The virtnet_xdp_handler() is re-used. But
1. We need to copy data to create skb for XDP_PASS.
2. We need to call xsk_buff_free() to release the buffer.
3. The handle for xdp_buff is difference.
If we pushed this logic into existing receive handle(merge and small),
we would have to maintain code scattered inside merge and small (and big).
So I think it is a good choice for us to put the xsk code into an
independent function.
Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
drivers/net/virtio/main.c | 40 ++++--
drivers/net/virtio/virtio_net.h | 8 ++
drivers/net/virtio/xsk.c | 217 ++++++++++++++++++++++++++++++++
drivers/net/virtio/xsk.h | 4 +
4 files changed, 256 insertions(+), 13 deletions(-)
diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c
index 264ab8aa5da5..b1567f0746e8 100644
--- a/drivers/net/virtio/main.c
+++ b/drivers/net/virtio/main.c
@@ -797,10 +797,10 @@ static void put_xdp_frags(struct xdp_buff *xdp)
}
}
-static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
- struct net_device *dev,
- unsigned int *xdp_xmit,
- struct virtnet_rq_stats *stats)
+int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
+ struct net_device *dev,
+ unsigned int *xdp_xmit,
+ struct virtnet_rq_stats *stats)
{
struct xdp_frame *xdpf;
int err;
@@ -1892,23 +1892,37 @@ static int virtnet_receive(struct virtnet_rq *rq, int budget,
{
struct virtnet_info *vi = rq->vq->vdev->priv;
struct virtnet_rq_stats stats = {};
+ void *buf, *ctx, *pctx = NULL;
unsigned int len;
int packets = 0;
- void *buf;
int i;
- if (!vi->big_packets || vi->mergeable_rx_bufs) {
- void *ctx;
+ if (rq->xsk.pool) {
+ struct sk_buff *skb;
+
+ while (packets < budget) {
+ buf = virtqueue_get_buf(rq->vq, &len);
+ if (!buf)
+ break;
+
+ skb = virtnet_receive_xsk_buf(vi, rq, buf, len, xdp_xmit, &stats);
+ if (skb)
+ virtnet_receive_done(vi, rq, skb);
- while (packets < budget &&
- (buf = virtnet_rq_get_buf(rq, &len, &ctx))) {
- receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
packets++;
}
} else {
- while (packets < budget &&
- (buf = virtnet_rq_get_buf(rq, &len, NULL)) != NULL) {
- receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats);
+ if (!vi->big_packets || vi->mergeable_rx_bufs)
+ pctx = &ctx;
+ else
+ ctx = NULL;
+
+ while (packets < budget) {
+ buf = virtnet_rq_get_buf(rq, &len, &ctx);
+ if (!buf)
+ break;
+
+ receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
packets++;
}
}
diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h
index eaa5da0b0b3c..ac1adb2015db 100644
--- a/drivers/net/virtio/virtio_net.h
+++ b/drivers/net/virtio/virtio_net.h
@@ -326,4 +326,12 @@ void virtnet_rq_free_unused_bufs(struct virtqueue *vq);
void virtnet_check_sq_full_and_disable(struct virtnet_info *vi,
struct net_device *dev,
struct virtnet_sq *sq);
+struct sk_buff *virtnet_skb_append_frag(struct sk_buff *head_skb,
+ struct sk_buff *curr_skb,
