Re: [Qemu-devel] [ RFC Patch v6 0/2] Support Receive-Segment-Offload(RSC) for WHQL

[Wei Xu <wexu@redhat.com>]

On 2016年05月30日 12:22, Jason Wang wrote:
>
>
> On 2016年05月29日 00:37, wexu@redhat.com wrote:
>> From: Wei Xu <wexu@redhat.com>
>>
>> Changes in V6:
>> - Sync upstream code
>> - Split new fields in 'virtio_net_hdr' to a seperate patch
>> - Remove feature bit code, replace it with a command line parameter
>> 'guest_rsc'
>> which is turned off by default.
>>
>> Changes in V5:
>> - Passed all IPv4/6 test cases
>> - Add new fields in 'virtio_net_hdr'
>> - Set 'gso_type' & 'coalesced packets' in new field.
>> - Bypass all 'tcp option' packet
>> - Bypass all 'pure ack' packet
>> - Bypass all 'duplicate ack' packet
>> - Change 'guest_rsc' feature bit to 'false' by default
>> - Feedbacks from v4, typo, etc.
>
> Change-log is very important for the ease and speed up reviewers. More
> details are more than welcomed. But I see some changes were not
> documented here. Please give a more complete one in next iteration.
OK.
>
>>
>> Note:
>> There is still a few pending issues about the feature bit, and need to be
>> discussed with windows driver maintainer, so linux guests with this patch
>> won't work at current, haven't figure it out yet, but i'm guessing it's
>> caused by the 'gso_type' is set to 'VIRTIO_NET_HDR_GSO_TCPV4/6',
>> will fix it after get the final solution, the below test steps and
>> performance data is based on v4.
>
> This is probably because you've increased the vnet header length.
>
>>
>> Another suggestion from Jason is to adjust part of the code to make it
>> more readable, since there maybe still few change about the flowchart
>> in the future, such as timestamp, duplicate ack, so i'd like to delay it
>> temporarily.
>>
>> Changes in V4:
>> - Add new host feature bit
>> - Replace using fixed header lenght with dynamic header lenght in
>> VirtIONet
>> - Change ip/ip6 header union in NetRscUnit to void* pointer
>> - Add macro prefix, adjust code indent, etc.
>>
>> Changes in V3:
>> - Removed big param list, replace it with 'NetRscUnit'
>> - Different virtio header size
>> - Modify callback function to direct call.
>> - Needn't check the failure of g_malloc()
>> - Other code format adjustment, macro naming, etc
>>
>> Changes in V2:
>> - Add detailed commit log
>>
>> 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
>>
>> Both IPv4 and IPv6 are supported, though performance with userspace
>> virtio
>> is slow than vhost-net, there is about 1.5x to 2x performance
>> improvement to
>> userspace virtio, this is done by turning this feature on and disable
>> 'tso/gso/gro' on corresponding tap interface and guest interface,
>> while get
>> less improment with all these feature on.
>>
>> Linux guest performance data(Netperf):
>> MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to
>> 192.168.2.101 () port 0 AF_INET : nodelay
>> Size   Size    Size     Time     Throughput
>> bytes  bytes   bytes    secs.    10^6bits/sec
>>
>>   87380  16384     64    6.00     1221.20
>>   87380  16384     64    6.00     1260.30
>>
>>   87380  16384    128    6.00     1978.51
>>   87380  16384    128    6.00     2286.05
>>
>>   87380  16384    256    6.00     2677.94
>>   87380  16384    256    6.00     4615.42
>>
>>   87380  16384    512    6.00     2956.54
>>   87380  16384    512    6.00     5356.39
>>
>>   87380  16384   1024    6.00     2798.17
>>   87380  16384   1024    6.00     4943.30
>>
>>   87380  16384   2048    6.00     2681.09
>>   87380  16384   2048    6.00     4835.81
>>
>>   87380  16384   4096    6.00     3390.14
>>   87380  16384   4096    6.00     5391.54
>>
>>   87380  16384   8092    6.00     3008.27
>>   87380  16384   8092    6.00     5381.68
>>
>>   87380  16384  10240    6.00     2999.89
>>   87380  16384  10240    6.00     5393.11
>>
>> Test steps:
>> Although this feature is mainly used for window guest, i used linux
>> guest to
>> help test the feature, to make things simple, i used 3 steps to test
>> the patch
>> as i moved on.
>>
>> 1. With a tcp socket client/server pair running on 2 linux guest, thus
>> i can
>> control
>> the traffic and debugging the code as i want.
>> 2. Netperf on linux guest test the throughput.
>> 3. WHQL test with 2 Windows guests.
>>
>> Wei Xu (3):
>>    virtio-net rsc: support coalescing ipv4 tcp traffic
>>    virtio-net rsc: support coalescing ipv6 tcp traffic
>>    virtio-net rsc: add 2 new rsc information fields to 'virtio_net_hdr'
>>
>>   hw/net/virtio-net.c                         | 642
>> +++++++++++++++++++++++++++-
>>   include/hw/virtio/virtio-net.h              |   2 +
>>   include/hw/virtio/virtio.h                  |  75 ++++
>>   include/standard-headers/linux/virtio_net.h |   3 +
>>   4 files changed, 721 insertions(+), 1 deletion(-)
>>
>