diff mbox series

[net-next,v5,07/15] virtio_net: refactor the xmit type

Message ID 20240614063933.108811-8-xuanzhuo@linux.alibaba.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series virtio-net: support AF_XDP zero copy | expand

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netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 845 this patch: 845
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 14 of 14 maintainers
netdev/build_clang success Errors and warnings before: 849 this patch: 849
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netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 115 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Xuan Zhuo June 14, 2024, 6:39 a.m. UTC 
Because the af-xdp and sq premapped mode will introduce two
new xmit type, so I refactor the xmit type mechanism first.

We use the last two bits of the pointer to distinguish the xmit type,
so we can distinguish four xmit types. Now we have two xmit types:
SKB and XDP.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 drivers/net/virtio_net.c | 58 +++++++++++++++++++++++++++-------------
 1 file changed, 40 insertions(+), 18 deletions(-)

Comments

Jason Wang June 17, 2024, 5 a.m. UTC | #1 
On Fri, Jun 14, 2024 at 2:40 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
>
> Because the af-xdp and sq premapped mode will introduce two
> new xmit type, so I refactor the xmit type mechanism first.
>
> We use the last two bits of the pointer to distinguish the xmit type,
> so we can distinguish four xmit types. Now we have two xmit types:
> SKB and XDP.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>  drivers/net/virtio_net.c | 58 +++++++++++++++++++++++++++-------------
>  1 file changed, 40 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 161694957065..e84a4624549b 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -47,8 +47,6 @@ module_param(napi_tx, bool, 0644);
>  #define VIRTIO_XDP_TX          BIT(0)
>  #define VIRTIO_XDP_REDIR       BIT(1)
>
> -#define VIRTIO_XDP_FLAG        BIT(0)
> -
>  /* RX packet size EWMA. The average packet size is used to determine the packet
>   * buffer size when refilling RX rings. As the entire RX ring may be refilled
>   * at once, the weight is chosen so that the EWMA will be insensitive to short-
> @@ -491,42 +489,62 @@ struct virtio_net_common_hdr {
>
>  static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
>
> -static bool is_xdp_frame(void *ptr)
> +enum virtnet_xmit_type {
> +       VIRTNET_XMIT_TYPE_SKB,
> +       VIRTNET_XMIT_TYPE_XDP,
> +};
> +
> +#define VIRTNET_XMIT_TYPE_MASK (VIRTNET_XMIT_TYPE_SKB | VIRTNET_XMIT_TYPE_XDP)
> +
> +static enum virtnet_xmit_type virtnet_xmit_ptr_strip(void **ptr)
>  {
> -       return (unsigned long)ptr & VIRTIO_XDP_FLAG;
> +       unsigned long p = (unsigned long)*ptr;
> +
> +       *ptr = (void *)(p & ~VIRTNET_XMIT_TYPE_MASK);
> +
> +       return p & VIRTNET_XMIT_TYPE_MASK;
>  }
>
> -static void *xdp_to_ptr(struct xdp_frame *ptr)
> +static void *virtnet_xmit_ptr_mix(void *ptr, enum virtnet_xmit_type type)

How about rename this to virtnet_ptr_to_token()?

>  {
> -       return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
> +       return (void *)((unsigned long)ptr | type);
>  }
>
> -static struct xdp_frame *ptr_to_xdp(void *ptr)
> +static int virtnet_add_outbuf(struct send_queue *sq, int num, void *data,
> +                             enum virtnet_xmit_type type)
>  {
> -       return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
> +       return virtqueue_add_outbuf(sq->vq, sq->sg, num,
> +                                   virtnet_xmit_ptr_mix(data, type),
> +                                   GFP_ATOMIC);

Nit: I think we can just open-code this instead of using a helper.

Others look good.

