Michael S. Tsirkin
2023-Apr-21 11:54 UTC
[PATCH net-next v2 05/14] virtio_net: introduce xdp res enums
On Fri, Apr 21, 2023 at 03:24:00PM +0800, Xuan Zhuo wrote:> On Fri, 21 Apr 2023 03:00:15 -0400, "Michael S. Tsirkin" <mst at redhat.com> wrote: > > On Tue, Apr 18, 2023 at 02:53:18PM +0800, Xuan Zhuo wrote: > > > virtnet_xdp_handler() is to process all the logic related to XDP. The > > > caller only needs to care about how to deal with the buf. So this commit > > > introduces new enums: > > > > > > 1. VIRTNET_XDP_RES_PASS: make skb by the buf > > > 2. VIRTNET_XDP_RES_DROP: xdp return drop action or some error, caller > > > should release the buf > > > 3. VIRTNET_XDP_RES_CONSUMED: xdp consumed the buf, the caller doesnot to > > > do anything > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > > > > > > I am not excited about using virtio specific enums then translating > > to standard ones. > > > My fault, my expression is not very complete. > > This is not a replacement, but just want to say, there are only three cases of > virtnet_xdp_handler. Caller only needs to handle this three cases. Instead > of paying attention to the detailed return results of XDP. > > In addition, virtnet_xdp_handler returns XDP_TX, but in fact, the work of XDP_TX > is already done in Virtnet_xdp_handler. Caller does not need to do anything for > XDP_TX, giving people a feeling, XDP_TX does not need to be processed. I think > it is not good. > > Thanks.I don't really get it, sorry. If it's possible to stick to XDP return codes, that is preferable.> > > > > > > --- > > > drivers/net/virtio_net.c | 42 ++++++++++++++++++++++++++-------------- > > > 1 file changed, 27 insertions(+), 15 deletions(-) > > > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > > > index 0fa64c314ea7..4dfdc211d355 100644 > > > --- a/drivers/net/virtio_net.c > > > +++ b/drivers/net/virtio_net.c > > > @@ -301,6 +301,15 @@ struct padded_vnet_hdr { > > > char padding[12]; > > > }; > > > > > > +enum { > > > + /* xdp pass */ > > > + VIRTNET_XDP_RES_PASS, > > > + /* drop packet. the caller needs to release the page. */ > > > + VIRTNET_XDP_RES_DROP, > > > + /* packet is consumed by xdp. the caller needs to do nothing. */ > > > + VIRTNET_XDP_RES_CONSUMED, > > > +}; > > > + > > > static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf); > > > static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf); > > > > > > @@ -803,14 +812,14 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, > > > > > > switch (act) { > > > case XDP_PASS: > > > - return act; > > > + return VIRTNET_XDP_RES_PASS; > > > > > > case XDP_TX: > > > stats->xdp_tx++; > > > xdpf = xdp_convert_buff_to_frame(xdp); > > > if (unlikely(!xdpf)) { > > > netdev_dbg(dev, "convert buff to frame failed for xdp\n"); > > > - return XDP_DROP; > > > + return VIRTNET_XDP_RES_DROP; > > > } > > > > > > err = virtnet_xdp_xmit(dev, 1, &xdpf, 0); > > > @@ -818,19 +827,20 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, > > > xdp_return_frame_rx_napi(xdpf); > > > } else if (unlikely(err < 0)) { > > > trace_xdp_exception(dev, xdp_prog, act); > > > - return XDP_DROP; > > > + return VIRTNET_XDP_RES_DROP; > > > } > > > + > > > *xdp_xmit |= VIRTIO_XDP_TX; > > > - return act; > > > + return VIRTNET_XDP_RES_CONSUMED; > > > > > > case XDP_REDIRECT: > > > stats->xdp_redirects++; > > > err = xdp_do_redirect(dev, xdp, xdp_prog); > > > if (err) > > > - return XDP_DROP; > > > + return VIRTNET_XDP_RES_DROP; > > > > > > *xdp_xmit |= VIRTIO_XDP_REDIR; > > > - return act; > > > + return VIRTNET_XDP_RES_CONSUMED; > > > > > > default: > > > bpf_warn_invalid_xdp_action(dev, xdp_prog, act); > > > @@ -839,7 +849,7 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, > > > trace_xdp_exception(dev, xdp_prog, act); > > > fallthrough; > > > case