virtio-net: disable guest csum during XDP set

We don't disable VIRTIO_NET_F_GUEST_CSUM if XDP was set. This means we
can receive partial csumed packets with metadata kept in the
vnet_hdr. This may have several side effects:

- It could be overridden by header adjustment, thus is might be not
  correct after XDP processing.
- There's no way to pass such metadata information through
  XDP_REDIRECT to another driver.
- XDP does not support checksum offload right now.

So simply disable guest csum if possible in this the case of XDP.

Fixes: 3f93522ffa ("virtio-net: switch off offloads on demand if possible on XDP set")
Reported-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Pavel Popa <pashinho1990@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jason Wang 2018-11-22 14:36:30 +08:00 committed by David S. Miller
parent 484afd1bd3
commit e59ff2c49a

View File

@ -70,7 +70,8 @@ static const unsigned long guest_offloads[] = {
VIRTIO_NET_F_GUEST_TSO4,
VIRTIO_NET_F_GUEST_TSO6,
VIRTIO_NET_F_GUEST_ECN,
VIRTIO_NET_F_GUEST_UFO
VIRTIO_NET_F_GUEST_UFO,
VIRTIO_NET_F_GUEST_CSUM
};
struct virtnet_stat_desc {
@ -2334,9 +2335,6 @@ static int virtnet_clear_guest_offloads(struct virtnet_info *vi)
if (!vi->guest_offloads)
return 0;
if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))
offloads = 1ULL << VIRTIO_NET_F_GUEST_CSUM;
return virtnet_set_guest_offloads(vi, offloads);
}
@ -2346,8 +2344,6 @@ static int virtnet_restore_guest_offloads(struct virtnet_info *vi)
if (!vi->guest_offloads)
return 0;
if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))
offloads |= 1ULL << VIRTIO_NET_F_GUEST_CSUM;
return virtnet_set_guest_offloads(vi, offloads);
}