[PATCH v3 7/8] vhost: vDPA blk device gets ready when any queue is ready

[Xia, Chenbo]

> -----Original Message-----
> From: Pei, Andy <andy.pei at intel.com>
> Sent: Wednesday, October 12, 2022 8:13 PM
> To: Xia, Chenbo <chenbo.xia at intel.com>; dev at dpdk.org
> Cc: Xu, Rosen <rosen.xu at intel.com>; Huang, Wei <wei.huang at intel.com>; Cao,
> Gang <gang.cao at intel.com>; maxime.coquelin at redhat.com
> Subject: RE: [PATCH v3 7/8] vhost: vDPA blk device gets ready when any
> queue is ready
> 
> Hi Chenbo,
> 
> Thanks for your reply.
> My reply is inline.
> 
> > -----Original Message-----
> > From: Xia, Chenbo <chenbo.xia at intel.com>
> > Sent: Wednesday, October 12, 2022 5:09 PM
> > To: Pei, Andy <andy.pei at intel.com>; dev at dpdk.org
> > Cc: Xu, Rosen <rosen.xu at intel.com>; Huang, Wei <wei.huang at intel.com>;
> > Cao, Gang <gang.cao at intel.com>; maxime.coquelin at redhat.com
> > Subject: RE: [PATCH v3 7/8] vhost: vDPA blk device gets ready when any
> > queue is ready
> >
> > > -----Original Message-----
> > > From: Pei, Andy <andy.pei at intel.com>
> > > Sent: Friday, September 16, 2022 2:16 PM
> > > To: dev at dpdk.org
> > > Cc: Xia, Chenbo <chenbo.xia at intel.com>; Xu, Rosen
> > > <rosen.xu at intel.com>; Huang, Wei <wei.huang at intel.com>; Cao, Gang
> > > <gang.cao at intel.com>; maxime.coquelin at redhat.com
> > > Subject: [PATCH v3 7/8] vhost: vDPA blk device gets ready when any
> > > queue is ready
> > >
> > > When boot from virtio blk device, seabios in QEMU only enables one
> queue.
> > > To work in this scenario, vDPA BLK device back-end conf_dev when any
> >
> > What is conf_dev?
> >
> I refer to
> 	/** Driver configure the device (Mandatory) */
> 	int (*dev_conf)(int vid);
> So do you think I should use "configure device"?

Yes. It will be better

> 
> > > queue is ready.
> > >
> > > Signed-off-by: Andy Pei <andy.pei at intel.com>
> > > Signed-off-by: Huang Wei <wei.huang at intel.com>
> > > ---
> > >  lib/vhost/vhost_user.c | 51
> > > ++++++++++++++++++++++++++++++++-------------
> > > -----
> > >  1 file changed, 33 insertions(+), 18 deletions(-)
> > >
> > > diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c index
> > > 4ad28ba..9169cf5 100644
> > > --- a/lib/vhost/vhost_user.c
> > > +++ b/lib/vhost/vhost_user.c
> > > @@ -1449,9 +1449,10 @@
> > >  }
> > >
> > >  #define VIRTIO_BUILTIN_NUM_VQS_TO_BE_READY 2u
> > > +#define VIRTIO_BLK_NUM_VQS_TO_BE_READY 1u
> > >
> > >  static int
> > > -virtio_is_ready(struct virtio_net *dev)
> > > +virtio_is_ready(struct virtio_net *dev, uint32_t vdpa_type)
> > >  {
> > >  	struct vhost_virtqueue *vq;
> > >  	uint32_t i, nr_vring = dev->nr_vring; @@ -1462,13 +1463,20 @@
> > >  	if (!dev->nr_vring)
> > >  		return 0;
> > >
> > > -	if (dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET) {
> > > -		nr_vring = VIRTIO_BUILTIN_NUM_VQS_TO_BE_READY;
> > > -
> > > -		if (dev->nr_vring < nr_vring)
> > > -			return 0;
> > > +	if (vdpa_type == RTE_VHOST_VDPA_DEVICE_TYPE_NET) {
> > > +		if (dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET)
> > > +			nr_vring =
> > VIRTIO_BUILTIN_NUM_VQS_TO_BE_READY;
> > > +	} else {
> > > +		/*
> > > +		 * vdpa_type == RTE_VHOST_VDPA_DEVICE_TYPE_BLK
> > > +		 * is the only case currently
> > > +		 */
> > > +		nr_vring = VIRTIO_BLK_NUM_VQS_TO_BE_READY;
> >
> > You should consider the case when vdpa device is not there. Maybe you
> can
> > use int for vdpa_type, -1 for non-vdpa.
> >
> I init vdpa_type to 0;
> #define RTE_VHOST_VDPA_DEVICE_TYPE_NET 0
> #define RTE_VHOST_VDPA_DEVICE_TYPE_BLK 1
> And get_dev_type only return RTE_VHOST_VDPA_DEVICE_TYPE_BLK or
> RTE_VHOST_VDPA_DEVICE_TYPE_NET.
> I think if when vdpa device is not there, this code runs in the original
> way.
> Do you think use init vdpa_type to -1 is better?

