Use page_pool for RX buffer allocation in mergeable and small buffer modes. skb_mark_for_recycle() enables page reuse.
Big packets mode is unchanged because it uses page->private for linked list chaining of multiple pages per buffer, which conflicts with page_pool's internal use of page->private. Page pools are created in ndo_open and destroyed in remove (not ndo_close). This follows existing driver behavior where RX buffers remain in the virtqueue across open/close cycles and are only freed on device removal. The rx_mode_work_enabled flag prevents virtnet_rx_mode_work() from sending control virtqueue commands while ndo_close is tearing down device state. With MEM_TYPE_PAGE_POOL, xdp_rxq_info_unreg() calls page_pool_destroy() during close, and concurrent rx_mode_work can cause virtqueue corruption. The check is after rtnl_lock() to synchronize with ndo_close(), which sets the flag under the same lock. Signed-off-by: Vishwanath Seshagiri <[email protected]> --- drivers/net/virtio_net.c | 246 ++++++++++++++++++++++++++++++++------- 1 file changed, 205 insertions(+), 41 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 22d894101c01..c36663525c17 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -26,6 +26,7 @@ #include <net/netdev_rx_queue.h> #include <net/netdev_queues.h> #include <net/xdp_sock_drv.h> +#include <net/page_pool/helpers.h> static int napi_weight = NAPI_POLL_WEIGHT; module_param(napi_weight, int, 0444); @@ -359,6 +360,8 @@ struct receive_queue { /* Page frag for packet buffer allocation. */ struct page_frag alloc_frag; + struct page_pool *page_pool; + /* RX: fragments + linear part + virtio header */ struct scatterlist sg[MAX_SKB_FRAGS + 2]; @@ -524,11 +527,13 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, struct virtnet_rq_stats *stats); static void virtnet_receive_done(struct virtnet_info *vi, struct receive_queue *rq, struct sk_buff *skb, u8 flags); -static struct sk_buff *virtnet_skb_append_frag(struct sk_buff *head_skb, +static struct sk_buff *virtnet_skb_append_frag(struct receive_queue *rq, + struct sk_buff *head_skb, struct sk_buff *curr_skb, struct page *page, void *buf, int len, int truesize); static void virtnet_xsk_completed(struct send_queue *sq, int num); +static void free_unused_bufs(struct virtnet_info *vi); enum virtnet_xmit_type { VIRTNET_XMIT_TYPE_SKB, @@ -709,15 +714,24 @@ static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) return p; } +static void virtnet_put_page(struct receive_queue *rq, struct page *page, + bool allow_direct) +{ + if (rq->page_pool) + page_pool_put_page(rq->page_pool, page, -1, allow_direct); + else + put_page(page); +} + static void virtnet_rq_free_buf(struct virtnet_info *vi, struct receive_queue *rq, void *buf) { if (vi->mergeable_rx_bufs) - put_page(virt_to_head_page(buf)); + virtnet_put_page(rq, virt_to_head_page(buf), false); else if (vi->big_packets) give_pages(rq, buf); else - put_page(virt_to_head_page(buf)); + virtnet_put_page(rq, virt_to_head_page(buf), false); } static void enable_delayed_refill(struct virtnet_info *vi) @@ -894,9 +908,11 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, if (unlikely(!skb)) return NULL; - page = (struct page *)page->private; - if (page) - give_pages(rq, page); + if (!rq->page_pool) { + page = (struct page *)page->private; + if (page) + give_pages(rq, page); + } goto ok; } @@ -931,7 +947,10 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset, frag_size, truesize); len -= frag_size; - page = (struct page *)page->private; + if (!rq->page_pool) + page = (struct page *)page->private; + else + page = NULL; offset = 0; } @@ -942,7 +961,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, hdr = skb_vnet_common_hdr(skb); memcpy(hdr, hdr_p, hdr_len); if (page_to_free) - put_page(page_to_free); + virtnet_put_page(rq, page_to_free, true); return skb; } @@ -982,15 +1001,10 @@ static void virtnet_rq_unmap(struct receive_queue *rq, void *buf, u32 len) static void *virtnet_rq_get_buf(struct