Re: [PATCH net-next v2 14/21] virtio_net: xsk: tx: virtnet_free_old_xmit() distinguishes xsk buffer

Xuan Zhuo
2023-11-09T11:17:09Z

On Thu, 9 Nov 2023 06:11:49 -0500, "Michael S. Tsirkin" <mst@redhat.com> wrote:
> On Tue, Nov 07, 2023 at 11:12:20AM +0800, Xuan Zhuo wrote:
> > virtnet_free_old_xmit distinguishes three type ptr(skb, xdp frame, xsk
> > buffer) by the last bits of the pointer.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > ---
> > drivers/net/virtio/virtio_net.h | 18 ++++++++++++++++--
> > drivers/net/virtio/xsk.h | 5 +++++
> > 2 files changed, 21 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h
> > index a431a2c1ee47..a13d6d301fdb 100644
> > --- a/drivers/net/virtio/virtio_net.h
> > +++ b/drivers/net/virtio/virtio_net.h
> > @@ -225,6 +225,11 @@ struct virtnet_info {
> > struct failover *failover;
> > };
> >
> > +static inline bool virtnet_is_skb_ptr(void *ptr)
> > +{
> > + return !((unsigned long)ptr & VIRTIO_XMIT_DATA_MASK);
> > +}
> > +
> > static inline bool virtnet_is_xdp_frame(void *ptr)
> > {
> > return (unsigned long)ptr & VIRTIO_XDP_FLAG;
> > @@ -235,6 +240,8 @@ static inline struct xdp_frame *virtnet_ptr_to_xdp(void *ptr)
> > return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
> > }
> >
> > +static inline u32 virtnet_ptr_to_xsk(void *ptr);
> > +
>
> I don't understand why you need this here.

The below function virtnet_free_old_xmit needs this.

Thanks.

>
>
> > static inline void *virtnet_sq_unmap(struct virtnet_sq *sq, void *data)
> > {
> > struct virtnet_sq_dma *next, *head;
> > @@ -261,11 +268,12 @@ static inline void *virtnet_sq_unmap(struct virtnet_sq *sq, void *data)
> > static inline void virtnet_free_old_xmit(struct virtnet_sq *sq, bool in_napi,
> > u64 *bytes, u64 *packets)
> > {
> > + unsigned int xsknum = 0;
> > unsigned int len;
> > void *ptr;
> >
> > while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
> > - if (!virtnet_is_xdp_frame(ptr)) {
> > + if (virtnet_is_skb_ptr(ptr)) {
> > struct sk_buff *skb;
> >
> > if (sq->do_dma)
> > @@ -277,7 +285,7 @@ static inline void virtnet_free_old_xmit(struct virtnet_sq *sq, bool in_napi,
> >
> > *bytes += skb->len;
> > napi_consume_skb(skb, in_napi);
> > - } else {
> > + } else if (virtnet_is_xdp_frame(ptr)) {
> > struct xdp_frame *frame;
> >
> > if (sq->do_dma)
> > @@ -287,9 +295,15 @@ static inline void virtnet_free_old_xmit(struct virtnet_sq *sq, bool in_napi,
> >
> > *bytes += xdp_get_frame_len(frame);
> > xdp_return_frame(frame);
> > + } else {
> > + *bytes += virtnet_ptr_to_xsk(ptr);
> > + ++xsknum;
> > }
> > (*packets)++;
> > }
> > +
> > + if (xsknum)
> > + xsk_tx_completed(sq->xsk.pool, xsknum);
> > }
> >
> > static inline bool virtnet_is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
> > diff --git a/drivers/net/virtio/xsk.h b/drivers/net/virtio/xsk.h
> > index 1bd19dcda649..7ebc9bda7aee 100644
> > --- a/drivers/net/virtio/xsk.h
> > +++ b/drivers/net/virtio/xsk.h
> > @@ -14,6 +14,11 @@ static inline void *virtnet_xsk_to_ptr(u32 len)
> > return (void *)(p | VIRTIO_XSK_FLAG);
> > }
> >
> > +static inline u32 virtnet_ptr_to_xsk(void *ptr)
> > +{
> > + return ((unsigned long)ptr) >> VIRTIO_XSK_FLAG_OFFSET;
> > +}
> > +
> > int virtnet_xsk_pool_setup(struct net_device *dev, struct netdev_bpf *xdp);
> > bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool,
> > int budget);
> > --
> > 2.32.0.3.g01195cf9f
>
>