| Message ID | 1377616142-29590-1-git-send-email-thuth@linux.vnet.ibm.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Thomas Huth <thuth@linux.vnet.ibm.com> Date: Tue, 27 Aug 2013 17:09:02 +0200 > If the VIRTIO_NET_F_GUEST_CSUM virtio feature is available, the guest > does not have to calculate the checksums on all received packets. This > is pretty much the same feature as RX checksum offloading on real > network cards, so the virtio-net driver should report this by setting > the NETIF_F_RXCSUM flag. When the user now runs "ethtool -k", he or she > can see whether the virtio-net interface has to calculate RX checksums > or not. > > Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Can one of the virtio_net folks please review this? Thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
David Miller <davem@davemloft.net> writes: > From: Thomas Huth <thuth@linux.vnet.ibm.com> > Date: Tue, 27 Aug 2013 17:09:02 +0200 > >> If the VIRTIO_NET_F_GUEST_CSUM virtio feature is available, the guest >> does not have to calculate the checksums on all received packets. This >> is pretty much the same feature as RX checksum offloading on real >> network cards, so the virtio-net driver should report this by setting >> the NETIF_F_RXCSUM flag. When the user now runs "ethtool -k", he or she >> can see whether the virtio-net interface has to calculate RX checksums >> or not. >> >> Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> > > Can one of the virtio_net folks please review this? Hmm, so NETIF_F_RXCSUM only exists for ethtool's benefit. Weird. But this patch is correct: Acked-by: Rusty Russell <rusty@rustcorp.com.au> Thanks, Rusty. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index f216002..defec2b 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1538,6 +1538,8 @@ static int virtnet_probe(struct virtio_device *vdev) dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO); /* (!csum && gso) case will be fixed by register_netdev() */ } + if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM)) + dev->features |= NETIF_F_RXCSUM; dev->vlan_features = dev->features;
If the VIRTIO_NET_F_GUEST_CSUM virtio feature is available, the guest does not have to calculate the checksums on all received packets. This is pretty much the same feature as RX checksum offloading on real network cards, so the virtio-net driver should report this by setting the NETIF_F_RXCSUM flag. When the user now runs "ethtool -k", he or she can see whether the virtio-net interface has to calculate RX checksums or not. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> --- drivers/net/virtio_net.c | 2 ++ 1 file changed, 2 insertions(+)