Re: [PATCH net v3 0/3] vsock/virtio: enable VQs early on probe and finish the setup before using them

[Stefan Hajnoczi]

On Wed, Mar 23, 2022 at 06:36:22PM +0100, Stefano Garzarella wrote:
> The first patch fixes a virtio-spec violation. The other two patches
> complete the driver configuration before using the VQs in the probe.
> 
> The patch order should simplify backporting in stable branches.
> 
> v3:
> - re-ordered the patch to improve bisectability [MST]
> 
> v2: https://lore.kernel.org/netdev/20220323084954.11769-1-sgarzare@xxxxxxxxxx/
> v1: https://lore.kernel.org/netdev/20220322103823.83411-1-sgarzare@xxxxxxxxxx/
> 
> Stefano Garzarella (3):
>   vsock/virtio: initialize vdev->priv before using VQs
>   vsock/virtio: read the negotiated features before using VQs
>   vsock/virtio: enable VQs early on probe
> 
>  net/vmw_vsock/virtio_transport.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> -- 
> 2.35.1
> 

A subtle point is that we still drop events and rx packets during the
window where DRIVER_OK has been set but vqs haven't been filled.
This is acceptable because it's unavoidable and equivalent to events
happening before DRIVER_OK is set. What this revision *does* fix is that
vq used buffer notifications are no longer lost. Good.

Reviewed-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>

Attachment: signature.asc
Description: PGP signature