Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 1671 insertions, 0 deletions

diff --git a/drivers/net/netdevsim/fib.c b/drivers/net/netdevsim/fib.c
new file mode 100644
index 000000000..55bcdefad
--- /dev/null
+++ b/drivers/net/netdevsim/fib.c
@@ -0,0 +1,1671 @@
+/*
+ * Copyright (c) 2018 Cumulus Networks. All rights reserved.
+ * Copyright (c) 2018 David Ahern <dsa@cumulusnetworks.com>
+ *
+ * This software is licensed under the GNU General License Version 2,
+ * June 1991 as shown in the file COPYING in the top-level directory of this
+ * source tree.
+ *
+ * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
+ * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
+ * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
+ * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/in6.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/rhashtable.h>
+#include <linux/spinlock_types.h>
+#include <linux/types.h>
+#include <net/fib_notifier.h>
+#include <net/inet_dscp.h>
+#include <net/ip_fib.h>
+#include <net/ip6_fib.h>
+#include <net/fib_rules.h>
+#include <net/net_namespace.h>
+#include <net/nexthop.h>
+#include <linux/debugfs.h>
+
+#include "netdevsim.h"
+
+struct nsim_fib_entry {
+	u64 max;
+	atomic64_t num;
+};
+
+struct nsim_per_fib_data {
+	struct nsim_fib_entry fib;
+	struct nsim_fib_entry rules;
+};
+
+struct nsim_fib_data {
+	struct notifier_block fib_nb;
+	struct nsim_per_fib_data ipv4;
+	struct nsim_per_fib_data ipv6;
+	struct nsim_fib_entry nexthops;
+	struct rhashtable fib_rt_ht;
+	struct list_head fib_rt_list;
+	struct mutex fib_lock; /* Protects FIB HT and list */
+	struct notifier_block nexthop_nb;
+	struct rhashtable nexthop_ht;
+	struct devlink *devlink;
+	struct work_struct fib_event_work;
+	struct work_struct fib_flush_work;
+	struct list_head fib_event_queue;
+	spinlock_t fib_event_queue_lock; /* Protects fib event queue list */
+	struct mutex nh_lock; /* Protects NH HT */
+	struct dentry *ddir;
+	bool fail_route_offload;
+	bool fail_res_nexthop_group_replace;
+	bool fail_nexthop_bucket_replace;
+	bool fail_route_delete;
+};
+
+struct nsim_fib_rt_key {
+	unsigned char addr[sizeof(struct in6_addr)];
+	unsigned char prefix_len;
+	int family;
+	u32 tb_id;
+};
+
+struct nsim_fib_rt {
+	struct nsim_fib_rt_key key;
+	struct rhash_head ht_node;
+	struct list_head list;	/* Member of fib_rt_list */
+};
+
+struct nsim_fib4_rt {
+	struct nsim_fib_rt common;
+	struct fib_info *fi;
+	dscp_t dscp;
+	u8 type;
+};
+
+struct nsim_fib6_rt {
+	struct nsim_fib_rt common;
+	struct list_head nh_list;
+	unsigned int nhs;
+};
+
+struct nsim_fib6_rt_nh {
+	struct list_head list;	/* Member of nh_list */
+	struct fib6_info *rt;
+};
+
+struct nsim_fib6_event {
+	struct fib6_info **rt_arr;
+	unsigned int nrt6;
+};
+
+struct nsim_fib_event {
+	struct list_head list; /* node in fib queue */
+	union {
+		struct fib_entry_notifier_info fen_info;
+		struct nsim_fib6_event fib6_event;
+	};
+	struct nsim_fib_data *data;
+	unsigned long event;
+	int family;
+};
+
+static const struct rhashtable_params nsim_fib_rt_ht_params = {
+	.key_offset = offsetof(struct nsim_fib_rt, key),
+	.head_offset = offsetof(struct nsim_fib_rt, ht_node),
+	.key_len = sizeof(struct nsim_fib_rt_key),
+	.automatic_shrinking = true,
+};
+
+struct nsim_nexthop {
+	struct rhash_head ht_node;
+	u64 occ;
+	u32 id;
+	bool is_resilient;
+};
+
+static const struct rhashtable_params nsim_nexthop_ht_params = {
+	.key_offset = offsetof(struct nsim_nexthop, id),
+	.head_offset = offsetof(struct nsim_nexthop, ht_node),
+	.key_len = sizeof(u32),
+	.automatic_shrinking = true,
+};
+
+u64 nsim_fib_get_val(struct nsim_fib_data *fib_data,
+		     enum nsim_resource_id res_id, bool max)
+{
+	struct nsim_fib_entry *entry;
+
+	switch (res_id) {
+	case NSIM_RESOURCE_IPV4_FIB:
+		entry = &fib_data->ipv4.fib;
+		break;
+	case NSIM_RESOURCE_IPV4_FIB_RULES:
+		entry = &fib_data->ipv4.rules;
+		break;
+	case NSIM_RESOURCE_IPV6_FIB:
+		entry = &fib_data->ipv6.fib;
+		break;
+	case NSIM_RESOURCE_IPV6_FIB_RULES:
+		entry = &fib_data->ipv6.rules;
+		break;
+	case NSIM_RESOURCE_NEXTHOPS:
+		entry = &fib_data->nexthops;
+		break;
+	default:
+		return 0;
+	}
+
+	return max ? entry->max : atomic64_read(&entry->num);
+}
+
+static void nsim_fib_set_max(struct nsim_fib_data *fib_data,
+			     enum nsim_resource_id res_id, u64 val)
+{
+	struct nsim_fib_entry *entry;
+
+	switch (res_id) {
+	case NSIM_RESOURCE_IPV4_FIB:
+		entry = &fib_data->ipv4.fib;
+		break;
+	case NSIM_RESOURCE_IPV4_FIB_RULES:
+		entry = &fib_data->ipv4.rules;
+		break;
+	case NSIM_RESOURCE_IPV6_FIB:
+		entry = &fib_data->ipv6.fib;
+		break;
+	case NSIM_RESOURCE_IPV6_FIB_RULES:
+		entry = &fib_data->ipv6.rules;
+		break;
+	case NSIM_RESOURCE_NEXTHOPS:
+		entry = &fib_data->nexthops;
+		break;
+	default:
+		WARN_ON(1);
+		return;
+	}
+	entry->max = val;
+}
+
+static int nsim_fib_rule_account(struct nsim_fib_entry *entry, bool add,
+				 struct netlink_ext_ack *extack)
+{
+	int err = 0;
+
+	if (add) {
+		if (!atomic64_add_unless(&entry->num, 1, entry->max)) {
+			err = -ENOSPC;
+			NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported fib rule entries");
+		}
+	} else {
+		atomic64_dec_if_positive(&entry->num);
+	}
+
+	return err;
+}
+
+static int nsim_fib_rule_event(struct nsim_fib_data *data,
+			       struct fib_notifier_info *info, bool add)
+{
