On Tue, Dec 03, 2019 at 12:59:24PM +0000, Stokes, Ian wrote: > > > On 12/3/2019 12:15 PM, Ilya Maximets wrote: > > On 02.12.2019 14:44, Flavio Leitner wrote: > > > Abbreviated as TSO, TCP Segmentation Offload is a feature which enables > > > the network stack to delegate the TCP segmentation to the NIC reducing > > > the per packet CPU overhead. > > > > Hi Flavio, > > > > Thanks for working on this. > > I didn't read the code carefully, just a couple of first look points: > > > > * Patch-set needs to have 'dpdk-latest' in a subject prefix. > > > > FYI, I'm creating a patch to move to 19.11 today for master, just validating > at the moment. Will send this evening.
Great! I will rebase on top of that before push tso v2. fbl > > Ian > > > * First patch seems to be OK even without TSO, batch_clone usually > > happens on clone action that implies further packet modifications, > > so it might make sense to have a headroom for that. > > > > * Maybe we need to enable LINEARBUF for usual vhost-user too just to > > avoid receiving of mutli-segment mbufs? > > > > * Third patch is not needed. Similar patch was already merged recently. > > > > * I don't see the call to rte_eth_tx_prepare(). It is required to prepare > > packets for TSO for Intel NICs that needs pseudo-header checksum > > precalculated. > > > > * Guest is allowed to disable offloading. In this case we're not allowed > > to send incomplete packets (no-checksum, oversized), they will be just > > dropped by the guest. > > > > * NICs could not support TSO. I see that you're moving this issue to the > > user by forcing to be sure that TSO is supported. Most of HW NICs > > nowadays should support TSO, so it might be not a big deal, but > > what about some software NIC that DPDK implements? I'm not sure. > > > > * Don't include virtio headers in dp-packet code. This will break non-Linux > > builds. In fact, construction of virtio-net header is only needed for > > netdev-linux, so it should be implemented there. > > > > * netdev-afxdp and netdev-windows are not handled by the patches. > > > > * I'm not sure if we need separate tso.{c,h} files. > > > > * Docs and log messages are very confusing because they makes impression > > that > > system datapath doesn't support TSO. Also, why we cant' have TSO > > without DPDK? > > You have a virtio header for netdev-linux, so we can use it. > > > > * Is it safe to just drop virtio header on packet receive? > > > > * Not sure if it fully safe to say that checksum is valid while it's not > > calculated. Have you checked this from the ipf and conntrack points of > > view. > > > > Best regards, Ilya Maximets. > > > _______________________________________________ > dev mailing list > d...@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev -- fbl _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev