| Message ID | 20221122074348.88601-10-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: > > Driver can pass the skb to stack by build_skb_from_xdp_buff(). > > Driver forwards multi-buffer packets using the send queue > when XDP_TX and XDP_REDIRECT, and clears the reference of multi > pages when XDP_DROP. > > Signed-off-by: Heng Qi <hengqi@linux.alibaba.com> > Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > --- > drivers/net/virtio_net.c | 65 ++++++---------------------------------- > 1 file changed, 9 insertions(+), 56 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 431f2126a2b5..bbd5cd9bfd47 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -1065,7 +1065,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > struct bpf_prog *xdp_prog; > unsigned int truesize = mergeable_ctx_to_truesize(ctx); > unsigned int headroom = mergeable_ctx_to_headroom(ctx); > - unsigned int metasize = 0; > unsigned int frame_sz; > int err; > > @@ -1137,63 +1136,22 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > > switch (act) { > case XDP_PASS: > - metasize = xdp.data - xdp.data_meta; > - > - /* recalculate offset to account for any header > - * adjustments and minus the metasize to copy the > - * metadata in page_to_skb(). Note other cases do not > - * build an skb and avoid using offset > - */ > - offset = xdp.data - page_address(xdp_page) - > - vi->hdr_len - metasize; > - > - /* recalculate len if xdp.data, xdp.data_end or > - * xdp.data_meta were adjusted > - */ > - len = xdp.data_end - xdp.data + vi->hdr_len + metasize; > - > - /* recalculate headroom if xdp.data or xdp_data_meta > - * were adjusted, note that offset should always point > - * to the start of the reserved bytes for virtio_net > - * header which are followed by xdp.data, that means > - * that offset is equal to the headroom (when buf is > - * starting at the beginning of the page, otherwise > - * there is a base offset inside the page) but it's used > - * with a different starting point (buf start) than > - * xdp.data (buf start + vnet hdr size). If xdp.data or > - * data_meta were adjusted by the xdp prog then the > - * headroom size has changed and so has the offset, we > - * can use data_hard_start, which points at buf start + > - * vnet hdr size, to calculate the new headroom and use > - * it later to compute buf start in page_to_skb() > - */ > - headroom = xdp.data - xdp.data_hard_start - metasize; > - > - /* We can only create skb based on xdp_page. */ > - if (unlikely(xdp_page != page)) { > - rcu_read_unlock(); > - put_page(page); > - head_skb = page_to_skb(vi, rq, xdp_page, offset, > - len, PAGE_SIZE); > - return head_skb; > - } > - break; > + head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz); > + rcu_read_unlock(); > + return head_skb; > case XDP_TX: > stats->xdp_tx++; > xdpf = xdp_convert_buff_to_frame(&xdp); > if (unlikely(!xdpf)) { > - if (unlikely(xdp_page != page)) > - put_page(xdp_page); > - goto err_xdp; > + pr_debug("%s: convert buff to frame failed for xdp\n", dev->name); netdev_dbg()? Thanks > + goto err_xdp_frags; > } > err = virtnet_xdp_xmit(dev, 1, &xdpf, 0); > if (unlikely(!err)) { > xdp_return_frame_rx_napi(xdpf); > } else if (unlikely(err < 0)) { > trace_xdp_exception(vi->dev, xdp_prog, act); > - if (unlikely(xdp_page != page)) > - put_page(xdp_page); > - goto err_xdp; > + goto err_xdp_frags; > } > *xdp_xmit |= VIRTIO_XDP_TX; > if (unlikely(xdp_page != page)) > @@ -1203,11 +1161,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > case XDP_REDIRECT: > stats->xdp_redirects++; > err = xdp_do_redirect(dev, &xdp, xdp_prog); > - if (err) { > - if (unlikely(xdp_page != page)) > - put_page(xdp_page); > - goto err_xdp; > - } > + if (err) > + goto err_xdp_frags; > *xdp_xmit |= VIRTIO_XDP_REDIR; > if (unlikely(xdp_page != page)) > put_page(page); > @@ -1220,9 +1175,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > trace_xdp_exception(vi->dev, xdp_prog, act); > fallthrough; > case XDP_DROP: > - if (unlikely(xdp_page != page)) > - __free_pages(xdp_page, 0); > - goto err_xdp; > + goto err_xdp_frags; > } > err_xdp_frags: > shinfo = xdp_get_shared_info_from_buff(&xdp); > -- > 2.19.1.6.gb485710b >
