Re: [PATCH bpf] xsk: mark napi_id on sendmsg()
From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Date: 2022-06-30 11:53:22
Also in:
bpf
Subsystem:
intel ethernet drivers, networking drivers, networking [general], the rest, xdp sockets (af_xdp) · Maintainers:
Tony Nguyen, Przemek Kitszel, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Magnus Karlsson, Maciej Fijalkowski
On Wed, Jun 29, 2022 at 05:17:07PM +0100, Jakub Kicinski wrote:
On Wed, 29 Jun 2022 09:16:29 -0700 Jakub Kicinski wrote:quoted
quoted
Would it make sense to introduce napi_id to xsk_buff_pool then? xp_set_rxq_info() could be setting it. We are sure that napi_id is the same for whole pool (each xdp_buff_xsk's rxq info).Would it be possible to move the marking to when the queue is getting bound instead of the recv/send paths?I mean when socket is getting bound.
So Bjorn said that it was the design choice to follow the standard sockets' approach. I'm including a dirty diff for a discussion which allows me to get napi_id at bind() time. But, this works for ice as this driver during the XDP prog/XSK pool load only disables the NAPI, so we are sure that napi_id stays the same. That might not be the case for other AF_XDP ZC enabled drivers though, they might delete the NAPI and this approach wouldn't work...or am I missing something? I'd prefer the diff below though as it simplifies the data path, but I can't say if it's safe to do so. We would have to be sure about drivers keeping their NAPI struct. This would also allow us to drop napi_id from xdp_rxq_info. Thoughts?
diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
index 49ba8bfdbf04..3d084558628e 100644
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c@@ -312,6 +312,7 @@ ice_xsk_pool_enable(struct ice_vsi *vsi, struct xsk_buff_pool *pool, u16 qid) return err; set_bit(qid, vsi->af_xdp_zc_qps); + xsk_pool_set_napi_id(pool, vsi->rx_rings[qid]->q_vector->napi.napi_id); return 0; }
@@ -348,7 +349,6 @@ int ice_xsk_pool_setup(struct ice_vsi *vsi, struct xsk_buff_pool *pool, u16 qid) pool_failure = pool_present ? ice_xsk_pool_enable(vsi, pool, qid) : ice_xsk_pool_disable(vsi, qid); - xsk_pool_if_up: if (if_running) { ret = ice_qp_ena(vsi, qid);
@@ -358,6 +358,7 @@ int ice_xsk_pool_setup(struct ice_vsi *vsi, struct xsk_buff_pool *pool, u16 qid) netdev_err(vsi->netdev, "ice_qp_ena error = %d\n", ret); } + failure: if (pool_failure) { netdev_err(vsi->netdev, "Could not %sable buffer pool, error = %d\n",
diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h
index 4aa031849668..1a20320cd556 100644
--- a/include/net/xdp_sock_drv.h
+++ b/include/net/xdp_sock_drv.h@@ -44,6 +44,14 @@ static inline void xsk_pool_set_rxq_info(struct xsk_buff_pool *pool, xp_set_rxq_info(pool, rxq); } +static inline void xsk_pool_set_napi_id(struct xsk_buff_pool *pool, + unsigned int napi_id) +{ +#ifdef CONFIG_NET_RX_BUSY_POLL + xp_set_napi_id(pool, napi_id); +#endif +} + static inline void xsk_pool_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs) {
@@ -198,6 +206,11 @@ static inline void xsk_pool_set_rxq_info(struct xsk_buff_pool *pool, { } +static inline void xsk_pool_set_napi_id(struct xsk_buff_pool *pool, + unsigned int napi_id) +{ +} + static inline void xsk_pool_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs) {
diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h
index 647722e847b4..60775a8d1bcb 100644
--- a/include/net/xsk_buff_pool.h
+++ b/include/net/xsk_buff_pool.h@@ -70,6 +70,7 @@ struct xsk_buff_pool { u32 chunk_size; u32 chunk_shift; u32 frame_len; + unsigned int napi_id; u8 cached_need_wakeup; bool uses_need_wakeup; bool dma_need_sync;
@@ -125,6 +126,7 @@ static inline void xp_init_xskb_dma(struct xdp_buff_xsk *xskb, struct xsk_buff_p /* AF_XDP ZC drivers, via xdp_sock_buff.h */ void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq); +void xp_set_napi_id(struct xsk_buff_pool *pool, unsigned int napi_id); int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev, unsigned long attrs, struct page **pages, u32 nr_pages); void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs);
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index eafd512d38b1..18ac3f32a48d 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c@@ -222,7 +222,6 @@ static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp) if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) return -EINVAL; - sk_mark_napi_id_once_xdp(&xs->sk, xdp); return 0; }
@@ -637,11 +636,8 @@ static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len if (unlikely(need_wait)) return -EOPNOTSUPP; - if (sk_can_busy_loop(sk)) { - if (xs->zc) - __sk_mark_napi_id_once(sk, xs->pool->heads[0].xdp.rxq->napi_id); + if (sk_can_busy_loop(sk)) sk_busy_loop(sk, 1); /* only support non-blocking sockets */ - } if (xs->zc && xsk_no_wakeup(sk)) return 0;
@@ -1015,6 +1011,8 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) xs->dev = dev; xs->zc = xs->umem->zc; xs->queue_id = qid; + if (xs->zc) + xs->sk.sk_napi_id = xs->pool->napi_id; xp_add_xsk(xs->pool, xs); out_unlock:
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index 87bdd71c7bb6..5ec6443be3fc 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c@@ -121,6 +121,14 @@ void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq) } EXPORT_SYMBOL(xp_set_rxq_info); +#ifdef CONFIG_NET_RX_BUSY_POLL +void xp_set_napi_id(struct xsk_buff_pool *pool, unsigned int napi_id) +{ + pool->napi_id = napi_id; +} +EXPORT_SYMBOL(xp_set_napi_id); +#endif + static void xp_disable_drv_zc(struct xsk_buff_pool *pool) { struct netdev_bpf bpf;