+ struct page *page, void *buf,
+ int len, int truesize);
+int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
+ struct net_device *dev,
+ unsigned int *xdp_xmit,
+ struct virtnet_rq_stats *stats);
#endif
diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c
index c54cd08e9c77..005bb5f66271 100644
--- a/drivers/net/virtio/xsk.c
+++ b/drivers/net/virtio/xsk.c
@@ -14,6 +14,223 @@ static void sg_fill_dma(struct scatterlist *sg, dma_addr_t addr, u32 len)
sg->length = len;
}
+static void xsk_drop_follow_bufs(struct net_device *dev,
+ struct virtnet_rq *rq,
+ u32 num_buf,
+ struct virtnet_rq_stats *stats)
+{
+ struct xdp_buff *xdp;
+ u32 len;
+
+ while (num_buf-- > 1) {
+ xdp = virtqueue_get_buf(rq->vq, &len);
+ if (unlikely(!xdp)) {
+ pr_debug("%s: rx error: %d buffers missing\n",
+ dev->name, num_buf);
+ DEV_STATS_INC(dev, rx_length_errors);
+ break;
+ }
+ u64_stats_add(&stats->bytes, len);
+ xsk_buff_free(xdp);
+ }
+}
+
+static struct xdp_buff *buf_to_xdp(struct virtnet_info *vi,
+ struct virtnet_rq *rq, void *buf, u32 len)
+{
+ struct xdp_buff *xdp;
+ u32 bufsize;
+
+ xdp = (struct xdp_buff *)buf;
+
+ bufsize = xsk_pool_get_rx_frame_size(rq->xsk.pool) + vi->hdr_len;
+
+ if (unlikely(len > bufsize)) {
+ pr_debug("%s: rx error: len %u exceeds truesize %u\n",
+ vi->dev->name, len, bufsize);
+ DEV_STATS_INC(vi->dev, rx_length_errors);
+ xsk_buff_free(xdp);
+ return NULL;
+ }
+
+ xsk_buff_set_size(xdp, len);
+ xsk_buff_dma_sync_for_cpu(xdp, rq->xsk.pool);
+
+ return xdp;
+}
+
+static int xsk_append_merge_buffer(struct virtnet_info *vi,
+ struct virtnet_rq *rq,
+ struct sk_buff *head_skb,
+ u32 num_buf,
+ struct virtio_net_hdr_mrg_rxbuf *hdr,
+ struct virtnet_rq_stats *stats)
+{
+ struct sk_buff *curr_skb;
+ struct xdp_buff *xdp;
+ u32 len, truesize;
+ struct page *page;
+ void *buf;
+
+ curr_skb = head_skb;
+
+ while (--num_buf) {
+ buf = virtqueue_get_buf(rq->vq, &len);
+ if (unlikely(!buf)) {
+ pr_debug("%s: rx error: %d buffers out of %d missing\n",
+ vi->dev->name, num_buf,
+ virtio16_to_cpu(vi->vdev,
+ hdr->num_buffers));
+ DEV_STATS_INC(vi->dev, rx_length_errors);
+ return -EINVAL;
+ }
+
+ u64_stats_add(&stats->bytes, len);
+
+ xdp = buf_to_xdp(vi, rq, buf, len);
+ if (!xdp)
+ goto err;
+
+ buf = napi_alloc_frag(len);
+ if (!buf) {
+ xsk_buff_free(xdp);
+ goto err;
+ }
+
+ memcpy(buf, xdp->data - vi->hdr_len, len);
+
+ xsk_buff_free(xdp);
+
+ page = virt_to_page(buf);
+
+ truesize = len;
+
+ curr_skb = virtnet_skb_append_frag(head_skb, curr_skb, page,
+ buf, len, truesize);
+ if (!curr_skb) {
+ put_page(page);
+ goto err;
+ }
+ }
+
+ return 0;
+
+err:
+ xsk_drop_follow_bufs(vi->dev, rq, num_buf, stats);
+ return -EINVAL;
+}
+
+static struct sk_buff *xdp_construct_skb(struct virtnet_rq *rq,
+ struct xdp_buff *xdp)
+{
+ unsigned int metasize = xdp->data - xdp->data_meta;
+ struct sk_buff *skb;
+ unsigned int size;
+
