[PATCH net-next v2 16/21] virtio_net: xsk: rx: introduce add_recvbuf_xsk()

Xuan Zhuo
2023-11-07T03:12:51Z

Implement the logic of filling rq with XSK buffers.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
drivers/net/virtio/main.c | 4 ++-
drivers/net/virtio/virtio_net.h | 5 ++++
drivers/net/virtio/xsk.c | 49 ++++++++++++++++++++++++++++++++-
drivers/net/virtio/xsk.h | 2 ++
4 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c
index 6210a6e37396..15943a22e17d 100644
--- a/drivers/net/virtio/main.c
+++ b/drivers/net/virtio/main.c
@@ -1798,7 +1798,9 @@ static bool try_fill_recv(struct virtnet_info *vi, struct virtnet_rq *rq,
bool oom;

do {
- if (vi->mergeable_rx_bufs)
+ if (rq->xsk.pool)
+ err = virtnet_add_recvbuf_xsk(vi, rq, rq->xsk.pool, gfp);
+ else if (vi->mergeable_rx_bufs)
err = add_recvbuf_mergeable(vi, rq, gfp);
else if (vi->big_packets)
err = add_recvbuf_big(vi, rq, gfp);
diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h
index a13d6d301fdb..1242785e311e 100644
--- a/drivers/net/virtio/virtio_net.h
+++ b/drivers/net/virtio/virtio_net.h
@@ -140,6 +140,11 @@ 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 ea5804ddd44e..e737c3353212 100644
--- a/drivers/net/virtio/xsk.c
+++ b/drivers/net/virtio/xsk.c
@@ -38,6 +38,41 @@ static void virtnet_xsk_check_queue(struct virtnet_sq *sq)
netif_stop_subqueue(dev, qnum);
}

+int virtnet_add_recvbuf_xsk(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;
+ }
+
+ 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;
+}
+
static int virtnet_xsk_xmit_one(struct virtnet_sq *sq,
struct xsk_buff_pool *pool,
struct xdp_desc *desc)
@@ -213,7 +248,7 @@ 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.
@@ -249,6 +284,16 @@ 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;
@@ -307,6 +352,8 @@ static int virtnet_xsk_pool_disable(struct net_device *dev, u16 qid)

dma_unmap_single(dma_dev, sq->xsk.hdr_dma_address, vi->hdr_len, DMA_TO_DEVICE);

+ 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