Re: [PATCH] ppc/pnv: Create BMC devices at machine init

From: David Gibson <david@gibson.dropbear.id.au>
To: "Cédric Le Goater" <clg@kaod.org>
Cc: qemu-ppc@nongnu.org, Corey Minyard <cminyard@mvista.com>,
	Oliver O'Halloran <oohall@gmail.com>,
	qemu-devel@nongnu.org
Subject: Re: [PATCH] ppc/pnv: Create BMC devices at machine init
Date: Wed, 20 Nov 2019 09:05:07 +1100	[thread overview]
Message-ID: <20191119220507.GX5582@umbus.fritz.box> (raw)
In-Reply-To: <2c2dfb82-e5cd-ef94-3542-8ec92b1ef001@kaod.org>

[-- Attachment #1: Type: text/plain, Size: 2461 bytes --]

On Tue, Nov 19, 2019 at 07:49:33AM +0100, Cédric Le Goater wrote:
> On 19/11/2019 01:52, David Gibson wrote:
> > On Mon, Nov 18, 2019 at 10:22:22AM +0100, Cédric Le Goater wrote:
> >> The BMC of the OpenPOWER systems monitors the machine state using
> >> sensors, controls the power and controls the access to the PNOR flash
> >> device containing the firmware image required to boot the host.
> >>
> >> QEMU models the power cycle process, access to the sensors and access
> >> to the PNOR device. But, for these features to be available, the QEMU
> >> PowerNV machine needs two extras devices on the command line, an IPMI
> >> BT device for communication and a BMC backend device:
> >>
> >>   -device ipmi-bmc-sim,id=bmc0 -device isa-ipmi-bt,bmc=bmc0,irq=10
> >>
> >> The BMC properties are then defined accordingly in the device tree and
> >> OPAL self adapts. If a BMC device and an IPMI BT device are not
> >> available, OPAL does not try to communicate with the BMC in any
> >> manner. This is not how real systems behave.
> >>
> >> To be closer to the default behavior, create an IPMI BMC simulator
> >> device and an IPMI BT device at machine initialization time. We loose
> >> the ability to define an external BMC device but there are benefits:
> >>
> >>   - a better match with real systems,
> >>   - a better test coverage of the OPAL code,
> >>   - system powerdown and reset commands that work,
> >>   - a QEMU device tree compliant with the specifications (*).
> >>
> >> (*) Still needs a MBOX device.
> >>
> >> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> > 
> > This doesn't apply to ppc-for-5.0 for me.  I'm not sure which change
> > in there it's conflicting with, but there seems to be something.
> 
> Sorry I should have been more precise.
> 
> 
> This is because we need an IPMI patch to be merged first in 
> Corey's tree :
> 
>   ipmi: Add support to customize OEM functions
>   http://patchwork.ozlabs.org/patch/1185187/
> 
> and another one merged in the PPC tree: 
> 
>   ppc/pnv: Add HIOMAP commands
>   http://patchwork.ozlabs.org/patch/1185185/
> 
> 
> David, if Corey agrees, I think it would be simpler if you took 
> them all.

Ok.  Corey, could I get an Acked-by from you?

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]