Thanks


>  }
>
>  static void __free_old_xmit(struct send_queue *sq, bool in_napi,
>                             struct virtnet_sq_free_stats *stats)
>  {
> +       struct xdp_frame *frame;
> +       struct sk_buff *skb;
>         unsigned int len;
>         void *ptr;
>
>         while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
>                 ++stats->packets;
>
> -               if (!is_xdp_frame(ptr)) {
> -                       struct sk_buff *skb = ptr;
> +               switch (virtnet_xmit_ptr_strip(&ptr)) {
> +               case VIRTNET_XMIT_TYPE_SKB:
> +                       skb = ptr;
>
>                         pr_debug("Sent skb %p\n", skb);
>
>                         stats->bytes += skb->len;
>                         napi_consume_skb(skb, in_napi);
> -               } else {
> -                       struct xdp_frame *frame = ptr_to_xdp(ptr);
> +                       break;
> +
> +               case VIRTNET_XMIT_TYPE_XDP:
> +                       frame = ptr;
>
>                         stats->bytes += xdp_get_frame_len(frame);
>                         xdp_return_frame(frame);
> +                       break;
>                 }
>         }
>  }
> @@ -1064,8 +1082,7 @@ static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
>                             skb_frag_size(frag), skb_frag_off(frag));
>         }
>
> -       err = virtqueue_add_outbuf(sq->vq, sq->sg, nr_frags + 1,
> -                                  xdp_to_ptr(xdpf), GFP_ATOMIC);
> +       err = virtnet_add_outbuf(sq, nr_frags + 1, xdpf, VIRTNET_XMIT_TYPE_XDP);
>         if (unlikely(err))
>                 return -ENOSPC; /* Caller handle free/refcnt */
>
> @@ -2557,7 +2574,7 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
>                         return num_sg;
>                 num_sg++;
>         }
> -       return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
> +       return virtnet_add_outbuf(sq, num_sg, skb, VIRTNET_XMIT_TYPE_SKB);
>  }
>
>  static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
> @@ -5263,10 +5280,15 @@ static void free_receive_page_frags(struct virtnet_info *vi)
>
>  static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf)
>  {
> -       if (!is_xdp_frame(buf))
> +       switch (virtnet_xmit_ptr_strip(&buf)) {
> +       case VIRTNET_XMIT_TYPE_SKB:
>                 dev_kfree_skb(buf);
> -       else
> -               xdp_return_frame(ptr_to_xdp(buf));
> +               break;
> +
> +       case VIRTNET_XMIT_TYPE_XDP:
> +               xdp_return_frame(buf);
> +               break;
> +       }
>  }
>
>  static void free_unused_bufs(struct virtnet_info *vi)
> --
> 2.32.0.3.g01195cf9f
>
Xuan Zhuo June 17, 2024, 7:21 a.m. UTC | #2 
On Mon, 17 Jun 2024 13:00:11 +0800, Jason Wang <jasowang@redhat.com> wrote:
> On Fri, Jun 14, 2024 at 2:40 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
> >
> > Because the af-xdp and sq premapped mode will introduce two
> > new xmit type, so I refactor the xmit type mechanism first.
> >
> > We use the last two bits of the pointer to distinguish the xmit type,
> > so we can distinguish four xmit types. Now we have two xmit types:
> > SKB and XDP.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > ---
> >  drivers/net/virtio_net.c | 58 +++++++++++++++++++++++++++-------------
> >  1 file changed, 40 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 161694957065..e84a4624549b 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -47,8 +47,6 @@ module_param(napi_tx, bool, 0644);
> >  #define VIRTIO_XDP_TX          BIT(0)
> >  #define VIRTIO_XDP_REDIR       BIT(1)
> >
> > -#define VIRTIO_XDP_FLAG        BIT(0)
> > -
> >  /* RX packet size EWMA. The average packet size is used to determine the packet
> >   * buffer size when refilling RX rings. As the entire RX ring may be refilled
> >   * at once, the weight is chosen so that the EWMA will be insensitive to short-
> > @@ -491,42 +489,62 @@ struct virtio_net_common_hdr {
> >
> >  static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
> >
> > -static bool is_xdp_frame(void *ptr)
> > +enum virtnet_xmit_type {
> > +       VIRTNET_XMIT_TYPE_SKB,
> > +       VIRTNET_XMIT_TYPE_XDP,
> > +};
> > +
> > +#define VIRTNET_XMIT_TYPE_MASK (VIRTNET_XMIT_TYPE_SKB | VIRTNET_XMIT_TYPE_XDP)
> > +
> > +static enum virtnet_xmit_type virtnet_xmit_ptr_strip(void **ptr)
> >  {
> > -       return (unsigned long)ptr & VIRTIO_XDP_FLAG;
> > +       unsigned long p = (unsigned long)*ptr;
> > +
> > +       *ptr = (void *)(p & ~VIRTNET_XMIT_TYPE_MASK);
> > +
> > +       return p & VIRTNET_XMIT_TYPE_MASK;
> >  }
> >
> > -static void *xdp_to_ptr(struct xdp_frame *ptr)
> > +static void *virtnet_xmit_ptr_mix(void *ptr, enum virtnet_xmit_type type)
>
> How about rename this to virtnet_ptr_to_token()?