在 2022/12/6 下午2:42, Jason Wang 写道: > On Tue, Nov 22, 2022 at 3:44 PM Heng Qi <hengqi@linux.alibaba.com> wrote: >> Driver can pass the skb to stack by build_skb_from_xdp_buff(). >> >> Driver forwards multi-buffer packets using the send queue >> when XDP_TX and XDP_REDIRECT, and clears the reference of multi >> pages when XDP_DROP. >> >> Signed-off-by: Heng Qi <hengqi@linux.alibaba.com> >> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> >> --- >> drivers/net/virtio_net.c | 65 ++++++---------------------------------- >> 1 file changed, 9 insertions(+), 56 deletions(-) >> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c >> index 431f2126a2b5..bbd5cd9bfd47 100644 >> --- a/drivers/net/virtio_net.c >> +++ b/drivers/net/virtio_net.c >> @@ -1065,7 +1065,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, >> struct bpf_prog *xdp_prog; >> unsigned int truesize = mergeable_ctx_to_truesize(ctx); >> unsigned int headroom = mergeable_ctx_to_headroom(ctx); >> - unsigned int metasize = 0; >> unsigned int frame_sz; >> int err; >> >> @@ -1137,63 +1136,22 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, >> >> switch (act) { >> case XDP_PASS: >> - metasize = xdp.data - xdp.data_meta; >> - >> - /* recalculate offset to account for any header >> - * adjustments and minus the metasize to copy the >> - * metadata in page_to_skb(). Note other cases do not >> - * build an skb and avoid using offset >> - */ >> - offset = xdp.data - page_address(xdp_page) - >> - vi->hdr_len - metasize; >> - >> - /* recalculate len if xdp.data, xdp.data_end or >> - * xdp.data_meta were adjusted >> - */ >> - len = xdp.data_end - xdp.data + vi->hdr_len + metasize; >> - >> - /* recalculate headroom if xdp.data or xdp_data_meta >> - * were adjusted, note that offset should always point >> - * to the start of the reserved bytes for virtio_net >> - * header which are followed by xdp.data, that means >> - * that offset is equal to the headroom (when buf is >> - * starting at the beginning of the page, otherwise >> - * there is a base offset inside the page) but it's used >> - * with a different starting point (buf start) than >> - * xdp.data (buf start + vnet hdr size). If xdp.data or >> - * data_meta were adjusted by the xdp prog then the >> - * headroom size has changed and so has the offset, we >> - * can use data_hard_start, which points at buf start + >> - * vnet hdr size, to calculate the new headroom and use >> - * it later to compute buf start in page_to_skb() >> - */ >> - headroom = xdp.data - xdp.data_hard_start - metasize; >> - >> - /* We can only create skb based on xdp_page. */ >> - if (unlikely(xdp_page != page)) { >> - rcu_read_unlock(); >> - put_page(page); >> - head_skb = page_to_skb(vi, rq, xdp_page, offset, >> - len, PAGE_SIZE); >> - return head_skb; >> - } >> - break; >> + head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz); >> + rcu_read_unlock(); >> + return head_skb; >> case XDP_TX: >> stats->xdp_tx++; >> xdpf = xdp_convert_buff_to_frame(&xdp); >> if (unlikely(!xdpf)) { >> - if (unlikely(xdp_page != page)) >> - put_page(xdp_page); >> - goto err_xdp; >> + pr_debug("%s: convert buff to frame failed for xdp\n", dev->name); > netdev_dbg()? Yes, I will fix it in the next version. Thanks. > > Thanks > >> + goto err_xdp_frags; >> } >> err = virtnet_xdp_xmit(dev, 1, &xdpf, 0); >> if (unlikely(!err)) { >> xdp_return_frame_rx_napi(xdpf); >> } else if (unlikely(err < 0)) { >> trace_xdp_exception(vi->dev, xdp_prog, act); >> - if (unlikely(xdp_page != page)) >> - put_page(xdp_page); >> - goto err_xdp; >> + goto err_xdp_frags; >> } >> *xdp_xmit |= VIRTIO_XDP_TX; >> if (unlikely(xdp_page != page)) >> @@ -1203,11 +1161,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, >> case XDP_REDIRECT: >> stats->xdp_redirects++; >> err = xdp_do_redirect(dev, &xdp, xdp_prog); >> - if (err) { >> - if (unlikely(xdp_page != page)) >> - put_page(xdp_page); >> - goto err_xdp; >> - } >> + if (err) >> + goto err_xdp_frags; >> *xdp_xmit |= VIRTIO_XDP_REDIR; >> if (unlikely(xdp_page != page)) >> put_page(page); >> @@ -1220,9 +1175,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, >> trace_xdp_exception(vi->dev, xdp_prog, act); >> fallthrough; >> case XDP_DROP: >> - if (unlikely(xdp_page != page)) >> - __free_pages(xdp_page, 0); >> - goto err_xdp; >> + goto err_xdp_frags; >> } >> err_xdp_frags: >> shinfo = xdp_get_shared_info_from_buff(&xdp); >> -- >> 2.19.1.6.gb485710b >>
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 431f2126a2b5..bbd5cd9bfd47 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1065,7 +1065,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, struct bpf_prog *xdp_prog; unsigned int truesize = mergeable_ctx_to_truesize(ctx); unsigned int headroom = mergeable_ctx_to_headroom(ctx); - unsigned int metasize = 0; unsigned int frame_sz; int err; @@ -1137,63 +1136,22 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, switch (act) { case XDP_PASS: - metasize = xdp.data - xdp.data_meta; - - /* recalculate offset to account for any header - * adjustments and minus the metasize to copy the - * metadata in page_to_skb(). Note other cases do not - * build an skb and avoid using offset - */ - offset = xdp.data - page_address(xdp_page) - - vi->hdr_len - metasize; - - /* recalculate len if xdp.data, xdp.data_end or - * xdp.data_meta were adjusted - */ - len = xdp.data_end - xdp.data + vi->hdr_len + metasize; - - /* recalculate headroom if xdp.data or xdp_data_meta - * were adjusted, note that offset should always point - * to the start of the reserved bytes for virtio_net - * header which are followed by xdp.data, that means - * that offset is equal to the headroom (when buf is - * starting at the beginning of the page, otherwise - * there is a base offset inside the page) but it's used - * with a different starting point (buf start) than - * xdp.data (buf start + vnet hdr size). If xdp.data or - * data_meta were adjusted by the xdp prog then the - * headroom size has changed and so has the offset, we - * can use data_hard_start, which points at buf start + - * vnet hdr size, to calculate the new headroom and use - * it later to compute buf start in page_to_skb() - */ - headroom = xdp.data - xdp.data_hard_start - metasize; - - /* We can only create skb based on xdp_page. */ - if (unlikely(xdp_page != page)) { - rcu_read_unlock(); - put_page(page); - head_skb = page_to_skb(vi, rq, xdp_page, offset, - len, PAGE_SIZE); - return head_skb; - } - break; + head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz); + rcu_read_unlock(); + return head_skb; case XDP_TX: stats->xdp_tx++; xdpf = xdp_convert_buff_to_frame(&xdp); if (unlikely(!xdpf)) { - if (unlikely(xdp_page != page)) - put_page(xdp_page); - goto err_xdp; + pr_debug("%s: convert buff to frame failed for xdp\n", dev->name); + goto err_xdp_frags; } err = virtnet_xdp_xmit(dev, 1, &xdpf, 0); if (unlikely(!err)) { xdp_return_frame_rx_napi(xdpf); } else if (unlikely(err < 0)) { trace_xdp_exception(vi->dev, xdp_prog, act); - if (unlikely(xdp_page != page)) - put_page(xdp_page); - goto err_xdp; + goto err_xdp_frags; } *xdp_xmit |= VIRTIO_XDP_TX; if (unlikely(xdp_page != page)) @@ -1203,11 +1161,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, case XDP_REDIRECT: stats->xdp_redirects++; err = xdp_do_redirect(dev, &xdp, xdp_prog); - if (err) { - if (unlikely(xdp_page != page)) - put_page(xdp_page); - goto err_xdp; - } + if (err) + goto err_xdp_frags; *xdp_xmit |= VIRTIO_XDP_REDIR; if (unlikely(xdp_page != page)) put_page(page); @@ -1220,9 +1175,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, trace_xdp_exception(vi->dev, xdp_prog, act); fallthrough; case XDP_DROP: - if (unlikely(xdp_page != page)) - __free_pages(xdp_page, 0); - goto err_xdp; + goto err_xdp_frags; } err_xdp_frags: shinfo = xdp_get_shared_info_from_buff(&xdp);