Thanks for the explanation. I could test what I needed to = test on an Intel C620 based platform.

Specifically I'= ;m trying to run a board in eSPI=C2=A0+ SAFS mode. SAFS is "Slave Atta= ched Flash Sharing" where the PCH loads all of its=C2=A0firmware (ME, = GbE, BIOS etc) via eSPI, e.g. from a BMC. See Intel document 329957 ("= Enhanced Serial Peripheral Interface (eSPI) - Addendum for Server Platforms= ") from=C2=A0https://downloadcenter.intel.com/download/27055/e= SPI=C2=A0for reference. However, even though the PCH (C620 series) read= s quite a lot of data via SAFS, the ME doesn't release the CPU and the = host wouldn't turn on. I had hoped that this is just the result of not = having FDRV (aka. FD0V) enabled in the PCH. In that case the ME should have= responded to IPMB and reported such. But the ME doesn't respond at all= on i2c in SAFS mode (checked via logic analyzer), so I'm at a loss of = what's wrong with it. In MAFS mode (i.e. when using SPI flash for=C2=A0= the PCH), the IPMB works as expected, so I know my setup is correct and it= 's actually the ME being unhappy in SAFS mode. I tried with ME in both = "operational" and "recovery" mode. I do see different b= ehavior in that the ME in "recovery" mode completely rewrites the= MFS section, so "something" must actually be running in the ME. = I guess the only other thing I haven't tried is to compare SAFS operati= ons with SPI operations (MAFS) to see what else it would be doing on SPI.

Oskar.

On Thu, Apr 23, 2020 at = 2:59 PM Vijay Khemka <vijaykhemka@= fb.com> wrote:

As i2c slave mqueue driver is not upstreamed and wit= h already having same functionality in ipmb-dev driver which is already in = uostream kernel, I don=E2=80=99t see any reason to use i2c slave mqueue dri= ver. I highly incourage people to use ipmb-dev driver with latest ipmbbridge. If there are any issues, please let us know= .

=C2=A0

Regards

-Vijay

=C2=A0

From: = Oskar Senft <osk@google.com>
Date: Thursday, April 23, 2020 at 8:34 AM
To: Vijay Khemka <vijaykhemka@fb.com>
Cc: OpenBMC Maillist <openbmc@lists.ozlabs.org>
Subject: Re: Access Intel ME IPMB from BMC

=C2=A0

On a side note regarding the ipmb-dev driver: It see= ms that the Documentation/IPMB.txt has gotten "lost". The only ve= rsion I could find is this:=C2=A0https://github.com/openbmc/linux/blob/51bd6f291583684f495ea4= 98984dfc22049d7fd2/Documentation/IPMB.txt. But it's not in any of the recent branches (dev-5.3 or dev-5.4).

=C2=A0

Should this file be resurrected?

=C2=A0

Oskar.

=C2=A0

On Thu, Apr 23, 2020 at 11:31 AM Oskar Senft <osk@google.com> wro= te:

Thanks again!

=C2=A0

ipmbbridge solved my problem. I found that my versio= n of OpenBMC (incl. kernel) used a slightly older version of ipmbbridge whi= ch still used the i2c slave mqueue, which worked fine. Reading a bit of sou= rce code made it clear how it worked. The key is to configure ipbm-channels.json with the correct i2c device and= the rest "just works".

=C2=A0

For the benefit of others: My understanding is that = the current version of ipmbbridge no longer uses the i2c slave mqueue but r= equires the ipmb-dev driver in the kernel. It's not necessary to actual= ly attach the driver to an i2c device as that can happen at runtime.

=C2=A0

Oskar.

=C2=A0

=C2=A0

On Mon, Apr 20, 2020 at 4:34 PM Vijay Khemka <vijaykhemka@fb.com= > wrote:

Hi Oskar,

You need to use ipmb-dev driver which is is being us= ed by ipmbbridge. You don=E2=80=99t need ipmb-host as we are having ipmbbri= dge to replace that.

=C2=A0

Regards

-Vijay

=C2=A0

From: Oskar Senft <osk@google.com>
Date: Monday, April 20, 2020 at 11:35 AM
To: Vijay Khemka <vijaykhemka@fb.com>
Cc: OpenBMC Maillist <openbmc@lists.ozlabs.org>
Subject: Re: Access Intel ME IPMB from BMC

=C2=A0

Hi Vijay

=C2=A0

Thanks for the pointer!

=C2=A0

I also found both=C2=A0https://github.com/Mellanox/ipmb-hos= t=C2=A0and=C2=A0https://github.com/op= enbmc/linux/blob/dev-5.4/drivers/char/ipmi/ipmb_dev_int.c.=C2=A0=

=C2=A0

Is it right that with=C2=A0ipmbbridge=C2=A0I don'= ;t need either of them since ipmbbridge=C2=A0uses the raw i2c dev?

=C2=A0

Thanks

Oskar.

=C2=A0

On Mon, Apr 20, 2020 at 2:12 PM Vijay Khemka <vijaykhemka@fb.com= > wrote:

Hi Oskar,

You need to configure your ME channel in ipmb channe= l config file https://github.com/openbmc/ipmbbridge/blob/master/ipmb-channels.json=

And make sure ipmbbridge is running. Then you can se= nd get device id command to ME from command line itself to test if everythi= ng is working.

=C2=A0

busctl call xyz.openbmc_project.Ipmi.Channel.Ipmb /xyz/openbmc_project/I= pmi/Channel/Ipmb org.openbmc.Ipmb sendRequest yyyyay 1 6 0 0x1 0<= /u>

=C2=A0

Regards

-Vijay

=C2=A0

From: openbmc <openbmc-b= ounces+vijaykhemka=3Dfb.com@lists.ozlabs.org> on behalf of Oskar Senft <osk@google.com>
Date: Saturday, April 18, 2020 at 6:47 PM
To: OpenBMC Maillist <openbmc@lists.ozlabs.org>
Subject: Access Intel ME IPMB from BMC

=C2=A0

Hi everyone

=C2=A0

I'm trying to find out how I can access the Inte= l ME via IPMB from the BMC (OpenBMC).

=C2=A0

From what I gathered, Intel ME's IPMB is on the = PCH's SMLink0. I know this is connected to one of the SMBus modules on = my AST2500. But what I can't find out is how I actually send commands there? I'm sure I'm missing a document that makes this ob= vious.

=C2=A0

Or is it as simple as=C2=A0dropping IPMI packets ont= o the bus?

=C2=A0

Is this by any chance already implemented in OpenBMC= ?

=C2=A0

Thanks for any hints!

=C2=A0

Oskar

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