Re: [PATCH/RFC net-next 8/9] nfp: add a stats handler for flower offloads
On Wed, 28 Jun 2017 01:21:48 +0200, Simon Horman wrote: > From: Pieter Jansen van Vuuren> > Previously there was no way of updating flow rule stats after they > have been offloaded to hardware. This is solved by keeping track of > stats received from hardware and providing this to the TC handler > on request. > > Signed-off-by: Pieter Jansen van Vuuren > Signed-off-by: Simon Horman > --- > drivers/net/ethernet/netronome/nfp/flower/main.h | 26 > .../net/ethernet/netronome/nfp/flower/metadata.c | 143 > - > .../net/ethernet/netronome/nfp/flower/offload.c| 14 +- > drivers/net/ethernet/netronome/nfp/nfp_net.h | 1 + > 4 files changed, 181 insertions(+), 3 deletions(-) > +void nfp_flower_populate_stats(struct nfp_fl_payload *nfp_flow) > +{ > + spin_lock(_flow->lock_nfp_flow_stats); > + nfp_flow->stats.pkts = 0; > + nfp_flow->stats.bytes = 0; > + nfp_flow->stats.used = jiffies; > + spin_unlock(_flow->lock_nfp_flow_stats); > +} This could be static AFAICT. > +void nfp_flower_stats_clear(struct nfp_fl_payload *nfp_flow) > +{ > + spin_lock(_flow->lock_nfp_flow_stats); > + nfp_flow->stats.pkts = 0; > + nfp_flow->stats.bytes = 0; > + spin_unlock(_flow->lock_nfp_flow_stats); > +} > + > +static void > +nfp_flower_update_stats(struct nfp_app *app, struct nfp_fl_stats_frame > *stats) > +{ > + struct nfp_fl_payload *nfp_flow; > + unsigned long flower_cookie; > + > + flower_cookie = be64_to_cpu(stats->stats_cookie); > + > + nfp_flow = nfp_flower_find_in_fl_table(app, flower_cookie); Since you're looking up in the hash table from softirq context and with RTNL held, I think you need RCU protection. My understanding is that the mask table is ever only modified with RTNL held so it needs no protection. The only thing that may come in without RTNL is a ctrl message carrying stat updates. It will try to lookup the flow and increment its statistics. So the use-after-free on statistics is the only danger we may run into here? (or accessing inconsistent hashtable) > + if (!nfp_flow) > + return; > + > + if (nfp_flow->meta.host_ctx_id != stats->stats_con_id) > + return; > + > + spin_lock(_flow->lock_nfp_flow_stats); > + nfp_flow->stats.pkts += be32_to_cpu(stats->pkt_count); > + nfp_flow->stats.bytes += be64_to_cpu(stats->byte_count); > + nfp_flow->stats.used = jiffies; > + spin_unlock(_flow->lock_nfp_flow_stats); > +} > + > +void nfp_flower_rx_flow_stats(struct nfp_app *app, struct sk_buff *skb) > +{ > + unsigned int msg_len = skb->len - NFP_FLOWER_CMSG_HLEN; > + struct nfp_fl_stats_frame *stats_frame; > + unsigned char *msg; > + int msg_offset = 0; > + > + msg = (unsigned char *)skb->data + NFP_FLOWER_CMSG_HLEN; nfp_flower_cmsg_get_data()? Or simply skb_pull() the header off before you invoke specific handlers in nfp_flower_cmsg_rx()? > + > + while (msg_len >= sizeof(struct nfp_fl_stats_frame)) { > + stats_frame = (struct nfp_fl_stats_frame *)msg + msg_offset; Looks suspicious. msg_offset counts bytes and you add it to a typed pointer... > + if (!stats_frame) > + break; This looks strange too, can stats_frame ever be NULL? I think this loop may be better written as: stats_frame = msg; for (i = 0; i < msg_len / sizeof(*stats_frame); i++) nfp_flower_update_stats(_frame[i] or stats_frame + i); > + nfp_flower_update_stats(app, stats_frame); > + > + msg_offset += sizeof(struct nfp_fl_stats_frame); > + msg_len -= sizeof(struct nfp_fl_stats_frame); > + } > +} > + > static struct nfp_flower_table * > nfp_flower_search_fl_table(struct nfp_app *app, unsigned long > tc_flower_cookie) > { > diff --git a/drivers/net/ethernet/netronome/nfp/flower/offload.c > b/drivers/net/ethernet/netronome/nfp/flower/offload.c > index a7f688bbc761..b39c96623657 100644 > --- a/drivers/net/ethernet/netronome/nfp/flower/offload.c > +++ b/drivers/net/ethernet/netronome/nfp/flower/offload.c > @@ -171,6 +171,7 @@ nfp_flower_allocate_new(struct nfp_fl_key_ls *key_layer) > goto err_free_mask; > > flow_pay->meta.flags = 0; > + spin_lock_init(_pay->lock_nfp_flow_stats); > > return flow_pay; > > @@ -294,7 +295,18 @@ nfp_flower_del_offload(struct nfp_app *app, struct > net_device *netdev, > static int > nfp_flower_get_stats(struct nfp_app *app, struct tc_cls_flower_offload *flow) > { > - return -EOPNOTSUPP; > + struct nfp_fl_payload *nfp_flow; > + > + nfp_flow = nfp_flower_find_in_fl_table(app, flow->cookie); > + if (!nfp_flow) > + return -EINVAL; > + > + tcf_exts_stats_update(flow->exts, nfp_flow->stats.bytes, > + nfp_flow->stats.pkts, nfp_flow->stats.used); So the spin_locks
