From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tetsuya Mukawa <mukawa@igel.co.jp>
Subject: Re: [RFC PATCH v2] vhost: Add VHOST PMD
Date: Mon, 19 Oct 2015 10:51:00 +0900
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To: Bruce Richardson <bruce.richardson@intel.com>
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On 2015/10/16 21:52, Bruce Richardson wrote:
> On Mon, Aug 31, 2015 at 12:55:26PM +0900, Tetsuya Mukawa wrote:
>> The patch introduces a new PMD. This PMD is implemented as thin wrapper
>> of librte_vhost. It means librte_vhost is also needed to compile the PMD.
>> The PMD can have 'iface' parameter like below to specify a path to connect
>> to a virtio-net device.
>>
>> $ ./testpmd -c f -n 4 --vdev 'eth_vhost0,iface=/tmp/sock0' -- -i
>>
>> To connect above testpmd, here is qemu command example.
>>
>> $ qemu-system-x86_64 \
>>         <snip>
>>         -chardev socket,id=chr0,path=/tmp/sock0 \
>>         -netdev vhost-user,id=net0,chardev=chr0,vhostforce \
>>         -device virtio-net-pci,netdev=net0
>>
>> Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
> With this PMD in place, is there any need to keep the existing vhost library
> around as a separate entity? Can the existing library be subsumed/converted into
> a standard PMD?
>
> /Bruce

Hi Bruce,

I concern about whether the PMD has all features of librte_vhost,
because librte_vhost provides more features and freedom than ethdev API
provides.
In some cases, user needs to choose limited implementation without
librte_vhost.
I am going to eliminate such cases while implementing the PMD.
But I don't have strong belief that we can remove librte_vhost now.

So how about keeping current separation in next DPDK?
I guess people will try to replace librte_vhost to vhost PMD, because
apparently using ethdev APIs will be useful in many cases.
And we will get feedbacks like "vhost PMD needs to support like this usage".
(Or we will not have feedbacks, but it's also OK.)
Then, we will be able to merge librte_vhost and vhost PMD.

Thanks,
Tetsuya