diff options
Diffstat (limited to 'kernel/bpf/cpumap.c')
| -rw-r--r-- | kernel/bpf/cpumap.c | 170 |
1 files changed, 143 insertions, 27 deletions
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index 27595fc6da56..f1c46529929b 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -52,7 +52,6 @@ struct xdp_bulk_queue { struct bpf_cpu_map_entry { u32 cpu; /* kthread CPU and map index */ int map_id; /* Back reference to map */ - u32 qsize; /* Queue size placeholder for map lookup */ /* XDP can run multiple RX-ring queues, need __percpu enqueue store */ struct xdp_bulk_queue __percpu *bulkq; @@ -62,10 +61,14 @@ struct bpf_cpu_map_entry { /* Queue with potential multi-producers, and single-consumer kthread */ struct ptr_ring *queue; struct task_struct *kthread; - struct work_struct kthread_stop_wq; + + struct bpf_cpumap_val value; + struct bpf_prog *prog; atomic_t refcnt; /* Control when this struct can be free'ed */ struct rcu_head rcu; + + struct work_struct kthread_stop_wq; }; struct bpf_cpu_map { @@ -80,6 +83,7 @@ static int bq_flush_to_queue(struct xdp_bulk_queue *bq); static struct bpf_map *cpu_map_alloc(union bpf_attr *attr) { + u32 value_size = attr->value_size; struct bpf_cpu_map *cmap; int err = -ENOMEM; u64 cost; @@ -90,7 +94,9 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr) /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 4 || - attr->value_size != 4 || attr->map_flags & ~BPF_F_NUMA_NODE) + (value_size != offsetofend(struct bpf_cpumap_val, qsize) && + value_size != offsetofend(struct bpf_cpumap_val, bpf_prog.fd)) || + attr->map_flags & ~BPF_F_NUMA_NODE) return ERR_PTR(-EINVAL); cmap = kzalloc(sizeof(*cmap), GFP_USER); @@ -212,6 +218,8 @@ static void __cpu_map_ring_cleanup(struct ptr_ring *ring) static void put_cpu_map_entry(struct bpf_cpu_map_entry *rcpu) { if (atomic_dec_and_test(&rcpu->refcnt)) { + if (rcpu->prog) + bpf_prog_put(rcpu->prog); /* The queue should be empty at this point */ __cpu_map_ring_cleanup(rcpu->queue); ptr_ring_cleanup(rcpu->queue, NULL); @@ -220,6 +228,75 @@ static void put_cpu_map_entry(struct bpf_cpu_map_entry *rcpu) } } +static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu, + void **frames, int n, + struct xdp_cpumap_stats *stats) +{ + struct xdp_rxq_info rxq; + struct xdp_buff xdp; + int i, nframes = 0; + + if (!rcpu->prog) + return n; + + rcu_read_lock_bh(); + + xdp_set_return_frame_no_direct(); + xdp.rxq = &rxq; + + for (i = 0; i < n; i++) { + struct xdp_frame *xdpf = frames[i]; + u32 act; + int err; + + rxq.dev = xdpf->dev_rx; + rxq.mem = xdpf->mem; + /* TODO: report queue_index to xdp_rxq_info */ + + xdp_convert_frame_to_buff(xdpf, &xdp); + + act = bpf_prog_run_xdp(rcpu->prog, &xdp); + switch (act) { + case XDP_PASS: + err = xdp_update_frame_from_buff(&xdp, xdpf); + if (err < 0) { + xdp_return_frame(xdpf); + stats->drop++; + } else { + frames[nframes++] = xdpf; + stats->pass++; + } + break; + case XDP_REDIRECT: + err = xdp_do_redirect(xdpf->dev_rx, &xdp, + rcpu->prog); + if (unlikely(err)) { + xdp_return_frame(xdpf); + stats->drop++; + } else { + stats->redirect++; + } + break; + default: + bpf_warn_invalid_xdp_action(act); + /* fallthrough */ + case XDP_DROP: + xdp_return_frame(xdpf); + stats->drop++; + break; + } + } + + if (stats->redirect) + xdp_do_flush_map(); + + xdp_clear_return_frame_no_direct(); + + rcu_read_unlock_bh(); /* resched point, may call do_softirq() */ + + return nframes; +} + #define CPUMAP_BATCH 8 static int cpu_map_kthread_run(void *data) @@ -234,11 +311,12 @@ static int cpu_map_kthread_run(void *data) * kthread_stop signal until queue is empty. */ while (!kthread_should_stop() || !__ptr_ring_empty(rcpu->queue)) { + struct xdp_cpumap_stats stats = {}; /* zero stats */ + gfp_t gfp = __GFP_ZERO | GFP_ATOMIC; unsigned int drops = 0, sched = 0; void *frames[CPUMAP_BATCH]; void *skbs[CPUMAP_BATCH]; - gfp_t gfp = __GFP_ZERO | GFP_ATOMIC; - int i, n, m; + int i, n, m, nframes; /* Release CPU reschedule checks */ if (__ptr_ring_empty(rcpu->queue)) { @@ -259,8 +337,8 @@ static int cpu_map_kthread_run(void *data) * kthread CPU pinned. Lockless access to ptr_ring * consume side valid as no-resize allowed of queue. */ - n = ptr_ring_consume_batched(rcpu->queue, frames, CPUMAP_BATCH); - + n = __ptr_ring_consume_batched(rcpu->queue, frames, + CPUMAP_BATCH); for (i = 0; i < n; i++) { void *f = frames[i]; struct page *page = virt_to_page(f); @@ -272,15 +350,19 @@ static int cpu_map_kthread_run(void *data) prefetchw(page); } - m = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, n, skbs); - if (unlikely(m == 0)) { - for (i = 0; i < n; i++) - skbs[i] = NULL; /* effect: xdp_return_frame */ - drops = n; + /* Support running another XDP prog on this CPU */ + nframes = cpu_map_bpf_prog_run_xdp(rcpu, frames, n, &stats); + if (nframes) { + m = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, nframes, skbs); + if (unlikely(m == 0)) { + for (i = 0; i < nframes; i++) + skbs[i] = NULL; /* effect: xdp_return_frame */ + drops += nframes; + } } local_bh_disable(); - for (i = 0; i < n; i++) { + for (i = 0; i < nframes; i++) { struct xdp_frame *xdpf = frames[i]; struct sk_buff *skb = skbs[i]; int ret; @@ -297,7 +379,7 @@ static int cpu_map_kthread_run(void *data) drops++; } /* Feedback loop via tracepoint */ - trace_xdp_cpumap_kthread(rcpu->map_id, n, drops, sched); + trace_xdp_cpumap_kthread(rcpu->map_id, n, drops, sched, &stats); local_bh_enable(); /* resched point, may call do_softirq() */ } @@ -307,13 +389,38 @@ static int cpu_map_kthread_run(void *data) return 0; } -static struct bpf_cpu_map_entry *__cpu_map_entry_alloc(u32 qsize, u32 cpu, - int map_id) +bool cpu_map_prog_allowed(struct bpf_map *map) { + return map->map_type == BPF_MAP_TYPE_CPUMAP && + map->value_size != offsetofend(struct bpf_cpumap_val, qsize); +} + +static int __cpu_map_load_bpf_program(struct bpf_cpu_map_entry *rcpu, int fd) +{ + struct bpf_prog *prog; + + prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_XDP); + if (IS_ERR(prog)) + return PTR_ERR(prog); + + if (prog->expected_attach_type != BPF_XDP_CPUMAP) { + bpf_prog_put(prog); + return -EINVAL; + } + + rcpu->value.bpf_prog.id = prog->aux->id; + rcpu->prog = prog; + + return 0; +} + +static struct bpf_cpu_map_entry * +__cpu_map_entry_alloc(struct bpf_cpumap_val *value, u32 cpu, int map_id) +{ + int numa, err, i, fd = value->bpf_prog.fd; gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; struct bpf_cpu_map_entry *rcpu; struct