Re: [Qemu-devel] Do you have a use for a tester of virtio-scsi with CD drives ?

[Zhi Yong Wu]

On Mon, Nov 7, 2011 at 7:13 PM, Paolo Bonzini <address@hidden> wrote:
> On 11/07/2011 11:04 AM, Thomas Schmitt wrote:
>> In a thread on linux-hotplug, /dev/sg* is declared to be deprecated
>> in favor of/dev/bsg/* and /dev/sr*.
>> Will this become a problem ?
>
> I think /dev/bsg is backwards-compatible more or less, but it would help
> if it had decent documentation in the kernel tree.
>
>> I did not succeed with googling for a way to get a block device
>> running on top of file=/dev/sg*,if=virtio.
>
> No, that's not possible with /dev/sg.  But I think this helps:
>
>   -drive file=/dev/sr0,if=none,id=scsicd
>   -device 
> virtio-blk,drive=scsicd,logical_block_size=2048,physical_block_size=2048
It didn't work for me
I started up one os=rh6.1 guest with above options.

On guest:
address@hidden ~]# mount /dev/sr0 /tmp/1
mount: you must specify the filesystem type
address@hidden ~]#

>
> At least here, dd works with this command line.  This probably will
> be fixed in QEMU 1.1 (i.e. the release after the next one).
>
>> The word "passthrough" does not show up in the context of drive
>> emulation in any documentation inside the git clone.
>> I only see statements about:  "passthrough" security model.
>> The word "virtio" is mentioned more often, but without much explanation
>> of -drive use cases and pitfalls. (Only docs/qdev-device-use.txt
>> has some more detailed information.)
>
> Yes, docs/qdev-device-use.txt helps.  "qemu -device virtio-blk,?" too.
>
>> Is there an external documentation emerging ?
>> I would like to read it and contribute my experiences.
>
> Hopefully, everything would just work. :)
>
> You can work on wiki.qemu.org in the meanwhile.
>
> Paolo
>
>



-- 
Regards,

Zhi Yong Wu