Re: [PATCH] virtio-blk: allow toggling host cache between writeback and writethrough

Sasha Levin
2012-07-04T16:26:19Z

On Tue, 2012-07-03 at 15:19 +0200, Paolo Bonzini wrote:
> diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h
> index e0edb40..18a1027 100644
> --- a/include/linux/virtio_blk.h
> +++ b/include/linux/virtio_blk.h
> @@ -37,8 +37,9 @@
> #define VIRTIO_BLK_F_RO 5 /* Disk is read-only */
> #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/
> #define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */
> -#define VIRTIO_BLK_F_FLUSH 9 /* Cache flush command support */
> +#define VIRTIO_BLK_F_WCE 9 /* Writeback mode enabled after reset */
> #define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */
> +#define VIRTIO_BLK_F_CONFIG_WCE 11 /* Writeback mode available in config */

Wouldn't this change break any usermode code that implements virtio-blk?