Re: [PATCH v2 09/13] vdpa net: block migration if the device has CVQ

[Jason Wang]

在 2023/2/22 15:28, Eugenio Perez Martin 写道:
On Wed, Feb 22, 2023 at 5:01 AM Jason Wang <jasow...@redhat.com> wrote:

在 2023/2/8 17:42, Eugenio Pérez 写道:
Devices with CVQ needs to migrate state beyond vq state.  Leaving this
to future series.

I may miss something but what is missed to support CVQ/MQ?

To restore all the device state set by CVQ in the migration source
(MAC, MQ, ...) before data vqs start. We don't have a reliable way to
not start data vqs until the device [1].

Thanks!

[1] https://lists.gnu.org/archive/html/qemu-devel/2023-01/msg02652.html


Right. It might be mention this defect in either the change log or 
somewhere in the code as a comment.

(Btw, I think we should fix those vDPA drivers).

Thanks



Thanks


Signed-off-by: Eugenio Pérez <epere...@redhat.com>
---
   net/vhost-vdpa.c | 6 ++++++
   1 file changed, 6 insertions(+)

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index bca13f97fd..309861e56c 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -955,11 +955,17 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char 
*name,
       }

       if (has_cvq) {
+        VhostVDPAState *s;
+
           nc = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name,
                                    vdpa_device_fd, i, 1, false,
                                    opts->x_svq, iova_range);
           if (!nc)
               goto err;
+
+        s = DO_UPCAST(VhostVDPAState, nc, nc);
+        error_setg(&s->vhost_vdpa.dev->migration_blocker,
+                   "net vdpa cannot migrate with MQ feature");
       }

       return 0;