DS_SAI length conflict between 07-437r4 and 07-169 & SPC-4

Black_David at emc.com Black_David at emc.com
Fri Jan 4 16:34:53 PST 2008


* From the T10 Reflector (t10 at t10.org), posted by:
* Black_David at emc.com
*
Ralph,
SAI space may be sparse.  For a 64-bit firmware implementation,
putting all 64 bits of the pointer to the internal data
structure in the SAI may be convenient (NB: with careful
verification to prevent use of invalid pointers by an attacker).
The flip side argument is that for reuse of ESP hardware, the
SAI probably needs to be 32 bits, and IKEv2-SCSI requires
enough changes to existing IKEv2 code that preserving IKEv2's
64 bit SAI (SPI) size may not be of much help to an implementer.
Thanks,
--David
> -----Original Message-----
> From: roweber at sempai.org [mailto:roweber at sempai.org] On 
> Behalf Of Ralph Weber
> Sent: Thursday, January 03, 2008 9:35 PM
> To: Black, David
> Cc: kdbutt at us.ibm.com; matt.ball at ieee.org; t10 at t10.org
> Subject: Re: DS_SAI length conflict between 07-437r4 and 
> 07-169 & SPC-4
> 
> David,
> 
> I am having the dickens of a time comprehending why a device server
> needs as many SAIs as an OSD has partitions. What am I missing?
> 
> All the best,
> 
> .Ralph
> 
> Black_David at emc.com wrote:
> > Kevin,
> > We need to make a decision on this one because there is no obvious
> > right answer. IETF uses separate SPIs (what T10 calls SAIs) for
> > IKEv2 and ESP - 8 bytes SPIs are used for IKEv2, but ESP uses 4 byte
> > SPIs. SCSI is using the same SPI for both purposes, and hence needs
> > to pick one length - I agree with your suggestion that 8 bytes (as
> > used in IKEv2-SCSI) is preferable. >From an implementation
standpoint
> > this would reduce the impact on reuse of the more complex IKEv2
> > implementations (more complex is by comparison to ESP).
> > Thanks,
> > --David
> > ----------------------------------------------------
> > David L. Black, Distinguished Engineer
> > EMC Corporation, 176 South St., Hopkinton, MA 01748
> > +1 (508) 293-7953 FAX: +1 (508) 293-7786
> > black_david at emc.com Mobile: +1 (978) 394-7754
> > ----------------------------------------------------
> >
> >
> >	
> --------------------------------------------------------------
> ----------
> >	*From:* Kevin D Butt [mailto:kdbutt at us.ibm.com]
> >	*Sent:* Friday, December 21, 2007 11:24 AM
> >	*To:* roweber at ieee.org; Black, David; matt.ball at ieee.org
> >	*Cc:* t10 at t10.org
> >	*Subject:* DS_SAI length conflict between 07-437r4 and 
> 07-169 & SPC-4
> >
> >
> >	Ralph, David, and Matt,
> >
> >	All the DS_SAI values in the ESP-SCSI (07-169r5) (e.g., 
> Table x3 -
> >	ESP-SCSI data-out buffer parameter list descriptor without
> >	initialization vector) are shown as 4-byte values as they are in
> >	SPC-4 Table 44 - Minimum SA parameters. However 07-437r4 shows
> >	them as 8-byte values. I think 07-437r4 is correct and SPC-4 and
> >	07-169 need to be modified to match.
> >
> >	Thanks,
> >
> >	Kevin D. Butt
> >	SCSI & Fibre Channel Architect, Tape Firmware
> >	MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
> >	Tel: 520-799-2869 / 520-799-5280
> >	Fax: 520-799-2723 (T/L:321)
> >	Email address: kdbutt at us.ibm.com
> >	http://www-03.ibm.com/servers/storage/ 
> >
> 
> 
> 
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