Re: [Qemu-devel] [PATCH] add suport for ATA_PASSTHROUGH_xx scsi command

[ronnie sahlberg]

Because opcode 0xA1 has a different meaning for CDROM/MMC devices.
On such devices 0xA1 means BLANK, so it would collide if QEMU some day
adds support for
re-writeable mmc device.


On Wed, Aug 1, 2012 at 6:45 PM, Paolo Bonzini <address@hidden> wrote:
> Il 01/08/2012 10:43, Cong Meng ha scritto:
>>>
>>> Please make this conditional on the type _not_ being TYPE_ROM.
>>
>> May I ask why cdrom device should be an exception?
>
> Because CD-ROM devices do not support ATA PASSTHROUGH (the SAT standard
> only describes direct access devices---type=0x00).  The 0xa1 command is
> "BLANK" for CD-ROMs.
>
> Paolo
>