Re: [PATCH v4 00/17] Wind River Systems AVP PMD vs virtio? - ivshmem is back

From: "Wiles, Keith" <keith.wiles@intel.com>
To: Vincent JARDIN <vincent.jardin@6wind.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>,
	"O'Driscoll, Tim" <tim.odriscoll@intel.com>,
	"Legacy, Allain (Wind River)" <allain.legacy@windriver.com>,
	"Yigit, Ferruh" <ferruh.yigit@intel.com>,
	"dev@dpdk.org" <dev@dpdk.org>,
	"Jolliffe, Ian (Wind River)" <ian.jolliffe@windriver.com>,
	"Richardson, Bruce" <bruce.richardson@intel.com>,
	"Mcnamara, John" <john.mcnamara@intel.com>,
	"thomas.monjalon@6wind.com" <thomas.monjalon@6wind.com>,
	"jerin.jacob@caviumnetworks.com" <jerin.jacob@caviumnetworks.com>,
	"3chas3@gmail.com" <3chas3@gmail.com>,
	"stefanha@gmail.com" <stefanha@gmail.com>,
	Markus Armbruster <armbru@redhat.com>
Subject: Re: [PATCH v4 00/17] Wind River Systems AVP PMD vs virtio? - ivshmem is back
Date: Fri, 17 Mar 2017 00:11:10 +0000	[thread overview]
Message-ID: <D95C149C-9811-45B9-B6D6-A1C6D6AE8A63@intel.com> (raw)
In-Reply-To: <73cdfe30-ed3b-6dd6-a2d8-fc2873fb65f3@6wind.com>

> On Mar 17, 2017, at 7:41 AM, Vincent JARDIN <vincent.jardin@6wind.com> wrote:
> 
> Let's be back to 2014 with Qemu's thoughts on it,
> +Stefan
> https://lists.linuxfoundation.org/pipermail/virtualization/2014-June/026767.html
> 
> and
> +Markus
> https://lists.linuxfoundation.org/pipermail/virtualization/2014-June/026713.html
> 
>> 6. Device models belong into QEMU
>> 
>>   Say you build an actual interface on top of ivshmem.  Then ivshmem in
>>   QEMU together with the supporting host code outside QEMU (see 3.) and
>>   the lower layer of the code using it in guests (kernel + user space)
>>   provide something that to me very much looks like a device model.
>> 
>>   Device models belong into QEMU.  It's what QEMU does.
> 
> 
> Le 17/03/2017 à 00:17, Stephen Hemminger a écrit :
>> On Wed, 15 Mar 2017 04:10:56 +0000
>> "O'Driscoll, Tim" <tim.odriscoll@intel.com> wrote:
>> 
>>> I've included a couple of specific comments inline below, and a general comment here.
>>> 
>>> We have somebody proposing to add a new driver to DPDK. It's standalone and doesn't affect any of the core libraries. They're willing to maintain the driver and have included a patch to update the maintainers file. They've also included the relevant documentation changes. I haven't seen any negative comment on the patches themselves except for a request from John McNamara for an update to the Release Notes that was addressed in a later version. I think we should be welcoming this into DPDK rather than questioning/rejecting it.
>>> 
>>> I'd suggest that this is a good topic for the next Tech Board meeting.
>> 
>> This is a virtualization driver for supporting DPDK on platform that provides an alternative
>> virtual network driver. I see no reason it shouldn't be part of DPDK. Given the unstable
>> ABI for drivers, supporting out of tree DPDK drivers is difficult. The DPDK should try
>> to be inclusive and support as many environments as possible.
>> 
> 
> On Qemu mailing list, back to 2014, I did push to build models of devices over ivshmem, like AVP, but folks did not want that we abuse of it. The Qemu community wants that we avoid unfocusing. So, by being too much inclusive, we abuse of the Qemu's capabilities.
> 
> So, because of being "inclusive", we should allow any cases, it is not a proper way to make sure that virtio gets all the focuses it deserves.
> 
> 

Why are we bring QEMU in to the picture it does not make a lot of sense to me. Stephen stated it well above and I hope my comments were stating the same conclusion. I do not see your real reasons for not allowing this driver into DPDK, it seems like some other hidden agenda is at play here, but I am a paranoid person :-)

Regards,
Keith