[PATCH 0/4] megaraid_sas HBA emulation

[Hannes Reinecke <hare@suse.de>]

Hi all,

this patchset implements an emulation for the megaraid_sas HBA.
It provides emulates an LSI MegaRAID SAS 8708EM2 HBA, ie
presenting to the guest a virtual SCSI adapter.
Internally it is using aio for read/write requests and
either SG_IO or SCSI command emulation for everything else.

The reason for choosing the megaraid_sas HBA and not, say,
implementing a virtio scsi interface is because:
- the megaraid_sas is using a very simple firmware interface,
  comparable to virtio
- the HBA driver are already existent, so I only have to
  write the backend :-)

The device can be accessed by

-drive if=raid,file=XXX

In order to support SCSI command emulation I had to update /
patch up the existing SCSI disk support. This might be
not to everyones taste, so I'm open to alternative
suggestions.

But I certainly do _not_ want to update the SCSI disk
emulation, as this is really quite tied to the SCSI parallel
interface used by the old lsi53c895a.c.
Plus it doesn't do scatter-gather list handling, which
is quite impossible to fix without proper documentation.

Of course, if anyone else would step in here, I won't object :-)

It currently runs guests with 2.6.27 and up; Windows XP
support is not quite there yet. Anything else might work;
if not, enable debugging and sent me the logfile.

As usual, comment / suggestions  etc welcome.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Markus Rex, HRB 16746 (AG Nürnberg)