I was talking about readability, current way will be confusing. So adding
-1 will be better. The check could be if (type == blk) ... else ... as
Type 0/-1 has the same handling.

Thanks,
Chenbo

> 
> 
> > Also note that below check is only needed for some cases.
> >
> Yes, I got it. I will fix it in next version.
> > Thanks,
> > Chenbo
> >
> > >  	}
> > >
> > > +	if (dev->nr_vring < nr_vring)
> > > +		return 0;
> > > +
> > >  	for (i = 0; i < nr_vring; i++) {
> > >  		vq = dev->virtqueue[i];
> > >
> > > @@ -3167,7 +3175,25 @@ static int is_vring_iotlb(struct virtio_net
> *dev,
> > >  	if (unlock_required)
> > >  		vhost_user_unlock_all_queue_pairs(dev);
> > >
> > > -	if (ret != 0 || !virtio_is_ready(dev))
> > > +	if (ret != 0)
> > > +		goto out;
> > > +
> > > +	vdpa_dev = dev->vdpa_dev;
> > > +	if (vdpa_dev) {
> > > +		if (vdpa_dev->ops->get_dev_type) {
> > > +			ret = vdpa_dev->ops->get_dev_type(vdpa_dev,
> > &vdpa_type);
> > > +			if (ret) {
> > > +				VHOST_LOG_CONFIG(dev->ifname, ERR,
> > > +					"failed to get vdpa dev type.\n");
> > > +				ret = -1;
> > > +				goto out;
> > > +			}
> > > +		} else {
> > > +			vdpa_type = RTE_VHOST_VDPA_DEVICE_TYPE_NET;
> > > +		}
> > > +	}
> > > +
> > > +	if (!virtio_is_ready(dev, vdpa_type))
> > >  		goto out;
> > >
> > >  	/*
> > > @@ -3181,20 +3207,9 @@ static int is_vring_iotlb(struct virtio_net
> *dev,
> > >  			dev->flags |= VIRTIO_DEV_RUNNING;
> > >  	}
> > >
> > > -	vdpa_dev = dev->vdpa_dev;
> > >  	if (!vdpa_dev)
> > >  		goto out;
> > >
> > > -	if (vdpa_dev->ops->get_dev_type) {
> > > -		ret = vdpa_dev->ops->get_dev_type(vdpa_dev, &vdpa_type);
> > > -		if (ret) {
> > > -			VHOST_LOG_CONFIG(dev->ifname, ERR, "failed to
> > get vdpa
> > > dev type.\n");
> > > -			ret = -1;
> > > -			goto out;
> > > -		}
> > > -	} else {
> > > -		vdpa_type = RTE_VHOST_VDPA_DEVICE_TYPE_NET;
> > > -	}
> > >  	if (vdpa_type == RTE_VHOST_VDPA_DEVICE_TYPE_BLK
> > >  		&& request != VHOST_USER_SET_VRING_CALL)
> > >  		goto out;
> > > --
> > > 1.8.3.1