On Mon, Oct 16, 2023 at 8:01 PM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote:
>
> Implement the logic of filling vq with XSK buffer.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> ---
> drivers/net/virtio/main.c | 13 +++++++
> drivers/net/virtio/virtio_net.h | 5 +++
> drivers/net/virtio/xsk.c | 66 ++++++++++++++++++++++++++++++++-
> drivers/net/virtio/xsk.h | 2 +
> 4 files changed, 85 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c
> index 58bb38f9b453..0e740447b142 100644
> --- a/drivers/net/virtio/main.c
> +++ b/drivers/net/virtio/main.c
> @@ -1787,9 +1787,20 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi,
> static bool try_fill_recv(struct virtnet_info *vi, struct virtnet_rq *rq,
> gfp_t gfp)
> {
> + struct xsk_buff_pool *pool;
> int err;
> bool oom;
>
> + rcu_read_lock();
A question here: should we sync with refill work during rx_pause?
> + pool = rcu_dereference(rq->xsk.pool);
> + if (pool) {
> + err = virtnet_add_recvbuf_xsk(vi, rq, pool, gfp);
> + oom = err == -ENOMEM;
> + rcu_read_unlock();
> + goto kick;
> + }
> + rcu_read_unlock();
And if we synchronize with that there's probably no need for the rcu
and we can merge the logic with the following ones?
Thanks
> +
> do {
> if (vi->mergeable_rx_bufs)
> err = add_recvbuf_mergeable(vi, rq, gfp);
> @@ -1802,6 +1813,8 @@ static bool try_fill_recv(struct virtnet_info *vi, struct virtnet_rq *rq,
> if (err)
> break;
> } while (rq->vq->num_free);
> +
> +kick:
> if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
> unsigned long flags;
>
> diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h
> index d4e620a084f4..6e71622fca45 100644
> --- a/drivers/net/virtio/virtio_net.h
> +++ b/drivers/net/virtio/virtio_net.h
> @@ -156,6 +156,11 @@ struct virtnet_rq {
>
> /* xdp rxq used by xsk */
> struct xdp_rxq_info xdp_rxq;
> +
> + struct xdp_buff **xsk_buffs;
> + u32 nxt_idx;
> + u32 num;
> + u32 size;
> } xsk;
> };
>
> diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c
> index 973e783260c3..841fb078882a 100644
> --- a/drivers/net/virtio/xsk.c
> +++ b/drivers/net/virtio/xsk.c
> @@ -37,6 +37,58 @@ static void virtnet_xsk_check_queue(struct virtnet_sq *sq)
> netif_stop_subqueue(dev, qnum);
> }
>
> +static int virtnet_add_recvbuf_batch(struct virtnet_info *vi, struct virtnet_rq *rq,
> + struct xsk_buff_pool *pool, gfp_t gfp)
> +{
> + struct xdp_buff **xsk_buffs;
> + dma_addr_t addr;
> + u32 len, i;
> + int err = 0;
> +
> + xsk_buffs = rq->xsk.xsk_buffs;
> +
> + if (rq->xsk.nxt_idx >= rq->xsk.num) {
> + rq->xsk.num = xsk_buff_alloc_batch(pool, xsk_buffs, rq->xsk.size);
> + if (!rq->xsk.num)
> + return -ENOMEM;
> + rq->xsk.nxt_idx = 0;
> + }
> +
> + while (rq->xsk.nxt_idx < rq->xsk.num) {
> + i = rq->xsk.nxt_idx;
> +
> + /* use the part of XDP_PACKET_HEADROOM as the virtnet hdr space */
> + addr = xsk_buff_xdp_get_dma(xsk_buffs[i]) - vi->hdr_len;
> + len = xsk_pool_get_rx_frame_size(pool) + vi->hdr_len;
> +
> + sg_init_table(rq->sg, 1);
> + sg_fill_dma(rq->sg, addr, len);
> +
> + err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, xsk_buffs[i], gfp);
> + if (err)
> + return err;
> +
> + rq->xsk.nxt_idx++;
> + }
> +
> + return 0;
> +}
> +
> +int virtnet_add_recvbuf_xsk(struct virtnet_info *vi, struct virtnet_rq *rq,
> + struct xsk_buff_pool *pool, gfp_t gfp)
> +{
> + int err;
> +
> + do {
> + err = virtnet_add_recvbuf_batch(vi, rq, pool, gfp);
> + if (err)
> + return err;
> +
> + } while (rq->vq->num_free);
> +
> + return 0;
> +}
> +
> static int virtnet_xsk_xmit_one(struct virtnet_sq *sq,
> struct xsk_buff_pool *pool,
> struct xdp_desc *desc)
> @@ -244,7 +296,7 @@ static int virtnet_xsk_pool_enable(struct net_device *dev,
> struct virtnet_sq *sq;
> struct device *dma_dev;
> dma_addr_t hdr_dma;
> - int err;
> + int err, size;
>
> /* In big_packets mode, xdp cannot work, so there is no need to
> * initialize xsk of rq.
> @@ -276,6 +328,16 @@ static int virtnet_xsk_pool_enable(struct net_device *dev,
> if (!dma_dev)
> return -EPERM;
>
> + size = virtqueue_get_vring_size(rq->vq);
> +
> + rq->xsk.xsk_buffs = kcalloc(size, sizeof(*rq->xsk.xsk_buffs), GFP_KERNEL);
> + if (!rq->xsk.xsk_buffs)
> + return -ENOMEM;
> +
> + rq->xsk.size = size;
> + rq->xsk.nxt_idx = 0;
> + rq->xsk.num = 0;
> +
> hdr_dma = dma_map_single(dma_dev, &xsk_hdr, vi->hdr_len, DMA_TO_DEVICE);
> if (dma_mapping_error(dma_dev, hdr_dma))
> return -ENOMEM;
> @@ -338,6 +400,8 @@ static int virtnet_xsk_pool_disable(struct net_device *dev, u16 qid)
> err1 = virtnet_sq_bind_xsk_pool(vi, sq, NULL);
> err2 = virtnet_rq_bind_xsk_pool(vi, rq, NULL);
>
> + kfree(rq->xsk.xsk_buffs);
> +
> return err1 | err2;
> }
>
> diff --git a/drivers/net/virtio/xsk.h b/drivers/net/virtio/xsk.h
> index 7ebc9bda7aee..bef41a3f954e 100644
> --- a/drivers/net/virtio/xsk.h
> +++ b/drivers/net/virtio/xsk.h
> @@ -23,4 +23,6 @@ int virtnet_xsk_pool_setup(struct net_device *dev, struct netdev_bpf *xdp);
> bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool,
> int budget);
> int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag);
> +int virtnet_add_recvbuf_xsk(struct virtnet_info *vi, struct virtnet_rq *rq,
> + struct xsk_buff_pool *pool, gfp_t gfp);
> #endif
> --
> 2.32.0.3.g01195cf9f
>
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