diff mbox series

[RFC,2/9] virtio_net: set up xdp for multi buffer packets

Message ID 20221122074348.88601-3-hengqi@linux.alibaba.com (mailing list archive)
State RFC
Delegated to: Netdev Maintainers
Headers show
Series virtio_net: support multi buffer xdp | expand

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netdev/header_inline success No static functions without inline keyword in header files
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Commit Message

Heng Qi Nov. 22, 2022, 7:43 a.m. UTC 
When the xdp program sets xdp.frags, which means it can process
multi-buffer packets, so we continue to open xdp support when
features such as GRO_HW are negotiated.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 drivers/net/virtio_net.c | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

Comments

Jason Wang Dec. 6, 2022, 5:29 a.m. UTC | #1 
On Tue, Nov 22, 2022 at 3:44 PM Heng Qi <hengqi@linux.alibaba.com> wrote:
>
> When the xdp program sets xdp.frags, which means it can process
> multi-buffer packets, so we continue to open xdp support when
> features such as GRO_HW are negotiated.
>
> Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>  drivers/net/virtio_net.c | 30 +++++++++++++++++-------------
>  1 file changed, 17 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index c5046d21b281..8f7d207d58d6 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -3080,14 +3080,21 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
>         u16 xdp_qp = 0, curr_qp;
>         int i, err;
>
> -       if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
> -           && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
> -               virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
> -               virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
> -               virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
> -               virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))) {
> -               NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing GRO_HW/CSUM, disable GRO_HW/CSUM first");
> -               return -EOPNOTSUPP;
> +       if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
> +               if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM)) {
> +                       NL_SET_ERR_MSG_MOD(extack, "Can't set XDP without frags while guest is implementing GUEST_CSUM");
> +                       return -EOPNOTSUPP;
> +               }
> +
> +               if (prog && !prog->aux->xdp_has_frags) {
> +                       if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
> +                           virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
> +                           virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
> +                           virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO)) {
> +                               NL_SET_ERR_MSG_MOD(extack, "Can't set XDP without frags while guest is implementing GUEST_GRO_HW");
> +                               return -EOPNOTSUPP;
> +                       }
> +               }
>         }
>
>         if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
> @@ -3095,8 +3102,8 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
>                 return -EINVAL;
>         }
>
> -       if (dev->mtu > max_sz) {
> -               NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
> +       if (prog && !prog->aux->xdp_has_frags && dev->mtu > max_sz) {
> +               NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP without frags");
>                 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
>                 return -EINVAL;
>         }
> @@ -3218,9 +3225,6 @@ static int virtnet_set_features(struct net_device *dev,
>         int err;
>
>         if ((dev->features ^ features) & NETIF_F_GRO_HW) {
> -               if (vi->xdp_enabled)
> -                       return -EBUSY;

This seems suspicious, GRO_HW could be re-enabled accidentally even if
it was disabled when attaching an XDP program that is not capable of
doing multi-buffer XDP?

