Xen and SCSI

Xen and SCSI

[Jeff Garzik]

FWIW, I'm about to complete a domU scsi driver for Xen (initiator, aka 
front-end).  Additionally, I'm writing "the other side", the associated 
target (tunnel, aka back-end) for dom0-style kernels.

I was planning on sending it to linux-scsi for review this week, then 
figure out the best path to get it upstream.

The basic message protocol draws heavily on native SCSI RPC model, and 
by that, I mean SAM and "SMP-ish".  This allows communication with any 
number of SCSI targets/LUNs/etc. between any domU or dom0.

Reading your email earlier today, I would recommend against using the 
SCSI generic driver, unless you're doing something strange like passing 
everything through userspace.  Just put SCSI commands on the request 
queue...

	Jeff

Re: Xen and SCSI

[FUJITA Tomonori]

From: Jeff Garzik <jeff@garzik.org>
Subject: [Xen-devel] Xen and SCSI
Date: Tue, 20 Jun 2006 17:34:43 -0400

> FWIW, I'm about to complete a domU scsi driver for Xen (initiator, aka 
> front-end).  Additionally, I'm writing "the other side", the associated 
> target (tunnel, aka back-end) for dom0-style kernels.

I wrote similar front-end and back-end drivers, kinda SRP initiator
and target drivers like IBM pServer virtual drivers. The drivers use
the SCSI target framework and SRP library that lives in -mm kernels.

I could submit the initial versions this week (hopefully).

Re: Xen and SCSI

[Anthony Liguori]

Hi Jeff,

Jeff Garzik wrote:
> FWIW, I'm about to complete a domU scsi driver for Xen (initiator, aka 
> front-end).  Additionally, I'm writing "the other side", the 
> associated target (tunnel, aka back-end) for dom0-style kernels.

Neat!  Is it a standard XenBus device?  Does it use the existing 
blkfront/blkback ring queue?  Do you have a sneak peak of the code you 
could possible point us to?

REgards,

Anthony Liguori

> I was planning on sending it to linux-scsi for review this week, then 
> figure out the best path to get it upstream.
>
> The basic message protocol draws heavily on native SCSI RPC model, and 
> by that, I mean SAM and "SMP-ish".  This allows communication with any 
> number of SCSI targets/LUNs/etc. between any domU or dom0.
>
> Reading your email earlier today, I would recommend against using the 
> SCSI generic driver, unless you're doing something strange like 
> passing everything through userspace.  Just put SCSI commands on the 
> request queue...
>
>     Jeff
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel