[EXTERNAL] how to get pci config space

[Richard Hanley]

Hi Jason,

I guess I missed this conversation when it first started. We have some
interest in getting PCIe metadata forwarded to the BMC. I kind of assumed
that the only way was to use a side-band channel, but I getting it through
PECI would be very interesting.

Nancy should have a better idea what we'd be looking for.

- Richard

On Wed, Jun 17, 2020 at 4:38 PM Bills, Jason M <
jason.m.bills at linux.intel.com> wrote:

> Hi Brad,
>
> On 4/30/2020 2:14 PM, Bills, Jason M wrote:
> >
> >
> > On 12/19/2019 12:45 AM, Neeraj Ladkani wrote:
> >> It depends on requirements like in our use case, our PCIe devices are
> >> fixed so we can preprogram a array in JSON file to include all PCI
> >> functions from a device but for someone else for example OEM who is
> >> selling the servers, it not possible to predict all PCI device can be
> >> connected on PCIe slot so we can let system firmware send this
> >> information or do RdPCIRd via PECI.
> >
> > Sorry for not replying earlier.  I had some legal questions that I was
> > waiting to be resolved.
> >
> > Intel has a downstream solution that uses PECI to get the PCIe
> > information onto D-Bus which is then published to Redfish.  I can now
> > share what we have upstream if there is interest.
> >
> > If so, I guess I'd need a new 'peci-pcie' repo to check into?
> Not sure if anyone saw this or if there is just no interest. :)
>
> Could you please create a peci-pcie repo for this application?
>
> Thanks!
> -Jason
>
> >
> > Thanks,
> > -Jason>
> >> I am not aware of any standards on "Implementation". I have seen
> >> typical implementations where system firmware sends post PCIe data (
> >> exact schema) to BMC using redfish and BMC produces this data over
> >> redfish ( just act like passthrough).
> >>
> >> Neeraj
> >>
> >> -----Original Message-----
> >> From: Brad Bishop <bradleyb at fuzziesquirrel.com>
> >> Sent: Wednesday, December 18, 2019 4:35 AM
> >> To: Neeraj Ladkani <neladk at microsoft.com>
> >> Cc: OpenBMC Maillist <openbmc at lists.ozlabs.org>
> >> Subject: Re: [EXTERNAL] how to get pci config space
> >>
> >> Thanks Neeraj
> >>
> >>> On Dec 18, 2019, at 2:18 AM, Neeraj Ladkani <neladk at microsoft.com>
> >>> wrote:
> >>>
> >>> IMO, we only need DeviceID and VendorID fields from PCIe Config space
> >>
> >> This would probably meet my need to dynamically tune fan control
> >> parameters.  Is it possible to populate instances of the pciedevice
> >> schema based on devid and vendorid alone?
> >>
> >>> and we can let system firmware send this information during boot
> >>
> >> This is how it works on Power systems before OpenBMC, but we have a
> >> custom protocol with a proprietary implementation.  The purpose of my
> >> note was to find out if there are typical implementations or even
> >> standards out there for doing this.
> >>
> >>> or preprogram the information to BMC using EntityManager.
> >>
> >> Can you elaborate on how this would work?  Given the number of pcie
> >> devices out there this seems like it would be hard to do it this way
> >> without a huge database of some kind on the bmc?
> >>
> >>> Regarding BMC-CPU(via PECI), BMC needs to send PECI command to CPU.
> >>> CPU should support RdPCICfg as supported PECI command and thus
> >>> respond with data.
> >>
> >> Ok - that sounds like its all in hardware.  But above it sounded like
> >> you suggest we skip RdPCICfg and instead let system firmware push this
> >> information down to the BMC - do I have it right?  If so why do you
> >> prefer that mechanism?
> >>
> >> thx!
> >>
> >> -brad
> >>
>
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