OEM i2c over IPMI

[Tanous, Ed]

> -----Original Message-----
> From: openbmc [mailto:openbmc-
> bounces+ed.tanous=intel.com at lists.ozlabs.org] On Behalf Of Patrick
> Venture
> Sent: Tuesday, October 2, 2018 1:00 PM
> To: OpenBMC Maillist <openbmc at lists.ozlabs.org>
> Subject: OEM i2c over IPMI
> 
> We have a linux kernel driver for i2c-via-ipmi that ties into
> https://gerrit.openbmc-project.xyz/12604 - I'm putting this upstream but
> since it's an IPMI OEM handler, it can nicely go into its own repository - I was
> curious if there was any OpenBMC interest?  If so, we can aim for the
> phosphor namespace, otherwise I'll just ask that it be pushed into a google
> repo.
> 

What does this command do that the existing master write-read command (section 22.11 of the IPMI spec) doesn't?

I know on past systems we've offered the OEM I2C command to get around the 8 channel limit for the stock command.  I can't tell if that's the case with this one, but we should probably have a statement on exactly what we're trying to solve compared to the IPMI master write read.

It should also be noted that master write-read opens up some pretty scary security scenarios, especially when done over IPMI.  We should probably make sure it's isolated to its own library so the high security systems can opt out of it if need be.

-Ed