Will fix.

>
> >  {
> > -       return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
> > +       return (void *)((unsigned long)ptr | type);
> >  }
> >
> > -static struct xdp_frame *ptr_to_xdp(void *ptr)
> > +static int virtnet_add_outbuf(struct send_queue *sq, int num, void *data,
> > +                             enum virtnet_xmit_type type)
> >  {
> > -       return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
> > +       return virtqueue_add_outbuf(sq->vq, sq->sg, num,
> > +                                   virtnet_xmit_ptr_mix(data, type),
> > +                                   GFP_ATOMIC);
>
> Nit: I think we can just open-code this instead of using a helper.

Will fix.

Thanks.


>
> Others look good.
>
> Thanks
>
>
> >  }
> >
> >  static void __free_old_xmit(struct send_queue *sq, bool in_napi,
> >                             struct virtnet_sq_free_stats *stats)
> >  {
> > +       struct xdp_frame *frame;
> > +       struct sk_buff *skb;
> >         unsigned int len;
> >         void *ptr;
> >
> >         while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
> >                 ++stats->packets;
> >
> > -               if (!is_xdp_frame(ptr)) {
> > -                       struct sk_buff *skb = ptr;
> > +               switch (virtnet_xmit_ptr_strip(&ptr)) {
> > +               case VIRTNET_XMIT_TYPE_SKB:
> > +                       skb = ptr;
> >
> >                         pr_debug("Sent skb %p\n", skb);
> >
> >                         stats->bytes += skb->len;
> >                         napi_consume_skb(skb, in_napi);
> > -               } else {
> > -                       struct xdp_frame *frame = ptr_to_xdp(ptr);
> > +                       break;
> > +
> > +               case VIRTNET_XMIT_TYPE_XDP:
> > +                       frame = ptr;
> >
> >                         stats->bytes += xdp_get_frame_len(frame);
> >                         xdp_return_frame(frame);
> > +                       break;
> >                 }
> >         }
> >  }
> > @@ -1064,8 +1082,7 @@ static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
> >                             skb_frag_size(frag), skb_frag_off(frag));
> >         }
> >
> > -       err = virtqueue_add_outbuf(sq->vq, sq->sg, nr_frags + 1,
> > -                                  xdp_to_ptr(xdpf), GFP_ATOMIC);
> > +       err = virtnet_add_outbuf(sq, nr_frags + 1, xdpf, VIRTNET_XMIT_TYPE_XDP);
> >         if (unlikely(err))
> >                 return -ENOSPC; /* Caller handle free/refcnt */
> >
> > @@ -2557,7 +2574,7 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
> >                         return num_sg;
> >                 num_sg++;
> >         }
> > -       return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
> > +       return virtnet_add_outbuf(sq, num_sg, skb, VIRTNET_XMIT_TYPE_SKB);
> >  }
> >
> >  static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
> > @@ -5263,10 +5280,15 @@ static void free_receive_page_frags(struct virtnet_info *vi)
> >
> >  static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf)
> >  {
> > -       if (!is_xdp_frame(buf))
> > +       switch (virtnet_xmit_ptr_strip(&buf)) {
> > +       case VIRTNET_XMIT_TYPE_SKB:
> >                 dev_kfree_skb(buf);
> > -       else
> > -               xdp_return_frame(ptr_to_xdp(buf));
> > +               break;
> > +
> > +       case VIRTNET_XMIT_TYPE_XDP:
> > +               xdp_return_frame(buf);
> > +               break;
> > +       }
> >  }
> >
> >  static void free_unused_bufs(struct virtnet_info *vi)
> > --
> > 2.32.0.3.g01195cf9f
> >
>
diff mbox series

Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 161694957065..e84a4624549b 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -47,8 +47,6 @@  module_param(napi_tx, bool, 0644);
 #define VIRTIO_XDP_TX		BIT(0)
 #define VIRTIO_XDP_REDIR	BIT(1)
 
