Re: [PATCH net-next v7 09/10] virtio_net: xsk: rx: support recv small mode
On Mon, 8 Jul 2024 16:08:44 +0800, Jason Wang wrote:
> On Mon, Jul 8, 2024 at 3:47 PM Xuan Zhuo wrote:
> >
> > On Mon, 8 Jul 2024 15:00:50 +0800, Jason Wang wrote:
> > > On Fri, Jul 5, 2024 at 3:38 PM Xuan Zhuo
> > > wrote:
> > > >
> > > > In the process:
> > > > 1. We may need to copy data to create skb for XDP_PASS.
> > > > 2. We may need to call xsk_buff_free() to release the buffer.
> > > > 3. The handle for xdp_buff is difference from the buffer.
> > > >
> > > > 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
> > > > ---
> > > >
> > > > v7:
> > > >1. rename xdp_construct_skb to xsk_construct_skb
> > > >2. refactor virtnet_receive()
> > > >
> > > > drivers/net/virtio_net.c | 176 +--
> > > > 1 file changed, 168 insertions(+), 8 deletions(-)
> > > >
> > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > > index 2b27f5ada64a..64d8cd481890 100644
> > > > --- a/drivers/net/virtio_net.c
> > > > +++ b/drivers/net/virtio_net.c
> > > > @@ -498,6 +498,12 @@ struct virtio_net_common_hdr {
> > > > };
> > > >
> > > > static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void
> > > > *buf);
> > > > +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 void virtnet_receive_done(struct virtnet_info *vi, struct
> > > > receive_queue *rq,
> > > > +struct sk_buff *skb, u8 flags);
> > > >
> > > > static bool is_xdp_frame(void *ptr)
> > > > {
> > > > @@ -1062,6 +1068,124 @@ static void sg_fill_dma(struct scatterlist *sg,
> > > > dma_addr_t addr, u32 len)
> > > > sg->length = len;
> > > > }
> > > >
> > > > +static struct xdp_buff *buf_to_xdp(struct virtnet_info *vi,
> > > > + struct receive_queue *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);
> > > > +
> > > > + return xdp;
> > > > +}
> > > > +
> > > > +static struct sk_buff *xsk_construct_skb(struct receive_queue *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_small(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 bpf_prog *prog;
> > > > + u32 ret;
> > > > +
> > > > + ret = XDP_PASS;
> > > > + rcu_read_lock();
> > > > + prog = rcu_dereference(rq->xdp_prog);
> > > > + if (prog)
> > > > + ret = virtnet_xdp_handler(prog, xdp, dev, xdp_xmit,
> > > > stats);
> > > > + rcu_read_unlock();
> > > > +
> > > > + switch (ret) {
> > > > + case XDP_PASS:
> > > > + return xsk_
Re: [PATCH net-next v7 09/10] virtio_net: xsk: rx: support recv small mode
On Mon, Jul 8, 2024 at 3:47 PM Xuan Zhuo wrote:
>
> On Mon, 8 Jul 2024 15:00:50 +0800, Jason Wang wrote:
> > On Fri, Jul 5, 2024 at 3:38 PM Xuan Zhuo wrote:
> > >
> > > In the process:
> > > 1. We may need to copy data to create skb for XDP_PASS.
> > > 2. We may need to call xsk_buff_free() to release the buffer.
> > > 3. The handle for xdp_buff is difference from the buffer.
> > >
> > > 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
> > > ---
> > >
> > > v7:
> > >1. rename xdp_construct_skb to xsk_construct_skb
> > >2. refactor virtnet_receive()
> > >
> > > drivers/net/virtio_net.c | 176 +--
> > > 1 file changed, 168 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > index 2b27f5ada64a..64d8cd481890 100644
> > > --- a/drivers/net/virtio_net.c
> > > +++ b/drivers/net/virtio_net.c
> > > @@ -498,6 +498,12 @@ struct virtio_net_common_hdr {
> > > };
> > >
> > > static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
> > > +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 void virtnet_receive_done(struct virtnet_info *vi, struct
> > > receive_queue *rq,
> > > +struct sk_buff *skb, u8 flags);
> > >
> > > static bool is_xdp_frame(void *ptr)
> > > {
> > > @@ -1062,6 +1068,124 @@ static void sg_fill_dma(struct scatterlist *sg,
> > > dma_addr_t addr, u32 len)
> > > sg->length = len;
> > > }
> > >
> > > +static struct xdp_buff *buf_to_xdp(struct virtnet_info *vi,
> > > + struct receive_queue *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);
> > > +
> > > + return xdp;
> > > +}
> > > +
> > > +static struct sk_buff *xsk_construct_skb(struct receive_queue *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_small(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 bpf_prog *prog;
> > > + u32 ret;
> > > +
> > > + ret = XDP_PASS;
> > > + rcu_read_lock();
> > > + prog = rcu_dereference(rq->xdp_prog);
> > > + if (prog)
> > > + ret = virtnet_xdp_handler(prog, xdp, dev, xdp_xmit,
> > > stats);
> > > + rcu_read_unlock();
> > > +
> > > + switch (ret) {
> > > + case XDP_PASS:
> > > + return xsk_construct_skb(rq, xdp);
> > > +
> > > + case XDP_TX:
> > > + case XDP_REDIRECT:
> > > + return NULL;
> > > +
> > > + default:
> > > + /* drop packet */
> > > + xsk_buff_free(xdp);
> > > + u64_stats_inc(&stats->drops);
> > > + return NULL;
> > > +
Re: [PATCH net-next v7 09/10] virtio_net: xsk: rx: support recv small mode
On Mon, 8 Jul 2024 15:00:50 +0800, Jason Wang wrote:
> On Fri, Jul 5, 2024 at 3:38 PM Xuan Zhuo wrote:
> >
> > In the process:
> > 1. We may need to copy data to create skb for XDP_PASS.
