Re: [dpdk-dev] [PATCH] net/vhost: Initialise vid to -1

["Chen, Junjie J" <junjie.j.chen@intel.com>]

Hi Maxime

I saw Yuanhan already did this. Two patches already in 17.11 LTS.

Cheers
JJ

> -----Original Message-----
> From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com]
> Sent: Friday, May 4, 2018 9:09 PM
> To: Loftus, Ciara <ciara.loftus@intel.com>; dev@dpdk.org
> Cc: Chen, Junjie J <junjie.j.chen@intel.com>
> Subject: Re: [dpdk-dev] [PATCH] net/vhost: Initialise vid to -1
> 
> 
> 
> On 05/03/2018 03:18 PM, Loftus, Ciara wrote:
> >>
> >>>
> >>> On 04/27/2018 04:19 PM, Ciara Loftus wrote:
> >>>> rte_eth_vhost_get_vid_from_port_id returns a value of 0 if called
> >>>> before the first call to the new_device callback. A vid value >=0
> >>>> suggests the device is active which is not the case in this
> >>>> instance. Initialise vid to a negative value to prevent this.
> >>>>
> >>>> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
> >>>> ---
> >>>>    drivers/net/vhost/rte_eth_vhost.c | 1 +
> >>>>    1 file changed, 1 insertion(+)
> >>>>
> >>>> diff --git a/drivers/net/vhost/rte_eth_vhost.c
> >>> b/drivers/net/vhost/rte_eth_vhost.c
> >>>> index 99a7727..f47950c 100644
> >>>> --- a/drivers/net/vhost/rte_eth_vhost.c
> >>>> +++ b/drivers/net/vhost/rte_eth_vhost.c
> >>>> @@ -1051,6 +1051,7 @@ eth_rx_queue_setup(struct rte_eth_dev *dev,
> >>> uint16_t rx_queue_id,
> >>>>    		return -ENOMEM;
> >>>>    	}
> >>>>
> >>>> +	vq->vid = -1;
> >>>>    	vq->mb_pool = mb_pool;
> >>>>    	vq->virtqueue_id = rx_queue_id * VIRTIO_QNUM + VIRTIO_TXQ;
> >>>>    	dev->data->rx_queues[rx_queue_id] = vq;
> >>>>
> >>>
> >>> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> >>>
> >>> Thanks,
> >>> Maxime
> >>
> >> On second thoughts, self-NACK.
> >>
> >> We need to provision for the case where we want to call
> >> eth_rx_queue_setup AFTER new_device. For instance when we want to
> >> change the mb_pool. In this case we need to maintain the same vid and
> >> not reset it to -1.
> >>
> >> Without this patch the original problem still exists and need to find
> >> an alternative workaround.
> >
> > Junjie's patches fix the issue I was observing. Thanks Junjie!
> >
> https://dpdk.org/browse/dpdk/commit/?id=30a701a53737a0b6f7953412cc3b3
> d
> > 36c1d49122
> >
> https://dpdk.org/browse/dpdk/commit/?id=e6722dee533cda3756fbc5c9ea4dd
> f
> > bf30276f1b
> >
> > Along with the v2 of this patch could they be considered for the 17.11 stable
> branch?
> 
> Yes, I think it is a good idea.
> It wasn't planned for -stable initially as it fixed a new use-case in v18.05.
> 
> Junjie, can you please generate a backport against v17.11 and post it to
> stable@dpdk.org, adding "PATCH v17.11 LTS" as subject prefix, and using -x
> option of when cherry-picking so that it references the patches in master?
> 
> Thanks in advance,
> Maxime
> > Thanks,
> > Ciara
> >
> >>
> >> Thanks,
> >> Ciara