Re: [Qemu-devel] [PATCH v2 1/3] scsi-disk: Allow overriding SCSI INQUIRY removable bit

[Markus Armbruster <armbru@redhat.com>]

Kevin Wolf <kwolf@redhat.com> writes:

> Am 21.01.2011 11:45, schrieb Stefan Hajnoczi:
>> On Tue, Jan 18, 2011 at 12:06 PM, Stefan Hajnoczi <stefanha@gmail.com> wrote:
>>> On Tue, Jan 18, 2011 at 11:39 AM, Kevin Wolf <kwolf@redhat.com> wrote:
>>>> Am 18.01.2011 11:10, schrieb Stefan Hajnoczi:
>>>>> Provide the "removable" qdev property bit to override the SCSI INQUIRY
>>>>> removable (RMB) bit for non-CDROM devices.  This will be used by USB
>>>>> Mass Storage Devices, which sometimes have this guest-visible bit set
>>>>> and sometimes do not.  They therefore requires a means for user
>>>>> configuration.
>>>>>
>>>>> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
>>>>
>>>> Should we print an error message when the user tries to make a CD-ROM
>>>> non-removable instead of silently ignoring the option?
>>>
>>> Good point.  I will add a check in scsi_disk_initfn() for v3.
>> 
>> Actually this case is hard to check against.  The removable property
>> is a boolean that defaults to false.  We can't detect the difference
>> between default, cleared, or set.
>
> Hm, I see... Maybe we should make scsi-disk and scsi-cdrom different
> devices in the long run,

Yes.  Need to dig out and rebase my patches for it.

>                          then scsi-cdrom could default to true (or
> rather not have the property at all).
>
>> I'm sending out a new version of the patch series that updates
>> docs/qdev-device-use.txt to describe how the removable property works.
>
> Okay, let's just document how it works.
>
> Kevin