receive_queue *rq, u32 *len, void **ctx) { struct virtnet_info *vi = rq->vq->vdev->priv; - void *buf; BUG_ON(vi->big_packets && !vi->mergeable_rx_bufs); - buf = virtqueue_get_buf_ctx(rq->vq, len, ctx); - if (buf) - virtnet_rq_unmap(rq, buf, *len); - - return buf; + return virtqueue_get_buf_ctx(rq->vq, len, ctx); } static void virtnet_rq_init_one_sg(struct receive_queue *rq, void *buf, u32 len) @@ -1084,9 +1098,6 @@ static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf) return; } - if (!vi->big_packets || vi->mergeable_rx_bufs) - virtnet_rq_unmap(rq, buf, 0); - virtnet_rq_free_buf(vi, rq, buf); } @@ -1352,7 +1363,7 @@ static int xsk_append_merge_buffer(struct virtnet_info *vi, truesize = len; - curr_skb = virtnet_skb_append_frag(head_skb, curr_skb, page, + curr_skb = virtnet_skb_append_frag(rq, head_skb, curr_skb, page, buf, len, truesize); if (!curr_skb) { put_page(page); @@ -1788,7 +1799,7 @@ static int virtnet_xdp_xmit(struct net_device *dev, return ret; } -static void put_xdp_frags(struct xdp_buff *xdp) +static void put_xdp_frags(struct xdp_buff *xdp, struct receive_queue *rq) { struct skb_shared_info *shinfo; struct page *xdp_page; @@ -1798,7 +1809,7 @@ static void put_xdp_frags(struct xdp_buff *xdp) shinfo = xdp_get_shared_info_from_buff(xdp); for (i = 0; i < shinfo->nr_frags; i++) { xdp_page = skb_frag_page(&shinfo->frags[i]); - put_page(xdp_page); + virtnet_put_page(rq, xdp_page, true); } } } @@ -1914,7 +1925,7 @@ static struct page *xdp_linearize_page(struct net_device *dev, off = buf - page_address(p); if (check_mergeable_len(dev, ctx, buflen)) { - put_page(p); + virtnet_put_page(rq, p, true); goto err_buf; } @@ -1922,14 +1933,14 @@ static struct page *xdp_linearize_page(struct net_device *dev, * is sending packet larger than the MTU. */ if ((page_off + buflen + tailroom) > PAGE_SIZE) { - put_page(p); + virtnet_put_page(rq, p, true); goto err_buf; } memcpy(page_address(page) + page_off, page_address(p) + off, buflen); page_off += buflen; - put_page(p); + virtnet_put_page(rq, p, true); } /* Headroom does not contribute to packet length */ @@ -1979,7 +1990,7 @@ static struct sk_buff *receive_small_xdp(struct net_device *dev, unsigned int headroom = vi->hdr_len + header_offset; struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset; struct page *page = virt_to_head_page(buf); - struct page *xdp_page; + struct page *xdp_page = NULL; unsigned int buflen; struct xdp_buff xdp; struct sk_buff *skb; @@ -2013,7 +2024,7 @@ static struct sk_buff *receive_small_xdp(struct net_device *dev, goto err_xdp; buf = page_address(xdp_page); - put_page(page); + virtnet_put_page(rq, page, true); page = xdp_page; } @@ -2045,13 +2056,19 @@ static struct sk_buff *receive_small_xdp(struct net_device *dev, if (metasize) skb_metadata_set(skb, metasize); + if (rq->page_pool && !xdp_page) + skb_mark_for_recycle(skb); + return skb; err_xdp: u64_stats_inc(&stats->xdp_drops); err: u64_stats_inc(&stats->drops); - put_page(page); + if (xdp_page) + put_page(page); + else + virtnet_put_page(rq, page, true); xdp_xmit: return NULL; } @@ -2099,12 +2116,15 @@ static struct sk_buff *receive_small(struct net_device *dev, } skb = receive_small_build_skb(vi, xdp_headroom, buf, len); - if (likely(skb)) + if (likely(skb)) { + if (rq->page_pool) + skb_mark_for_recycle(skb); return skb; + } err: u64_stats_inc(&stats->drops); - put_page(page); + virtnet_put_page(rq, page, true); return NULL; } @@ -2159,7 +2179,7 @@ static void mergeable_buf_free(struct receive_queue *rq, int num_buf, } u64_stats_add(&stats->bytes, len); page = virt_to_head_page(buf); - put_page(page); + virtnet_put_page(rq, page, true); } } @@ -2270,7 +2290,7 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev, offset = buf - page_address(page); if (check_mergeable_len(dev, ctx, len)) { - put_page(page); + virtnet_put_page(rq, page, true); goto err; } @@ -2289,7 +2309,7 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev, return 0; err: - put_xdp_frags(xdp); + put_xdp_frags(xdp, rq); return -EINVAL; } @@ -2364,7 +2384,7 @@ static void *mergeable_xdp_get_buf(struct virtnet_info *vi, *frame_sz = PAGE_SIZE; - put_page(*page); + virtnet_put_page(rq, *page, true); *page = xdp_page; @@ -2386,6 +2406,7 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev, struct page *page = virt_to_head_page(buf); int offset = buf - page_address(page); unsigned int xdp_frags_truesz = 0; + struct page *org_page = page; struct sk_buff *head_skb; unsigned int frame_sz; struct xdp_buff xdp; @@ -2410,6 +2431,8 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev, head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz); if (unlikely(!head_skb)) break; + if (rq->page_pool && page == org_page) + skb_mark_for_recycle(head_skb); return head_skb; case XDP_TX: @@ -2420,10 +2443,13 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev, break; } - put_xdp_frags(&xdp); + put_xdp_frags(&xdp, rq); err_xdp: - put_page(page); + if (page != org_page) + put_page(page); + else + virtnet_put_page(rq, page, true); mergeable_buf_free(rq, num_buf, dev, stats); u64_stats_inc(&stats->xdp_drops); @@ -2431,7 +2457,8 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev, return NULL; } -static struct sk_buff *virtnet_skb_append_frag(struct sk_buff *head_skb, +static struct sk_buff *virtnet_skb_append_frag(struct receive_queue *rq, + struct sk_buff *head_skb, struct sk_buff *curr_skb, struct page *page, void *buf, int len, int truesize) @@ -2463,7 +2490,7 @@ static struct sk_buff *virtnet_skb_append_frag(struct sk_buff *head_skb, offset = buf - page_address(page); if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) { - put_page(page); + virtnet_put_page(rq, page, true); skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1, len, truesize); } else { @@ -2512,10 +2539,13 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, } head_skb = page_to_skb(vi, rq, page, offset, len, truesize, headroom); + if (unlikely(!head_skb)) + goto err_skb; + curr_skb = head_skb; - if (unlikely(!curr_skb)) - goto err_skb; + if (rq->page_pool) + skb_mark_for_recycle(head_skb); while (--num_buf) { buf = virtnet_rq_get_buf(rq, &len, &ctx); if (unlikely(!buf)) { @@ -2534,7 +2564,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, goto err_skb; truesize = mergeable_ctx_to_truesize(ctx); - curr_skb = virtnet_skb_append_frag(head_skb, curr_skb, page, + curr_skb = virtnet_skb_append_frag(rq, head_skb, curr_skb, page, buf, len, truesize); if (!curr_skb) goto err_skb; @@ -2544,7 +2574,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, return head_skb; err_skb: - put_page(page); + virtnet_put_page(rq, page, true); mergeable_buf_free(rq, num_buf, dev, stats); err_buf: @@ -2683,6 +2713,8 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq, static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq, gfp_t gfp) { + unsigned int offset; + struct page *page; char *buf; unsigned int xdp_headroom = virtnet_get_headroom(vi); void *ctx = (void *)(unsigned long)xdp_headroom; @@ -2692,6 +2724,24 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq, len = SKB_DATA_ALIGN(len) + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + if (rq->page_pool) { + page = page_pool_alloc_frag(rq->page_pool, &offset, len, gfp); + if (unlikely(!page)) + return -ENOMEM; + + buf = page_address(page) + offset; + buf += VIRTNET_RX_PAD + xdp_headroom; + + sg_init_table(rq->sg, 1); + sg_set_buf(&rq->sg[0], buf, vi->hdr_len + GOOD_PACKET_LEN); + + err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp); + if (err < 0) + page_pool_put_page(rq->page_pool, + virt_to_head_page(buf), -1, false); + return err; + } + if (unlikely(!skb_page_frag_refill(len, &rq->alloc_frag, gfp))) return -ENOMEM; @@ -2786,6 +2836,8 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0; unsigned int room = SKB_DATA_ALIGN(headroom + tailroom); unsigned int len, hole; + unsigned int offset; + struct page *page; void *ctx; char *buf; int err; @@ -2796,6 +2848,39 