On Thu, Feb 13, 2020 at 01:42:32PM +0100, Ilya Maximets wrote: > On 2/13/20 12:30 PM, Flavio Leitner wrote: > > On Thu, Feb 13, 2020 at 11:10:15AM +0100, Ilya Maximets wrote: > >> On 2/13/20 12:44 AM, Flavio Leitner wrote: > >>> On Wed, Feb 12, 2020 at 04:31:09PM -0300, Flavio Leitner wrote: > >>>> On Wed, Feb 12, 2020 at 04:26:46PM +0100, Ilya Maximets wrote: > >>>>> On 2/10/20 8:18 PM, Flavio Leitner wrote: > >>>>>> Disable ECN and UFO since this is not supported yet. Also, disable > >>>>>> all other features when userspace_tso is not enabled. > >>>>> > >>>>> Disabling UFO saves us from receiving of a big unfragmented > >>>>> UDP packets, but UDP packets will still have bad checksums > >>>>> and will be dropped by the kernel on receive side. > >>>>> So, this is only part of a fix. > >>>> > >>>> Yes, this patch is not intended to fix the UDP checksum problem. > >>>> Unless you see a way to do that with changing the flags below. > >>> > >>> BTW, why do you think there is a problem with UDP checksum? > >>> We set VIRTIO_NET_HDR_F_NEEDS_CSUM which should be all it is needed. > >> > >> At least we're sending UDP packets on a wire without > >> requesting Tx UDP checksum offloading from HW NICs. > > > > Packets from virtual machines relies on DPDK vhost library, and as > > far as I can see, it does set PKT_TX_UDP_CKSUM properly. > > vhost library will properly set flags, however, OVS doesn't care > about this case, e.g. we're not enabling DEV_TX_OFFLOAD_UDP_CKSUM > while configuring physical devices. Even though most of the DPDK > drivers will enable UDP checksum offload support regardless of this > flag, this is still a logical error and we can't rely on this > behavior.
Ah, now I see what you're saying. I think we can support UDP csum, so will post another separate patch fixing it. Thanks, -- fbl _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