+	struct netlink_ext_ack *extack = info->extack;
+	int err = 0;
+
+	switch (info->family) {
+	case AF_INET:
+		err = nsim_fib_rule_account(&data->ipv4.rules, add, extack);
+		break;
+	case AF_INET6:
+		err = nsim_fib_rule_account(&data->ipv6.rules, add, extack);
+		break;
+	}
+
+	return err;
+}
+
+static int nsim_fib_account(struct nsim_fib_entry *entry, bool add)
+{
+	int err = 0;
+
+	if (add) {
+		if (!atomic64_add_unless(&entry->num, 1, entry->max))
+			err = -ENOSPC;
+	} else {
+		atomic64_dec_if_positive(&entry->num);
+	}
+
+	return err;
+}
+
+static void nsim_fib_rt_init(struct nsim_fib_data *data,
+			     struct nsim_fib_rt *fib_rt, const void *addr,
+			     size_t addr_len, unsigned int prefix_len,
+			     int family, u32 tb_id)
+{
+	memcpy(fib_rt->key.addr, addr, addr_len);
+	fib_rt->key.prefix_len = prefix_len;
+	fib_rt->key.family = family;
+	fib_rt->key.tb_id = tb_id;
+	list_add(&fib_rt->list, &data->fib_rt_list);
+}
+
+static void nsim_fib_rt_fini(struct nsim_fib_rt *fib_rt)
+{
+	list_del(&fib_rt->list);
+}
+
+static struct nsim_fib_rt *nsim_fib_rt_lookup(struct rhashtable *fib_rt_ht,
+					      const void *addr, size_t addr_len,
+					      unsigned int prefix_len,
+					      int family, u32 tb_id)
+{
+	struct nsim_fib_rt_key key;
+
+	memset(&key, 0, sizeof(key));
+	memcpy(key.addr, addr, addr_len);
+	key.prefix_len = prefix_len;
+	key.family = family;
+	key.tb_id = tb_id;
+
+	return rhashtable_lookup_fast(fib_rt_ht, &key, nsim_fib_rt_ht_params);
+}
+
+static struct nsim_fib4_rt *
+nsim_fib4_rt_create(struct nsim_fib_data *data,
+		    struct fib_entry_notifier_info *fen_info)
+{
+	struct nsim_fib4_rt *fib4_rt;
+
+	fib4_rt = kzalloc_obj(*fib4_rt);
+	if (!fib4_rt)
+		return NULL;
+
+	nsim_fib_rt_init(data, &fib4_rt->common, &fen_info->dst, sizeof(u32),
+			 fen_info->dst_len, AF_INET, fen_info->tb_id);
+
+	fib4_rt->fi = fen_info->fi;
+	fib_info_hold(fib4_rt->fi);
+	fib4_rt->dscp = fen_info->dscp;
+	fib4_rt->type = fen_info->type;
+
+	return fib4_rt;
+}
+
+static void nsim_fib4_rt_destroy(struct nsim_fib4_rt *fib4_rt)
+{
+	fib_info_put(fib4_rt->fi);
+	nsim_fib_rt_fini(&fib4_rt->common);
+	kfree(fib4_rt);
+}
+
+static struct nsim_fib4_rt *
+nsim_fib4_rt_lookup(struct rhashtable *fib_rt_ht,
+		    const struct fib_entry_notifier_info *fen_info)
+{
+	struct nsim_fib_rt *fib_rt;
+
+	fib_rt = nsim_fib_rt_lookup(fib_rt_ht, &fen_info->dst, sizeof(u32),
+				    fen_info->dst_len, AF_INET,
+				    fen_info->tb_id);
+	if (!fib_rt)
+		return NULL;
+
+	return container_of(fib_rt, struct nsim_fib4_rt, common);
+}
+
+static void
+nsim_fib4_rt_offload_failed_flag_set(struct net *net,
+				     struct fib_entry_notifier_info *fen_info)
+{
+	u32 *p_dst = (u32 *)&fen_info->dst;
+	struct fib_rt_info fri;
+
+	fri.fi = fen_info->fi;
+	fri.tb_id = fen_info->tb_id;
+	fri.dst = cpu_to_be32(*p_dst);
+	fri.dst_len = fen_info->dst_len;
+	fri.dscp = fen_info->dscp;
+	fri.type = fen_info->type;
+	fri.offload = false;
+	fri.trap = false;
+	fri.offload_failed = true;
+	fib_alias_hw_flags_set(net, &fri);
+}
+
+static void nsim_fib4_rt_hw_flags_set(struct net *net,
+				      const struct nsim_fib4_rt *fib4_rt,
+				      bool trap)
+{
+	u32 *p_dst = (u32 *) fib4_rt->common.key.addr;
+	int dst_len = fib4_rt->common.key.prefix_len;
+	struct fib_rt_info fri;
+
+	fri.fi = fib4_rt->fi;
+	fri.tb_id = fib4_rt->common.key.tb_id;
+	fri.dst = cpu_to_be32(*p_dst);
+	fri.dst_len = dst_len;
+	fri.dscp = fib4_rt->dscp;
+	fri.type = fib4_rt->type;
+	fri.offload = false;
+	fri.trap = trap;
+	fri.offload_failed = false;
+	fib_alias_hw_flags_set(net, &fri);
+}
+
+static int nsim_fib4_rt_add(struct nsim_fib_data *data,
+			    struct nsim_fib4_rt *fib4_rt)
+{
+	struct net *net = devlink_net(data->devlink);
+	int err;
+
+	err = rhashtable_insert_fast(&data->fib_rt_ht,
+				     &fib4_rt->common.ht_node,
+				     nsim_fib_rt_ht_params);
+	if (err)
+		goto err_fib_dismiss;
+
+	/* Simulate hardware programming latency. */
+	msleep(1);
+	nsim_fib4_rt_hw_flags_set(net, fib4_rt, true);
+
+	return 0;
+
+err_fib_dismiss:
+	/* Drop the accounting that was increased from the notification
+	 * context when FIB_EVENT_ENTRY_REPLACE was triggered.
+	 */
+	nsim_fib_account(&data->ipv4.fib, false);
+	return err;
+}
+
+static int nsim_fib4_rt_replace(struct nsim_fib_data *data,
+				struct nsim_fib4_rt *fib4_rt,
+				struct nsim_fib4_rt *fib4_rt_old)
+{
+	struct net *net = devlink_net(data->devlink);
+	int err;
+
+	/* We are replacing a route, so need to remove the accounting which
+	 * was increased when FIB_EVENT_ENTRY_REPLACE was triggered.
+	 */
+	err = nsim_fib_account(&data->ipv4.fib, false);
+	if (err)
+		return err;
+	err = rhashtable_replace_fast(&data->fib_rt_ht,
+				      &fib4_rt_old->common.ht_node,
+				      &fib4_rt->common.ht_node,
+				      nsim_fib_rt_ht_params);
+	if (err)
+		return err;
+
+	msleep(1);
+	nsim_fib4_rt_hw_flags_set(net, fib4_rt, true);
+
+	nsim_fib4_rt_hw_flags_set(net, fib4_rt_old, false);
+	nsim_fib4_rt_destroy(fib4_rt_old);
+
+	return 0;
+}
+
+static int nsim_fib4_rt_insert(struct nsim_fib_data *data,
+			       struct fib_entry_notifier_info *fen_info)
+{
+	struct nsim_fib4_rt *fib4_rt, *fib4_rt_old;
+	int err;
+
+	if (data->fail_route_offload) {
+		/* For testing purposes, user set debugfs fail_route_offload
+		 * value to true. Simulate hardware programming latency and then
+		 * fail.
