diff options
| author | Kevin Wolf <kwolf@redhat.com> | 2024-03-15 16:59:49 +0100 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2024-03-26 14:21:26 +0100 |
| commit | 2c66de61f88dc9620a32239f7dd61524a57f66b0 (patch) | |
| tree | 9afc1c2f0dd6031b29b3d814cf5f6e7e81f8ced1 /hw/net | |
| parent | d9e4070603b9727a8c33d9aa7d2aacf5eed0c0f7 (diff) | |
vdpa-dev: Fix initialisation order to restore VDUSE compatibility
VDUSE requires that virtqueues are first enabled before the DRIVER_OK
status flag is set; with the current API of the kernel module, it is
impossible to enable the opposite order in our block export code because
userspace is not notified when a virtqueue is enabled.
This requirement also mathces the normal initialisation order as done by
the generic vhost code in QEMU. However, commit 6c482547 accidentally
changed the order for vdpa-dev and broke access to VDUSE devices with
this.
This changes vdpa-dev to use the normal order again and use the standard
vhost callback .vhost_set_vring_enable for this. VDUSE devices can be
used with vdpa-dev again after this fix.
vhost_net intentionally avoided enabling the vrings for vdpa and does
this manually later while it does enable them for other vhost backends.
Reflect this in the vhost_net code and return early for vdpa, so that
the behaviour doesn't change for this device.
Cc: qemu-stable@nongnu.org
Fixes: 6c4825476a43 ('vdpa: move vhost_vdpa_set_vring_ready to the caller')
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20240315155949.86066-1-kwolf@redhat.com>
Reviewed-by: Eugenio Pérez <eperezma@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'hw/net')
| -rw-r--r-- | hw/net/vhost_net.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c index e8e1661646..fd1a93701a 100644 --- a/hw/net/vhost_net.c +++ b/hw/net/vhost_net.c @@ -541,6 +541,16 @@ int vhost_set_vring_enable(NetClientState *nc, int enable) VHostNetState *net = get_vhost_net(nc); const VhostOps *vhost_ops = net->dev.vhost_ops; + /* + * vhost-vdpa network devices need to enable dataplane virtqueues after + * DRIVER_OK, so they can recover device state before starting dataplane. + * Because of that, we don't enable virtqueues here and leave it to + * net/vhost-vdpa.c. + */ + if (nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) { + return 0; + } + nc->vring_enable = enable; if (vhost_ops && vhost_ops->vhost_set_vring_enable) { |