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

From: Michael S. Tsirkin
Date: Tue Jan 13 2015 - 14:49:20 EST


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
>
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