+ size = xdp->data_end - xdp->data_hard_start;
+ skb = napi_alloc_skb(&rq->napi, size);
+ if (unlikely(!skb)) {
+ xsk_buff_free(xdp);
+ return NULL;
+ }
+
+ skb_reserve(skb, xdp->data_meta - xdp->data_hard_start);
+
+ size = xdp->data_end - xdp->data_meta;
+ memcpy(__skb_put(skb, size), xdp->data_meta, size);
+
+ if (metasize) {
+ __skb_pull(skb, metasize);
+ skb_metadata_set(skb, metasize);
+ }
+
+ xsk_buff_free(xdp);
+
+ return skb;
+}
+
+static struct sk_buff *virtnet_receive_xsk_merge(struct net_device *dev, struct virtnet_info *vi,
+ struct virtnet_rq *rq, struct xdp_buff *xdp,
+ unsigned int *xdp_xmit,
+ struct virtnet_rq_stats *stats)
+{
+ struct virtio_net_hdr_mrg_rxbuf *hdr;
+ struct bpf_prog *prog;
+ struct sk_buff *skb;
+ u32 ret, num_buf;
+
+ hdr = xdp->data - vi->hdr_len;
+ num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
+
+ ret = XDP_PASS;
+ rcu_read_lock();
+ prog = rcu_dereference(rq->xdp_prog);
+ /* TODO: support multi buffer. */
+ if (prog && num_buf == 1)
+ ret = virtnet_xdp_handler(prog, xdp, dev, xdp_xmit, stats);
+ rcu_read_unlock();
+
+ switch (ret) {
+ case XDP_PASS:
+ skb = xdp_construct_skb(rq, xdp);
+ if (!skb)
+ goto drop_bufs;
+
+ if (xsk_append_merge_buffer(vi, rq, skb, num_buf, hdr, stats)) {
+ dev_kfree_skb(skb);
+ goto drop;
+ }
+
+ return skb;
+
+ case XDP_TX:
+ case XDP_REDIRECT:
+ return NULL;
+
+ default:
+ /* drop packet */
+ xsk_buff_free(xdp);
+ }
+
+drop_bufs:
+ xsk_drop_follow_bufs(dev, rq, num_buf, stats);
+
+drop:
+ u64_stats_inc(&stats->drops);
+ return NULL;
+}
+
+struct sk_buff *virtnet_receive_xsk_buf(struct virtnet_info *vi, struct virtnet_rq *rq,
+ void *buf, u32 len,
+ unsigned int *xdp_xmit,
+ struct virtnet_rq_stats *stats)
+{
+ struct net_device *dev = vi->dev;
+ struct sk_buff *skb = NULL;
+ struct xdp_buff *xdp;
+
+ if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
+ pr_debug("%s: short packet %i\n", dev->name, len);
+ DEV_STATS_INC(dev, rx_length_errors);
+
+ xsk_buff_free(xdp);
+ return NULL;
+ }
+
+ len -= vi->hdr_len;
+
+ u64_stats_add(&stats->bytes, len);
+
+ xdp = buf_to_xdp(vi, rq, buf, len);
+ if (!xdp)
+ return NULL;
+
+ if (vi->mergeable_rx_bufs)
+ skb = virtnet_receive_xsk_merge(dev, vi, rq, xdp, xdp_xmit, stats);
+
+ return skb;
+}
+
int virtnet_add_recvbuf_xsk(struct virtnet_info *vi, struct virtnet_rq *rq,
struct xsk_buff_pool *pool, gfp_t gfp)
{
diff --git a/drivers/net/virtio/xsk.h b/drivers/net/virtio/xsk.h
index bef41a3f954e..e78fcd0a4946 100644
--- a/drivers/net/virtio/xsk.h
+++ b/drivers/net/virtio/xsk.h
@@ -25,4 +25,8 @@ bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool,
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);
+struct sk_buff *virtnet_receive_xsk_buf(struct virtnet_info *vi, struct virtnet_rq *rq,
+ void *buf, u32 len,
+ unsigned int *xdp_xmit,
+ struct virtnet_rq_stats *stats);
#endif
--
2.32.0.3.g01195cf9f
