[PATCH 0/6] virtio: graceful failure with get == NULL

Michael S. Tsirkin
2015-01-13T19:49:09Z

On Tue, Jan 13, 2015 at 04:43:07PM +0200, Michael S. Tsirkin
wrote:
> virtio 1.0 says device configuration is optional, but most drivers treat it
as
> mandatory.  Even if presented by device, guest bios might disable the BAR
> holding that configuration, so we can't assume it's there, but we
also don't
> want to fail if not in case drivers can cope with it's absence - such
as caif
> or rng.
>
> Add code to drivers to check presence of get callback and fail gracefully.

Rusty, in case it's not clear: I'd like to hear
your opinion on these patches, since virtio pci modern
driver I'm now preparing for submission, depends on this.


> Michael S. Tsirkin (6):
>   virtio/9p: verify device has config space
>   virtio/blk: verify device has config space
>   virtio/console: verify device has config space
>   virtio/net: verify device has config space
>   virtio/scsi: verify device has config space
>   virtio/balloon: verify device has config space
>
>  drivers/block/virtio_blk.c      | 6 ++++++
>  drivers/char/virtio_console.c   | 6 ++++++
>  drivers/net/virtio_net.c        | 6 ++++++
>  drivers/scsi/virtio_scsi.c      | 6 ++++++
>  drivers/virtio/virtio_balloon.c | 6 ++++++
>  net/9p/trans_virtio.c           | 6 ++++++
>  6 files changed, 36 insertions(+)
>
> --
> MST
>