XDP_DROP: > > > - return XDP_DROP; > > > + return VIRTNET_XDP_RES_DROP; > > > } > > > } > > > > > > @@ -987,17 +997,18 @@ static struct sk_buff *receive_small(struct net_device *dev, > > > act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats); > > > > > > switch (act) { > > > - case XDP_PASS: > > > + case VIRTNET_XDP_RES_PASS: > > > /* Recalculate length in case bpf program changed it */ > > > delta = orig_data - xdp.data; > > > len = xdp.data_end - xdp.data; > > > metasize = xdp.data - xdp.data_meta; > > > break; > > > - case XDP_TX: > > > - case XDP_REDIRECT: > > > + > > > + case VIRTNET_XDP_RES_CONSUMED: > > > rcu_read_unlock(); > > > goto xdp_xmit; > > > - default: > > > + > > > + case VIRTNET_XDP_RES_DROP: > > > goto err_xdp; > > > } > > > } > > > @@ -1324,18 +1335,19 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > > > act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats); > > > > > > switch (act) { > > > - case XDP_PASS: > > > + case VIRTNET_XDP_RES_PASS: > > > head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz); > > > if (unlikely(!head_skb)) > > > goto err_xdp_frags; > > > > > > rcu_read_unlock(); > > > return head_skb; > > > - case XDP_TX: > > > - case XDP_REDIRECT: > > > + > > > + case VIRTNET_XDP_RES_CONSUMED: > > > rcu_read_unlock(); > > > goto xdp_xmit; > > > - default: > > > + > > > + case VIRTNET_XDP_RES_DROP: > > > break; > > > } > > > err_xdp_frags: > > > -- > > > 2.32.0.3.g01195cf9f > >
Xuan Zhuo
2023-Apr-23 01:57 UTC
[PATCH net-next v2 05/14] virtio_net: introduce xdp res enums
On Fri, 21 Apr 2023 07:54:11 -0400, "Michael S. Tsirkin" <mst at redhat.com> wrote:> On Fri, Apr 21, 2023 at 03:24:00PM +0800, Xuan Zhuo wrote: > > On Fri, 21 Apr 2023 03:00:15 -0400, "Michael S. Tsirkin" <mst at redhat.com> wrote: > > > On Tue, Apr 18, 2023 at 02:53:18PM +0800, Xuan Zhuo wrote: > > > > virtnet_xdp_handler() is to process all the logic related to XDP. The > > > > caller only needs to care about how to deal with the buf. So this commit > > > > introduces new enums: > > > > > > > > 1. VIRTNET_XDP_RES_PASS: make skb by the buf > > > > 2. VIRTNET_XDP_RES_DROP: xdp return drop action or some error, caller > > > > should release the buf > > > > 3. VIRTNET_XDP_RES_CONSUMED: xdp consumed the buf, the caller doesnot to > > > > do anything > > > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > > > > > > > > > I am not excited about using virtio specific enums then translating > > > to standard ones. > > > > > > My fault, my expression is not very complete. > > > > This is not a replacement, but just want to say, there are only three cases of > > virtnet_xdp_handler. Caller only needs to handle this three cases. Instead > > of paying attention to the detailed return results of XDP. > > > > In addition, virtnet_xdp_handler returns XDP_TX, but in fact, the work of XDP_TX > > is already done in Virtnet_xdp_handler. Caller does not need to do anything for > > XDP_TX, giving people a feeling, XDP_TX does not need to be processed. I think > > it is not good. > > > > Thanks. > > I don't really get it, sorry. If it's possible to stick to > XDP return codes, that is preferable.Although, I still think that it would be better to use VIRTNET_XDP_RES_*, and other drivers did the same thing. If you still insist, I can remove this commit. In addition, I think squashing this patch to the previous patch may be more suitable. Just like I done in last patchset. @Jason Because what I want to express is that virtnet_xdp_handler() has only three kinds of returns, caller does not need to pay attention to the details of XDP returns. Thanks.