Re: [Qemu-devel] virtio block device and sysfs

[Jamie Lokier <jamie@shareable.org>]

Anthony Liguori wrote:
> On 03/06/2010 04:42 PM, Marc Haber wrote:
> >Hi,
> >
> >I am looking to get in touch with somebody who knows more about the
> >connection between host configuration, qemu, kvm, and the virtio block
> >device driver guest side than I know.
> >
> >My goal is to have a possibility to give a "speaking" name to any
> >block device handed into a guest instance by the host. That name
> >should be visible inside the guest, just as a LV is visible with its
> >name in the system running the LVM.
> >
> >For example I would like to say on the qemu or kvm command line
> >'-drive file=some-file,label=some-label,if=virtio', and have the
> >string "some-label" show up somewhere in /sys/block in the guest, much
> >as /sys/block/sda/device/model shows the hardware vendor and type for
> >a standard SATA disk. The guest could then handle the information
> >passed into it by the host with udev rules, allowing fstab constructs
> >like "mount /dev/virtio/block/by-label/some-label as /usr"
> >   
> 
> You probably would just want to plumb ,serial=X into the virtio-blk 
> config space and have the driver use it.  Then you can do 
> /dev/block/by-id/XXXXX

Sounds good to me.

This is looking a bit similar to the user-specified names in
virtio-serial.  Is it worth looking for a generic, common mechanism to
pass user-specified names to all virtio device types?

-- Jamie