[PATCH net-next v3 5/8] virtio-net: xsk zero copy xmit support xsk unaligned mode
flat view
STALE2010d
REVIEWED: 1 (1M)
From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Date: 2021-03-31 07:12:51
Also in:
bpf
Subsystem:
networking drivers, the rest, virtio net driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, "Michael S. Tsirkin", Jason Wang, Eugenio Pérez
Revision v3 of 4 in this series; 1 review trailer.
Revisions (4)
- v1 [diff vs current]
- v2 [diff vs current]
- v3 current
- v4 [diff vs current]
In xsk unaligned mode, the frame pointed to by desc may span two consecutive pages, but not more than two pages. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Reviewed-by: Dust Li <dust.li@linux.alibaba.com> --- drivers/net/virtio_net.c | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index c8a317a93ef7..259fafcf6028 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c@@ -2562,24 +2562,42 @@ static void virtnet_xsk_check_space(struct send_queue *sq) static int virtnet_xsk_xmit(struct send_queue *sq, struct xsk_buff_pool *pool, struct xdp_desc *desc) { + u32 offset, n, i, copy, copied; struct virtnet_info *vi; struct page *page; void *data; - u32 offset; + int err, m; u64 addr; - int err; vi = sq->vq->vdev->priv; addr = desc->addr; + data = xsk_buff_raw_get_data(pool, addr); + offset = offset_in_page(data); + m = desc->len - (PAGE_SIZE - offset); + /* xsk unaligned mode, desc will use two page */ + if (m > 0) + n = 3; + else + n = 2; - sg_init_table(sq->sg, 2); + sg_init_table(sq->sg, n); sg_set_buf(sq->sg, &xsk_hdr, vi->hdr_len); - page = xsk_buff_xdp_get_page(pool, addr); - sg_set_page(sq->sg + 1, page, desc->len, offset); - err = virtqueue_add_outbuf(sq->vq, sq->sg, 2, NULL, GFP_ATOMIC); + copied = 0; + for (i = 1; i < n; ++i) { + copy = min_t(int, desc->len - copied, PAGE_SIZE - offset); + + page = xsk_buff_xdp_get_page(pool, addr + copied); + + sg_set_page(sq->sg + i, page, copy, offset); + copied += copy; + if (offset) + offset = 0; + } + + err = virtqueue_add_outbuf(sq->vq, sq->sg, n, NULL, GFP_ATOMIC); if (unlikely(err)) sq->xsk.last_desc = *desc;
--
2.31.0