qemu for bmc

[Patrick Venture]

On Thu, Nov 19, 2020 at 8:56 AM Patrick Venture <venture at google.com> wrote:
>
> On Wed, Nov 18, 2020 at 11:41 PM Cédric Le Goater <clg at kaod.org> wrote:
> >
> > Hello,
> >
> > On 11/18/20 10:11 PM, Patrick Venture wrote:
> > > Patrick;
> > >
> > > I was looking at a patch series of yours that landed,
> > > https://github.com/qemu/qemu/blob/master/hw/arm/aspeed.c#L517 <-- in
> > > this line you're referencing a device that appears to be missing from
> > > qemu - namely, the pca i2c mux.
> > >
> > > My question is to the community at large, and you also, is anyone
> > > currently implementing this i2c-mux or a similar one?
> >
> > I haven't seen any patches for this device on the QEMU mailing
> > list.
> >
> > John Wang from Bytedance has started developing some new I2C
> > device models for their G220A board. We hope to get that merged
> > in 6.0.
> >
> > If you are interested, we maintain a brief TODO list here
> >
> >   https://github.com/openbmc/qemu/wiki
>
> Thanks, I'll take a look.
>
> >
> > Feel free to update.
> >
> >
> > In terms of priority, I think that the support to boot from eMMC
> > on the AST2600 is an important one. Reviewing the FSI patches
> > also but that's an IBM thing, so it might not interest the
> > community that much.
> >
> > There are quite a few I2C models missing.
>
> Yes.
>
> >
> > All Aspeed models could be more precise.
> >
> >
> > Google and Nuvoton have merged their models for the npcm750-evb
> > and quanta-gsj boards. It would be good to have some interaction
> > with them, on bus/device modeling but also on full system emulation.
>
> Yeah, I believe you've seen my team's patches adding nuvoton support
> to Qemu.  It's a WIP, but we're making a lot of headway and hope to
> have more Nuvoton 730/750 qemu devices sent to qemu over the coming
> days, weeks, etc.
>
> One of the big gaps that I'm seeing is that we weren't yet looking at
> the rest of the board as closely, to see what other devices are
> missing, such as the i2c-muxes, etc.  This will be a really good
> community convergence point as there are only so many i2c-muxes,
> voltage regulators, temperature sensors, that are in common use.
>
> I'll go through some of our plans as stated and add them to the todo
> list.  My team currently isn't focused on aspeed support at present,
> but we're keeping an eye on it and are definitely excited to see
> others contributing in that space!

Cedric,

I noticed you wrote the smbus_ipmi device in qemu.  It looks like this
is meant to operate on the host-side using the SSIF driver.  I'm
looking at the Kudo BMC board which uses SSIF on the BMC side, and
don't see an SSIF driver yet in openbmc/ilnux, but I wanted to
validate that the host-side of the equation is what you've provided in
Qemu?  Perhaps a silly question, but I've been caught off guard by
some bad assumptions recently. :)

Thanks,
Patrick

>
> >
> > Cheers,
> >
> > C.
>
> - Patrick