On Mon, Jan 26, 2015 at 09:37:03AM -0500, Vladislav Yasevich wrote: > commit 3d0ad09412ffe00c9afa201d01effdb6023d09b4 > Author: Ben Hutchings <ben@xxxxxxxxxxxxxxx> > Date: Thu Oct 30 18:27:12 2014 +0000 > > drivers/net: Disable UFO through virtio > > Turned off UFO support to virtio-net based devices due to issues > with IPv6 fragment id generation for UFO packets. The issue > was that IPv6 UFO/GSO implementation expects the fragment id > to be supplied in skb_shinfo(). However, for packets generated > by the VMs, the fragment id is not supplied which causes all > IPv6 fragments to have the id of 0. > > The problem is that turning off UFO support on tap/macvtap > as well as virtio devices caused issues with migrations. > Migrations would fail when moving a vm from a kernel supporting > expecting UFO to work to the newer kernels that disabled UFO. > > This series provides a partial solution to address the migration > issue. The series reserves a bit in the skb and sets the bit > with the ipv6 fragment id has been generated for the packet. > UFO/GSO code then checks the bit to see if the fragment id > is already present or if a new fragment id needs to be generated. > This solution allows host-originated UFO packets to keep a > better randomized fragment id, as well as generating a randomized > id for VM generated traffic (solving the fragment id 0 issue). > > Vladislav Yasevich (3): > ipv6: Select fragment id during UFO/GSO segmentation if not set. > Revert "drivers/net, ipv6: Select IPv6 fragment idents for virtio UFO > packets" > Revert "drivers/net: Disable UFO through virtio" > > drivers/net/macvtap.c | 16 ++++++++-------- > drivers/net/tun.c | 25 +++++++++---------------- > drivers/net/virtio_net.c | 24 ++++++++++-------------- > include/linux/skbuff.h | 3 ++- > include/net/ipv6.h | 2 ++ > net/ipv6/ip6_output.c | 4 ++-- > net/ipv6/output_core.c | 9 ++++++++- > net/ipv6/udp_offload.c | 10 +++++++++- > 8 files changed, 50 insertions(+), 43 deletions(-) Should also help a lot to put UDP performance where it was. Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > -- > 1.9.3 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
