Re: [dpdk-dev] [PATCH v2 4/4] vhost: fix offload flags in Rx path

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 4/29/21 10:04 AM, David Marchand wrote:
> The vhost library current configures Tx offloading (PKT_TX_*) on any

s/current/currently/

> packet received from a guest virtio device which asks for some offloading.
> 
> This is problematic, as Tx offloading is something that the application
> must ask for: the application needs to configure devices
> to support every used offloads (ip, tcp checksumming, tso..), and the
> various l2/l3/l4 lengths must be set following any processing that
> happened in the application itself.
> 
> On the other hand, the received packets are not marked wrt current
> packet l3/l4 checksumming info.
> 
> Copy virtio rx processing to fix those offload flags but accepting
> VIRTIO_NET_HDR_GSO_ECN and VIRTIO_NET_HDR_GSO_UDP too.
> 
> The vhost example has been updated accordingly: TSO is applied to any
> packet marked LRO.
> 
> Fixes: 859b480d5afd ("vhost: add guest offload setting")
> 
> Signed-off-by: David Marchand <david.marchand@redhat.com>
> ---
> Changes since v1:
> - updated vhost example,
> - restored VIRTIO_NET_HDR_GSO_ECN and VIRTIO_NET_HDR_GSO_UDP support,
> - restored log on buggy offload request,
> 
> ---
>  examples/vhost/main.c  |  42 +++++++------
>  lib/vhost/virtio_net.c | 139 +++++++++++++++++------------------------
>  2 files changed, 78 insertions(+), 103 deletions(-)

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>