248,7 @@ int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
 }
 
 const struct bpf_map_ops htab_percpu_map_ops = {
+	.map_alloc_check = htab_map_alloc_check,
 	.map_alloc = htab_map_alloc,
 	.map_free = htab_map_free,
 	.map_get_next_key = htab_map_get_next_key,
@@ -1245,6 +1258,7 @@ const struct bpf_map_ops htab_percpu_map_ops = {
 };
 
 const struct bpf_map_ops htab_lru_percpu_map_ops = {
+	.map_alloc_check = htab_map_alloc_check,
 	.map_alloc = htab_map_alloc,
 	.map_free = htab_map_free,
 	.map_get_next_key = htab_map_get_next_key,
@@ -1253,11 +1267,11 @@ const struct bpf_map_ops htab_lru_percpu_map_ops = {
 	.map_delete_elem = htab_lru_map_delete_elem,
 };
 
-static struct bpf_map *fd_htab_map_alloc(union bpf_attr *attr)
+static int fd_htab_map_alloc_check(union bpf_attr *attr)
 {
 	if (attr->value_size != sizeof(u32))
-		return ERR_PTR(-EINVAL);
-	return htab_map_alloc(attr);
+		return -EINVAL;
+	return htab_map_alloc_check(attr);
 }
 
 static void fd_htab_map_free(struct bpf_map *map)
@@ -1328,7 +1342,7 @@ static struct bpf_map *htab_of_map_alloc(union bpf_attr *attr)
 	if (IS_ERR(inner_map_meta))
 		return inner_map_meta;
 
-	map = fd_htab_map_alloc(attr);
+	map = htab_map_alloc(attr);
 	if (IS_ERR(map)) {
 		bpf_map_meta_free(inner_map_meta);
 		return map;
@@ -1372,6 +1386,7 @@ static void htab_of_map_free(struct bpf_map *map)
 }
 
 const struct bpf_map_ops htab_of_maps_map_ops = {
+	.map_alloc_check = fd_htab_map_alloc_check,
 	.map_alloc = htab_of_map_alloc,
 	.map_free = htab_of_map_free,
 	.map_get_next_key = htab_map_get_next_key,
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
index 885e45479680..584e02227671 100644
--- a/kernel/bpf/lpm_trie.c
+++ b/kernel/bpf/lpm_trie.c
@@ -522,12 +522,7 @@ static struct bpf_map *trie_alloc(union bpf_attr *attr)
 		return ERR_PTR(-ENOMEM);
 
 	/* copy mandatory map attributes */
-	trie->map.map_type = attr->map_type;
-	trie->map.key_size = attr->key_size;
-	trie->map.value_size = attr->value_size;
-	trie->map.max_entries = attr->max_entries;
-	trie->map.map_flags = attr->map_flags;
-	trie->map.numa_node = bpf_map_attr_numa_node(attr);
+	bpf_map_init_from_attr(&trie->map, attr);
 	trie->data_size = attr->key_size -
 			  offsetof(struct bpf_lpm_trie_key, data);
 	trie->max_prefixlen = trie->data_size * 8;
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
index 040d4e0edf3f..453785fa1881 100644
--- a/kernel/bpf/offload.c
+++ b/kernel/bpf/offload.c
@@ -24,15 +24,27 @@
 #include <linux/rtnetlink.h>
 #include <linux/rwsem.h>
 
-/* Protects bpf_prog_offload_devs and offload members of all progs.
+/* Protects bpf_prog_offload_devs, bpf_map_offload_devs and offload members
+ * of all progs.
  * RTNL lock cannot be taken when holding this lock.
  */
 static DECLARE_RWSEM(bpf_devs_lock);
 static LIST_HEAD(bpf_prog_offload_devs);
+static LIST_HEAD(bpf_map_offload_devs);
+
+static int bpf_dev_offload_check(struct net_device *netdev)
+{
+	if (!netdev)
+		return -EINVAL;
+	if (!netdev->netdev_ops->ndo_bpf)
+		return -EOPNOTSUPP;
+	return 0;
+}
 
 int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
 {
-	struct bpf_dev_offload *offload;
+	struct bpf_prog_offload *offload;
+	int err;
 
 	if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS &&
 	    attr->prog_type != BPF_PROG_TYPE_XDP)
@@ -49,12 +61,15 @@ int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
 
 	offload->netdev = dev_get_by_index(current->nsproxy->net_ns,
 					   attr->prog_ifindex);
-	if (!offload->netdev)
-		goto err_free;
+	err = bpf_dev_offload_check(offload->netdev);
+	if (err)
+		goto err_maybe_put;
 
 	down_write(&bpf_devs_lock);
-	if (offload->netdev->reg_state != NETREG_REGISTERED)
+	if (offload->netdev->reg_state != NETREG_REGISTERED) {
+		err = -EINVAL;
 		goto err_unlock;
+	}
 	prog->aux->offload = offload;
 	list_add_tail(&offload->offloads, &bpf_prog_offload_devs);
 	dev_put(offload->netdev);
@@ -63,16 +78,17 @@ int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
 	return 0;
 err_unlock:
 	up_write(&bpf_devs_lock);
-	dev_put(offload->netdev);
-err_free:
+err_maybe_put:
+	if (offload->netdev)
+		dev_put(offload->netdev);
 	kfree(offload);
-	return -EINVAL;
+	return err;
 }
 
 static int __bpf_offload_ndo(struct bpf_prog *prog, enum bpf_netdev_command cmd,
 			     struct netdev_bpf *data)
 {
-	struct bpf_dev_offload *offload = prog->aux->offload;
+	struct bpf_prog_offload *offload = prog->aux->offload;
 	struct net_device *netdev;
 
 	ASSERT_RTNL();
@@ -80,8 +96,6 @@ static int __bpf_offload_ndo(struct bpf_prog *prog, enum bpf_netdev_command cmd,
 	if (!offload)
 		return -ENODEV;
 	netdev = offload->netdev;
-	if (!netdev->netdev_ops->ndo_bpf)
-		return -EOPNOTSUPP;
 
 	data->command = cmd;
 
@@ -110,7 +124,7 @@ exit_unlock:
 int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
 				 int insn_idx, int prev_insn_idx)
 {
-	struct bpf_dev_offload *offload;
+	struct bpf_prog_offload *offload;
 	int ret = -ENODEV;
 
 	down_read(&bpf_devs_lock);
@@ -124,7 +138,7 @@ int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
 
 static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
 {
-	struct bpf_dev_offload *offload = prog->aux->offload;
+	struct bpf_prog_offload *offload = prog->aux->offload;
 	struct netdev_bpf data = {};
 
 	data.offload.prog = prog;
@@ -238,11 +252,186 @@ int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
 const struct bpf_prog_ops bpf_offload_prog_ops = {
 };
 
+static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap,
+			       enum bpf_netdev_command cmd)
+{
+	struct netdev_bpf data = {};
+	struct net_device *netdev;
+
+	ASSERT_RTNL();
+
+	data.command = cmd;
+	data.offmap = offmap;
+	/* Caller must make sure netdev is valid */
+	netdev = offmap->netdev;
+
+	return netdev->netdev_ops->ndo_bpf(netdev, &data);
+}
+
+struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr)
+{
+	struct net *net = current->nsproxy->net_ns;
+	struct bpf_offloaded_map *offmap;
+	int err;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return ERR_PTR(-EPERM);
+	if (attr->map_type != BPF_MAP_TYPE_HASH)
+		return ERR_PTR(-EINVAL);
+
+	offmap = kzalloc(sizeof(*offmap), GFP_USER);
+	if (!offmap)
+		return ERR_PTR(-ENOMEM);
+
+	bpf_map_init_from_attr(&offmap->map, attr);
+
+	rtnl_lock();
+	down_write(&bpf_devs_lock);
+	offmap->netdev = __dev_get_by_index(net, attr->map_ifindex);
+	err = bpf_dev_offload_check(offmap->netdev);
+	if (err)
+		goto err_unlock;
+
+	err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC);
+	if (err)
+		goto err_unlock;
+
+	list_add_tail(&offmap->offloads, &bpf_map_offload_devs);
+	up_write(&bpf_devs_lock);
+	rtnl_unlock();
+
+	return &offmap->map;
+
+err_unlock:
+	up_write(&bpf_devs_lock);
+	rtnl_unlock();
+	kfree(offmap);
+	return ERR_PTR(err);
+}
+
+static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap)
+{
+	WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE));
+	/* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */
+	bpf_map_free_id(&offmap->map, true);
+	list_del_init(&offmap->offloads);
+	offmap->netdev = NULL;
+}
+
+void bpf_map_offload_map_free(struct bpf_map *map)
+{
+	struct bpf_offloaded_map *offmap = map_to_offmap(map);
+
+	rtnl_lock();
+	down_write(&bpf_devs_lock);
+	if (offmap->netdev)
+		__bpf_map_offload_destroy(offmap);
+	up_write(&bpf_devs_lock);
+	rtnl_unlock();
+
+	kfree(offmap);
+}
+
+int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value)
+{
+	struct bpf_offloaded_map *offmap = map_to_offmap(map);
+	int ret = -ENODEV;
+
+	down_read(&bpf_devs_lock);
+	if (offmap->netdev)
+		ret = offmap->dev_ops->map_lookup_elem(offmap, key, value);
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+int bpf_map_offload_update_elem(struct bpf_map *map,
+				void *key, void *value, u64 flags)
+{
+	struct bpf_offloaded_map *offmap = map_to_offmap(map);
+	int ret = -ENODEV;
+
+	if (unlikely(flags > BPF_EXIST))
+		return -EINVAL;
+
+	down_read(&bpf_devs_lock);
+	if (offmap->netdev)
+		ret = offmap->dev_ops->map_update_elem(offmap, key, value,
+						       flags);
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+int bpf_map_offload_delete_elem(struct bpf_map *map, void *key)
+{
+	struct bpf_offloaded_map *offmap = map_to_offmap(map);
+	int ret = -ENODEV;
+
+	down_read(&bpf_devs_lock);
+	if (offmap->netdev)
+		ret = offmap->dev_ops->map_delete_elem(offmap, key);
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+	struct bpf_offloaded_map *offmap = map_to_offmap(map);
+	int ret = -ENODEV;
+
+	down_read(&bpf_devs_lock);
+	if (offmap->netdev)
+		ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key);
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+bool bpf_offload_dev_match(struct bpf_prog *prog, struct bpf_map *map)
+{
+	struct bpf_offloaded_map *offmap;
+	struct bpf_prog_offload *offload;
+	bool ret;
+
+	if (!!bpf_prog_is_dev_bound(prog->aux) != !!bpf_map_is_dev_bound(map))
+		return false;
+	if (!bpf_prog_is_dev_bound(prog->aux))
+		return true;
+
+	down_read(&bpf_devs_lock);
+	offload = prog->aux->offload;
+	offmap = map_to_offmap(map);
+
+	ret = offload && offload->netdev == offmap->netdev;
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
+static void bpf_offload_orphan_all_progs(struct net_device *netdev)
+{
+	struct bpf_prog_offload *offload, *tmp;
+
+	list_for_each_entry_safe(offload, tmp, &bpf_prog_offload_devs, offloads)
+		if (offload->netdev == netdev)
+			__bpf_prog_offload_destroy(offload->prog);
+}
+
+static void bpf_offload_orphan_all_maps(struct net_device *netdev)
+{
+	struct bpf_offloaded_map *offmap, *tmp;
+
+	list_for_each_entry_safe(offmap, tmp, &bpf_map_offload_devs, offloads)
+		if (offmap->netdev == netdev)
+			__bpf_map_offload_destroy(offmap);
+}
+
 static int bpf_offload_notification(struct notifier_block *notifier,
 				    ulong event, void *ptr)
 {
 	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
-	struct bpf_dev_offload *offload, *tmp;
 
