Merge branch 'bpf-offload-sharing'

Jakub Kicinski says:

====================
This patchset adds support for sharing BPF objects within one ASIC.
This will allow us to reuse of the same program on multiple ports of
a device leading to better code store utilization.  It also enables
sharing maps between programs attached to different ports of a device.

v2:
 - rename bpf_offload_match() to bpf_offload_prog_map_match();
 - add split patches 7 into 5, 7 and 8.
====================

Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

drivers/net/ethernet/netronome/nfp/bpf/main.c

@@ -404,6 +404,20 @@ err_release_free:
 	return -EINVAL;
 }
 
+static int nfp_bpf_ndo_init(struct nfp_app *app, struct net_device *netdev)
+{
+	struct nfp_app_bpf *bpf = app->priv;
+
+	return bpf_offload_dev_netdev_register(bpf->bpf_dev, netdev);
+}
+
+static void nfp_bpf_ndo_uninit(struct nfp_app *app, struct net_device *netdev)
+{
+	struct nfp_app_bpf *bpf = app->priv;
+
+	bpf_offload_dev_netdev_unregister(bpf->bpf_dev, netdev);
+}
+
 static int nfp_bpf_init(struct nfp_app *app)
 {
 	struct nfp_app_bpf *bpf;
@@ -427,6 +441,11 @@ static int nfp_bpf_init(struct nfp_app *app)
 	if (err)
 		goto err_free_neutral_maps;
 
+	bpf->bpf_dev = bpf_offload_dev_create();
+	err = PTR_ERR_OR_ZERO(bpf->bpf_dev);
+	if (err)
+		goto err_free_neutral_maps;
+
 	return 0;
 
 err_free_neutral_maps:
@@ -445,6 +464,7 @@ static void nfp_bpf_clean(struct nfp_app *app)
 {
 	struct nfp_app_bpf *bpf = app->priv;
 
+	bpf_offload_dev_destroy(bpf->bpf_dev);
 	WARN_ON(!skb_queue_empty(&bpf->cmsg_replies));
 	WARN_ON(!list_empty(&bpf->map_list));
 	WARN_ON(bpf->maps_in_use || bpf->map_elems_in_use);
@@ -466,6 +486,9 @@ const struct nfp_app_type app_bpf = {
 
 	.extra_cap	= nfp_bpf_extra_cap,
 
+	.ndo_init	= nfp_bpf_ndo_init,
+	.ndo_uninit	= nfp_bpf_ndo_uninit,
+
 	.vnic_alloc	= nfp_bpf_vnic_alloc,
 	.vnic_free	= nfp_bpf_vnic_free,
 

drivers/net/ethernet/netronome/nfp/bpf/main.h

@@ -110,6 +110,8 @@ enum pkt_vec {
  * struct nfp_app_bpf - bpf app priv structure
  * @app:		backpointer to the app
  *
+ * @bpf_dev:		BPF offload device handle
+ *
  * @tag_allocator:	bitmap of control message tags in use
  * @tag_alloc_next:	next tag bit to allocate
  * @tag_alloc_last:	next tag bit to be freed
@@ -150,6 +152,8 @@ enum pkt_vec {
 struct nfp_app_bpf {
 	struct nfp_app *app;
 
+	struct bpf_offload_dev *bpf_dev;
+
 	DECLARE_BITMAP(tag_allocator, U16_MAX + 1);
 	u16 tag_alloc_next;
 	u16 tag_alloc_last;

drivers/net/ethernet/netronome/nfp/bpf/offload.c

@@ -566,14 +566,8 @@ int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
 {
 	int err;
 
-	if (prog) {
-		struct bpf_prog_offload *offload = prog->aux->offload;
-
-		if (!offload)
-			return -EINVAL;
-		if (offload->netdev != nn->dp.netdev)
-			return -EINVAL;
-	}
+	if (prog && !bpf_offload_dev_match(prog, nn->dp.netdev))
+		return -EINVAL;
 
 	if (prog && old_prog) {
 		u8 cap;

drivers/net/ethernet/netronome/nfp/nfp_app.c

@@ -86,6 +86,23 @@ const char *nfp_app_mip_name(struct nfp_app *app)
 	return nfp_mip_name(app->pf->mip);
 }
 
+int nfp_app_ndo_init(struct net_device *netdev)
+{
+	struct nfp_app *app = nfp_app_from_netdev(netdev);
+
+	if (!app || !app->type->ndo_init)
+		return 0;
+	return app->type->ndo_init(app, netdev);
+}
+
+void nfp_app_ndo_uninit(struct net_device *netdev)
+{
+	struct nfp_app *app = nfp_app_from_netdev(netdev);
+
+	if (app && app->type->ndo_uninit)
+		app->type->ndo_uninit(app, netdev);
+}
+
 u64 *nfp_app_port_get_stats(struct nfp_port *port, u64 *data)
 {
 	if (!port || !port->app || !port->app->type->port_get_stats)

drivers/net/ethernet/netronome/nfp/nfp_app.h

@@ -78,6 +78,8 @@ extern const struct nfp_app_type app_abm;
  * @init:	perform basic app checks and init
  * @clean:	clean app state
  * @extra_cap:	extra capabilities string
+ * @ndo_init:	vNIC and repr netdev .ndo_init
+ * @ndo_uninit:	vNIC and repr netdev .ndo_unint
  * @vnic_alloc:	allocate vNICs (assign port types, etc.)
  * @vnic_free:	free up app's vNIC state
  * @vnic_init:	vNIC netdev was registered
@@ -117,6 +119,9 @@ struct nfp_app_type {
 
 	const char *(*extra_cap)(struct nfp_app *app, struct nfp_net *nn);
 
+	int (*ndo_init)(struct nfp_app *app, struct net_device *netdev);
+	void (*ndo_uninit)(struct nfp_app *app, struct net_device *netdev);
+
 	int (*vnic_alloc)(struct nfp_app *app, struct nfp_net *nn,
 			  unsigned int id);
 	void (*vnic_free)(struct nfp_app *app, struct nfp_net *nn);
@@ -200,6 +205,9 @@ static inline void nfp_app_clean(struct nfp_app *app)
 		app->type->clean(app);
 }
 
+int nfp_app_ndo_init(struct net_device *netdev);
+void nfp_app_ndo_uninit(struct net_device *netdev);
+
 static inline int nfp_app_vnic_alloc(struct nfp_app *app, struct nfp_net *nn,
 				     unsigned int id)
 {

drivers/net/ethernet/netronome/nfp/nfp_net_common.c

@@ -3480,6 +3480,8 @@ static int nfp_net_set_mac_address(struct net_device *netdev, void *addr)
 }
 
 const struct net_device_ops nfp_net_netdev_ops = {
+	.ndo_init		= nfp_app_ndo_init,
+	.ndo_uninit		= nfp_app_ndo_uninit,
 	.ndo_open		= nfp_net_netdev_open,
 	.ndo_stop		= nfp_net_netdev_close,
 	.ndo_start_xmit		= nfp_net_tx,

drivers/net/ethernet/netronome/nfp/nfp_net_repr.c

@@ -262,6 +262,8 @@ err_port_disable:
 }
 
 const struct net_device_ops nfp_repr_netdev_ops = {
+	.ndo_init		= nfp_app_ndo_init,
+	.ndo_uninit		= nfp_app_ndo_uninit,
 	.ndo_open		= nfp_repr_open,
 	.ndo_stop		= nfp_repr_stop,
 	.ndo_start_xmit		= nfp_repr_xmit,

drivers/net/netdevsim/bpf.c

@@ -238,8 +238,8 @@ static int nsim_bpf_create_prog(struct netdevsim *ns, struct bpf_prog *prog)
 	state->state = "verify";
 
 	/* Program id is not populated yet when we create the state. */
-	sprintf(name, "%u", ns->prog_id_gen++);
-	state->ddir = debugfs_create_dir(name, ns->ddir_bpf_bound_progs);
+	sprintf(name, "%u", ns->sdev->prog_id_gen++);
+	state->ddir = debugfs_create_dir(name, ns->sdev->ddir_bpf_bound_progs);
 	if (IS_ERR_OR_NULL(state->ddir)) {
 		kfree(state);
 		return -ENOMEM;
@@ -250,7 +250,7 @@ static int nsim_bpf_create_prog(struct netdevsim *ns, struct bpf_prog *prog)
 			    &state->state, &nsim_bpf_string_fops);
 	debugfs_create_bool("loaded", 0400, state->ddir, &state->is_loaded);
 
-	list_add_tail(&state->l, &ns->bpf_bound_progs);
+	list_add_tail(&state->l, &ns->sdev->bpf_bound_progs);
 
 	prog->aux->offload->dev_priv = state;
 
@@ -294,7 +294,7 @@ nsim_setup_prog_hw_checks(struct netdevsim *ns, struct netdev_bpf *bpf)
 		NSIM_EA(bpf->extack, "xdpoffload of non-bound program");
 		return -EINVAL;
 	}
-	if (bpf->prog->aux->offload->netdev != ns->netdev) {
+	if (!bpf_offload_dev_match(bpf->prog, ns->netdev)) {
 		NSIM_EA(bpf->extack, "program bound to different dev");
 		return -EINVAL;
 	}
@@ -497,7 +497,7 @@ nsim_bpf_map_alloc(struct netdevsim *ns, struct bpf_offloaded_map *offmap)
 	}
 
 	offmap->dev_ops = &nsim_bpf_map_ops;
-	list_add_tail(&nmap->l, &ns->bpf_bound_maps);
+	list_add_tail(&nmap->l, &ns->sdev->bpf_bound_maps);
 
 	return 0;
 
@@ -582,8 +582,26 @@ int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf)
 
 int nsim_bpf_init(struct netdevsim *ns)
 {
-	INIT_LIST_HEAD(&ns->bpf_bound_progs);
-	INIT_LIST_HEAD(&ns->bpf_bound_maps);
+	int err;
+
+	if (ns->sdev->refcnt == 1) {
+		INIT_LIST_HEAD(&ns->sdev->bpf_bound_progs);
+		INIT_LIST_HEAD(&ns->sdev->bpf_bound_maps);
+
+		ns->sdev->ddir_bpf_bound_progs =
+			debugfs_create_dir("bpf_bound_progs", ns->sdev->ddir);
+		if (IS_ERR_OR_NULL(ns->sdev->ddir_bpf_bound_progs))
+			return -ENOMEM;
+
+		ns->sdev->bpf_dev = bpf_offload_dev_create();
+		err = PTR_ERR_OR_ZERO(ns->sdev->bpf_dev);
+		if (err)
+			return err;
+	}
+
+	err = bpf_offload_dev_netdev_register(ns->sdev->bpf_dev, ns->netdev);
+	if (err)
+		goto err_destroy_bdev;
 
 	debugfs_create_u32("bpf_offloaded_id", 0400, ns->ddir,
 			   &ns->bpf_offloaded_id);
@@ -593,10 +611,6 @@ int nsim_bpf_init(struct netdevsim *ns)
 			    &ns->bpf_bind_accept);
 	debugfs_create_u32("bpf_bind_verifier_delay", 0600, ns->ddir,
 			   &ns->bpf_bind_verifier_delay);
-	ns->ddir_bpf_bound_progs =
-		debugfs_create_dir("bpf_bound_progs", ns->ddir);
-	if (IS_ERR_OR_NULL(ns->ddir_bpf_bound_progs))
-		return -ENOMEM;
 
 	ns->bpf_tc_accept = true;
 	debugfs_create_bool("bpf_tc_accept", 0600, ns->ddir,
@@ -615,13 +629,23 @@ int nsim_bpf_init(struct netdevsim *ns)
 			    &ns->bpf_map_accept);
 
 	return 0;
+
+err_destroy_bdev:
+	if (ns->sdev->refcnt == 1)
+		bpf_offload_dev_destroy(ns->sdev->bpf_dev);
+	return err;
 }
 
 void nsim_bpf_uninit(struct netdevsim *ns)
 {
-	WARN_ON(!list_empty(&ns->bpf_bound_progs));
-	WARN_ON(!list_empty(&ns->bpf_bound_maps));
 	WARN_ON(ns->xdp.prog);
 	WARN_ON(ns->xdp_hw.prog);
 	WARN_ON(ns->bpf_offloaded);
+	bpf_offload_dev_netdev_unregister(ns->sdev->bpf_dev, ns->netdev);
+
+	if (ns->sdev->refcnt == 1) {
+		WARN_ON(!list_empty(&ns->sdev->bpf_bound_progs));
+		WARN_ON(!list_empty(&ns->sdev->bpf_bound_maps));
+		bpf_offload_dev_destroy(ns->sdev->bpf_dev);
+	}
 }

drivers/net/netdevsim/netdev.c

@@ -22,6 +22,7 @@
 #include <net/netlink.h>
 #include <net/pkt_cls.h>
 #include <net/rtnetlink.h>
+#include <net/switchdev.h>
 
 #include "netdevsim.h"
 
@@ -144,8 +145,29 @@ static struct device_type nsim_dev_type = {
 	.release = nsim_dev_release,
 };
 
+static int
+nsim_port_attr_get(struct net_device *dev, struct switchdev_attr *attr)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	switch (attr->id) {
+	case SWITCHDEV_ATTR_ID_PORT_PARENT_ID:
+		attr->u.ppid.id_len = sizeof(ns->sdev->switch_id);
+		memcpy(&attr->u.ppid.id, &ns->sdev->switch_id,
+		       attr->u.ppid.id_len);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static const struct switchdev_ops nsim_switchdev_ops = {
+	.switchdev_port_attr_get	= nsim_port_attr_get,
+};
+
 static int nsim_init(struct net_device *dev)
 {
+	char sdev_ddir_name[10], sdev_link_name[32];
 	struct netdevsim *ns = netdev_priv(dev);
 	int err;
 
@@ -154,9 +176,32 @@ static int nsim_init(struct net_device *dev)
 	if (IS_ERR_OR_NULL(ns->ddir))
 		return -ENOMEM;
 
+	if (!ns->sdev) {
+		ns->sdev = kzalloc(sizeof(*ns->sdev), GFP_KERNEL);
+		if (!ns->sdev) {
+			err = -ENOMEM;
+			goto err_debugfs_destroy;
+		}
+		ns->sdev->refcnt = 1;
+		ns->sdev->switch_id = nsim_dev_id;
+		sprintf(sdev_ddir_name, "%u", ns->sdev->switch_id);
+		ns->sdev->ddir = debugfs_create_dir(sdev_ddir_name,
+						    nsim_sdev_ddir);
+		if (IS_ERR_OR_NULL(ns->sdev->ddir)) {
+			err = PTR_ERR_OR_ZERO(ns->sdev->ddir) ?: -EINVAL;
+			goto err_sdev_free;
+		}
+	} else {
+		sprintf(sdev_ddir_name, "%u", ns->sdev->switch_id);
+		ns->sdev->refcnt++;
+	}
+
+	sprintf(sdev_link_name, "../../" DRV_NAME "_sdev/%s", sdev_ddir_name);
+	debugfs_create_symlink("sdev", ns->ddir, sdev_link_name);
+
 	err = nsim_bpf_init(ns);
 	if (err)
-		goto err_debugfs_destroy;
+		goto err_sdev_destroy;
 
 	ns->dev.id = nsim_dev_id++;
 	ns->dev.bus = &nsim_bus;
@@ -166,6 +211,7 @@ static int nsim_init(struct net_device *dev)
 		goto err_bpf_uninit;
 
 	SET_NETDEV_DEV(dev, &ns->dev);
+	SWITCHDEV_SET_OPS(dev, &nsim_switchdev_ops);
 
 	err = nsim_devlink_setup(ns);
 	if (err)
@@ -179,6 +225,12 @@ err_unreg_dev:
 	device_unregister(&ns->dev);
 err_bpf_uninit:
 	nsim_bpf_uninit(ns);
+err_sdev_destroy:
+	if (!--ns->sdev->refcnt) {
+		debugfs_remove_recursive(ns->sdev->ddir);
+err_sdev_free:
+		kfree(ns->sdev);
+	}
 err_debugfs_destroy:
 	debugfs_remove_recursive(ns->ddir);
 	return err;
@@ -192,6 +244,10 @@ static void nsim_uninit(struct net_device *dev)
 	nsim_devlink_teardown(ns);
 	debugfs_remove_recursive(ns->ddir);
 	nsim_bpf_uninit(ns);
+	if (!--ns->sdev->refcnt) {
+		debugfs_remove_recursive(ns->sdev->ddir);
+		kfree(ns->sdev);
+	}
 }
 
 static void nsim_free(struct net_device *dev)
@@ -470,14 +526,48 @@ static int nsim_validate(struct nlattr *tb[], struct nlattr *data[],
 	return 0;
 }
 
+static int nsim_newlink(struct net *src_net, struct net_device *dev,
+			struct nlattr *tb[], struct nlattr *data[],
+			struct netlink_ext_ack *extack)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (tb[IFLA_LINK]) {
+		struct net_device *joindev;
+		struct netdevsim *joinns;
+
+		joindev = __dev_get_by_index(src_net,
+					     nla_get_u32(tb[IFLA_LINK]));
+		if (!joindev)
+			return -ENODEV;
+		if (joindev->netdev_ops != &nsim_netdev_ops)
+			return -EINVAL;
+
+		joinns = netdev_priv(joindev);
+		if (!joinns->sdev || !joinns->sdev->refcnt)
+			return -EINVAL;
+		ns->sdev = joinns->sdev;
+	}
+
+	return register_netdevice(dev);
+}
+
+static void nsim_dellink(struct net_device *dev, struct list_head *head)
+{
+	unregister_netdevice_queue(dev, head);
+}
+
 static struct rtnl_link_ops nsim_link_ops __read_mostly = {
 	.kind		= DRV_NAME,
 	.priv_size	= sizeof(struct netdevsim),
 	.setup		= nsim_setup,
 	.validate	= nsim_validate,
+	.newlink	= nsim_newlink,
+	.dellink	= nsim_dellink,
 };
 
 struct dentry *nsim_ddir;
+struct dentry *nsim_sdev_ddir;
 
 static int __init nsim_module_init(void)
 {
@@ -487,9 +577,15 @@ static int __init nsim_module_init(void)
 	if (IS_ERR_OR_NULL(nsim_ddir))
 		return -ENOMEM;
 
+	nsim_sdev_ddir = debugfs_create_dir(DRV_NAME "_sdev", NULL);
+	if (IS_ERR_OR_NULL(nsim_sdev_ddir)) {
+		err = -ENOMEM;
+		goto err_debugfs_destroy;
+	}
+
 	err = bus_register(&nsim_bus);
 	if (err)
-		goto err_debugfs_destroy;
+		goto err_sdir_destroy;
 
 	err = nsim_devlink_init();
 	if (err)
@@ -505,6 +601,8 @@ err_dl_fini:
 	nsim_devlink_exit();
 err_unreg_bus:
 	bus_unregister(&nsim_bus);
+err_sdir_destroy:
+	debugfs_remove_recursive(nsim_sdev_ddir);
 err_debugfs_destroy:
 	debugfs_remove_recursive(nsim_ddir);
 	return err;
@@ -515,6 +613,7 @@ static void __exit nsim_module_exit(void)
 	rtnl_link_unregister(&nsim_link_ops);
 	nsim_devlink_exit();
 	bus_unregister(&nsim_bus);
+	debugfs_remove_recursive(nsim_sdev_ddir);
 	debugfs_remove_recursive(nsim_ddir);
 }
 

drivers/net/netdevsim/netdevsim.h

@@ -27,9 +27,25 @@
 #define NSIM_EA(extack, msg)	NL_SET_ERR_MSG_MOD((extack), msg)
 
 struct bpf_prog;
+struct bpf_offload_dev;
 struct dentry;
 struct nsim_vf_config;
 
+struct netdevsim_shared_dev {
+	unsigned int refcnt;
+	u32 switch_id;
+
+	struct dentry *ddir;
+
+	struct bpf_offload_dev *bpf_dev;
+
+	struct dentry *ddir_bpf_bound_progs;
+	u32 prog_id_gen;
+
+	struct list_head bpf_bound_progs;
+	struct list_head bpf_bound_maps;
+};
+
 #define NSIM_IPSEC_MAX_SA_COUNT		33
 #define NSIM_IPSEC_VALID		BIT(31)
 
@@ -59,6 +75,7 @@ struct netdevsim {
 	struct u64_stats_sync syncp;
 
 	struct device dev;
+	struct netdevsim_shared_dev *sdev;
 
 	struct dentry *ddir;
 
@@ -71,12 +88,8 @@ struct netdevsim {
 	struct xdp_attachment_info xdp;
 	struct xdp_attachment_info xdp_hw;
 
-	u32 prog_id_gen;
-
 	bool bpf_bind_accept;
 	u32 bpf_bind_verifier_delay;
-	struct dentry *ddir_bpf_bound_progs;
-	struct list_head bpf_bound_progs;
 
 	bool bpf_tc_accept;
 	bool bpf_tc_non_bound_accept;
@@ -84,7 +97,6 @@ struct netdevsim {
 	bool bpf_xdpoffload_accept;
 
 	bool bpf_map_accept;
-	struct list_head bpf_bound_maps;
 #if IS_ENABLED(CONFIG_NET_DEVLINK)
 	struct devlink *devlink;
 #endif
@@ -92,6 +104,7 @@ struct netdevsim {
 };
 
 extern struct dentry *nsim_ddir;
+extern struct dentry *nsim_sdev_ddir;
 
 #ifdef CONFIG_BPF_SYSCALL
 int nsim_bpf_init(struct netdevsim *ns);

include/linux/bpf.h

@@ -85,6 +85,7 @@ struct bpf_map {
 	char name[BPF_OBJ_NAME_LEN];
 };
 
+struct bpf_offload_dev;
 struct bpf_offloaded_map;
 
 struct bpf_map_dev_ops {
@@ -648,7 +649,15 @@ int bpf_map_offload_delete_elem(struct bpf_map *map, void *key);
 int bpf_map_offload_get_next_key(struct bpf_map *map,
 				 void *key, void *next_key);
 
-bool bpf_offload_dev_match(struct bpf_prog *prog, struct bpf_map *map);
+bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map);
+
+struct bpf_offload_dev *bpf_offload_dev_create(void);
+void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev);
+int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
+				    struct net_device *netdev);
+void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
+				       struct net_device *netdev);
+bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev);
 
 #if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL)
 int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr);

kernel/bpf/offload.c

@@ -18,19 +18,43 @@
 #include <linux/bug.h>
 #include <linux/kdev_t.h>
 #include <linux/list.h>
+#include <linux/lockdep.h>
 #include <linux/netdevice.h>
 #include <linux/printk.h>
 #include <linux/proc_ns.h>
+#include <linux/rhashtable.h>
 #include <linux/rtnetlink.h>
 #include <linux/rwsem.h>
 
-/* Protects bpf_prog_offload_devs, bpf_map_offload_devs and offload members
+/* Protects offdevs, members of bpf_offload_netdev 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);
+
+struct bpf_offload_dev {
+	struct list_head netdevs;
+};
+
+struct bpf_offload_netdev {
+	struct rhash_head l;
+	struct net_device *netdev;
+	struct bpf_offload_dev *offdev;
+	struct list_head progs;
+	struct list_head maps;
+	struct list_head offdev_netdevs;
+};
+
+static const struct rhashtable_params offdevs_params = {
+	.nelem_hint		= 4,
+	.key_len		= sizeof(struct net_device *),
+	.key_offset		= offsetof(struct bpf_offload_netdev, netdev),
+	.head_offset		= offsetof(struct bpf_offload_netdev, l),
+	.automatic_shrinking	= true,
+};
+
+static struct rhashtable offdevs;
+static bool offdevs_inited;
 
 static int bpf_dev_offload_check(struct net_device *netdev)
 {
@@ -41,8 +65,19 @@ static int bpf_dev_offload_check(struct net_device *netdev)
 	return 0;
 }
 
+static struct bpf_offload_netdev *
+bpf_offload_find_netdev(struct net_device *netdev)
+{
+	lockdep_assert_held(&bpf_devs_lock);
+
+	if (!offdevs_inited)
+		return NULL;
+	return rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
+}
+
 int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
 {
+	struct bpf_offload_netdev *ondev;
 	struct bpf_prog_offload *offload;
 	int err;
 
@@ -66,12 +101,13 @@ int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
 		goto err_maybe_put;
 
 	down_write(&bpf_devs_lock);
-	if (offload->netdev->reg_state != NETREG_REGISTERED) {
+	ondev = bpf_offload_find_netdev(offload->netdev);
+	if (!ondev) {
 		err = -EINVAL;
 		goto err_unlock;
 	}
 	prog->aux->offload = offload;
-	list_add_tail(&offload->offloads, &bpf_prog_offload_devs);
+	list_add_tail(&offload->offloads, &ondev->progs);
 	dev_put(offload->netdev);
 	up_write(&bpf_devs_lock);
 
@@ -294,6 +330,7 @@ static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap,
 struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr)
 {
 	struct net *net = current->nsproxy->net_ns;
+	struct bpf_offload_netdev *ondev;
 	struct bpf_offloaded_map *offmap;
 	int err;
 
@@ -316,11 +353,17 @@ struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr)
 	if (err)
 		goto err_unlock;
 
+	ondev = bpf_offload_find_netdev(offmap->netdev);
+	if (!ondev) {
+		err = -EINVAL;
+		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);
+	list_add_tail(&offmap->offloads, &ondev->maps);
 	up_write(&bpf_devs_lock);
 	rtnl_unlock();
 
@@ -468,77 +511,159 @@ int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map)
 	return 0;
 }
 
-bool bpf_offload_dev_match(struct bpf_prog *prog, struct bpf_map *map)
+static bool __bpf_offload_dev_match(struct bpf_prog *prog,
+				    struct net_device *netdev)
 {
-	struct bpf_offloaded_map *offmap;
+	struct bpf_offload_netdev *ondev1, *ondev2;
 	struct bpf_prog_offload *offload;
-	bool ret;
 
 	if (!bpf_prog_is_dev_bound(prog->aux))
 		return false;
-	if (!bpf_map_is_dev_bound(map))
-		return bpf_map_offload_neutral(map);
 
-	down_read(&bpf_devs_lock);
 	offload = prog->aux->offload;
-	offmap = map_to_offmap(map);
+	if (!offload)
+		return false;
+	if (offload->netdev == netdev)
+		return true;
 
