From: Wei Xu <address@hidden>
This patch is to support WHQL test for Windows guest, while this
feature also benifits other guest works as a kernel 'gro' like
feature with userspace implementation.
Feature information:
http://msdn.microsoft.com/en-us/library/windows/hardware/jj853324
v6->v7
- Change the drain timer from 'virtual' to 'host' since it invisible
to guest.
- Move the buffer list empty check to virtio_net_rsc_do_coalesc().
- The header comparision is a bit odd for ipv4 in this patch, it
should be simpler with equal check, but this is also a helper for ipv6
in next patch, and ipv6 used a different size address fields, so i used
an 'address + size' byte comparision for address, and change comparing
the tcp port with 'int' equal check.
- Add count for packets whose size less than a normal tcp packet in
sanity check.
- Move constant value comparison to the right side of the equal symbol.
- Use host header length in stead of guest header length to verify a
packet in virtio_net_rsc_receive(), in case of the different header
length for guest and host.
- Check whether the packet size is enough to hold a legal packet before
extract ip unit.
- Bypass ip/tcp ECN packets.
- Expand the feature bit definition from 32 to 64 bits.
Other notes:
- About tcp windows scale, we don't have connection tracking about all
tcp connections, so we don't know what the exact window size is using,
thus this feature may get negative influence to it, have to turn this
feature off for such a user case currently.
- There are 2 new fields in the virtio net header, it's not in either
kernel tree or maintainer's tree right now, I just put it directly here.
- The statistics is kept in this version since it's helpful for
troubleshooting.