+		 */
+		msleep(1);
+		return -EINVAL;
+	}
+
+	fib4_rt = nsim_fib4_rt_create(data, fen_info);
+	if (!fib4_rt)
+		return -ENOMEM;
+
+	fib4_rt_old = nsim_fib4_rt_lookup(&data->fib_rt_ht, fen_info);
+	if (!fib4_rt_old)
+		err = nsim_fib4_rt_add(data, fib4_rt);
+	else
+		err = nsim_fib4_rt_replace(data, fib4_rt, fib4_rt_old);
+
+	if (err)
+		nsim_fib4_rt_destroy(fib4_rt);
+
+	return err;
+}
+
+static void nsim_fib4_rt_remove(struct nsim_fib_data *data,
+				const struct fib_entry_notifier_info *fen_info)
+{
+	struct nsim_fib4_rt *fib4_rt;
+
+	fib4_rt = nsim_fib4_rt_lookup(&data->fib_rt_ht, fen_info);
+	if (!fib4_rt)
+		return;
+
+	rhashtable_remove_fast(&data->fib_rt_ht, &fib4_rt->common.ht_node,
+			       nsim_fib_rt_ht_params);
+	nsim_fib4_rt_destroy(fib4_rt);
+}
+
+static int nsim_fib4_event(struct nsim_fib_data *data,
+			   struct fib_entry_notifier_info *fen_info,
+			   unsigned long event)
+{
+	int err = 0;
+
+	switch (event) {
+	case FIB_EVENT_ENTRY_REPLACE:
+		err = nsim_fib4_rt_insert(data, fen_info);
+		if (err) {
+			struct net *net = devlink_net(data->devlink);
+
+			nsim_fib4_rt_offload_failed_flag_set(net, fen_info);
+		}
+		break;
+	case FIB_EVENT_ENTRY_DEL:
+		nsim_fib4_rt_remove(data, fen_info);
+		break;
+	default:
+		break;
+	}
+
+	return err;
+}
+
+static struct nsim_fib6_rt_nh *
+nsim_fib6_rt_nh_find(const struct nsim_fib6_rt *fib6_rt,
+		     const struct fib6_info *rt)
+{
+	struct nsim_fib6_rt_nh *fib6_rt_nh;
+
+	list_for_each_entry(fib6_rt_nh, &fib6_rt->nh_list, list) {
+		if (fib6_rt_nh->rt == rt)
+			return fib6_rt_nh;
+	}
+
+	return NULL;
+}
+
+static int nsim_fib6_rt_nh_add(struct nsim_fib6_rt *fib6_rt,
+			       struct fib6_info *rt)
+{
+	struct nsim_fib6_rt_nh *fib6_rt_nh;
+
+	fib6_rt_nh = kzalloc_obj(*fib6_rt_nh);
+	if (!fib6_rt_nh)
+		return -ENOMEM;
+
+	fib6_info_hold(rt);
+	fib6_rt_nh->rt = rt;
+	list_add_tail(&fib6_rt_nh->list, &fib6_rt->nh_list);
+	fib6_rt->nhs++;
+
+	return 0;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static void nsim_rt6_release(struct fib6_info *rt)
+{
+	fib6_info_release(rt);
+}
+#else
+static void nsim_rt6_release(struct fib6_info *rt)
+{
+}
+#endif
+
+static void nsim_fib6_rt_nh_del(struct nsim_fib6_rt *fib6_rt,
+				const struct fib6_info *rt)
+{
+	struct nsim_fib6_rt_nh *fib6_rt_nh;
+
+	fib6_rt_nh = nsim_fib6_rt_nh_find(fib6_rt, rt);
+	if (!fib6_rt_nh)
+		return;
+
+	fib6_rt->nhs--;
+	list_del(&fib6_rt_nh->list);
+	nsim_rt6_release(fib6_rt_nh->rt);
+	kfree(fib6_rt_nh);
+}
+
+static struct nsim_fib6_rt *
+nsim_fib6_rt_create(struct nsim_fib_data *data,
+		    struct fib6_info **rt_arr, unsigned int nrt6)
+{
+	struct fib6_info *rt = rt_arr[0];
+	struct nsim_fib6_rt *fib6_rt;
+	int i = 0;
+	int err;
+
+	fib6_rt = kzalloc_obj(*fib6_rt);
+	if (!fib6_rt)
+		return ERR_PTR(-ENOMEM);
+
+	nsim_fib_rt_init(data, &fib6_rt->common, &rt->fib6_dst.addr,
+			 sizeof(rt->fib6_dst.addr), rt->fib6_dst.plen, AF_INET6,
+			 rt->fib6_table->tb6_id);
+
+	/* We consider a multipath IPv6 route as one entry, but it can be made
+	 * up from several fib6_info structs (one for each nexthop), so we
+	 * add them all to the same list under the entry.
+	 */
+	INIT_LIST_HEAD(&fib6_rt->nh_list);
+
+	for (i = 0; i < nrt6; i++) {
+		err = nsim_fib6_rt_nh_add(fib6_rt, rt_arr[i]);
+		if (err)
+			goto err_fib6_rt_nh_del;
+	}
+
+	return fib6_rt;
+
+err_fib6_rt_nh_del:
+	for (i--; i >= 0; i--) {
+		nsim_fib6_rt_nh_del(fib6_rt, rt_arr[i]);
+	}
+	nsim_fib_rt_fini(&fib6_rt->common);
+	kfree(fib6_rt);
+	return ERR_PTR(err);
+}
+
+static void nsim_fib6_rt_destroy(struct nsim_fib6_rt *fib6_rt)
+{
+	struct nsim_fib6_rt_nh *iter, *tmp;
+
+	list_for_each_entry_safe(iter, tmp, &fib6_rt->nh_list, list)
+		nsim_fib6_rt_nh_del(fib6_rt, iter->rt);
+	WARN_ON_ONCE(!list_empty(&fib6_rt->nh_list));
+	nsim_fib_rt_fini(&fib6_rt->common);
+	kfree(fib6_rt);
+}
+
+static struct nsim_fib6_rt *
+nsim_fib6_rt_lookup(struct rhashtable *fib_rt_ht, const struct fib6_info *rt)
+{
+	struct nsim_fib_rt *fib_rt;
+
+	fib_rt = nsim_fib_rt_lookup(fib_rt_ht, &rt->fib6_dst.addr,
+				    sizeof(rt->fib6_dst.addr),
+				    rt->fib6_dst.plen, AF_INET6,
+				    rt->fib6_table->tb6_id);
+	if (!fib_rt)
+		return NULL;
+
+	return container_of(fib_rt, struct nsim_fib6_rt, common);
+}
+
+static int nsim_fib6_rt_append(struct nsim_fib_data *data,
+			       struct nsim_fib6_event *fib6_event)
+{
+	struct fib6_info *rt = fib6_event->rt_arr[0];
+	struct nsim_fib6_rt *fib6_rt;
+	int i, err;
+
+	if (data->fail_route_offload) {
+		/* For testing purposes, user set debugfs fail_route_offload
+		 * value to true. Simulate hardware programming latency and then
+		 * fail.
