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

[Marc Haber]

Hi,

On Mon, Mar 22, 2010 at 10:22:14AM -0400, john cooper wrote:
> Marc Haber wrote:
> > On Tue, Mar 09, 2010 at 03:34:07PM -0600, Anthony Liguori wrote:
> >> On 03/06/2010 04:42 PM, Marc Haber wrote:
> >>> 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
> > 
> > It the serial "number" can be alphanumeric, that would be great to have.
> 
> It is simply a string of 20 characters, which AFAICT has
> its roots in the ATA S/N convention along with many other
> puzzling present day evils.

That would be enough for my purposes, but more would be acceptable as
well.

> All that said, I like the alternate choice of adding a
> special virtio request far better.  It is actually simpler
> (and more maintainable IMO) than going through the
> gyrations of stuffing the S/N data through PCI config
> space.

Whatever is more easily implemented ;)    How would a Windows
installation see the label then?

Has my wish made its way on the official wishlist and/or roadmap?

Greetings
Marc

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