Thanks

> -
>                 if (features & NETIF_F_GRO_HW)
>                         offloads = vi->guest_offloads_capable;
>                 else
> --
> 2.19.1.6.gb485710b
>
Heng Qi Dec. 8, 2022, 8:21 a.m. UTC | #2 
在 2022/12/6 下午1:29, Jason Wang 写道:
> On Tue, Nov 22, 2022 at 3:44 PM Heng Qi <hengqi@linux.alibaba.com> wrote:
>> When the xdp program sets xdp.frags, which means it can process
>> multi-buffer packets, so we continue to open xdp support when
>> features such as GRO_HW are negotiated.
>>
>> Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
>> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
>> ---
>>   drivers/net/virtio_net.c | 30 +++++++++++++++++-------------
>>   1 file changed, 17 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index c5046d21b281..8f7d207d58d6 100644
>> --- a/drivers/net/virtio_net.c
>> +++ b/drivers/net/virtio_net.c
>> @@ -3080,14 +3080,21 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
>>          u16 xdp_qp = 0, curr_qp;
>>          int i, err;
>>
>> -       if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
>> -           && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
>> -               virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
>> -               virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
>> -               virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
>> -               virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))) {
>> -               NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing GRO_HW/CSUM, disable GRO_HW/CSUM first");
>> -               return -EOPNOTSUPP;
>> +       if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
>> +               if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM)) {
>> +                       NL_SET_ERR_MSG_MOD(extack, "Can't set XDP without frags while guest is implementing GUEST_CSUM");
>> +                       return -EOPNOTSUPP;
>> +               }
>> +
>> +               if (prog && !prog->aux->xdp_has_frags) {
>> +                       if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
>> +                           virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
>> +                           virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
>> +                           virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO)) {
>> +                               NL_SET_ERR_MSG_MOD(extack, "Can't set XDP without frags while guest is implementing GUEST_GRO_HW");
>> +                               return -EOPNOTSUPP;
>> +                       }
>> +               }
>>          }
>>
>>          if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
>> @@ -3095,8 +3102,8 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
>>                  return -EINVAL;
>>          }
>>
>> -       if (dev->mtu > max_sz) {
>> -               NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
>> +       if (prog && !prog->aux->xdp_has_frags && dev->mtu > max_sz) {
>> +               NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP without frags");
>>                  netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
>>                  return -EINVAL;
>>          }
>> @@ -3218,9 +3225,6 @@ static int virtnet_set_features(struct net_device *dev,
>>          int err;
>>
>>          if ((dev->features ^ features) & NETIF_F_GRO_HW) {
>> -               if (vi->xdp_enabled)
>> -                       return -EBUSY;
> This seems suspicious, GRO_HW could be re-enabled accidentally even if
> it was disabled when attaching an XDP program that is not capable of
> doing multi-buffer XDP?

Yes, we shouldn't drop this check, because GRO_HW is unfriendly to xdp 
programs without xdp.frags.

Thanks.

>
> Thanks
>
>> -
>>                  if (features & NETIF_F_GRO_HW)
>>                          offloads = vi->guest_offloads_capable;
>>                  else
>> --
>> 2.19.1.6.gb485710b
>>
diff mbox series

Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index c5046d21b281..8f7d207d58d6 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3080,14 +3080,21 @@  static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 	u16 xdp_qp = 0, curr_qp;
 	int i, err;
 
-	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
-	    && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
-	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
-	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
-		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
-		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))) {
-		NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing GRO_HW/CSUM, disable GRO_HW/CSUM first");
-		return -EOPNOTSUPP;
+	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
+		if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM)) {
+			NL_SET_ERR_MSG_MOD(extack, "Can't set XDP without frags while guest is implementing GUEST_CSUM");
+			return -EOPNOTSUPP;
+		}
+
+		if (prog && !prog->aux->xdp_has_frags) {
+			if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
+			    virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
+			    virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
+			    virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO)) {
+				NL_SET_ERR_MSG_MOD(extack, "Can't set XDP without frags while guest is implementing GUEST_GRO_HW");
+				return -EOPNOTSUPP;
+			}
+		}
 	}
 
 	if (vi->mergeable_rx_bufs && !vi->any_header_sg) {
@@ -3095,8 +3102,8 @@  static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 		return -EINVAL;
 	}
 
-	if (dev->mtu > max_sz) {
-		NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
+	if (prog && !prog->aux->xdp_has_frags && dev->mtu > max_sz) {
+		NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP without frags");
 		netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
 		return -EINVAL;
 	}
@@ -3218,9 +3225,6 @@  static int virtnet_set_features(struct net_device *dev,
 	int err;
 
 	if ((dev->features ^ features) & NETIF_F_GRO_HW) {
-		if (vi->xdp_enabled)
-			return -EBUSY;
-
 		if (features & NETIF_F_GRO_HW)
 			offloads = vi->guest_offloads_capable;
 		else