> -----Original Message-----
> From: Pei, Andy <andy....@intel.com>
> Sent: Thursday, October 13, 2022 3:56 PM
> To: Xia, Chenbo <chenbo....@intel.com>; dev@dpdk.org
> Cc: Xu, Rosen <rosen...@intel.com>; Huang, Wei <wei.hu...@intel.com>;
> Cao, Gang <gang....@intel.com>; maxime.coque...@redhat.com
> Subject: RE: [PATCH v3 8/8] vhost: improve vDPA blk device readiness
> condition
>
> Hi Chenbo,
>
> Thanks for your reply, my reply is inline.
>
> > -----Original Message-----
> > From: Xia, Chenbo <chenbo....@intel.com>
> > Sent: Wednesday, October 12, 2022 5:36 PM
> > To: Pei, Andy <andy....@intel.com>; dev@dpdk.org
> > Cc: Xu, Rosen <rosen...@intel.com>; Huang, Wei <wei.hu...@intel.com>;
> > Cao, Gang <gang....@intel.com>; maxime.coque...@redhat.com
> > Subject: RE: [PATCH v3 8/8] vhost: improve vDPA blk device readiness
> > condition
> >
> > > -----Original Message-----
> > > From: Pei, Andy <andy....@intel.com>
> > > Sent: Friday, September 16, 2022 2:17 PM
> > > To: dev@dpdk.org
> > > Cc: Xia, Chenbo <chenbo....@intel.com>; Xu, Rosen
> > > <rosen...@intel.com>; Huang, Wei <wei.hu...@intel.com>; Cao, Gang
> > > <gang....@intel.com>; maxime.coque...@redhat.com
> > > Subject: [PATCH v3 8/8] vhost: improve vDPA blk device readiness
> > > condition
> > >
> > > In the virtio blk vDPA live migration use case, for the target VM,
> > > before the live migration process, QEMU will set call fd to all
> > > queues of vDPA back-end. QEMU and vDPA back-end stand by until live
> > > migration starts. During live migration process, QEMU sets kick fd
> > > and new call fd. However, after the kick fd is set to the vDPA
> > > back-end, the vDPA back-end configures device and data path starts.
> > > The new call fd will cause some kind of "re-configuration", this kind of
> "re-configuration"
> > > cause IO drop.
> > > After this patch, vDPA back-end configures device after kick fd and
> > > call fd are well set and make sure no IO drops.
> > > This patch only impact virtio blk vDPA device and does not impact
> > > net device.
> >
> > IIUC, this is an improvement for MQ to make sure all call fds are
> > well-set, but previously it only makes sure one is well-set. If I am
> > right, the title and commit message should describe it in better way.
> >
> > Thanks,
> > Chenbo
> >
> In the virtio blk vDPA live migration use case, for the target VM, before the
> live migration process, QEMU will set call fd to all queues of vDPA back-end.
> QEMU and vDPA back-end stand by until live migration starts.
> During live migration process, QEMU sets kick fd to all queues one by one,
> and new call fd all queues one by one.
> However, after the kick fd is set to the vDPA back-end, with the original
> call fd,
> the queue is ready.
> Then the vDPA back-end configures device and data path starts.
> The new call fd will cause some kind of "re-configuration", this kind of "re-
> configuration" cause IO drop.
> After this patch, vDPA back-end configures device after kick fd and call fd
> are
> well set and make sure no IO drops.
> This patch only impact virtio blk vDPA device and does not impact net device.
>
> Is this new commit message good?
Explanation seems duplicate with former commit
" vhost: fix virtio block vDPA live migration IO drop".
So I will make it simple here,
"To support multi-queue, configure device after call fd of all queues are set."
I will use " vhost: improve vDPA blk device configure condition" for title
To reduce confusion.
> > >
> > > Signed-off-by: Andy Pei <andy....@intel.com>
> > > Signed-off-by: Huang Wei <wei.hu...@intel.com>
> > > ---
> > > lib/vhost/vhost_user.c | 13 ++++++++++---
> > > 1 file changed, 10 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c index
> > > 9169cf5..14ff266 100644
> > > --- a/lib/vhost/vhost_user.c
> > > +++ b/lib/vhost/vhost_user.c
> > > @@ -2983,6 +2983,7 @@ static int is_vring_iotlb(struct virtio_net *dev,
> > > uint32_t vdpa_type = 0;
> > > uint32_t request;
> > > uint32_t i;
> > > + uint16_t blk_call_fd;
> > >
> > > dev = get_device(vid);
> > > if (dev == NULL)
> > > @@ -3210,9 +3211,15 @@ static int is_vring_iotlb(struct virtio_net *dev,
> > > if (!vdpa_dev)
> > > goto out;
> > >
> > > - if (vdpa_type == RTE_VHOST_VDPA_DEVICE_TYPE_BLK
> > > - && request != VHOST_USER_SET_VRING_CALL)
> > > - goto out;
> > > + if (vdpa_type == RTE_VHOST_VDPA_DEVICE_TYPE_BLK) {
> > > + if (request == VHOST_USER_SET_VRING_CALL) {
> > > + blk_call_fd = ctx.msg.payload.u64 &
> > > VHOST_USER_VRING_IDX_MASK;
> > > + if (blk_call_fd != dev->nr_vring - 1)
> > > + goto out;
> > > + } else {
> > > + goto out;
> > > + }
> > > + }
> > >
> > > if (!(dev->flags & VIRTIO_DEV_VDPA_CONFIGURED)) {
> > > if (vdpa_dev->ops->dev_conf(dev->vid))
> > > --
> > > 1.8.3.1
