Re: [PATCH net-next v6 09/10] virtio_net: xsk: rx: support recv merge mode
On Fri, 28 Jun 2024 10:19:44 +0800, Jason Wang wrote:
> On Tue, Jun 18, 2024 at 3:57 PM Xuan Zhuo wrote:
> >
> > Support AF-XDP for merge mode.
> >
> > Signed-off-by: Xuan Zhuo
> > ---
> > drivers/net/virtio_net.c | 139 +++
> > 1 file changed, 139 insertions(+)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 06608d696e2e..cfa106aa8039 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -504,6 +504,10 @@ 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);
> > +static 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);
> >
> > static bool is_xdp_frame(void *ptr)
> > {
> > @@ -1128,6 +1132,139 @@ static struct sk_buff
> > *virtnet_receive_xsk_small(struct net_device *dev, struct
> > }
> > }
> >
> > +static void xsk_drop_follow_bufs(struct net_device *dev,
> > +struct receive_queue *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 int xsk_append_merge_buffer(struct virtnet_info *vi,
> > + struct receive_queue *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);
>
> So we don't do this for non xsk paths. Any reason we can't reuse the
> existing codes?
Do you mean this code:
while (--num_buf) {
int num_skb_frags;
-> buf = virtnet_rq_get_buf(rq, &len, &ctx);
if (unlikely(!buf)) {
pr_debug("%s: rx error: %d buffers out of %d missing\n",
dev->name, num_buf,
virtio16_to_cpu(vi->vdev,
hdr->num_buffers));
DEV_STATS_INC(dev, rx_length_errors);
goto err_buf;
}
u64_stats_add(&stats->bytes, len);
page = virt_to_head_page(buf);
-> truesize = mergeable_ctx_to_truesize(ctx);
-> headroom = mergeable_ctx_to_headroom(ctx);
-> tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
-> room = SKB_DATA_ALIGN(headroom + tailroom);
-> if (unlikely(len > truesize - room)) {
-> pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
-> dev->name, len, (unsigned long)(truesize -
room));
-> DEV_STATS_INC(dev, rx_length_errors);
-> goto err_skb;
-> }
curr_skb = virtnet_skb_append_frag(head_skb, curr_skb, page,
buf
Re: [PATCH net-next v6 09/10] virtio_net: xsk: rx: support recv merge mode
On Tue, Jun 18, 2024 at 3:57 PM Xuan Zhuo wrote:
>
> Support AF-XDP for merge mode.
>
> Signed-off-by: Xuan Zhuo
> ---
> drivers/net/virtio_net.c | 139 +++
> 1 file changed, 139 insertions(+)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 06608d696e2e..cfa106aa8039 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -504,6 +504,10 @@ 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);
> +static 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);
>
> static bool is_xdp_frame(void *ptr)
> {
> @@ -1128,6 +1132,139 @@ static struct sk_buff
> *virtnet_receive_xsk_small(struct net_device *dev, struct
> }
> }
>
> +static void xsk_drop_follow_bufs(struct net_device *dev,
> +struct receive_queue *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 int xsk_append_merge_buffer(struct virtnet_info *vi,
> + struct receive_queue *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);
So we don't do this for non xsk paths. Any reason we can't reuse the
existing codes?
Thanks
Re: [PATCH net-next v6 09/10] virtio_net: xsk: rx: support recv merge mode
On Thu, 20 Jun 2024 12:37:43 +0200, Paolo Abeni wrote:
> On Tue, 2024-06-18 at 15:56 +0800, Xuan Zhuo wrote:
> > Support AF-XDP for merge mode.
> >
> > Signed-off-by: Xuan Zhuo
> > ---
> > drivers/net/virtio_net.c | 139 +++
> > 1 file changed, 139 insertions(+)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 06608d696e2e..cfa106aa8039 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -504,6 +504,10 @@ 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);
> > +static 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);
> >
> > static bool is_xdp_frame(void *ptr)
> > {
> > @@ -1128,6 +1132,139 @@ static struct sk_buff
> > *virtnet_receive_xsk_small(struct net_device *dev, struct
> > }
> > }
> >
> > +static void xsk_drop_follow_bufs(struct net_device *dev,
> > +struct receive_queue *rq,
> > +u32 num_buf,
> > +struct virtnet_rq_stats *stats)
> > +{
> > + struct xdp_buff *xdp;
> > + u32 len;
> > +
> > + while (num_buf-- > 1) {
>
> Why do you skip the last buffer? I thought it should be dropped, too?!?
Here, we just need to drop the follow bufs (num_buf - 1). The first one have be
dropped.
Thanks.
>
> Thanks!
>
> Paolo
>
Re: [PATCH net-next v6 09/10] virtio_net: xsk: rx: support recv merge mode
On Tue, 2024-06-18 at 15:56 +0800, Xuan Zhuo wrote:
> Support AF-XDP for merge mode.
>
> Signed-off-by: Xuan Zhuo
> ---
> drivers/net/virtio_net.c | 139 +++
> 1 file changed, 139 insertions(+)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 06608d696e2e..cfa106aa8039 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -504,6 +504,10 @@ 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);
> +static 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);
>
> static bool is_xdp_frame(void *ptr)
> {
> @@ -1128,6 +1132,139 @@ static struct sk_buff
> *virtnet_receive_xsk_small(struct net_device *dev, struct
> }
> }
>
> +static void xsk_drop_follow_bufs(struct net_device *dev,
> + struct receive_queue *rq,
> + u32 num_buf,
> + struct virtnet_rq_stats *stats)
> +{
> + struct xdp_buff *xdp;
> + u32 len;
> +
> + while (num_buf-- > 1) {
Why do you skip the last buffer? I thought it should be dropped, too?!?
Thanks!
Paolo
[PATCH net-next v6 09/10] virtio_net: xsk: rx: support recv merge mode
Support AF-XDP for merge mode.
Signed-off-by: Xuan Zhuo
---
drivers/net/virtio_net.c | 139 +++
1 file changed, 139 insertions(+)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 06608d696e2e..cfa106aa8039 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -504,6 +504,10 @@ 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);
+static 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);
static bool is_xdp_frame(void *ptr)
{
@@ -1128,6 +1132,139 @@ static struct sk_buff *virtnet_receive_xsk_small(struct
net_device *dev, struct
}
}
+static void xsk_drop_follow_bufs(struct net_device *dev,
+struct receive_queue *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 int xsk_append_merge_buffer(struct virtnet_info *vi,
+ struct receive_queue *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 *virtnet_receive_xsk_merge(struct net_device *dev,
struct virtnet_info *vi,
+struct receive_queue *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;
+ }
+