> > 2. We may need to call xsk_buff_free() to release the buffer.
> > 3. The handle for xdp_buff is difference from the buffer.
> >
> > 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
> > ---
> >
> > v7:
> >1. rename xdp_construct_skb to xsk_construct_skb
> >2. refactor virtnet_receive()
> >
> > drivers/net/virtio_net.c | 176 +--
> > 1 file changed, 168 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 2b27f5ada64a..64d8cd481890 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -498,6 +498,12 @@ struct virtio_net_common_hdr {
> > };
> >
> > static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
> > +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 void virtnet_receive_done(struct virtnet_info *vi, struct
> > receive_queue *rq,
> > +struct sk_buff *skb, u8 flags);
> >
> > static bool is_xdp_frame(void *ptr)
> > {
> > @@ -1062,6 +1068,124 @@ static void sg_fill_dma(struct scatterlist *sg,
> > dma_addr_t addr, u32 len)
> > sg->length = len;
> > }
> >
> > +static struct xdp_buff *buf_to_xdp(struct virtnet_info *vi,
> > + struct receive_queue *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);
> > +
> > + return xdp;
> > +}
> > +
> > +static struct sk_buff *xsk_construct_skb(struct receive_queue *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_small(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 bpf_prog *prog;
> > + u32 ret;
> > +
> > + ret = XDP_PASS;
> > + rcu_read_lock();
> > + prog = rcu_dereference(rq->xdp_prog);
> > + if (prog)
> > + ret = virtnet_xdp_handler(prog, xdp, dev, xdp_xmit, stats);
> > + rcu_read_unlock();
> > +
> > + switch (ret) {
> > + case XDP_PASS:
> > + return xsk_construct_skb(rq, xdp);
> > +
> > + case XDP_TX:
> > + case XDP_REDIRECT:
> > + return NULL;
> > +
> > + default:
> > + /* drop packet */
> > + xsk_buff_free(xdp);
> > + u64_stats_inc(&stats->drops);
> > + return NULL;
> > + }
> > +}
> > +
> > +static void virtnet_receive_xsk_buf(struct virtnet_info *vi, struct
> > receive_queue *rq,
> > + void *buf, u32 len,
> > + unsigned int *xdp_xmit,
> > + struct virtnet_rq_stats *stats)
> > +{
> > +
Re: [PATCH net-next v7 09/10] virtio_net: xsk: rx: support recv small mode
On Fri, Jul 5, 2024 at 3:38 PM Xuan Zhuo wrote:
>
> In the process:
> 1. We may need to copy data to create skb for XDP_PASS.
> 2. We may need to call xsk_buff_free() to release the buffer.
> 3. The handle for xdp_buff is difference from the buffer.
>
> 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
> ---
>
> v7:
>1. rename xdp_construct_skb to xsk_construct_skb
>2. refactor virtnet_receive()
>
> drivers/net/virtio_net.c | 176 +--
> 1 file changed, 168 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 2b27f5ada64a..64d8cd481890 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -498,6 +498,12 @@ struct virtio_net_common_hdr {
> };
>
> static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
> +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 void virtnet_receive_done(struct virtnet_info *vi, struct
> receive_queue *rq,
> +struct sk_buff *skb, u8 flags);
>
> static bool is_xdp_frame(void *ptr)
> {
> @@ -1062,6 +1068,124 @@ static void sg_fill_dma(struct scatterlist *sg,
> dma_addr_t addr, u32 len)
> sg->length = len;
> }
>
> +static struct xdp_buff *buf_to_xdp(struct virtnet_info *vi,
> + struct receive_queue *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);
> +
> + return xdp;
> +}
> +
> +static struct sk_buff *xsk_construct_skb(struct receive_queue *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_small(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 bpf_prog *prog;
> + u32 ret;
> +
> + ret = XDP_PASS;
> + rcu_read_lock();
> + prog = rcu_dereference(rq->xdp_prog);
> + if (prog)
> + ret = virtnet_xdp_handler(prog, xdp, dev, xdp_xmit, stats);
> + rcu_read_unlock();
> +
> + switch (ret) {
> + case XDP_PASS:
> + return xsk_construct_skb(rq, xdp);
> +
> + case XDP_TX:
> + case XDP_REDIRECT:
> + return NULL;
> +
> + default:
> + /* drop packet */
> + xsk_buff_free(xdp);
> + u64_stats_inc(&stats->drops);
> + return NULL;
> + }
> +}
> +
> +static void virtnet_receive_xsk_buf(struct virtnet_info *vi, struct
> receive_queue *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;
> + u8 flags;
> +
> + len -= vi->hdr_len;
> +
> + u64_stats_add(&stats->bytes, len);
> +
> + xdp = buf_to_xdp(vi, rq, buf, len);
> + if (!xdp)
> + return;
> +
> + if (unlikely(