 	ASSERT_RTNL();
 
@@ -253,11 +442,8 @@ static int bpf_offload_notification(struct notifier_block *notifier,
 			break;
 
 		down_write(&bpf_devs_lock);
-		list_for_each_entry_safe(offload, tmp, &bpf_prog_offload_devs,
-					 offloads) {
-			if (offload->netdev == netdev)
-				__bpf_prog_offload_destroy(offload->prog);
-		}
+		bpf_offload_orphan_all_progs(netdev);
+		bpf_offload_orphan_all_maps(netdev);
 		up_write(&bpf_devs_lock);
 		break;
 	default:
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 079968680bc3..0314d1783d77 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -513,13 +513,7 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
 	if (!stab)
 		return ERR_PTR(-ENOMEM);
 
-	/* mandatory map attributes */
-	stab->map.map_type = attr->map_type;
-	stab->map.key_size = attr->key_size;
-	stab->map.value_size = attr->value_size;
-	stab->map.max_entries = attr->max_entries;
-	stab->map.map_flags = attr->map_flags;
-	stab->map.numa_node = bpf_map_attr_numa_node(attr);
+	bpf_map_init_from_attr(&stab->map, attr);
 
 	/* make sure page count doesn't overflow */
 	cost = (u64) stab->map.max_entries * sizeof(struct sock *);
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index 6c63c2222ea8..b0ecf43f5894 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -88,14 +88,10 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr)
 	if (cost >= U32_MAX - PAGE_SIZE)
 		goto free_smap;
 
-	smap->map.map_type = attr->map_type;
-	smap->map.key_size = attr->key_size;
+	bpf_map_init_from_attr(&smap->map, attr);
 	smap->map.value_size = value_size;
-	smap->map.max_entries = attr->max_entries;
-	smap->map.map_flags = attr->map_flags;
 	smap->n_buckets = n_buckets;
 	smap->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
-	smap->map.numa_node = bpf_map_attr_numa_node(attr);
 
 	err = bpf_map_precharge_memlock(smap->map.pages);
 	if (err)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 2bac0dc8baba..c691b9e972e3 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -94,18 +94,34 @@ static int check_uarg_tail_zero(void __user *uaddr,
 	return 0;
 }
 
+const struct bpf_map_ops bpf_map_offload_ops = {
+	.map_alloc = bpf_map_offload_map_alloc,
+	.map_free = bpf_map_offload_map_free,
+};
+
 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
 {
+	const struct bpf_map_ops *ops;
 	struct bpf_map *map;
+	int err;
 
-	if (attr->map_type >= ARRAY_SIZE(bpf_map_types) ||
-	    !bpf_map_types[attr->map_type])
+	if (attr->map_type >= ARRAY_SIZE(bpf_map_types))
+		return ERR_PTR(-EINVAL);
+	ops = bpf_map_types[attr->map_type];
+	if (!ops)
 		return ERR_PTR(-EINVAL);
 
-	map = bpf_map_types[attr->map_type]->map_alloc(attr);
+	if (ops->map_alloc_check) {
+		err = ops->map_alloc_check(attr);
+		if (err)
+			return ERR_PTR(err);
+	}
+	if (attr->map_ifindex)
+		ops = &bpf_map_offload_ops;
+	map = ops->map_alloc(attr);
 	if (IS_ERR(map))
 		return map;
-	map->ops = bpf_map_types[attr->map_type];
+	map->ops = ops;
 	map->map_type = attr->map_type;
 	return map;
 }
@@ -134,6 +150,16 @@ void bpf_map_area_free(void *area)
 	kvfree(area);
 }
 
+void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
+{
+	map->map_type = attr->map_type;
+	map->key_size = attr->key_size;
+	map->value_size = attr->value_size;
+	map->max_entries = attr->max_entries;
+	map->map_flags = attr->map_flags;
+	map->numa_node = bpf_map_attr_numa_node(attr);
+}
+
 int bpf_map_precharge_memlock(u32 pages)
 {
 	struct user_struct *user = get_current_user();
@@ -189,16 +215,25 @@ static int bpf_map_alloc_id(struct bpf_map *map)
 	return id > 0 ? 0 : id;
 }
 
-static void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
+void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
 {
 	unsigned long flags;
 
+	/* Offloaded maps are removed from the IDR store when their device
+	 * disappears - even if someone holds an fd to them they are unusable,
+	 * the memory is gone, all ops will fail; they are simply waiting for
+	 * refcnt to drop to be freed.
+	 */
+	if (!map->id)
+		return;
+
 	if (do_idr_lock)
 		spin_lock_irqsave(&map_idr_lock, flags);
 	else
 		__acquire(&map_idr_lock);
 
 	idr_remove(&map_idr, map->id);
+	map->id = 0;
 
 	if (do_idr_lock)
 		spin_unlock_irqrestore(&map_idr_lock, flags);
@@ -378,7 +413,7 @@ static int bpf_obj_name_cpy(char *dst, const char *src)
 	return 0;
 }
 
-#define BPF_MAP_CREATE_LAST_FIELD map_name
+#define BPF_MAP_CREATE_LAST_FIELD map_ifindex
 /* called via syscall */
 static int map_create(union bpf_attr *attr)
 {
@@ -566,8 +601,10 @@ static int map_lookup_elem(union bpf_attr *attr)
 	if (!value)
 		goto free_key;
 
-	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
-	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
+	if (bpf_map_is_dev_bound(map)) {
+		err = bpf_map_offload_lookup_elem(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+		   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
 		err = bpf_percpu_hash_copy(map, key, value);
 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
 		err = bpf_percpu_array_copy(map, key, value);
@@ -654,7 +691,10 @@ static int map_update_elem(union bpf_attr *attr)
 		goto free_value;
 
 	/* Need to create a kthread, thus must support schedule */
-	if (map->map_type == BPF_MAP_TYPE_CPUMAP) {
+	if (bpf_map_is_dev_bound(map)) {
+		err = bpf_map_offload_update_elem(map, key, value, attr->flags);
+		goto out;
+	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP) {
 		err = map->ops->map_update_elem(map, key, value, attr->flags);
 		goto out;
 	}
@@ -731,6 +771,11 @@ static int map_delete_elem(union bpf_attr *attr)
 		goto err_put;
 	}
 
+	if (bpf_map_is_dev_bound(map)) {
+		err = bpf_map_offload_delete_elem(map, key);
+		goto out;
+	}
+
 	preempt_disable();
 	__this_cpu_inc(bpf_prog_active);
 	rcu_read_lock();
@@ -738,7 +783,7 @@ static int map_delete_elem(union bpf_attr *attr)
 	rcu_read_unlock();
 	__this_cpu_dec(bpf_prog_active);
 	preempt_enable();
-
+out:
 	if (!err)
 		trace_bpf_map_delete_elem(map, ufd, key);
 	kfree(key);
@@ -788,9 +833,15 @@ static int map_get_next_key(union bpf_attr *attr)
 	if (!next_key)
 		goto free_key;
 
+	if (bpf_map_is_dev_bound(map)) {
+		err = bpf_map_offload_get_next_key(map, key, next_key);
+		goto out;
+	}
+
 	rcu_read_lock();
 	err = map->ops->map_get_next_key(map, key, next_key);
 	rcu_read_unlock();
+out:
 	if (err)
 		goto free_next_key;
 
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 48b61caa94cb..ceabb394d2dc 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4816,6 +4816,13 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
 			return -EINVAL;
 		}
 	}
+
+	if ((bpf_prog_is_dev_bound(prog->aux) || bpf_map_is_dev_bound(map)) &&
+	    !bpf_offload_dev_match(prog, map)) {
+		verbose(env, "offload device mismatch between prog and map\n");
+		return -EINVAL;
+	}
+
 	return 0;
 }