+		 */
+		msleep(1);
+		return -EINVAL;
+	}
+
+	fib6_rt = nsim_fib6_rt_lookup(&data->fib_rt_ht, rt);
+	if (!fib6_rt)
+		return -EINVAL;
+
+	for (i = 0; i < fib6_event->nrt6; i++) {
+		err = nsim_fib6_rt_nh_add(fib6_rt, fib6_event->rt_arr[i]);
+		if (err)
+			goto err_fib6_rt_nh_del;
+
+		WRITE_ONCE(fib6_event->rt_arr[i]->trap, true);
+	}
+
+	return 0;
+
+err_fib6_rt_nh_del:
+	for (i--; i >= 0; i--) {
+		WRITE_ONCE(fib6_event->rt_arr[i]->trap, false);
+		nsim_fib6_rt_nh_del(fib6_rt, fib6_event->rt_arr[i]);
+	}
+	return err;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static void nsim_fib6_rt_offload_failed_flag_set(struct nsim_fib_data *data,
+						 struct fib6_info **rt_arr,
+						 unsigned int nrt6)
+
+{
+	struct net *net = devlink_net(data->devlink);
+	int i;
+
+	for (i = 0; i < nrt6; i++)
+		fib6_info_hw_flags_set(net, rt_arr[i], false, false, true);
+}
+#else
+static void nsim_fib6_rt_offload_failed_flag_set(struct nsim_fib_data *data,
+						 struct fib6_info **rt_arr,
+						 unsigned int nrt6)
+{
+}
+#endif
+
+#if IS_ENABLED(CONFIG_IPV6)
+static void nsim_fib6_rt_hw_flags_set(struct nsim_fib_data *data,
+				      const struct nsim_fib6_rt *fib6_rt,
+				      bool trap)
+{
+	struct net *net = devlink_net(data->devlink);
+	struct nsim_fib6_rt_nh *fib6_rt_nh;
+
+	list_for_each_entry(fib6_rt_nh, &fib6_rt->nh_list, list)
+		fib6_info_hw_flags_set(net, fib6_rt_nh->rt, false, trap, false);
+}
+#else
+static void nsim_fib6_rt_hw_flags_set(struct nsim_fib_data *data,
+				      const struct nsim_fib6_rt *fib6_rt,
+				      bool trap)
+{
+}
+#endif
+
+static int nsim_fib6_rt_add(struct nsim_fib_data *data,
+			    struct nsim_fib6_rt *fib6_rt)
+{
+	int err;
+
+	err = rhashtable_insert_fast(&data->fib_rt_ht,
+				     &fib6_rt->common.ht_node,
+				     nsim_fib_rt_ht_params);
+
+	if (err)
+		goto err_fib_dismiss;
+
+	msleep(1);
+	nsim_fib6_rt_hw_flags_set(data, fib6_rt, true);
+
+	return 0;
+
+err_fib_dismiss:
+	/* Drop the accounting that was increased from the notification
+	 * context when FIB_EVENT_ENTRY_REPLACE was triggered.
+	 */
+	nsim_fib_account(&data->ipv6.fib, false);
+	return err;
+}
+
+static int nsim_fib6_rt_replace(struct nsim_fib_data *data,
+				struct nsim_fib6_rt *fib6_rt,
+				struct nsim_fib6_rt *fib6_rt_old)
+{
+	int err;
+
+	/* We are replacing a route, so need to remove the accounting which
+	 * was increased when FIB_EVENT_ENTRY_REPLACE was triggered.
+	 */
+	err = nsim_fib_account(&data->ipv6.fib, false);
+	if (err)
+		return err;
+
+	err = rhashtable_replace_fast(&data->fib_rt_ht,
+				      &fib6_rt_old->common.ht_node,
+				      &fib6_rt->common.ht_node,
+				      nsim_fib_rt_ht_params);
+
+	if (err)
+		return err;
+
+	msleep(1);
+	nsim_fib6_rt_hw_flags_set(data, fib6_rt, true);
+
+	nsim_fib6_rt_hw_flags_set(data, fib6_rt_old, false);
+	nsim_fib6_rt_destroy(fib6_rt_old);
+
+	return 0;
+}
+
+static int nsim_fib6_rt_insert(struct nsim_fib_data *data,
+			       struct nsim_fib6_event *fib6_event)
+{
+	struct fib6_info *rt = fib6_event->rt_arr[0];
+	struct nsim_fib6_rt *fib6_rt, *fib6_rt_old;
+	int err;
+
+	if (data->fail_route_offload) {
+		/* For testing purposes, user set debugfs fail_route_offload
+		 * value to true. Simulate hardware programming latency and then
+		 * fail.
+		 */
+		msleep(1);
+		return -EINVAL;
+	}
+
+	fib6_rt = nsim_fib6_rt_create(data, fib6_event->rt_arr,
+				      fib6_event->nrt6);
+	if (IS_ERR(fib6_rt))
+		return PTR_ERR(fib6_rt);
+
+	fib6_rt_old = nsim_fib6_rt_lookup(&data->fib_rt_ht, rt);
+	if (!fib6_rt_old)
+		err = nsim_fib6_rt_add(data, fib6_rt);
+	else
+		err = nsim_fib6_rt_replace(data, fib6_rt, fib6_rt_old);
+
+	if (err)
+		nsim_fib6_rt_destroy(fib6_rt);
+
+	return err;
+}
+
+static void nsim_fib6_rt_remove(struct nsim_fib_data *data,
+				struct nsim_fib6_event *fib6_event)
+{
+	struct fib6_info *rt = fib6_event->rt_arr[0];
+	struct nsim_fib6_rt *fib6_rt;
+	int i;
+
+	/* Multipath routes are first added to the FIB trie and only then
+	 * notified. If we vetoed the addition, we will get a delete
+	 * notification for a route we do not have. Therefore, do not warn if
+	 * route was not found.
+	 */
+	fib6_rt = nsim_fib6_rt_lookup(&data->fib_rt_ht, rt);
+	if (!fib6_rt)
+		return;
+
+	/* If not all the nexthops are deleted, then only reduce the nexthop
+	 * group.
+	 */
+	if (fib6_event->nrt6 != fib6_rt->nhs) {
+		for (i = 0; i < fib6_event->nrt6; i++)
+			nsim_fib6_rt_nh_del(fib6_rt, fib6_event->rt_arr[i]);
+		return;
+	}
+
+	rhashtable_remove_fast(&data->fib_rt_ht, &fib6_rt->common.ht_node,
+			       nsim_fib_rt_ht_params);
+	nsim_fib6_rt_destroy(fib6_rt);
+}
+
+static int nsim_fib6_event_init(struct nsim_fib6_event *fib6_event,
+				struct fib6_entry_notifier_info *fen6_info)
+{
+	struct fib6_info *rt = fen6_info->rt;
+	struct fib6_info **rt_arr;
+	struct fib6_info *iter;
+	unsigned int nrt6;
+	int i = 0;
+
+	nrt6 = fen6_info->nsiblings + 1;
+
+	rt_arr = kzalloc_objs(struct fib6_info *, nrt6, GFP_ATOMIC);
+	if (!rt_arr)
+		return -ENOMEM;
+
+	fib6_event->rt_arr = rt_arr;
+	fib6_event->nrt6 = nrt6;
+
+	rt_arr[0] = rt;
+	fib6_info_hold(rt);
+
+	if (!fen6_info->nsiblings)
+		return 0;
+
+	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
+		if (i == fen6_info->nsiblings)
+			break;
+
+		rt_arr[i + 1] = iter;
+		fib6_info_hold(iter);
+		i++;
+	}
+	WARN_ON_ONCE(i != fen6_info->nsiblings);
+
+	return 0;
+}
+
+static void nsim_fib6_event_fini(struct nsim_fib6_event *fib6_event)
+{
+	int i;
+
+	for (i = 0; i < fib6_event->nrt6; i++)
+		nsim_rt6_release(fib6_event->rt_arr[i]);
+	kfree(fib6_event->rt_arr);
+}
+
+static int nsim_fib6_event(struct nsim_fib_data *data,
+			   struct nsim_fib6_event *fib6_event,
+			   unsigned long event)
+{
+	int err;
+
+	if (fib6_event->rt_arr[0]->fib6_src.plen)
+		return 0;
+
+	switch (event) {
+	case FIB_EVENT_ENTRY_REPLACE:
+		err = nsim_fib6_rt_insert(data, fib6_event);
+		if (err)
+			goto err_rt_offload_failed_flag_set;
+		break;
+	case FIB_EVENT_ENTRY_APPEND:
+		err = nsim_fib6_rt_append(data, fib6_event);
+		if (err)
+			goto err_rt_offload_failed_flag_set;
+		break;
+	case FIB_EVENT_ENTRY_DEL:
+		nsim_fib6_rt_remove(data, fib6_event);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+
+err_rt_offload_failed_flag_set:
+	nsim_fib6_rt_offload_failed_flag_set(data, fib6_event->rt_arr,
+					     fib6_event->nrt6);
+	return err;
+}
+
+static void nsim_fib_event(struct nsim_fib_event *fib_event)
+{
+	switch (fib_event->family) {
+	case AF_INET:
+		nsim_fib4_event(fib_event->data, &fib_event->fen_info,
+				fib_event->event);
+		fib_info_put(fib_event->fen_info.fi);
+		break;
+	case AF_INET6:
+		nsim_fib6_event(fib_event->data, &fib_event->fib6_event,
+				fib_event->event);
+		nsim_fib6_event_fini(&fib_event->fib6_event);
+		break;
+	}
+}
+
+static int nsim_fib4_prepare_event(struct fib_notifier_info *info,
+				   struct nsim_fib_event *fib_event,
+				   unsigned long event)
+{
+	struct nsim_fib_data *data = fib_event->data;
+	struct fib_entry_notifier_info *fen_info;
+	struct netlink_ext_ack *extack;
+	int err = 0;
+
+	fen_info = container_of(info, struct fib_entry_notifier_info,
+				info);
+	fib_event->fen_info = *fen_info;
+	extack = info->extack;
+
+	switch (event) {
+	case FIB_EVENT_ENTRY_REPLACE:
+		err = nsim_fib_account(&data->ipv4.fib, true);
+		if (err) {
+			NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported fib entries");
+			return err;
+		}
+		break;
+	case FIB_EVENT_ENTRY_DEL:
+		if (data->fail_route_delete) {
+			NL_SET_ERR_MSG_MOD(extack, "Failed to process route deletion");
+			return -EINVAL;
+		}
+		nsim_fib_account(&data->ipv4.fib, false);
+		break;
+	}
+
+	/* Take reference on fib_info to prevent it from being
+	 * freed while event is queued. Release it afterwards.
+	 */
+	fib_info_hold(fib_event->fen_info.fi);
+
+	return 0;
+}
+
+static int nsim_fib6_prepare_event(struct fib_notifier_info *info,
+				   struct nsim_fib_event *fib_event,
+				   unsigned long event)
+{
+	struct nsim_fib_data *data = fib_event->data;
+	struct fib6_entry_notifier_info *fen6_info;
+	struct netlink_ext_ack *extack;
+	int err = 0;
+
+	fen6_info = container_of(info, struct fib6_entry_notifier_info,
+				 info);
+
+	err = nsim_fib6_event_init(&fib_event->fib6_event, fen6_info);
+	if (err)
+		return err;
+
+	extack = info->extack;
+	switch (event) {
+	case FIB_EVENT_ENTRY_REPLACE:
+		err = nsim_fib_account(&data->ipv6.fib, true);
+		if (err) {
+			NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported fib entries");
+			goto err_fib6_event_fini;
+		}
+		break;
+	case FIB_EVENT_ENTRY_DEL:
+		if (data->fail_route_delete) {
+			err = -EINVAL;
+			NL_SET_ERR_MSG_MOD(extack, "Failed to process route deletion");
+			goto err_fib6_event_fini;
+		}
+		nsim_fib_account(&data->ipv6.fib, false);
+		break;
+	}
+
+	return 0;
+
+err_fib6_event_fini:
+	nsim_fib6_event_fini(&fib_event->fib6_event);
+	return err;
+}
+
+static int nsim_fib_event_schedule_work(struct nsim_fib_data *data,
+					struct fib_notifier_info *info,
+					unsigned long event)
+{
+	struct nsim_fib_event *fib_event;
+	int err;
+
+	if (info->family != AF_INET && info->family != AF_INET6)
+		/* netdevsim does not support 'RTNL_FAMILY_IP6MR' and
+		 * 'RTNL_FAMILY_IPMR' and should ignore them.
+		 */
+		return NOTIFY_DONE;
+
+	fib_event = kzalloc_obj(*fib_event, GFP_ATOMIC);
+	if (!fib_event)
+		goto err_fib_event_alloc;
+
+	fib_event->data = data;
+	fib_event->event = event;
+	fib_event->family = info->family;
+
+	switch (info->family) {
+	case AF_INET:
+		err = nsim_fib4_prepare_event(info, fib_event, event);
+		break;
+	case AF_INET6:
+		err = nsim_fib6_prepare_event(info, fib_event, event);
+		break;
+	}
+
+	if (err)
+		goto err_fib_prepare_event;
+
+	/* Enqueue the event and trigger the work */
+	spin_lock_bh(&data->fib_event_queue_lock);
+	list_add_tail(&fib_event->list, &data->fib_event_queue);
+	spin_unlock_bh(&data->fib_event_queue_lock);
+	schedule_work(&data->fib_event_work);
+
+	return NOTIFY_DONE;
+
+err_fib_prepare_event:
+	kfree(fib_event);
+err_fib_event_alloc:
+	if (event == FIB_EVENT_ENTRY_DEL)
+		schedule_work(&data->fib_flush_work);
+	return NOTIFY_BAD;
+}
+
+static int nsim_fib_event_nb(struct notifier_block *nb, unsigned long event,
+			     void *ptr)
+{
+	struct nsim_fib_data *data = container_of(nb, struct nsim_fib_data,
+						  fib_nb);
+	struct fib_notifier_info *info = ptr;
+	int err;
+
+	switch (event) {
+	case FIB_EVENT_RULE_ADD:
+	case FIB_EVENT_RULE_DEL:
+		err = nsim_fib_rule_event(data, info,
+					  event == FIB_EVENT_RULE_ADD);
+		return notifier_from_errno(err);
+	case FIB_EVENT_ENTRY_REPLACE:
+	case FIB_EVENT_ENTRY_APPEND:
+	case FIB_EVENT_ENTRY_DEL:
+		return nsim_fib_event_schedule_work(data, info, event);
+	}
+
+	return NOTIFY_DONE;
+}
+
+static void nsim_fib4_rt_free(struct nsim_fib_rt *fib_rt,
+			      struct nsim_fib_data *data)
+{
+	struct devlink *devlink = data->devlink;
+	struct nsim_fib4_rt *fib4_rt;
+
+	fib4_rt = container_of(fib_rt, struct nsim_fib4_rt, common);
+	nsim_fib4_rt_hw_flags_set(devlink_net(devlink), fib4_rt, false);
+	nsim_fib_account(&data->ipv4.fib, false);
+	nsim_fib4_rt_destroy(fib4_rt);
+}
+
+static void nsim_fib6_rt_free(struct nsim_fib_rt *fib_rt,
+			      struct nsim_fib_data *data)
+{
+	struct nsim_fib6_rt *fib6_rt;
+
+	fib6_rt = container_of(fib_rt, struct nsim_fib6_rt, common);
+	nsim_fib6_rt_hw_flags_set(data, fib6_rt, false);
+	nsim_fib_account(&data->ipv6.fib, false);
+	nsim_fib6_rt_destroy(fib6_rt);
+}
+
+static void nsim_fib_rt_free(void *ptr, void *arg)
+{
+	struct nsim_fib_rt *fib_rt = ptr;
+	struct nsim_fib_data *data = arg;
+
+	switch (fib_rt->key.family) {
+	case AF_INET:
+		nsim_fib4_rt_free(fib_rt, data);
+		break;
+	case AF_INET6:
+		nsim_fib6_rt_free(fib_rt, data);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+	}
+}
+
+/* inconsistent dump, trying again */
+static void nsim_fib_dump_inconsistent(struct notifier_block *nb)
+{
+	struct nsim_fib_data *data = container_of(nb, struct nsim_fib_data,
+						  fib_nb);
+	struct nsim_fib_rt *fib_rt, *fib_rt_tmp;
+
+	/* Flush the work to make sure there is no race with notifications. */
+	flush_work(&data->fib_event_work);
+
+	/* The notifier block is still not registered, so we do not need to
+	 * take any locks here.
+	 */
+	list_for_each_entry_safe(fib_rt, fib_rt_tmp, &data->fib_rt_list, list) {
+		rhashtable_remove_fast(&data->fib_rt_ht, &fib_rt->ht_node,
+				       nsim_fib_rt_ht_params);
+		nsim_fib_rt_free(fib_rt, data);
+	}
+
+	atomic64_set(&data->ipv4.rules.num, 0ULL);
+	atomic64_set(&data->ipv6.rules.num, 0ULL);
+}
+
+static struct nsim_nexthop *nsim_nexthop_create(struct nsim_fib_data *data,
+						struct nh_notifier_info *info)
+{
+	struct nsim_nexthop *nexthop;
+	u64 occ = 0;
+	int i;
+
+	nexthop = kzalloc_obj(*nexthop);
+	if (!nexthop)
+		return ERR_PTR(-ENOMEM);
+
+	nexthop->id = info->id;
+
+	/* Determine the number of nexthop entries the new nexthop will
+	 * occupy.
+	 */
+
+	switch (info->type) {
+	case NH_NOTIFIER_INFO_TYPE_SINGLE:
+		occ = 1;
+		break;
+	case NH_NOTIFIER_INFO_TYPE_GRP:
+		for (i = 0; i < info->nh_grp->num_nh; i++)
+			occ += info->nh_grp->nh_entries[i].weight;
+		break;
+	case NH_NOTIFIER_INFO_TYPE_RES_TABLE:
+		occ = info->nh_res_table->num_nh_buckets;
+		nexthop->is_resilient = true;
+		break;
+	default:
+		NL_SET_ERR_MSG_MOD(info->extack, "Unsupported nexthop type");
+		kfree(nexthop);
+		return ERR_PTR(-EOPNOTSUPP);
+	}
+
+	nexthop->occ = occ;
+	return nexthop;
+}
+
+static void nsim_nexthop_destroy(struct nsim_nexthop *nexthop)
+{
+	kfree(nexthop);
+}
+
+static int nsim_nexthop_account(struct nsim_fib_data *data, u64 occ,
+				bool add, struct netlink_ext_ack *extack)
+{
+	int i, err = 0;
+
+	if (add) {
+		for (i = 0; i < occ; i++)
+			if (!atomic64_add_unless(&data->nexthops.num, 1,
+						 data->nexthops.max)) {
+				err = -ENOSPC;
+				NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported nexthops");
+				goto err_num_decrease;
+			}
+	} else {
+		if (WARN_ON(occ > atomic64_read(&data->nexthops.num)))
+			return -EINVAL;
+		atomic64_sub(occ, &data->nexthops.num);
+	}
+
+	return err;
+
+err_num_decrease:
+	atomic64_sub(i, &data->nexthops.num);
+	return err;
+
+}
+
+static void nsim_nexthop_hw_flags_set(struct net *net,
+				      const struct nsim_nexthop *nexthop,
+				      bool trap)
+{
+	int i;
+
+	nexthop_set_hw_flags(net, nexthop->id, false, trap);
+
+	if (!nexthop->is_resilient)
+		return;
+
+	for (i = 0; i < nexthop->occ; i++)
+		nexthop_bucket_set_hw_flags(net, nexthop->id, i, false, trap);
+}
+
+static int nsim_nexthop_add(struct nsim_fib_data *data,
+			    struct nsim_nexthop *nexthop,
+			    struct netlink_ext_ack *extack)
+{
+	struct net *net = devlink_net(data->devlink);
+	int err;
+
+	err = nsim_nexthop_account(data, nexthop->occ, true, extack);
+	if (err)
+		return err;
+
+	err = rhashtable_insert_fast(&data->nexthop_ht, &nexthop->ht_node,
+				     nsim_nexthop_ht_params);
+	if (err) {
+		NL_SET_ERR_MSG_MOD(extack, "Failed to insert nexthop");
+		goto err_nexthop_dismiss;
+	}
+
+	nsim_nexthop_hw_flags_set(net, nexthop, true);
+
+	return 0;
+
+err_nexthop_dismiss:
+	nsim_nexthop_account(data, nexthop->occ, false, extack);
+	return err;
+}
+
+static int nsim_nexthop_replace(struct nsim_fib_data *data,
+				struct nsim_nexthop *nexthop,
+				struct nsim_nexthop *nexthop_old,
+				struct netlink_ext_ack *extack)
+{
+	struct net *net = devlink_net(data->devlink);
+	int err;
+
+	err = nsim_nexthop_account(data, nexthop->occ, true, extack);
+	if (err)
+		return err;
+
+	err = rhashtable_replace_fast(&data->nexthop_ht,
+				      &nexthop_old->ht_node, &nexthop->ht_node,
+				      nsim_nexthop_ht_params);
+	if (err) {
+		NL_SET_ERR_MSG_MOD(extack, "Failed to replace nexthop");
+		goto err_nexthop_dismiss;
+	}
+
+	nsim_nexthop_hw_flags_set(net, nexthop, true);
+	nsim_nexthop_account(data, nexthop_old->occ, false, extack);
+	nsim_nexthop_destroy(nexthop_old);
+
+	return 0;
+
+err_nexthop_dismiss:
+	nsim_nexthop_account(data, nexthop->occ, false, extack);
+	return err;
+}
+
+static int nsim_nexthop_insert(struct nsim_fib_data *data,
+			       struct nh_notifier_info *info)
+{
+	struct nsim_nexthop *nexthop, *nexthop_old;
+	int err;
+
+	nexthop = nsim_nexthop_create(data, info);
+	if (IS_ERR(nexthop))
+		return PTR_ERR(nexthop);
+
+	nexthop_old = rhashtable_lookup_fast(&data->nexthop_ht, &info->id,
+					     nsim_nexthop_ht_params);
+	if (!nexthop_old)
+		err = nsim_nexthop_add(data, nexthop, info->extack);
+	else
+		err = nsim_nexthop_replace(data, nexthop, nexthop_old,
+					   info->extack);
+
+	if (err)
+		nsim_nexthop_destroy(nexthop);
+
+	return err;
+}
+
+static void nsim_nexthop_remove(struct nsim_fib_data *data,
+				struct nh_notifier_info *info)
+{
+	struct nsim_nexthop *nexthop;
+
+	nexthop = rhashtable_lookup_fast(&data->nexthop_ht, &info->id,
+					 nsim_nexthop_ht_params);
+	if (!nexthop)
+		return;
+
+	rhashtable_remove_fast(&data->nexthop_ht, &nexthop->ht_node,
+			       nsim_nexthop_ht_params);
+	nsim_nexthop_account(data, nexthop->occ, false, info->extack);
+	nsim_nexthop_destroy(nexthop);
+}
+
+static int nsim_nexthop_res_table_pre_replace(struct nsim_fib_data *data,
+					      struct nh_notifier_info *info)
+{
+	if (data->fail_res_nexthop_group_replace) {
+		NL_SET_ERR_MSG_MOD(info->extack, "Failed to replace a resilient nexthop group");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int nsim_nexthop_bucket_replace(struct nsim_fib_data *data,
