| Message ID | 20221122074348.88601-6-hengqi@linux.alibaba.com (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | virtio_net: support multi buffer xdp | expand |
On Tue, Nov 22, 2022 at 3:44 PM Heng Qi <hengqi@linux.alibaba.com> wrote: > > Support xdp for multi buffer packets. > > Putting the first buffer as the linear part for xdp_buff, > and the rest of the buffers as non-linear fragments to struct > skb_shared_info in the tailroom belonging to xdp_buff. > > Signed-off-by: Heng Qi <hengqi@linux.alibaba.com> > Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > --- > drivers/net/virtio_net.c | 74 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 74 insertions(+) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index cd65f85d5075..20784b1d8236 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -911,6 +911,80 @@ static struct sk_buff *receive_big(struct net_device *dev, > return NULL; > } > > +static int virtnet_build_xdp_buff(struct net_device *dev, > + struct virtnet_info *vi, > + struct receive_queue *rq, > + struct xdp_buff *xdp, > + void *buf, > + unsigned int len, > + unsigned int frame_sz, > + u16 *num_buf, > + unsigned int *xdp_frags_truesize, > + struct virtnet_rq_stats *stats) > +{ > + unsigned int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); > + struct virtio_net_hdr_mrg_rxbuf *hdr = buf; > + unsigned int truesize, headroom; > + struct skb_shared_info *shinfo; > + unsigned int xdp_frags_truesz = 0; > + unsigned int cur_frag_size; > + struct page *page; > + skb_frag_t *frag; > + int offset; > + void *ctx; > + > + xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq); > + xdp_prepare_buff(xdp, buf - VIRTIO_XDP_HEADROOM, > + VIRTIO_XDP_HEADROOM + vi->hdr_len, len - vi->hdr_len, true); > + shinfo = xdp_get_shared_info_from_buff(xdp); > + shinfo->nr_frags = 0; > + shinfo->xdp_frags_size = 0; > + > + if ((*num_buf - 1) > MAX_SKB_FRAGS) > + return -EINVAL; > + > + while ((--*num_buf) >= 1) { > + buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx); So this works only for a mergeable buffer, I wonder if it's worth it to make it work for big mode as well. Or at least we can mention it as a TODO somewhere and rename this function (with mergeable suffix). Others look good. Thanks > + 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.rx_length_errors++; > + return -EINVAL; > + } > + > + if (!xdp_buff_has_frags(xdp)) > + xdp_buff_set_frags_flag(xdp); > + > + stats->bytes += len; > + page = virt_to_head_page(buf); > + offset = buf - page_address(page); > + truesize = mergeable_ctx_to_truesize(ctx); > + headroom = mergeable_ctx_to_headroom(ctx); > + > + cur_frag_size = truesize + (headroom ? (headroom + tailroom) : 0); > + xdp_frags_truesz += cur_frag_size; > + if (unlikely(len > truesize || cur_frag_size > PAGE_SIZE)) { > + pr_debug("%s: rx error: len %u exceeds truesize %lu\n", > + dev->name, len, (unsigned long)ctx); > + dev->stats.rx_length_errors++; > + return -EINVAL; > + } > + > + frag = &shinfo->frags[shinfo->nr_frags++]; > + __skb_frag_set_page(frag, page); > + skb_frag_off_set(frag, offset); > + skb_frag_size_set(frag, len); > + if (page_is_pfmemalloc(page)) > + xdp_buff_set_frag_pfmemalloc(xdp); > + > + shinfo->xdp_frags_size += len; > + } > + > + *xdp_frags_truesize = xdp_frags_truesz; > + return 0; > +} > + > static struct sk_buff *receive_mergeable(struct net_device *dev, > struct virtnet_info *vi, > struct receive_queue *rq, > -- > 2.19.1.6.gb485710b >
在 2022/12/6 下午2:14, Jason Wang 写道: > On Tue, Nov 22, 2022 at 3:44 PM Heng Qi <hengqi@linux.alibaba.com> wrote: >> Support xdp for multi buffer packets. >> >> Putting the first buffer as the linear part for xdp_buff, >> and the rest of the buffers as non-linear fragments to struct >> skb_shared_info in the tailroom belonging to xdp_buff. >> >> Signed-off-by: Heng Qi <hengqi@linux.alibaba.com> >> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> >> --- >> drivers/net/virtio_net.c | 74 ++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 74 insertions(+) >> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c >> index cd65f85d5075..20784b1d8236 100644 >> --- a/drivers/net/virtio_net.c >> +++ b/drivers/net/virtio_net.c >> @@ -911,6 +911,80 @@ static struct sk_buff *receive_big(struct net_device *dev, >> return NULL; >> } >> >> +static int virtnet_build_xdp_buff(struct net_device *dev, >> + struct virtnet_info *vi, >> + struct receive_queue *rq, >> + struct xdp_buff *xdp, >> + void *buf, >> + unsigned int len, >> + unsigned int frame_sz, >> + u16 *num_buf, >> + unsigned int *xdp_frags_truesize, >> + struct virtnet_rq_stats *stats) >> +{ >> + unsigned int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); >> + struct virtio_net_hdr_mrg_rxbuf *hdr = buf; >> + unsigned int truesize, headroom; >> + struct skb_shared_info *shinfo; >> + unsigned int xdp_frags_truesz = 0; >> + unsigned int cur_frag_size; >> + struct page *page; >> + skb_frag_t *frag; >> + int offset; >> + void *ctx; >> + >> + xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq); >> + xdp_prepare_buff(xdp, buf - VIRTIO_XDP_HEADROOM, >> + VIRTIO_XDP_HEADROOM + vi->hdr_len, len - vi->hdr_len, true); >> + shinfo = xdp_get_shared_info_from_buff(xdp); >> + shinfo->nr_frags = 0; >> + shinfo->xdp_frags_size = 0; >> + >> + if ((*num_buf - 1) > MAX_SKB_FRAGS) >> + return -EINVAL; >> + >> + while ((--*num_buf) >= 1) { >> + buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx); > So this works only for a mergeable buffer, I wonder if it's worth it > to make it work for big mode as well. Or at least we can mention it as > a TODO somewhere and rename this function (with mergeable suffix). Yes, I'm leaning towards the latter, I'll rename it with a mergeable suffix in the next version. Thanks. > > Others look good. > > Thanks > >> + 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.rx_length_errors++; >> + return -EINVAL; >> + } >> + >> + if (!xdp_buff_has_frags(xdp)) >> + xdp_buff_set_frags_flag(xdp); >> + >> + stats->bytes += len; >> + page = virt_to_head_page(buf); >> + offset = buf - page_address(page); >> + truesize = mergeable_ctx_to_truesize(ctx); >> + headroom = mergeable_ctx_to_headroom(ctx); >> + >> + cur_frag_size = truesize + (headroom ? (headroom + tailroom) : 0); >> + xdp_frags_truesz += cur_frag_size; >> + if (unlikely(len > truesize || cur_frag_size > PAGE_SIZE)) { >> + pr_debug("%s: rx error: len %u exceeds truesize %lu\n", >> + dev->name, len, (unsigned long)ctx); >> + dev->stats.rx_length_errors++; >> + return -EINVAL; >> + } >> + >> + frag = &shinfo->frags[shinfo->nr_frags++]; >> + __skb_frag_set_page(frag, page); >> + skb_frag_off_set(frag, offset); >> + skb_frag_size_set(frag, len); >> + if (page_is_pfmemalloc(page)) >> + xdp_buff_set_frag_pfmemalloc(xdp); >> + >> + shinfo->xdp_frags_size += len; >> + } >> + >> + *xdp_frags_truesize = xdp_frags_truesz; >> + return 0; >> +} >> + >> static struct sk_buff *receive_mergeable(struct net_device *dev, >> struct virtnet_info *vi, >> struct receive_queue *rq, >> -- >> 2.19.1.6.gb485710b >>
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index cd65f85d5075..20784b1d8236 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -911,6 +911,80 @@ static struct sk_buff *receive_big(struct net_device *dev, return NULL; } +static int virtnet_build_xdp_buff(struct net_device *dev, + struct virtnet_info *vi, + struct receive_queue *rq, + struct xdp_buff *xdp, + void *buf, + unsigned int len, + unsigned int frame_sz, + u16 *num_buf, + unsigned int *xdp_frags_truesize, + struct virtnet_rq_stats *stats) +{ + unsigned int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + struct virtio_net_hdr_mrg_rxbuf *hdr = buf; + unsigned int truesize, headroom; + struct skb_shared_info *shinfo; + unsigned int xdp_frags_truesz = 0; + unsigned int cur_frag_size; + struct page *page; + skb_frag_t *frag; + int offset; + void *ctx; + + xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq); + xdp_prepare_buff(xdp, buf - VIRTIO_XDP_HEADROOM, + VIRTIO_XDP_HEADROOM + vi->hdr_len, len - vi->hdr_len, true); + shinfo = xdp_get_shared_info_from_buff(xdp); + shinfo->nr_frags = 0; + shinfo->xdp_frags_size = 0; + + if ((*num_buf - 1) > MAX_SKB_FRAGS) + return -EINVAL; + + while ((--*num_buf) >= 1) { + buf = virtqueue_get_buf_ctx(rq->vq, &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.rx_length_errors++; + return -EINVAL; + } + + if (!xdp_buff_has_frags(xdp)) + xdp_buff_set_frags_flag(xdp); + + stats->bytes += len; + page = virt_to_head_page(buf); + offset = buf - page_address(page); + truesize = mergeable_ctx_to_truesize(ctx); + headroom = mergeable_ctx_to_headroom(ctx); + + cur_frag_size = truesize + (headroom ? (headroom + tailroom) : 0); + xdp_frags_truesz += cur_frag_size; + if (unlikely(len > truesize || cur_frag_size > PAGE_SIZE)) { + pr_debug("%s: rx error: len %u exceeds truesize %lu\n", + dev->name, len, (unsigned long)ctx); + dev->stats.rx_length_errors++; + return -EINVAL; + } + + frag = &shinfo->frags[shinfo->nr_frags++]; + __skb_frag_set_page(frag, page); + skb_frag_off_set(frag, offset); + skb_frag_size_set(frag, len); + if (page_is_pfmemalloc(page)) + xdp_buff_set_frag_pfmemalloc(xdp); + + shinfo->xdp_frags_size += len; + } + + *xdp_frags_truesize = xdp_frags_truesz; + return 0; +} + static struct sk_buff *receive_mergeable(struct net_device *dev, struct virtnet_info *vi, struct receive_queue *rq,