Xuan Zhuo
2023-Apr-04 07:06 UTC
[PATCH net-next 3/8] virtio_net: introduce virtnet_xdp_handler() to seprate the logic of run xdp
On Tue, 4 Apr 2023 15:01:36 +0800, Jason Wang <jasowang at redhat.com> wrote:> On Tue, Apr 4, 2023 at 2:55?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote: > > > > On Tue, 4 Apr 2023 14:35:05 +0800, Jason Wang <jasowang at redhat.com> wrote: > > > On Tue, Apr 4, 2023 at 2:22?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote: > > > > > > > > On Tue, 4 Apr 2023 13:04:02 +0800, Jason Wang <jasowang at redhat.com> wrote: > > > > > On Mon, Apr 3, 2023 at 12:17?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote: > > > > > > > > > > > > On Mon, 3 Apr 2023 10:43:03 +0800, Jason Wang <jasowang at redhat.com> wrote: > > > > > > > On Tue, Mar 28, 2023 at 8:04?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote: > > > > > > > > > > > > > > > > At present, we have two similar logic to perform the XDP prog. > > > > > > > > > > > > > > > > Therefore, this PATCH separates the code of executing XDP, which is > > > > > > > > conducive to later maintenance. > > > > > > > > > > > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > > > > > > > > --- > > > > > > > > drivers/net/virtio_net.c | 142 +++++++++++++++++++++------------------ > > > > > > > > 1 file changed, 75 insertions(+), 67 deletions(-) > > > > > > > > > > > > > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > > > > > > > > index bb426958cdd4..72b9d6ee4024 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, > > > > > > > > +}; > > > > > > > > > > > > > > I'd prefer this to be done on top unless it is a must. But I don't see > > > > > > > any advantage of introducing this, it's partial mapping of XDP action > > > > > > > and it needs to be extended when XDP action is extended. (And we've > > > > > > > already had: VIRTIO_XDP_REDIR and VIRTIO_XDP_TX ...) > > > > > > > > > > > > No, these are the three states of buffer after XDP processing. > > > > > > > > > > > > * PASS: goto make skb > > > > > > > > > > XDP_PASS goes for this. > > > > > > > > > > > * DROP: we should release buffer > > > > > > > > > > XDP_DROP and error conditions go with this. > > > > > > > > > > > * CUNSUMED: xdp prog used the buffer, we do nothing > > > > > > > > > > XDP_TX/XDP_REDIRECTION goes for this. > > > > > > > > > > So t virtnet_xdp_handler() just maps XDP ACTION plus the error > > > > > conditions to the above three states. > > > > > > > > > > We can simply map error to XDP_DROP like: > > > > > > > > > > case XDP_TX: > > > > > stats->xdp_tx++; > > > > > xdpf = xdp_convert_buff_to_frame(xdp); > > > > > if (unlikely(!xdpf)) > > > > > return XDP_DROP; > > > > > > > > > > A good side effect is to avoid the xdp_xmit pointer to be passed to > > > > > the function. > > > > > > > > > > > > So, I guess you mean this: > > > > > > > > switch (act) { > > > > case XDP_PASS: > > > > /* handle pass */ > > > > return skb; > > > > > > > > case XDP_TX: > > > > *xdp_xmit |= VIRTIO_XDP_TX; > > > > goto xmit; > > > > > > > > case XDP_REDIRECT: > > > > *xdp_xmit |= VIRTIO_XDP_REDIR; > > > > goto xmit; > > > > > > > > case XDP_DROP: > > > > default: > > > > goto err_xdp; > > > > } > > > > > > > > I have to say there is no problem from the perspective of code implementation. > > > > > > Note that this is the current logic where it is determined in > > > receive_small() and receive_mergeable(). > > > > Yes, but the purpose of this patches is to simplify the call. > > You mean simplify the receive_small()/mergeable()?YES.