Re: [Qemu-devel] [ RFC Patch v7 0/2] Support Receive-Segment-Offload(RSC) for WHQL

[Wei Xu <wexu@redhat.com>]

On 2016年11月24日 12:28, Jason Wang wrote:
>
>
> On 2016年11月01日 01:41, wexu@redhat.com wrote:
>> From: Wei Xu <wexu@redhat.com>
>>
>> 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.
>
> Please do not adding more and more stuffs in the same patch. Instead,
> you can add them by using new patches on top. This can greatly simplify
> the reviewers' work. E.g in this version, it looks like the parts of
> virtio extension brings lots of troubles. So I suggest to split the
> patch into several parts:
>
> - helpers (e.g macro for ECN bit)
> - core coalescing logic which has been reviewed for several version,
> please do not add more functions to this part. This part could be even
> disabled in the code until virtio part is introduced.
> - virtio extension (e.g virtio-net header extension and feature bits)
> - stats

OK, get split it in next version.

>
> Thanks