-#define VIRTIO_XDP_FLAG	BIT(0)
-
 /* RX packet size EWMA. The average packet size is used to determine the packet
  * buffer size when refilling RX rings. As the entire RX ring may be refilled
  * at once, the weight is chosen so that the EWMA will be insensitive to short-
@@ -491,42 +489,62 @@  struct virtio_net_common_hdr {
 
 static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
 
-static bool is_xdp_frame(void *ptr)
+enum virtnet_xmit_type {
+	VIRTNET_XMIT_TYPE_SKB,
+	VIRTNET_XMIT_TYPE_XDP,
+};
+
+#define VIRTNET_XMIT_TYPE_MASK (VIRTNET_XMIT_TYPE_SKB | VIRTNET_XMIT_TYPE_XDP)
+
+static enum virtnet_xmit_type virtnet_xmit_ptr_strip(void **ptr)
 {
-	return (unsigned long)ptr & VIRTIO_XDP_FLAG;
+	unsigned long p = (unsigned long)*ptr;
+
+	*ptr = (void *)(p & ~VIRTNET_XMIT_TYPE_MASK);
+
+	return p & VIRTNET_XMIT_TYPE_MASK;
 }
 
-static void *xdp_to_ptr(struct xdp_frame *ptr)
+static void *virtnet_xmit_ptr_mix(void *ptr, enum virtnet_xmit_type type)
 {
-	return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
+	return (void *)((unsigned long)ptr | type);
 }
 
-static struct xdp_frame *ptr_to_xdp(void *ptr)
+static int virtnet_add_outbuf(struct send_queue *sq, int num, void *data,
+			      enum virtnet_xmit_type type)
 {
-	return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
+	return virtqueue_add_outbuf(sq->vq, sq->sg, num,
+				    virtnet_xmit_ptr_mix(data, type),
+				    GFP_ATOMIC);
 }
 
 static void __free_old_xmit(struct send_queue *sq, bool in_napi,
 			    struct virtnet_sq_free_stats *stats)
 {
+	struct xdp_frame *frame;
+	struct sk_buff *skb;
 	unsigned int len;
 	void *ptr;
 
 	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
 		++stats->packets;
 
-		if (!is_xdp_frame(ptr)) {
-			struct sk_buff *skb = ptr;
+		switch (virtnet_xmit_ptr_strip(&ptr)) {
+		case VIRTNET_XMIT_TYPE_SKB:
+			skb = ptr;
 
 			pr_debug("Sent skb %p\n", skb);
 
 			stats->bytes += skb->len;
 			napi_consume_skb(skb, in_napi);
-		} else {
-			struct xdp_frame *frame = ptr_to_xdp(ptr);
+			break;
+
+		case VIRTNET_XMIT_TYPE_XDP:
+			frame = ptr;
 
 			stats->bytes += xdp_get_frame_len(frame);
 			xdp_return_frame(frame);
+			break;
 		}
 	}
 }
@@ -1064,8 +1082,7 @@  static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
 			    skb_frag_size(frag), skb_frag_off(frag));
 	}
 
-	err = virtqueue_add_outbuf(sq->vq, sq->sg, nr_frags + 1,
-				   xdp_to_ptr(xdpf), GFP_ATOMIC);
+	err = virtnet_add_outbuf(sq, nr_frags + 1, xdpf, VIRTNET_XMIT_TYPE_XDP);
 	if (unlikely(err))
 		return -ENOSPC; /* Caller handle free/refcnt */
 
@@ -2557,7 +2574,7 @@  static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 			return num_sg;
 		num_sg++;
 	}
-	return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
+	return virtnet_add_outbuf(sq, num_sg, skb, VIRTNET_XMIT_TYPE_SKB);
 }
 
 static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
@@ -5263,10 +5280,15 @@  static void free_receive_page_frags(struct virtnet_info *vi)
 
 static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf)
 {
-	if (!is_xdp_frame(buf))
+	switch (virtnet_xmit_ptr_strip(&buf)) {
+	case VIRTNET_XMIT_TYPE_SKB:
 		dev_kfree_skb(buf);
-	else
-		xdp_return_frame(ptr_to_xdp(buf));
+		break;
+
+	case VIRTNET_XMIT_TYPE_XDP:
+		xdp_return_frame(buf);
+		break;
+	}
 }
 
 static void free_unused_bufs(struct virtnet_info *vi)