xdp_bulk_queue *bq; - int numa, err, i; /* Have map->numa_node, but choose node of redirect target CPU */ numa = cpu_to_node(cpu); @@ -338,19 +445,22 @@ static struct bpf_cpu_map_entry *__cpu_map_entry_alloc(u32 qsize, u32 cpu, if (!rcpu->queue) goto free_bulkq; - err = ptr_ring_init(rcpu->queue, qsize, gfp); + err = ptr_ring_init(rcpu->queue, value->qsize, gfp); if (err) goto free_queue; rcpu->cpu = cpu; rcpu->map_id = map_id; - rcpu->qsize = qsize; + rcpu->value.qsize = value->qsize; + + if (fd > 0 && __cpu_map_load_bpf_program(rcpu, fd)) + goto free_ptr_ring; /* Setup kthread */ rcpu->kthread = kthread_create_on_node(cpu_map_kthread_run, rcpu, numa, "cpumap/%d/map:%d", cpu, map_id); if (IS_ERR(rcpu->kthread)) - goto free_ptr_ring; + goto free_prog; get_cpu_map_entry(rcpu); /* 1-refcnt for being in cmap->cpu_map[] */ get_cpu_map_entry(rcpu); /* 1-refcnt for kthread */ @@ -361,6 +471,9 @@ static struct bpf_cpu_map_entry *__cpu_map_entry_alloc(u32 qsize, u32 cpu, return rcpu; +free_prog: + if (rcpu->prog) + bpf_prog_put(rcpu->prog); free_ptr_ring: ptr_ring_cleanup(rcpu->queue, NULL); free_queue: @@ -437,12 +550,12 @@ static int cpu_map_update_elem(struct bpf_map *map, void *key, void *value, u64 map_flags) { struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); + struct bpf_cpumap_val cpumap_value = {}; struct bpf_cpu_map_entry *rcpu; - /* Array index key correspond to CPU number */ u32 key_cpu = *(u32 *)key; - /* Value is the queue size */ - u32 qsize = *(u32 *)value; + + memcpy(&cpumap_value, value, map->value_size); if (unlikely(map_flags > BPF_EXIST)) return -EINVAL; @@ -450,18 +563,18 @@ static int cpu_map_update_elem(struct bpf_map *map, void *key, void *value, return -E2BIG; if (unlikely(map_flags == BPF_NOEXIST)) return -EEXIST; - if (unlikely(qsize > 16384)) /* sanity limit on qsize */ + if (unlikely(cpumap_value.qsize > 16384)) /* sanity limit on qsize */ return -EOVERFLOW; /* Make sure CPU is a valid possible cpu */ if (key_cpu >= nr_cpumask_bits || !cpu_possible(key_cpu)) return -ENODEV; - if (qsize == 0) { + if (cpumap_value.qsize == 0) { rcpu = NULL; /* Same as deleting */ } else { /* Updating qsize cause re-allocation of bpf_cpu_map_entry */ - rcpu = __cpu_map_entry_alloc(qsize, key_cpu, map->id); + rcpu = __cpu_map_entry_alloc(&cpumap_value, key_cpu, map->id); if (!rcpu) return -ENOMEM; rcpu->cmap = cmap; @@ -523,7 +636,7 @@ static void *cpu_map_lookup_elem(struct bpf_map *map, void *key) struct bpf_cpu_map_entry *rcpu = __cpu_map_lookup_elem(map, *(u32 *)key); - return rcpu ? &rcpu->qsize : NULL; + return rcpu ? &rcpu->value : NULL; } static int cpu_map_get_next_key(struct bpf_map *map, void *key, void *next_key) @@ -543,6 +656,7 @@ static int cpu_map_get_next_key(struct bpf_map *map, void *key, void *next_key) return 0; } +static int cpu_map_btf_id; const struct bpf_map_ops cpu_map_ops = { .map_alloc = cpu_map_alloc, .map_free = cpu_map_free, @@ -551,6 +665,8 @@ const struct bpf_map_ops cpu_map_ops = { .map_lookup_elem = cpu_map_lookup_elem, .map_get_next_key = cpu_map_get_next_key, .map_check_btf = map_check_no_btf, + .map_btf_name = "bpf_cpu_map", + .map_btf_id = &cpu_map_btf_id, }; static int bq_flush_to_queue(struct xdp_bulk_queue *bq) |