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, */ len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room); + if (rq->page_pool) { + page = page_pool_alloc_frag(rq->page_pool, &offset, + len + room, gfp); + if (unlikely(!page)) + return -ENOMEM; + + buf = page_address(page) + offset; + buf += headroom; /* advance address leaving hole at front of pkt */ + + hole = PAGE_SIZE - (offset + len + room); + if (hole < len + room) { + /* To avoid internal fragmentation, if there is very likely not + * enough space for another buffer, add the remaining space to + * the current buffer. + * XDP core assumes that frame_size of xdp_buff and the length + * of the frag are PAGE_SIZE, so we disable the hole mechanism. + */ + if (!headroom) + len += hole; + } + + ctx = mergeable_len_to_ctx(len + room, headroom); + + sg_init_table(rq->sg, 1); + sg_set_buf(&rq->sg[0], buf, len); + + err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp); + if (err < 0) + page_pool_put_page(rq->page_pool, + virt_to_head_page(buf), -1, false); + return err; + } + if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp))) return -ENOMEM; @@ -3181,7 +3266,10 @@ static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index) return err; err = xdp_rxq_info_reg_mem_model(&vi->rq[qp_index].xdp_rxq, - MEM_TYPE_PAGE_SHARED, NULL); + vi->rq[qp_index].page_pool ? + MEM_TYPE_PAGE_POOL : + MEM_TYPE_PAGE_SHARED, + vi->rq[qp_index].page_pool); if (err < 0) goto err_xdp_reg_mem_model; @@ -3221,11 +3309,77 @@ static void virtnet_update_settings(struct virtnet_info *vi) vi->duplex = duplex; } +static int virtnet_create_page_pools(struct virtnet_info *vi) +{ + int i, err; + + for (i = 0; i < vi->curr_queue_pairs; i++) { + struct receive_queue *rq = &vi->rq[i]; + struct page_pool_params pp_params = { 0 }; + + if (rq->page_pool) + continue; + + if (rq->xsk_pool) + continue; + + if (!vi->mergeable_rx_bufs && vi->big_packets) + continue; + + pp_params.order = 0; + pp_params.pool_size = virtqueue_get_vring_size(rq->vq); + pp_params.nid = dev_to_node(vi->vdev->dev.parent); + pp_params.dev = vi->vdev->dev.parent; + pp_params.netdev = vi->dev; + pp_params.napi = &rq->napi; + pp_params.flags = 0; + + rq->page_pool = page_pool_create(&pp_params); + if (IS_ERR(rq->page_pool)) { + err = PTR_ERR(rq->page_pool); + rq->page_pool = NULL; + goto err_cleanup; + } + } + return 0; + +err_cleanup: + while (--i >= 0) { + struct receive_queue *rq = &vi->rq[i]; + + if (rq->page_pool) { + page_pool_destroy(rq->page_pool); + rq->page_pool = NULL; + } + } + return err; +} + +static void virtnet_destroy_page_pools(struct virtnet_info *vi) +{ + int i; + + for (i = 0; i < vi->max_queue_pairs; i++) { + struct receive_queue *rq = &vi->rq[i]; + + if (rq->page_pool) { + page_pool_destroy(rq->page_pool); + rq->page_pool = NULL; + } + } +} + static int virtnet_open(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); int i, err; + err = virtnet_create_page_pools(vi); + if (err) + return err; + + vi->rx_mode_work_enabled = true; + enable_delayed_refill(vi); for (i = 0; i < vi->max_queue_pairs; i++) { @@ -3251,6 +3405,7 @@ static int virtnet_open(struct net_device *dev) return 0; err_enable_qp: + vi->rx_mode_work_enabled = false; disable_delayed_refill(vi); cancel_delayed_work_sync(&vi->refill); @@ -3856,6 +4011,8 @@ static int virtnet_close(struct net_device *dev) */ cancel_work_sync(&vi->config_work); + vi->rx_mode_work_enabled = false; + for (i = 0; i < vi->max_queue_pairs; i++) { virtnet_disable_queue_pair(vi, i); virtnet_cancel_dim(vi, &vi->rq[i].dim); @@ -3892,6 +4049,11 @@ static void virtnet_rx_mode_work(struct work_struct *work) rtnl_lock(); + if (!vi->rx_mode_work_enabled) { + rtnl_unlock(); + return; + } + *promisc_allmulti = !!(dev->flags & IFF_PROMISC); sg_init_one(sg, promisc_allmulti, sizeof(*promisc_allmulti)); @@ -7193,6 +7355,8 @@ static void remove_vq_common(struct virtnet_info *vi) free_receive_page_frags(vi); + virtnet_destroy_page_pools(vi); + virtnet_del_vqs(vi); } -- 2.47.3
