On Tue, 24 Feb 2026 12:28:50 +0530, Srujana Challa <[email protected]> wrote: > Since NETDEV_RSS_KEY_LEN was increased to 256 in net-next, use > BUILD_BUG_ON to enforce the limit at compile time and remove the > redundant runtime max check. > > Signed-off-by: Srujana Challa <[email protected]> > --- > drivers/net/virtio_net.c | 8 +------- > 1 file changed, 1 insertion(+), 7 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index eeefe8abc122..768ad5523dfa 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -6639,13 +6639,7 @@ static int virtnet_validate(struct virtio_device *vdev) > __virtio_clear_bit(vdev, VIRTIO_NET_F_RSS); > __virtio_clear_bit(vdev, VIRTIO_NET_F_HASH_REPORT); > } > - if (key_sz > NETDEV_RSS_KEY_LEN) { > - dev_warn(&vdev->dev, > - "rss_max_key_size=%u exceeds driver limit %u, > disabling RSS\n", > - key_sz, NETDEV_RSS_KEY_LEN); > - __virtio_clear_bit(vdev, VIRTIO_NET_F_RSS); > - __virtio_clear_bit(vdev, VIRTIO_NET_F_HASH_REPORT); > - } > + BUILD_BUG_ON(type_max(key_sz) >= NETDEV_RSS_KEY_LEN);
Do we really need this check? If I understand correctly, the intention is to cap key_sz at 256. However, since key_sz is of type u8, its maximum value is inherently 255, making this check redundant. This is not only limited by this kernel code, the virtio-net spec defines this. Moreover, if NETDEV_RSS_KEY_LEN is ever reduced to a value smaller than 256 in the future, this check would no longer enforce the intended limit correctly. Moreover, you should add a cover letter. Thanks. > } > > return 0; > -- > 2.25.1 >