> > > > > > > > > > > > > > But if the a new ACTION liking XDP_TX,XDP_REDIRECT is added in the future, then > > > > we must modify all the callers. > > > > > > This is fine since we only use a single type for XDP action. > > > > a single type? > > Instead of (partial) duplicating XDP actions in the new enums.I think it's really misunderstand here. So your thought is these? VIRTNET_XDP_RES_PASS, VIRTNET_XDP_RES_TX_REDIRECT, VIRTNET_XDP_RES_DROP,> > > > > > > > > > This is the benefit of using CUNSUMED. > > > > > > It's very hard to say, e.g if we want to support cloning in the future. > > > > cloning? You mean clone one new buffer. > > > > It is true that no matter what realization, the logic must be modified. > > Yes. > > > > > > > > > > > > > > I think it is a good advantage to put xdp_xmit in virtnet_xdp_handler(), > > > > which makes the caller not care too much about these details. > > > > > > This part I don't understand, having xdp_xmit means the caller need to > > > know whether it is xmited or redirected. The point of the enum is to > > > hide the XDP actions, but it's conflict with what xdp_xmit who want to > > > expose (part of) the XDP actions. > > > > I mean, no matter what virtnet_xdp_handler () returns? XDP_ACTION or some one I > > defined, I want to hide the modification of xdp_xmit to virtnet_xdp_handler(). > > > > Even if virtnet_xdp_handler() returns XDP_TX, we can also complete the > > modification of XDP_XMIT within Virtnet_xdp_handler(). > > > > > > > > > > > If you take into > > > > account the problem of increasing the number of parameters, I advise to put it > > > > in rq. > > > > > > I don't have strong opinion to introduce the enum, > > > > OK, I will drop these new enums. > > Just to make sure we are at the same page. I mean, if there is no > objection from others, I'm ok to have an enum, but we need to use a > separate patch to do that.Do you refer to introduce enums alone without virtnet_xdp_handler()?> > > > > > what I want to say > > > is, use a separated patch to do that. > > > > Does this part refer to putting xdp_xmit in rq? > > I mean it's better to be done separately. But I don't see the > advantage of this other than reducing the parameters.I think so also. Thanks.> > Thanks > > > > > Thanks. > > > > > > > > > > Thanks > > > > > > > > > > > Thanks. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > The latter two are not particularly related to XDP ACTION. And it does not need > > > > > > to extend when XDP action is extended. At least I have not thought of this > > > > > > situation. > > > > > > > > > > What's the advantages of such indirection compared to using XDP action directly? > > > > > > > > > > Thanks > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > + > > > > > > > > static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf); > > > > > > > > static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf); > > > > > > > > > > > > > > > > @@ -789,6 +798,59 @@ static int virtnet_xdp_xmit(struct net_device *dev, > > > > > > > > return ret; > > > > > > > > } > > > > > > > > > > > > > > > > +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) > > > > > > > > +{ > > > > > > > > + struct xdp_frame *xdpf; > > > > > > > > + int err; > > > > > > > > + u32 act; > > > > > > > > + > > > > > > > > + act = bpf_prog_run_xdp(xdp_prog, xdp); > > > > > > > > + stats->xdp_packets++; > > > > > > > > + > > > > > > > > + switch (act) { > > > > > > > > + case XDP_PASS: > > > > > > > > + return VIRTNET_XDP_RES_PASS; > > > > > > > > + > > > > > > > > + case XDP_TX: > > > > > > > > + stats->xdp_tx++; > > > > > > > > + xdpf = xdp_convert_buff_to_frame(xdp); > > > > > > > > + if (unlikely(!xdpf)) > > > > > > > > + return VIRTNET_XDP_RES_DROP; > > > > > > > > + > > > > > > > > + 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(dev, xdp_prog, act); > > > > > > > > + return VIRTNET_XDP_RES_DROP; > > > > > > > > + } > > > > > > > > + > > > > > > > > + *xdp_xmit |= VIRTIO_XDP_TX; > > > > > > > > + return VIRTNET_XDP_RES_CONSUMED; > > > > > > > > + > > > > > > > > + case XDP_REDIRECT: > > > > > > > > + stats->xdp_redirects++; > > > > > > > > + err = xdp_do_redirect(dev, xdp, xdp_prog); > > > > > > > > + if (err) > > > > > > > > + return