+				       struct nh_notifier_info *info)
+{
+	if (data->fail_nexthop_bucket_replace) {
+		NL_SET_ERR_MSG_MOD(info->extack, "Failed to replace nexthop bucket");
+		return -EINVAL;
+	}
+
+	nexthop_bucket_set_hw_flags(info->net, info->id,
+				    info->nh_res_bucket->bucket_index,
+				    false, true);
+
+	return 0;
+}
+
+static int nsim_nexthop_event_nb(struct notifier_block *nb, unsigned long event,
+				 void *ptr)
+{
+	struct nsim_fib_data *data = container_of(nb, struct nsim_fib_data,
+						  nexthop_nb);
+	struct nh_notifier_info *info = ptr;
+	int err = 0;
+
+	mutex_lock(&data->nh_lock);
+	switch (event) {
+	case NEXTHOP_EVENT_REPLACE:
+		err = nsim_nexthop_insert(data, info);
+		break;
+	case NEXTHOP_EVENT_DEL:
+		nsim_nexthop_remove(data, info);
+		break;
+	case NEXTHOP_EVENT_RES_TABLE_PRE_REPLACE:
+		err = nsim_nexthop_res_table_pre_replace(data, info);
+		break;
+	case NEXTHOP_EVENT_BUCKET_REPLACE:
+		err = nsim_nexthop_bucket_replace(data, info);
+		break;
+	default:
+		break;
+	}
+
+	mutex_unlock(&data->nh_lock);
+	return notifier_from_errno(err);
+}
+
+static void nsim_nexthop_free(void *ptr, void *arg)
+{
+	struct nsim_nexthop *nexthop = ptr;
+	struct nsim_fib_data *data = arg;
+	struct net *net;
+
+	net = devlink_net(data->devlink);
+	nsim_nexthop_hw_flags_set(net, nexthop, false);
+	nsim_nexthop_account(data, nexthop->occ, false, NULL);
+	nsim_nexthop_destroy(nexthop);
+}
+
+static ssize_t nsim_nexthop_bucket_activity_write(struct file *file,
+						  const char __user *user_buf,
+						  size_t size, loff_t *ppos)
+{
+	struct nsim_fib_data *data = file->private_data;
+	struct net *net = devlink_net(data->devlink);
+	struct nsim_nexthop *nexthop;
+	unsigned long *activity;
+	loff_t pos = *ppos;
+	u16 bucket_index;
+	char buf[128];
+	int err = 0;
+	u32 nhid;
+
+	if (pos != 0)
+		return -EINVAL;
+	if (size > sizeof(buf) - 1)
+		return -EINVAL;
+	if (copy_from_user(buf, user_buf, size))
+		return -EFAULT;
+	buf[size] = 0;
+
+	if (sscanf(buf, "%u %hu", &nhid, &bucket_index) != 2)
+		return -EINVAL;
+
+	rtnl_lock();
+
+	nexthop = rhashtable_lookup_fast(&data->nexthop_ht, &nhid,
+					 nsim_nexthop_ht_params);
+	if (!nexthop || !nexthop->is_resilient ||
+	    bucket_index >= nexthop->occ) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	activity = bitmap_zalloc(nexthop->occ, GFP_KERNEL);
+	if (!activity) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	bitmap_set(activity, bucket_index, 1);
+	nexthop_res_grp_activity_update(net, nhid, nexthop->occ, activity);
+	bitmap_free(activity);
+
+out:
+	rtnl_unlock();
+
+	*ppos = size;
+	return err ?: size;
+}
+
+static const struct file_operations nsim_nexthop_bucket_activity_fops = {
+	.open = simple_open,
+	.write = nsim_nexthop_bucket_activity_write,
+	.owner = THIS_MODULE,
+};
+
+static u64 nsim_fib_ipv4_resource_occ_get(void *priv)
+{
+	struct nsim_fib_data *data = priv;
+
+	return nsim_fib_get_val(data, NSIM_RESOURCE_IPV4_FIB, false);
+}
+
+static u64 nsim_fib_ipv4_rules_res_occ_get(void *priv)
+{
+	struct nsim_fib_data *data = priv;
+
+	return nsim_fib_get_val(data, NSIM_RESOURCE_IPV4_FIB_RULES, false);
+}
+
+static u64 nsim_fib_ipv6_resource_occ_get(void *priv)
+{
+	struct nsim_fib_data *data = priv;
+
+	return nsim_fib_get_val(data, NSIM_RESOURCE_IPV6_FIB, false);
+}
+
+static u64 nsim_fib_ipv6_rules_res_occ_get(void *priv)
+{
+	struct nsim_fib_data *data = priv;
+
+	return nsim_fib_get_val(data, NSIM_RESOURCE_IPV6_FIB_RULES, false);
+}
+
+static u64 nsim_fib_nexthops_res_occ_get(void *priv)
+{
+	struct nsim_fib_data *data = priv;
+
+	return nsim_fib_get_val(data, NSIM_RESOURCE_NEXTHOPS, false);
+}
+
+static void nsim_fib_set_max_all(struct nsim_fib_data *data,
+				 struct devlink *devlink)
+{
+	static const enum nsim_resource_id res_ids[] = {
+		NSIM_RESOURCE_IPV4_FIB, NSIM_RESOURCE_IPV4_FIB_RULES,
+		NSIM_RESOURCE_IPV6_FIB, NSIM_RESOURCE_IPV6_FIB_RULES,
+		NSIM_RESOURCE_NEXTHOPS,
+	};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(res_ids); i++) {
+		int err;
+		u64 val;
+
+		err = devl_resource_size_get(devlink, res_ids[i], &val);
+		if (err)
+			val = (u64) -1;
+		nsim_fib_set_max(data, res_ids[i], val);
+	}
+}
+
+static void nsim_fib_event_work(struct work_struct *work)
+{
+	struct nsim_fib_data *data = container_of(work, struct nsim_fib_data,
+						  fib_event_work);
+	struct nsim_fib_event *fib_event, *next_fib_event;
+
+	LIST_HEAD(fib_event_queue);
+
+	spin_lock_bh(&data->fib_event_queue_lock);
+	list_splice_init(&data->fib_event_queue, &fib_event_queue);
+	spin_unlock_bh(&data->fib_event_queue_lock);
+
+	mutex_lock(&data->fib_lock);
+	list_for_each_entry_safe(fib_event, next_fib_event, &fib_event_queue,
+				 list) {
+		nsim_fib_event(fib_event);
+		list_del(&fib_event->list);
+		kfree(fib_event);
+		cond_resched();
+	}
+	mutex_unlock(&data->fib_lock);
+}
+
+static void nsim_fib_flush_work(struct work_struct *work)
+{
+	struct nsim_fib_data *data = container_of(work, struct nsim_fib_data,
+						  fib_flush_work);
+	struct nsim_fib_rt *fib_rt, *fib_rt_tmp;
+
+	/* Process pending work. */
+	flush_work(&data->fib_event_work);
+
+	mutex_lock(&data->fib_lock);
+	list_for_each_entry_safe(fib_rt, fib_rt_tmp, &data->fib_rt_list, list) {
+		rhashtable_remove_fast(&data->fib_rt_ht, &fib_rt->ht_node,
+				       nsim_fib_rt_ht_params);
+		nsim_fib_rt_free(fib_rt, data);
+	}
+	mutex_unlock(&data->fib_lock);
+}
+
+static int
+nsim_fib_debugfs_init(struct nsim_fib_data *data, struct nsim_dev *nsim_dev)
+{
+	data->ddir = debugfs_create_dir("fib", nsim_dev->ddir);
+	if (IS_ERR(data->ddir))
+		return PTR_ERR(data->ddir);
+
+	data->fail_route_offload = false;
+	debugfs_create_bool("fail_route_offload", 0600, data->ddir,
+			    &data->fail_route_offload);
+
+	data->fail_res_nexthop_group_replace = false;
+	debugfs_create_bool("fail_res_nexthop_group_replace", 0600, data->ddir,
+			    &data->fail_res_nexthop_group_replace);
+
+	data->fail_nexthop_bucket_replace = false;
+	debugfs_create_bool("fail_nexthop_bucket_replace", 0600, data->ddir,
+			    &data->fail_nexthop_bucket_replace);
+
+	debugfs_create_file("nexthop_bucket_activity", 0200, data->ddir,
+			    data, &nsim_nexthop_bucket_activity_fops);
+
+	data->fail_route_delete = false;
+	debugfs_create_bool("fail_route_delete", 0600, data->ddir,
+			    &data->fail_route_delete);
+	return 0;
+}
+
+static void nsim_fib_debugfs_exit(struct nsim_fib_data *data)
+{
+	debugfs_remove_recursive(data->ddir);
+}
+
+struct nsim_fib_data *nsim_fib_create(struct devlink *devlink,
+				      struct netlink_ext_ack *extack)
+{
+	struct nsim_fib_data *data;
+	struct nsim_dev *nsim_dev;
+	int err;
+
+	data = kzalloc_obj(*data);
+	if (!data)
+		return ERR_PTR(-ENOMEM);
+	data->devlink = devlink;
+
+	nsim_dev = devlink_priv(devlink);
+
+	mutex_init(&data->nh_lock);
+	err = rhashtable_init(&data->nexthop_ht, &nsim_nexthop_ht_params);
+	if (err)
+		goto err_nh_lock_destroy;
+
+	mutex_init(&data->fib_lock);
+	INIT_LIST_HEAD(&data->fib_rt_list);
+	err = rhashtable_init(&data->fib_rt_ht, &nsim_fib_rt_ht_params);
+	if (err)
+		goto err_rhashtable_nexthop_destroy;
+
+	INIT_WORK(&data->fib_event_work, nsim_fib_event_work);
+	INIT_WORK(&data->fib_flush_work, nsim_fib_flush_work);
+	INIT_LIST_HEAD(&data->fib_event_queue);
+	spin_lock_init(&data->fib_event_queue_lock);
+
+	nsim_fib_set_max_all(data, devlink);
+
+	data->nexthop_nb.notifier_call = nsim_nexthop_event_nb;
+	err = register_nexthop_notifier(devlink_net(devlink), &data->nexthop_nb,
+					extack);
+	if (err) {
+		pr_err("Failed to register nexthop notifier\n");
+		goto err_rhashtable_fib_destroy;
+	}
+
+	data->fib_nb.notifier_call = nsim_fib_event_nb;
+	err = register_fib_notifier(devlink_net(devlink), &data->fib_nb,
+				    nsim_fib_dump_inconsistent, extack);
+	if (err) {
+		pr_err("Failed to register fib notifier\n");
+		goto err_nexthop_nb_unregister;
+	}
+
+	err = nsim_fib_debugfs_init(data, nsim_dev);
+	if (err)
+		goto err_fib_notifier_unregister;
+
+	devl_resource_occ_get_register(devlink,
+				       NSIM_RESOURCE_IPV4_FIB,
+				       nsim_fib_ipv4_resource_occ_get,
+				       data);
+	devl_resource_occ_get_register(devlink,
+				       NSIM_RESOURCE_IPV4_FIB_RULES,
+				       nsim_fib_ipv4_rules_res_occ_get,
+				       data);
+	devl_resource_occ_get_register(devlink,
+				       NSIM_RESOURCE_IPV6_FIB,
+				       nsim_fib_ipv6_resource_occ_get,
+				       data);
+	devl_resource_occ_get_register(devlink,
+				       NSIM_RESOURCE_IPV6_FIB_RULES,
+				       nsim_fib_ipv6_rules_res_occ_get,
+				       data);
+	devl_resource_occ_get_register(devlink,
+				       NSIM_RESOURCE_NEXTHOPS,
+				       nsim_fib_nexthops_res_occ_get,
+				       data);
+	return data;
+
+err_fib_notifier_unregister:
+	unregister_fib_notifier(devlink_net(devlink), &data->fib_nb);
+err_nexthop_nb_unregister:
+	unregister_nexthop_notifier(devlink_net(devlink), &data->nexthop_nb);
+err_rhashtable_fib_destroy:
+	cancel_work_sync(&data->fib_flush_work);
+	flush_work(&data->fib_event_work);
+	rhashtable_free_and_destroy(&data->fib_rt_ht, nsim_fib_rt_free,
+				    data);
+err_rhashtable_nexthop_destroy:
+	rhashtable_free_and_destroy(&data->nexthop_ht, nsim_nexthop_free,
+				    data);
+	mutex_destroy(&data->fib_lock);
+err_nh_lock_destroy:
+	mutex_destroy(&data->nh_lock);
+	kfree(data);
+	return ERR_PTR(err);
+}
+
+void nsim_fib_destroy(struct devlink *devlink, struct nsim_fib_data *data)
+{
+	devl_resource_occ_get_unregister(devlink,
+					 NSIM_RESOURCE_NEXTHOPS);
+	devl_resource_occ_get_unregister(devlink,
+					 NSIM_RESOURCE_IPV6_FIB_RULES);
+	devl_resource_occ_get_unregister(devlink,
+					 NSIM_RESOURCE_IPV6_FIB);
+	devl_resource_occ_get_unregister(devlink,
+					 NSIM_RESOURCE_IPV4_FIB_RULES);
+	devl_resource_occ_get_unregister(devlink,
+					 NSIM_RESOURCE_IPV4_FIB);
+	nsim_fib_debugfs_exit(data);
+	unregister_fib_notifier(devlink_net(devlink), &data->fib_nb);
+	unregister_nexthop_notifier(devlink_net(devlink), &data->nexthop_nb);
+	cancel_work_sync(&data->fib_flush_work);
+	flush_work(&data->fib_event_work);
+	rhashtable_free_and_destroy(&data->fib_rt_ht, nsim_fib_rt_free,
+				    data);
+	rhashtable_free_and_destroy(&data->nexthop_ht, nsim_nexthop_free,
+				    data);
+	WARN_ON_ONCE(!list_empty(&data->fib_event_queue));
+	WARN_ON_ONCE(!list_empty(&data->fib_rt_list));
+	mutex_destroy(&data->fib_lock);
+	mutex_destroy(&data->nh_lock);
+	kfree(data);
+}