Re: [Qemu-devel] [PATCH 1/2] scsi: Make LUN 0 a simple enclosure

["Daniel P. Berrange" <berrange@redhat.com>]

On Thu, Aug 03, 2017 at 03:27:00PM +0200, Hannes Reinecke wrote:
> Instead of having an 'invisible' LUN0 (in case LUN 0 is not connected)
> this patch maks LUN0 a enclosure service, exposing it to the OS.
> 
> Signed-off-by: Hannes Reinecke <hare@suse.com>
> ---
>  hw/scsi/scsi-bus.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 55 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
> index 23c51de..c89e82d 100644
> --- a/hw/scsi/scsi-bus.c
> +++ b/hw/scsi/scsi-bus.c
> @@ -493,10 +493,11 @@ static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
>      if (r->req.lun != 0) {
>          r->buf[0] = TYPE_NO_LUN;
>      } else {
> -        r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
> +        r->buf[0] = TYPE_ENCLOSURE;
>          r->buf[2] = 5; /* Version */
>          r->buf[3] = 2 | 0x10; /* HiSup, response data format */
>          r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
> +        r->buf[6] = 0x40; /* Enclosure service */
>          r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
>          memcpy(&r->buf[8], "QEMU    ", 8);
>          memcpy(&r->buf[16], "QEMU TARGET     ", 16);

I would think this needs to be tied into machine type version, otherwise
when you migrate old to new QEMU, LUN0 is suddenly going to change beneath
the running guest ?

Regards,
Daniel
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