Re: [dpdk-dev] [PATCH 7/7] vhost: simplify features set/get

["Xu, Qian Q" <qian.q.xu@intel.com>]

-----Original Message-----
From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Maxime Coquelin
Sent: Thursday, August 25, 2016 3:19 PM
To: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH 7/7] vhost: simplify features set/get



On 08/25/2016 05:03 AM, Yuanhan Liu wrote:
> On Wed, Aug 24, 2016 at 10:11:57AM +0200, Maxime Coquelin wrote:
>>
>>
>> On 08/18/2016 10:48 AM, Yuanhan Liu wrote:
>>> No need to use a pointer to store/retrieve features.
>>>
>>> Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
>>> ---
>>> lib/librte_vhost/vhost_user.c | 20 ++++++++------------
>>> 1 file changed, 8 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/lib/librte_vhost/vhost_user.c 
>>> b/lib/librte_vhost/vhost_user.c index ef4a0c1..eee99e9 100644
>>> --- a/lib/librte_vhost/vhost_user.c
>>> +++ b/lib/librte_vhost/vhost_user.c
>>> @@ -155,23 +155,22 @@ vhost_user_reset_owner(struct virtio_net *dev)
>>> /*
>>>  * The features that we support are requested.
>>>  */
>>> -static int
>>> -vhost_user_get_features(uint64_t *pu)
>>> +static uint64_t
>>> +vhost_user_get_features(void)
>>> {
>>> -	*pu = VHOST_FEATURES;
>>> -	return 0;
>>> +	return VHOST_FEATURES;
>>> }
>>
>> This is not the topic of this series, but I wonder if it could make 
>> sense to be able to override supported features at device init time.
>
> Not quite sure I understood it correctly: is 
> rte_vhost_feature_disable() the answer you are looking for?
Not really.

I meant a per-device supported features, and something you could set also via the vhost PMD options, without needing to recompile.

But maybe it would make more sense to do it a guest level?

Maxime

-------Agreed, as you know we have the vhost PMD port and virtio-user PMD port and we can launch both vhost/virtio on the host, but we 
Can't set the mergeable in the command line, we may need add some feature settings for virtio-user interface. It will be much easier to 
Run tests or application. 

Qian