[PATCH/RFC net-next 8/9] nfp: add a stats handler for flower offloads
From: Pieter Jansen van VuurenPreviously there was no way of updating flow rule stats after they have been offloaded to hardware. This is solved by keeping track of stats received from hardware and providing this to the TC handler on request. Signed-off-by: Pieter Jansen van Vuuren Signed-off-by: Simon Horman --- drivers/net/ethernet/netronome/nfp/flower/main.h | 26 .../net/ethernet/netronome/nfp/flower/metadata.c | 143 - .../net/ethernet/netronome/nfp/flower/offload.c| 14 +- drivers/net/ethernet/netronome/nfp/nfp_net.h | 1 + 4 files changed, 181 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/flower/main.h b/drivers/net/ethernet/netronome/nfp/flower/main.h index cc184618306c..8490ef1129ea 100644 --- a/drivers/net/ethernet/netronome/nfp/flower/main.h +++ b/drivers/net/ethernet/netronome/nfp/flower/main.h @@ -38,6 +38,7 @@ #include #include "cmsg.h" +#include "../nfp_net.h" #define NFP_FLOWER_ALLOWED_VER 0x00010001UL @@ -46,9 +47,13 @@ struct tc_to_netdev; struct net_device; struct nfp_app; +#define NFP_FL_REPEATED_HASH_MAX BIT(17) #define NFP_FLOWER_HASH_BITS 10 #define NFP_FLOWER_HASH_SEED 129004 +#define NFP_FL_STATS_ENTRY_RS BIT(20) +#define NFP_FL_STATS_ELEM_RS 4 + #define NFP_FLOWER_MASK_ENTRY_RS 256 #define NFP_FLOWER_MASK_ELEMENT_RS 1 #define NFP_FLOWER_MASK_HASH_BITS 10 @@ -66,10 +71,17 @@ struct nfp_fl_mask_id { u8 init_unallocated; }; +struct nfp_fl_stats_id { + struct circ_buf free_list; + u32 init_unalloc; + u8 repeated_em_count; +}; + /** * struct nfp_flower_priv - Flower APP per-vNIC priv data * @nn:Pointer to vNIC * @flower_version:HW version of flower + * @stats_ids: List of free stats ids * @mask_ids: List of free mask ids * @mask_table:Hash table used to store masks * @flow_table:Hash table used to store flower rules @@ -77,6 +89,7 @@ struct nfp_fl_mask_id { struct nfp_flower_priv { struct nfp_net *nn; u64 flower_version; + struct nfp_fl_stats_id stats_ids; struct nfp_fl_mask_id mask_ids; DECLARE_HASHTABLE(mask_table, NFP_FLOWER_MASK_HASH_BITS); DECLARE_HASHTABLE(flow_table, NFP_FLOWER_HASH_BITS); @@ -101,11 +114,20 @@ struct nfp_fl_rule_metadata { struct nfp_fl_payload { struct nfp_fl_rule_metadata meta; + spinlock_t lock_nfp_flow_stats; /* serialize flow stats access. */ + struct nfp_stat_pair stats; char *unmasked_data; char *mask_data; char *action_data; }; +struct nfp_fl_stats_frame { + __be32 stats_con_id; + __be32 pkt_count; + __be64 byte_count; + __be64 stats_cookie; +}; + int nfp_flower_metadata_init(struct nfp_app *app); void nfp_flower_metadata_cleanup(struct nfp_app *app); @@ -132,4 +154,8 @@ nfp_flower_find_in_fl_table(struct nfp_app *app, int nfp_flower_remove_fl_table(struct nfp_app *app, unsigned long tc_flower_cookie); +void nfp_flower_rx_flow_stats(struct nfp_app *app, struct sk_buff *skb); +void nfp_flower_populate_stats(struct nfp_fl_payload *nfp_flow); +void nfp_flower_stats_clear(struct nfp_fl_payload *nfp_flow); + #endif diff --git a/drivers/net/ethernet/netronome/nfp/flower/metadata.c b/drivers/net/ethernet/netronome/nfp/flower/metadata.c index acbf4c757988..75a98da049f7 100644 --- a/drivers/net/ethernet/netronome/nfp/flower/metadata.c +++ b/drivers/net/ethernet/netronome/nfp/flower/metadata.c @@ -39,6 +39,7 @@ #include #include "main.h" +#include "cmsg.h" struct nfp_mask_id_table { struct hlist_node link; @@ -53,6 +54,115 @@ struct nfp_flower_table { struct hlist_node link; }; +static int nfp_release_stats_entry(struct nfp_app *app, u32 stats_context_id) +{ + struct nfp_flower_priv *priv = app->priv; + struct circ_buf *ring; + + ring = >stats_ids.free_list; + /* Check if buffer is full. */ + if (!CIRC_SPACE(ring->head, ring->tail, NFP_FL_STATS_ENTRY_RS * + NFP_FL_STATS_ELEM_RS - + NFP_FL_STATS_ELEM_RS + 1)) + return -ENOBUFS; + + memcpy(>buf[ring->head], _context_id, NFP_FL_STATS_ELEM_RS); + ring->head = (ring->head + NFP_FL_STATS_ELEM_RS) % +(NFP_FL_STATS_ENTRY_RS * NFP_FL_STATS_ELEM_RS); + + return 0; +} + +static int nfp_get_stats_entry(struct nfp_app *app, u32 *stats_context_id) +{ + struct nfp_flower_priv *priv = app->priv; + u32 freed_stats_id, temp_stats_id; + struct circ_buf *ring; + + ring = >stats_ids.free_list; + freed_stats_id = NFP_FL_STATS_ENTRY_RS; + /* Check for unallocated entries first. */ + if