VIRTNET_XDP_RES_DROP; > > > > > > > > + > > > > > > > > + *xdp_xmit |= VIRTIO_XDP_REDIR; > > > > > > > > + return VIRTNET_XDP_RES_CONSUMED; > > > > > > > > + > > > > > > > > + default: > > > > > > > > + bpf_warn_invalid_xdp_action(dev, xdp_prog, act); > > > > > > > > + fallthrough; > > > > > > > > + case XDP_ABORTED: > > > > > > > > + trace_xdp_exception(dev, xdp_prog, act); > > > > > > > > + fallthrough; > > > > > > > > + case XDP_DROP: > > > > > > > > + return VIRTNET_XDP_RES_DROP; > > > > > > > > + } > > > > > > > > +} > > > > > > > > + > > > > > > > > static unsigned int virtnet_get_headroom(struct virtnet_info *vi) > > > > > > > > { > > > > > > > > return vi->xdp_enabled ? VIRTIO_XDP_HEADROOM : 0; > > > > > > > > @@ -876,7 +938,6 @@ static struct sk_buff *receive_small(struct net_device *dev, > > > > > > > > struct page *page = virt_to_head_page(buf); > > > > > > > > unsigned int delta = 0; > > > > > > > > struct page *xdp_page; > > > > > > > > - int err; > > > > > > > > unsigned int metasize = 0; > > > > > > > > > > > > > > > > len -= vi->hdr_len; > > > > > > > > @@ -898,7 +959,6 @@ static struct sk_buff *receive_small(struct net_device *dev, > > > > > > > > xdp_prog = rcu_dereference(rq->xdp_prog); > > > > > > > > if (xdp_prog) { > > > > > > > > struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset; > > > > > > > > - struct xdp_frame *xdpf; > > > > > > > > struct xdp_buff xdp; > > > > > > > > void *orig_data; > > > > > > > > u32 act; > > > > > > > > @@ -931,46 +991,22 @@ static struct sk_buff *receive_small(struct net_device *dev, > > > > > > > > xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len, > > > > > > > > xdp_headroom, len, true); > > > > > > > > orig_data = xdp.data; > > > > > > > > - act = bpf_prog_run_xdp(xdp_prog, &xdp); > > > > > > > > - stats->xdp_packets++; > > > > > > > > + > > > > > > > > + 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: > > > > > > > > - stats->xdp_tx++; > > > > > > > > - xdpf = xdp_convert_buff_to_frame(&xdp); > > > > > > > > - if (unlikely(!xdpf)) > > > > > > > > - goto err_xdp; > > > > > > > > - 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); > > > > > > > > - goto err_xdp; > > > > > > > > - } > > > > > > > > - *xdp_xmit |= VIRTIO_XDP_TX; > > > > > > > > - rcu_read_unlock(); > > > > > > > > - goto xdp_xmit; > > > > > > > > - case XDP_REDIRECT: > > > > > > > > - stats->xdp_redirects++; > > > > > > > > - err = xdp_do_redirect(dev, &xdp, xdp_prog); > > > > > > > > - if (err) > > > > > > > > - goto err_xdp; > > > > > > > > - *xdp_xmit |= VIRTIO_XDP_REDIR; > > > > > > > > + > > > > > > > > + case VIRTNET_XDP_RES_CONSUMED: > > > > > > > > rcu_read_unlock(); > > > > > > > > goto xdp_xmit; > > > > > > > > - default: > > > > > > > > - bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act); > > > > > > > > - fallthrough; > > > > > > > > - case XDP_ABORTED: > > > > > > > > - trace_xdp_exception(vi->dev, xdp_prog, act); > > > > > > > > - goto err_xdp; > > > > > > > > - case XDP_DROP: > > > > > > > > + > > > > > > > > + case VIRTNET_XDP_RES_DROP: > > > > > > > > goto err_xdp; > > > > > > > > } > > > > > > > > } > > > > > > > > @@ -1277,7 +1313,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > > > > > > > > if (xdp_prog) { > > > > > > > > unsigned int xdp_frags_truesz = 0; > > > > > > > > struct skb_shared_info *shinfo; > > > > > > > > - struct xdp_frame *xdpf; > > > > > > > > struct page *xdp_page; > > > > > > > > struct xdp_buff xdp; > > > > > > > > void *data; > > > > > > > > @@ -1294,49 +1329,22 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > > > > > > > > if (unlikely(err)) > > > > > > > > goto err_xdp_frags; > > > > > > > > > > > > > > > > - act = bpf_prog_run_xdp(xdp_prog, &xdp); > > > > > > > > - stats->xdp_packets++; > > > > > > > > + 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: > > > > > > > > - stats->xdp_tx++; > > > > > > > > - xdpf = xdp_convert_buff_to_frame(&xdp); > > > > > > > > - if (unlikely(!xdpf)) { > > > > > > > > - netdev_dbg(dev, "convert buff to frame failed for xdp\n"); > > > > > > > > > > > > > > Nit: This debug is lost after the conversion. > > > > > > > > > > > > Will fix. > > > > > > > > > > > > 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); > > > > > > > > - goto err_xdp_frags; > > > > > > > > - } > > > > > > > > - *xdp_xmit |= VIRTIO_XDP_TX; > > > > > > > > - rcu_read_unlock(); > > > > > > > > - goto xdp_xmit; > > > > > > > > - case XDP_REDIRECT: > > > > > > > > - stats->xdp_redirects++; > > > > > > > > - err = xdp_do_redirect(dev, &xdp, xdp_prog); > > > > > > > > - if (err) > > > > > > > > - goto err_xdp_frags; > > > > > > > > - *xdp_xmit |= VIRTIO_XDP_REDIR; > > > > > > > > + > > > > > > > > + case VIRTNET_XDP_RES_CONSUMED: > > > > > > > > rcu_read_unlock(); > > > > > > > > goto xdp_xmit; > > > > > > > > - default: > > > > > > > > - bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act); > > > > > > > > - fallthrough; > > > > > > > > - case XDP_ABORTED: > > > > > > > > - trace_xdp_exception(vi->dev, xdp_prog, act); > > > > > > > > - fallthrough; > > > > > > > > - case XDP_DROP: > > > > > > > > + > > > > > > > > + case VIRTNET_XDP_RES_DROP: > > > > > > > > goto err_xdp_frags; > > > > > > > > } > > > > > > > > err_xdp_frags: > > > > > > > > -- > > > > > > > > 2.32.0.3.g01195cf9f > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
Jason Wang
2023-Apr-04 08:03 UTC
[PATCH net-next 3/8] virtio_net: introduce virtnet_xdp_handler() to seprate the logic of run xdp
On Tue, Apr 4, 2023 at 3:12?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote:> > On Tue, 4 Apr 2023 15:01:36 +0800, Jason Wang <jasowang at redhat.com> wrote: > > On Tue, Apr 4, 2023 at 2:55?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote: > > > > > > On Tue, 4 Apr 2023 14:35:05 +0800, Jason Wang <jasowang at redhat.com> wrote: > > > > On Tue, Apr 4, 2023 at 2:22?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote: > > > > > > > > > > On Tue, 4 Apr 2023 13:04:02 +0800, Jason Wang <jasowang at redhat.com> wrote: > > > > > > On Mon, Apr 3, 2023 at 12:17?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote: > > > > > > > > > > > > > > On Mon, 3 Apr 2023 10:43:03 +0800, Jason Wang <jasowang at redhat.com> wrote: > > > > > > > > On Tue, Mar 28, 2023 at 8:04?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote: > > > > > > > > > > > > > > > > > > At present, we have two similar logic to perform the XDP prog. > > > > > > > > > > > > > > > > > > Therefore, this PATCH separates the code of executing XDP, which is > > > > > > > > > conducive to later maintenance. > > > > > > > > > > > > > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > > > > > > > > > --- > > > > > > > > > drivers/net/virtio_net.c | 142 +++++++++++++++++++++------------------ > > > > > > > > > 1 file changed, 75 insertions(+), 67 deletions(-) > > > > > > > > > > > > > > > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > > > > > > > > > index bb426958cdd4..72b9d6ee4024 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, > > > > > > > > > +}; > > > > > > > > > > > > > > > > I'd prefer this to be done on top unless it is a must. But I don't see > > > > > > > > any advantage of introducing this, it's partial mapping of XDP action > > > > > > > > and it needs to be extended when XDP action is extended. (And we've > > > > > > > > already had: VIRTIO_XDP_REDIR and VIRTIO_XDP_TX ...) > > > > > > > > > > > > > > No, these are the three states of buffer after XDP processing. > > > > > > > > > > > > > > * PASS: goto make skb > > > > > > > > > > > > XDP_PASS goes for this. > > > > > > > > > > > > > * DROP: we should release buffer > > > > > > > > > > > > XDP_DROP and error conditions go with this. > > > > > > > > > > > > > * CUNSUMED: xdp prog used the buffer, we do nothing > > > > > > > > > > > > XDP_TX/XDP_REDIRECTION goes for this. > > > > > > > > > > > > So t virtnet_xdp_handler() just maps XDP ACTION plus the error > > > > > > conditions to the above three states. > > > > > > > > > > > > We can simply map error to XDP_DROP like: > > > > > > > > > > > > case XDP_TX: > > > > > > stats->xdp_tx++; > > > > > > xdpf = xdp_convert_buff_to_frame(xdp); > > > > > > if (unlikely(!xdpf)) > > > > > > return XDP_DROP; > > > > > > > > > > > > A good side effect is to avoid the xdp_xmit pointer to be passed to > > > > > > the function. > > > > > > > > > > > > > > > So, I guess you mean this: > > > > > > > > > > switch (act) { > > > > > case XDP_PASS: > > > > > /* handle pass */ > > > > > return skb; > > > > > > > > > > case XDP_TX: > > > > > *xdp_xmit |= VIRTIO_XDP_TX; > > > > > goto xmit; > > > > > > > > > > case XDP_REDIRECT: > > > > > *xdp_xmit |= VIRTIO_XDP_REDIR; > > > > > goto xmit; > > > > > > > > > > case XDP_DROP: > > > > > default: > > > > > goto err_xdp; > > > > > } > > > > > > > > > > I have to say there is no problem from the perspective of code implementation. > > > > > > > > Note that this is the current logic where it is determined in > > > > receive_small() and receive_mergeable(). > > > > > > Yes, but the purpose of this patches is to simplify the call. > > > > You mean simplify the receive_small()/mergeable()? > > YES. > > > > > > > > > > > > > > > > > > > > > But if the a new ACTION liking XDP_TX,XDP_REDIRECT is added in the future, then > > > > > we must modify all the callers. > > > > > > > > This is fine since we only use a single type for XDP action. > > > > > > a single type? > > > > Instead of (partial) duplicating XDP actions in the new enums. > > > I think it's really misunderstand here. So your thought is these? > > VIRTNET_XDP_RES_PASS, > VIRTNET_XDP_RES_TX_REDIRECT, > VIRTNET_XDP_RES_DROP,No, I meant the enum you introduced.> > > > > > > > > > > > > > > > > This is the benefit of using CUNSUMED. > > > > > > > > It's very hard to say, e.g if we want to support cloning in the future. > > > > > > cloning? You mean clone one new buffer. > > > > > > It is true that no matter what realization, the logic must be modified. > > > > Yes. > > > > > > > > > > > > > > > > > > > I think it is a good advantage to put xdp_xmit in virtnet_xdp_handler(), > > > > > which makes the caller not care too much about these details. > > > > > > > > This part I don't understand, having xdp_xmit means the caller need to > > > > know whether it is xmited or redirected. The point of the enum is to > > > > hide the XDP actions, but it's conflict with what xdp_xmit who want to > > > > expose (part of) the XDP actions. > > > > > > I mean, no matter what virtnet_xdp_handler () returns? XDP_ACTION or some one I > > > defined, I want to hide the modification of xdp_xmit to virtnet_xdp_handler(). > > > > > > Even if virtnet_xdp_handler() returns XDP_TX, we can also complete the > > > modification of XDP_XMIT within Virtnet_xdp_handler(). > > > > > > > > > > > > > > > If you take into > > > > > account the problem of increasing the number of parameters, I advise to put it > > > > > in rq. > > > > > > > > I don't have strong opinion to introduce the enum, > > > > > > OK, I will drop these new enums. > > > > Just to make sure we are at the same page. I mean, if there is no > > objection from others, I'm ok to have an enum, but we need to use a > > separate patch to do that. > > Do you refer to introduce enums alone without virtnet_xdp_handler()?I meant, having two patches 1) split out virtnet_xdp_handler() without introducing any new enums 2) introduce the new enum to simplify the codes Thanks> > > > > > > > > > what I want to say > > > > is, use a separated patch to do that. > > > > > > Does this part refer to putting xdp_xmit in rq? > > > > I mean it's better to be done separately. But I don't see the > > advantage of this other than reducing the parameters. > > I think so also. > > Thanks. > > > > > > Thanks > > > > > > > > Thanks. > > > > > > > > > > > > > > Thanks > > > > > > > > > > > > > > Thanks. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > The latter two are not particularly related to XDP ACTION. And it does not need > > > > > > > to extend when XDP action is extended. At least I have not thought of this > > > > > > > situation. > > > > > > > > > > > > What's the advantages of such indirection compared to using XDP action directly? > > > > > > > > > > > > Thanks > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > + > > > > > > > > > static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf); > > > > > > > > > static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf); > > > > > > > > > > > > > > > > > > @@ -789,6 +798,59 @@ static int virtnet_xdp_xmit(struct net_device *dev, > > > > > > > > > return ret; > > > > > > > > > } > > > > > > > > > > > > > > > > > > +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) > > > > > > > > > +{ > > > > > > > > > + struct xdp_frame *xdpf; > > > > > > > > > + int err; > > > > > > > > > + u32 act; > > > > > > > > > + > > > > > > > > > + act = bpf_prog_run_xdp(xdp_prog, xdp); > > > > > > > > > + stats->xdp_packets++; > > > > > > > > > + > > > > > > > > > + switch (act) { > > > > > > > > > + case XDP_PASS: > > > > > > > > > + return VIRTNET_XDP_RES_PASS; > > > > > > > > > + > > > > > > > > > + case XDP_TX: > > > > > > > > > + stats->xdp_tx++; > > > > > > > > > + xdpf = xdp_convert_buff_to_frame(xdp); > > > > > > > > > + if (unlikely(!xdpf)) > > > > > > > > > + return VIRTNET_XDP_RES_DROP; > > > > > > > > > + > > > > > > > > > + 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(dev, xdp_prog, act); > > > > > > > > > + return VIRTNET_XDP_RES_DROP; > > > > > > > > > + } > > > > > > > > > + > > > > > > > > > + *xdp_xmit |= VIRTIO_XDP_TX; > > > > > > > > > + return VIRTNET_XDP_RES_CONSUMED; > > > > > > > > > + > > > > > > > > > + case XDP_REDIRECT: > > > > > > > > > + stats->xdp_redirects++; > > > > > > > > > + err = xdp_do_redirect(dev, xdp, xdp_prog); > > > > > > > > > + if (err) > > > > > > > > > + return VIRTNET_XDP_RES_DROP; > > > > > > > > > + > > > > > > > > > + *xdp_xmit |= VIRTIO_XDP_REDIR; > > > > > > > > > + return VIRTNET_XDP_RES_CONSUMED; > > > > > > > > > + > > > > > > > > > + default: > > > > > > > > > + bpf_warn_invalid_xdp_action(dev, xdp_prog, act); > > > > > > > > > + fallthrough; > > > > > > > > > + case XDP_ABORTED: > > > > > > > > > + trace_xdp_exception(dev, xdp_prog, act); > > > > > > > > > + fallthrough; > > > > > > > > > + case XDP_DROP: > > > > > > > > > + return VIRTNET_XDP_RES_DROP; > > > > > > > > > + } > > > > > > > > > +} > > > > > > > > > + > > > > > > > > > static unsigned int virtnet_get_headroom(struct virtnet_info *vi) > > > > > > > > > { > > > > > > > > > return vi->xdp_enabled ? VIRTIO_XDP_HEADROOM : 0; > > > > > > > > > @@ -876,7 +938,6 @@ static struct sk_buff *receive_small(struct net_device *dev, > > > > > > > > > struct page *page = virt_to_head_page(buf); > > > > > > > > > unsigned int delta = 0; > > > > > > > > > struct page *xdp_page; > > > > > > > > > - int err; > > > > > > > > > unsigned int metasize = 0; > > > > > > > > > > > > > > > > > > len -= vi->hdr_len; > > > > > > > > > @@ -898,7 +959,6 @@ static struct sk_buff *receive_small(struct net_device *dev, > > > > > > > > > xdp_prog = rcu_dereference(rq->xdp_prog); > > > > > > > > > if (xdp_prog) { > > > > > > > > > struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset; > > > > > > > > > - struct xdp_frame *xdpf; > > > > > > > > > struct xdp_buff xdp; > > > > > > > > > void *orig_data; > > > > > > > > > u32 act; > > > > > > > > > @@ -931,46 +991,22 @@ static struct sk_buff *receive_small(struct net_device *dev, > > > > > > > > > xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len, > > > > > > > > > xdp_headroom, len, true); > > > > > > > > > orig_data = xdp.data; > > > > > > > > > - act = bpf_prog_run_xdp(xdp_prog, &xdp); > > > > > > > > > - stats->xdp_packets++; > > > > > > > > > + > > > > > > > > > + 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: > > > > > > > > > - stats->xdp_tx++; > > > > > > > > > - xdpf = xdp_convert_buff_to_frame(&xdp); > > > > > > > > > - if (unlikely(!xdpf)) > > > > > > > > > - goto err_xdp; > > > > > > > > > - 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); > > > > > > > > > - goto err_xdp; > > > > > > > > > - } > > > > > > > > > - *xdp_xmit |= VIRTIO_XDP_TX; > > > > > > > > > - rcu_read_unlock(); > > > > > > > > > - goto xdp_xmit; > > > > > > > > > - case XDP_REDIRECT: > > > > > > > > > - stats->xdp_redirects++; > > > > > > > > > - err = xdp_do_redirect(dev, &xdp, xdp_prog); > > > > > > > > > - if (err) > > > > > > > > > - goto err_xdp; > > > > > > > > > - *xdp_xmit |= VIRTIO_XDP_REDIR; > > > > > > > > > + > > > > > > > > > + case VIRTNET_XDP_RES_CONSUMED: > > > > > > > > > rcu_read_unlock(); > > > > > > > > > goto xdp_xmit; > > > > > > > > > - default: > > > > > > > > > - bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act); > > > > > > > > > - fallthrough; > > > > > > > > > - case XDP_ABORTED: > > > > > > > > > - trace_xdp_exception(vi->dev, xdp_prog, act); > > > > > > > > > - goto err_xdp; > > > > > > > > > - case XDP_DROP: > > > > > > > > > + > > > > > > > > > + case VIRTNET_XDP_RES_DROP: > > > > > > > > > goto err_xdp; > > > > > > > > > } > > > > > > > > > } > > > > > > > > > @@ -1277,7 +1313,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > > > > > > > > > if (xdp_prog) { > > > > > > > > > unsigned int xdp_frags_truesz = 0; > > > > > > > > > struct skb_shared_info *shinfo; > > > > > > > > > - struct xdp_frame *xdpf; > > > > > > > > > struct page *xdp_page; > > > > > > > > > struct xdp_buff xdp; > > > > > > > > > void *data; > > > > > > > > > @@ -1294,49 +1329,22 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > > > > > > > > > if (unlikely(err)) > > > > > > > > > goto err_xdp_frags; > > > > > > > > > > > > > > > > > > - act = bpf_prog_run_xdp(xdp_prog, &xdp); > > > > > > > > > - stats->xdp_packets++; > > > > > > > > > + 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: > > > > > > > > > - stats->xdp_tx++; > > > > > > > > > - xdpf = xdp_convert_buff_to_frame(&xdp); > > > > > > > > > - if (unlikely(!xdpf)) { > > > > > > > > > - netdev_dbg(dev, "convert buff to frame failed for xdp\n"); > > > > > > > > > > > > > > > > Nit: This debug is lost after the conversion. > > > > > > > > > > > > > > Will fix. > > > > > > > > > > > > > > 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); > > > > > > > > > - goto err_xdp_frags; > > > > > > > > > - } > > > > > > > > > - *xdp_xmit |= VIRTIO_XDP_TX; > > > > > > > > > - rcu_read_unlock(); > > > > > > > > > - goto xdp_xmit; > > > > > > > > > - case XDP_REDIRECT: > > > > > > > > > - stats->xdp_redirects++; > > > > > > > > > - err = xdp_do_redirect(dev, &xdp, xdp_prog); > > > > > > > > > - if (err) > > > > > > > > > - goto err_xdp_frags; > > > > > > > > > - *xdp_xmit |= VIRTIO_XDP_REDIR; > > > > > > > > > + > > > > > > > > > + case VIRTNET_XDP_RES_CONSUMED: > > > > > > > > > rcu_read_unlock(); > > > > > > > > > goto xdp_xmit; > > > > > > > > > - default: > > > > > > > > > - bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act); > > > > > > > > > - fallthrough; > > > > > > > > > - case XDP_ABORTED: > > > > > > > > > - trace_xdp_exception(vi->dev, xdp_prog, act); > > > > > > > > > - fallthrough; > > > > > > > > > - case XDP_DROP: > > > > > > > > > + > > > > > > > > > + case VIRTNET_XDP_RES_DROP: > > > > > > > > > goto err_xdp_frags; > > > > > > > > > } > > > > > > > > > err_xdp_frags: > > > > > > > > > -- > > > > > > > > > 2.32.0.3.g01195cf9f > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >