Re: [PATCH v2] net/colo: check vnet_hdr_support flag when using virtio-net

[Eric Blake]

On Thu, Aug 19, 2021 at 09:27:17AM +0800, Tao Xu wrote:
> When COLO use only one vnet_hdr_support parameter between
> COLO network filter(filter-mirror, filter-redirector or
> filter-rewriter and colo-compare, packet will not be parsed
> correctly. Acquire network driver related to COLO, if it is
> nirtio-net, check vnet_hdr_support flag of COLO network filter
> and colo-compare.
> 
> Signed-off-by: Tao Xu <tao3.xu@intel.com>
> Signed-off-by: Zhang Chen <chen.zhang@intel.com>
> ---

> +++ b/qapi/qom.json
> @@ -241,6 +241,11 @@
>  # @notify_dev: name of the character device backend to be used to communicate
>  #              with the remote colo-frame (only for Xen COLO)
>  #
> +# @netdev: id of the network device backend to colo-compare, although
> +#          colo-compare doesn't depend on network device directly, this
> +#          parameter help colo-compare know what network driver it is
> +#          working on

Missing a '(since 6.2)' tag.

Grammar suggestion: s/colo-compare, although/colo-compare. Although/
s/help/helps/



> +#
>  # @compare_timeout: the maximum time to hold a packet from @primary_in for
>  #                   comparison with an incoming packet on @secondary_in in
>  #                   milliseconds (default: 3000)
> @@ -264,6 +269,7 @@
>              'outdev': 'str',
>              'iothread': 'str',
>              '*notify_dev': 'str',
> +            '*netdev': 'str',
>              '*compare_timeout': 'uint64',
>              '*expired_scan_cycle': 'uint32',
>              '*max_queue_size': 'uint32',
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 83aa59a920..b31ce3c87d 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -4957,12 +4957,14 @@ SRST
>          stored. The file format is libpcap, so it can be analyzed with
>          tools such as tcpdump or Wireshark.
>  
> -    ``-object 
> colo-compare,id=id,primary_in=chardevid,secondary_in=chardevid,outdev=chardevid,iothread=id[,vnet_hdr_support][,notify_dev=id][,compare_timeout=@var{ms}][,expired_scan_cycle=@var{ms}][,max_queue_size=@var{size}]``
> +    ``-object 
> colo-compare,id=id,primary_in=chardevid,secondary_in=chardevid,outdev=chardevid,iothread=id[,netdev=netdevid][,vnet_hdr_support][,notify_dev=id][,compare_timeout=@var{ms}][,expired_scan_cycle=@var{ms}][,max_queue_size=@var{size}]``
>          Colo-compare gets packet from primary\_in chardevid and
>          secondary\_in, then compare whether the payload of primary packet
>          and secondary packet are the same. If same, it will output
>          primary packet to out\_dev, else it will notify COLO-framework to do
> -        checkpoint and send primary packet to out\_dev. In order to
> +        checkpoint and send primary packet to out\_dev. Although colo-compare
> +        does not depend on network device directly, netdevid help

s/help/helps/

> +        colo-compare know what network driver it is working on. In order to
>          improve efficiency, we need to put the task of comparison in
>          another iothread. If it has the vnet\_hdr\_support flag,
>          colo compare will send/recv packet with vnet\_hdr\_len.
> -- 
> 2.25.1
> 
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org