From 2c66de61f88dc9620a32239f7dd61524a57f66b0 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Fri, 15 Mar 2024 16:59:49 +0100 Subject: vdpa-dev: Fix initialisation order to restore VDUSE compatibility MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Message-ID: <20240315155949.86066-1-kwolf@redhat.com> Reviewed-by: Eugenio Pérez Reviewed-by: Stefano Garzarella Signed-off-by: Kevin Wolf --- hw/virtio/vdpa-dev.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'hw/virtio/vdpa-dev.c') diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c index eb9ecea83b..13e87f06f6 100644 --- a/hw/virtio/vdpa-dev.c +++ b/hw/virtio/vdpa-dev.c @@ -253,14 +253,11 @@ static int vhost_vdpa_device_start(VirtIODevice *vdev, Error **errp) s->dev.acked_features = vdev->guest_features; - ret = vhost_dev_start(&s->dev, vdev, false); + ret = vhost_dev_start(&s->dev, vdev, true); if (ret < 0) { error_setg_errno(errp, -ret, "Error starting vhost"); goto err_guest_notifiers; } - for (i = 0; i < s->dev.nvqs; ++i) { - vhost_vdpa_set_vring_ready(&s->vdpa, i); - } s->started = true; /* -- cgit 1.4.1