> > > > > > > > > > > > --- > > > > drivers/net/virtio_net.c | 42 ++++++++++++++++++++++++++-------------- > > > > 1 file changed, 27 insertions(+), 15 deletions(-) > > > > > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > > > > index 0fa64c314ea7..4dfdc211d355 100644 > > > > --- a/drivers/net/virtio_net.c > > > > +++ b/drivers/net/virtio_net.c > > > > @@ -301,6 +301,15 @@ struct padded_vnet_hdr { > > > > char padding[12]; > > > > }; > > > > > > > > +enum { > > > > + /* xdp pass */ > > > > + VIRTNET_XDP_RES_PASS, > > > > + /* drop packet. the caller needs to release the page. */ > > > > + VIRTNET_XDP_RES_DROP, > > > > + /* packet is consumed by xdp. the caller needs to do nothing. */ > > > > + VIRTNET_XDP_RES_CONSUMED, > > > > +}; > > > > + > > > > static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf); > > > > static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf); > > > > > > > > @@ -803,14 +812,14 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, > > > > > > > > switch (act) { > > > > case XDP_PASS: > > > > - return act; > > > > + return VIRTNET_XDP_RES_PASS; > > > > > > > > case XDP_TX: > > > > stats->xdp_tx++; > > > > xdpf = xdp_convert_buff_to_frame(xdp); > > > > if (unlikely(!xdpf)) { > > > > netdev_dbg(dev, "convert buff to frame failed for xdp\n"); > > > > - return XDP_DROP; > > > > + return VIRTNET_XDP_RES_DROP; > > > > } > > > > > > > > err = virtnet_xdp_xmit(dev, 1, &xdpf, 0); > > > > @@ -818,19 +827,20 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, > > > > xdp_return_frame_rx_napi(xdpf); > > > > } else if (unlikely(err < 0)) { > > > > trace_xdp_exception(dev, xdp_prog, act); > > > > - return XDP_DROP; > > > > + return VIRTNET_XDP_RES_DROP; > > > > } > > > > + > > > > *xdp_xmit |= VIRTIO_XDP_TX; > > > > - return act; > > > > + return VIRTNET_XDP_RES_CONSUMED; > > > > > > > > case XDP_REDIRECT: > > > > stats->xdp_redirects++; > > > > err = xdp_do_redirect(dev, xdp, xdp_prog); > > > > if (err) > > > > - return XDP_DROP; > > > > + return VIRTNET_XDP_RES_DROP; > > > > > > > > *xdp_xmit |= VIRTIO_XDP_REDIR; > > > > - return act; > > > > + return VIRTNET_XDP_RES_CONSUMED; > > > > > > > > default: > > > > bpf_warn_invalid_xdp_action(dev, xdp_prog, act); > > > > @@ -839,7 +849,7 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, > > > > trace_xdp_exception(dev, xdp_prog, act); > > > > fallthrough; > > > > case XDP_DROP: > > > > - return XDP_DROP; > > > > + return VIRTNET_XDP_RES_DROP; > > > > } > > > > } > > > > > > > > @@ -987,17 +997,18 @@ static struct sk_buff *receive_small(struct net_device *dev, > > > > act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats); > > > > > > > > switch (act) { > > > > - case XDP_PASS: > > > > + case VIRTNET_XDP_RES_PASS: > > > > /* Recalculate length in case bpf program changed it */ > > > > delta = orig_data - xdp.data; > > > > len = xdp.data_end - xdp.data; > > > > metasize = xdp.data - xdp.data_meta; > > > > break; > > > > - case XDP_TX: > > > > - case XDP_REDIRECT: > > > > + > > > > + case VIRTNET_XDP_RES_CONSUMED: > > > > rcu_read_unlock(); > > > > goto xdp_xmit; > > > > - default: > > > > + > > > > + case VIRTNET_XDP_RES_DROP: > > > > goto err_xdp; > > > > } > > > > } > > > > @@ -1324,18 +1335,19 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > > > > act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats); > > > > > > > > switch (act) { > > > > - case XDP_PASS: > > > > + case VIRTNET_XDP_RES_PASS: > > > > head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz); > > > > if (unlikely(!head_skb)) > > > > goto err_xdp_frags; > > > > > > > > rcu_read_unlock(); > > > > return head_skb; > > > > - case XDP_TX: > > > > - case XDP_REDIRECT: > > > > + > > > > + case VIRTNET_XDP_RES_CONSUMED: > > > > rcu_read_unlock(); > > > > goto xdp_xmit; > > > > - default: > > > > + > > > > + case VIRTNET_XDP_RES_DROP: > > > > break; > > > > } > > > > err_xdp_frags: > > > > -- > > > > 2.32.0.3.g01195cf9f > > > >