Virtualization - Mar 2022 - [PATCH net v2 1/3] vsock/virtio: enable VQs early on probe

virtio spec requires drivers to set DRIVER_OK before using VQs.
This is set automatically after probe returns, but virtio-vsock
driver uses VQs in the probe function to fill rx and event VQs
with new buffers.

Let's fix this, calling virtio_device_ready() before using VQs
in the probe function.

Fixes: 0ea9e1d3a9e3 ("VSOCK: Introduce virtio_transport.ko")
Signed-off-by: Stefano Garzarella <sgarzare at redhat.com>
---
 net/vmw_vsock/virtio_transport.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 5afc194a58bb..b1962f8cd502 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -622,6 +622,8 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
 	INIT_WORK(&vsock->event_work, virtio_transport_event_work);
 	INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
 
+	virtio_device_ready(vdev);
+
 	mutex_lock(&vsock->tx_lock);
 	vsock->tx_run = true;
 	mutex_unlock(&vsock->tx_lock);
-- 
2.35.1

On Wed, Mar 23, 2022 at 09:49:52AM +0100, Stefano Garzarella
wrote:
> virtio spec requires drivers to set DRIVER_OK before using VQs.
> This is set automatically after probe returns, but virtio-vsock
> driver uses VQs in the probe function to fill rx and event VQs
> with new buffers.
> 
> Let's fix this, calling virtio_device_ready() before using VQs
> in the probe function.
> 
> Fixes: 0ea9e1d3a9e3 ("VSOCK: Introduce virtio_transport.ko")
> Signed-off-by: Stefano Garzarella <sgarzare at redhat.com>
> ---
>  net/vmw_vsock/virtio_transport.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/vmw_vsock/virtio_transport.c
b/net/vmw_vsock/virtio_transport.c
> index 5afc194a58bb..b1962f8cd502 100644
> --- a/net/vmw_vsock/virtio_transport.c
> +++ b/net/vmw_vsock/virtio_transport.c
> @@ -622,6 +622,8 @@ static int virtio_vsock_probe(struct virtio_device
*vdev)
>  	INIT_WORK(&vsock->event_work, virtio_transport_event_work);
>  	INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
>  
> +	virtio_device_ready(vdev);
Can rx and event virtqueue interrupts be lost if they occur before we
assign vdev->priv later in virtio_vsock_probe()?

Stefan
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