On Fri, Mar 25, 2016 at 02:01:32PM +0800, Yuanhan Liu wrote:
> Commit d0cf91303d73 ("vhost: add Tx offload capabilities") has only
> done partial settings for enabling TSO, and left the following part
> to the application, say vhost-switch example, by commit 9fd72e3cbd29
> ("examples/vhost: add virtio offload").
>
> - Setting PKT_TX_IP_CKSUM and ipv4_hdr->hdr_checksum = 0 for IPv4.
>
> - calculate the pseudo header checksum without taking ip_len in
> account, and set it in the TCP header
>
> Here we complete the left part in vhost side, so that an user (such
> as OVS) can do minimal (or even no) changes to get TSO enabled.
>
> Signed-off-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>
...
> + ipv4_hdr->hdr_checksum = 0;
Nah.. we can't do that here. This hurts VM2VM case badly.
Thanks Qian for letting me be aware of it.
--yliu