-	ret = offload && offload->netdev == offmap->netdev;
+	ondev1 = bpf_offload_find_netdev(offload->netdev);
+	ondev2 = bpf_offload_find_netdev(netdev);
+
+	return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev;
+}
+
+bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev)
+{
+	bool ret;
+
+	down_read(&bpf_devs_lock);
+	ret = __bpf_offload_dev_match(prog, netdev);
 	up_read(&bpf_devs_lock);
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(bpf_offload_dev_match);
 
-static void bpf_offload_orphan_all_progs(struct net_device *netdev)
+bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map)
 {
-	struct bpf_prog_offload *offload, *tmp;
+	struct bpf_offloaded_map *offmap;
+	bool ret;
 
-	list_for_each_entry_safe(offload, tmp, &bpf_prog_offload_devs, offloads)
-		if (offload->netdev == netdev)
-			__bpf_prog_offload_destroy(offload->prog);
+	if (!bpf_map_is_dev_bound(map))
+		return bpf_map_offload_neutral(map);
+	offmap = map_to_offmap(map);
+
+	down_read(&bpf_devs_lock);
+	ret = __bpf_offload_dev_match(prog, offmap->netdev);
+	up_read(&bpf_devs_lock);
+
+	return ret;
 }
 
-static void bpf_offload_orphan_all_maps(struct net_device *netdev)
+int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
+				    struct net_device *netdev)
 {
-	struct bpf_offloaded_map *offmap, *tmp;
+	struct bpf_offload_netdev *ondev;
+	int err;
 
-	list_for_each_entry_safe(offmap, tmp, &bpf_map_offload_devs, offloads)
-		if (offmap->netdev == netdev)
-			__bpf_map_offload_destroy(offmap);
+	ondev = kzalloc(sizeof(*ondev), GFP_KERNEL);
+	if (!ondev)
+		return -ENOMEM;
+
+	ondev->netdev = netdev;
+	ondev->offdev = offdev;
+	INIT_LIST_HEAD(&ondev->progs);
+	INIT_LIST_HEAD(&ondev->maps);
+
+	down_write(&bpf_devs_lock);
+	err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params);
+	if (err) {
+		netdev_warn(netdev, "failed to register for BPF offload\n");
+		goto err_unlock_free;
+	}
+
+	list_add(&ondev->offdev_netdevs, &offdev->netdevs);
+	up_write(&bpf_devs_lock);
+	return 0;
+
+err_unlock_free:
+	up_write(&bpf_devs_lock);
+	kfree(ondev);
+	return err;
 }
+EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register);
 
-static int bpf_offload_notification(struct notifier_block *notifier,
-				    ulong event, void *ptr)
+void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
+				       struct net_device *netdev)
 {
-	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
+	struct bpf_offload_netdev *ondev, *altdev;
+	struct bpf_offloaded_map *offmap, *mtmp;
+	struct bpf_prog_offload *offload, *ptmp;
 
 	ASSERT_RTNL();
 
-	switch (event) {
-	case NETDEV_UNREGISTER:
-		/* ignore namespace changes */
-		if (netdev->reg_state != NETREG_UNREGISTERING)
-			break;
-
-		down_write(&bpf_devs_lock);
-		bpf_offload_orphan_all_progs(netdev);
-		bpf_offload_orphan_all_maps(netdev);
-		up_write(&bpf_devs_lock);
-		break;
-	default:
-		break;
+	down_write(&bpf_devs_lock);
+	ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
+	if (WARN_ON(!ondev))
+		goto unlock;
+
+	WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params));
+	list_del(&ondev->offdev_netdevs);
+
+	/* Try to move the objects to another netdev of the device */
+	altdev = list_first_entry_or_null(&offdev->netdevs,
+					  struct bpf_offload_netdev,
+					  offdev_netdevs);
+	if (altdev) {
+		list_for_each_entry(offload, &ondev->progs, offloads)
+			offload->netdev = altdev->netdev;
+		list_splice_init(&ondev->progs, &altdev->progs);
+
+		list_for_each_entry(offmap, &ondev->maps, offloads)
+			offmap->netdev = altdev->netdev;
+		list_splice_init(&ondev->maps, &altdev->maps);
+	} else {
+		list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads)
+			__bpf_prog_offload_destroy(offload->prog);
+		list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads)
+			__bpf_map_offload_destroy(offmap);
 	}
-	return NOTIFY_OK;
-}
 
-static struct notifier_block bpf_offload_notifier = {
-	.notifier_call = bpf_offload_notification,
-};
+	WARN_ON(!list_empty(&ondev->progs));
+	WARN_ON(!list_empty(&ondev->maps));
+	kfree(ondev);
+unlock:
+	up_write(&bpf_devs_lock);
+}
+EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister);
 
-static int __init bpf_offload_init(void)
+struct bpf_offload_dev *bpf_offload_dev_create(void)
 {
-	register_netdevice_notifier(&bpf_offload_notifier);
-	return 0;
+	struct bpf_offload_dev *offdev;
+	int err;
+
+	down_write(&bpf_devs_lock);
+	if (!offdevs_inited) {
+		err = rhashtable_init(&offdevs, &offdevs_params);
+		if (err)
+			return ERR_PTR(err);
+		offdevs_inited = true;
+	}
+	up_write(&bpf_devs_lock);
+
+	offdev = kzalloc(sizeof(*offdev), GFP_KERNEL);
+	if (!offdev)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&offdev->netdevs);
+
+	return offdev;
 }
+EXPORT_SYMBOL_GPL(bpf_offload_dev_create);
 
-subsys_initcall(bpf_offload_init);
+void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev)
+{
+	WARN_ON(!list_empty(&offdev->netdevs));
+	kfree(offdev);
+}
+EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy);

kernel/bpf/verifier.c

@@ -5054,7 +5054,7 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
 	}
 
 	if ((bpf_prog_is_dev_bound(prog->aux) || bpf_map_is_dev_bound(map)) &&
-	    !bpf_offload_dev_match(prog, map)) {
+	    !bpf_offload_prog_map_match(prog, map)) {
 		verbose(env, "offload device mismatch between prog and map\n");
 		return -EINVAL;
 	}

tools/testing/selftests/bpf/test_offload.py

@@ -158,8 +158,9 @@ def tool(name, args, flags, JSON=True, ns="", fail=True, include_stderr=False):
     else:
         return ret, out
 
-def bpftool(args, JSON=True, ns="", fail=True):
-    return tool("bpftool", args, {"json":"-p"}, JSON=JSON, ns=ns, fail=fail)
+def bpftool(args, JSON=True, ns="", fail=True, include_stderr=False):
+    return tool("bpftool", args, {"json":"-p"}, JSON=JSON, ns=ns,
+                fail=fail, include_stderr=include_stderr)
 
 def bpftool_prog_list(expected=None, ns=""):
     _, progs = bpftool("prog show", JSON=True, ns=ns, fail=True)
@@ -201,6 +202,21 @@ def bpftool_map_list_wait(expected=0, n_retry=20):
         time.sleep(0.05)
     raise Exception("Time out waiting for map counts to stabilize want %d, have %d" % (expected, nmaps))
 
+def bpftool_prog_load(sample, file_name, maps=[], prog_type="xdp", dev=None,
+                      fail=True, include_stderr=False):
+    args = "prog load %s %s" % (os.path.join(bpf_test_dir, sample), file_name)
+    if prog_type is not None:
+        args += " type " + prog_type
+    if dev is not None:
+        args += " dev " + dev
+    if len(maps):
+        args += " map " + " map ".join(maps)
+
+    res = bpftool(args, fail=fail, include_stderr=include_stderr)
+    if res[0] == 0:
+        files.append(file_name)
+    return res
+
 def ip(args, force=False, JSON=True, ns="", fail=True, include_stderr=False):
     if force:
         args = "-force " + args
@@ -307,21 +323,25 @@ class NetdevSim:
     Class for netdevsim netdevice and its attributes.
     """
 
-    def __init__(self):
+    def __init__(self, link=None):
+        self.link = link
+
         self.dev = self._netdevsim_create()
         devs.append(self)
 
         self.ns = ""
 
         self.dfs_dir = '/sys/kernel/debug/netdevsim/%s' % (self.dev['ifname'])
+        self.sdev_dir = self.dfs_dir + '/sdev/'
         self.dfs_refresh()
 
     def __getitem__(self, key):
         return self.dev[key]
 
     def _netdevsim_create(self):
+        link = "" if self.link is None else "link " + self.link.dev['ifname']
         _, old  = ip("link show")
-        ip("link add sim%d type netdevsim")
+        ip("link add sim%d {link} type netdevsim".format(link=link))
         _, new  = ip("link show")
 
         for dev in new:
@@ -345,12 +365,12 @@ class NetdevSim:
         return data.strip()
 
     def dfs_num_bound_progs(self):
-        path = os.path.join(self.dfs_dir, "bpf_bound_progs")
+        path = os.path.join(self.sdev_dir, "bpf_bound_progs")
         _, progs = cmd('ls %s' % (path))
         return len(progs.split())
 
     def dfs_get_bound_progs(self, expected):
-        progs = DebugfsDir(os.path.join(self.dfs_dir, "bpf_bound_progs"))
+        progs = DebugfsDir(os.path.join(self.sdev_dir, "bpf_bound_progs"))
         if expected is not None:
             if len(progs) != expected:
                 fail(True, "%d BPF programs bound, expected %d" %
@@ -847,6 +867,25 @@ try:
     sim.set_mtu(1500)
 
     sim.wait_for_flush()
+    start_test("Test non-offload XDP attaching to HW...")
+    bpftool_prog_load("sample_ret0.o", "/sys/fs/bpf/nooffload")
+    nooffload = bpf_pinned("/sys/fs/bpf/nooffload")
+    ret, _, err = sim.set_xdp(nooffload, "offload",
+                              fail=False, include_stderr=True)
+    fail(ret == 0, "attached non-offloaded XDP program to HW")
+    check_extack_nsim(err, "xdpoffload of non-bound program.", args)
+    rm("/sys/fs/bpf/nooffload")
+
+    start_test("Test offload XDP attaching to drv...")
+    bpftool_prog_load("sample_ret0.o", "/sys/fs/bpf/offload",
+                      dev=sim['ifname'])
+    offload = bpf_pinned("/sys/fs/bpf/offload")
+    ret, _, err = sim.set_xdp(offload, "drv", fail=False, include_stderr=True)
+    fail(ret == 0, "attached offloaded XDP program to drv")
+    check_extack(err, "using device-bound program without HW_MODE flag is not supported.", args)
+    rm("/sys/fs/bpf/offload")
+    sim.wait_for_flush()
+
     start_test("Test XDP offload...")
     _, _, err = sim.set_xdp(obj, "offload", verbose=True, include_stderr=True)
     ipl = sim.ip_link_show(xdp=True)
@@ -1140,6 +1179,106 @@ try:
     fail(ret == 0,
          "netdevsim didn't refuse to create a map with offload disabled")
 
+    sim.remove()
+
+    start_test("Test multi-dev ASIC program reuse...")
+    simA = NetdevSim()
+    simB1 = NetdevSim()
+    simB2 = NetdevSim(link=simB1)
+    simB3 = NetdevSim(link=simB1)
+    sims = (simA, simB1, simB2, simB3)
+    simB = (simB1, simB2, simB3)
+
+    bpftool_prog_load("sample_map_ret0.o", "/sys/fs/bpf/nsimA",
+                      dev=simA['ifname'])
+    progA = bpf_pinned("/sys/fs/bpf/nsimA")
+    bpftool_prog_load("sample_map_ret0.o", "/sys/fs/bpf/nsimB",
+                      dev=simB1['ifname'])
+    progB = bpf_pinned("/sys/fs/bpf/nsimB")
+
+    simA.set_xdp(progA, "offload", JSON=False)
+    for d in simB:
+        d.set_xdp(progB, "offload", JSON=False)
+
+    start_test("Test multi-dev ASIC cross-dev replace...")
+    ret, _ = simA.set_xdp(progB, "offload", force=True, JSON=False, fail=False)
+    fail(ret == 0, "cross-ASIC program allowed")
+    for d in simB:
+        ret, _ = d.set_xdp(progA, "offload", force=True, JSON=False, fail=False)
+        fail(ret == 0, "cross-ASIC program allowed")
+
+    start_test("Test multi-dev ASIC cross-dev install...")
+    for d in sims:
+        d.unset_xdp("offload")
+
+    ret, _, err = simA.set_xdp(progB, "offload", force=True, JSON=False,
+                               fail=False, include_stderr=True)
+    fail(ret == 0, "cross-ASIC program allowed")
+    check_extack_nsim(err, "program bound to different dev.", args)
+    for d in simB:
+        ret, _, err = d.set_xdp(progA, "offload", force=True, JSON=False,
+                                fail=False, include_stderr=True)
+        fail(ret == 0, "cross-ASIC program allowed")
+        check_extack_nsim(err, "program bound to different dev.", args)
+
+    start_test("Test multi-dev ASIC cross-dev map reuse...")
+
+    mapA = bpftool("prog show %s" % (progA))[1]["map_ids"][0]
+    mapB = bpftool("prog show %s" % (progB))[1]["map_ids"][0]
+
+    ret, _ = bpftool_prog_load("sample_map_ret0.o", "/sys/fs/bpf/nsimB_",
+                               dev=simB3['ifname'],
+                               maps=["idx 0 id %d" % (mapB)],
+                               fail=False)
+    fail(ret != 0, "couldn't reuse a map on the same ASIC")
+    rm("/sys/fs/bpf/nsimB_")
+
+    ret, _, err = bpftool_prog_load("sample_map_ret0.o", "/sys/fs/bpf/nsimA_",
+                                    dev=simA['ifname'],
+                                    maps=["idx 0 id %d" % (mapB)],
+                                    fail=False, include_stderr=True)
+    fail(ret == 0, "could reuse a map on a different ASIC")
+    fail(err.count("offload device mismatch between prog and map") == 0,
+         "error message missing for cross-ASIC map")
+
+    ret, _, err = bpftool_prog_load("sample_map_ret0.o", "/sys/fs/bpf/nsimB_",
+                                    dev=simB1['ifname'],
+                                    maps=["idx 0 id %d" % (mapA)],
+                                    fail=False, include_stderr=True)
+    fail(ret == 0, "could reuse a map on a different ASIC")
+    fail(err.count("offload device mismatch between prog and map") == 0,
+         "error message missing for cross-ASIC map")
+
+    start_test("Test multi-dev ASIC cross-dev destruction...")
+    bpftool_prog_list_wait(expected=2)
+
+    simA.remove()
+    bpftool_prog_list_wait(expected=1)
+
+    ifnameB = bpftool("prog show %s" % (progB))[1]["dev"]["ifname"]
+    fail(ifnameB != simB1['ifname'], "program not bound to originial device")
+    simB1.remove()
+    bpftool_prog_list_wait(expected=1)
+
+    start_test("Test multi-dev ASIC cross-dev destruction - move...")
+    ifnameB = bpftool("prog show %s" % (progB))[1]["dev"]["ifname"]
+    fail(ifnameB not in (simB2['ifname'], simB3['ifname']),
+         "program not bound to remaining devices")
+
+    simB2.remove()
+    ifnameB = bpftool("prog show %s" % (progB))[1]["dev"]["ifname"]
+    fail(ifnameB != simB3['ifname'], "program not bound to remaining device")
+
+    simB3.remove()
+    bpftool_prog_list_wait(expected=0)
+
+    start_test("Test multi-dev ASIC cross-dev destruction - orphaned...")
+    ret, out = bpftool("prog show %s" % (progB), fail=False)
+    fail(ret == 0, "got information about orphaned program")
+    fail("error" not in out, "no error reported for get info on orphaned")
+    fail(out["error"] != "can't get prog info: No such device",
+         "wrong error for get info on orphaned")
+
     print("%s: OK" % (os.path.basename(__file__)))
 
 finally: