[RFC,v2,0/3] Initial PECI bus support

Message

Titus Rwantare Sept. 13, 2022, 6:21 p.m. UTC

The Platform Environment Control Interface (PECI), is a way for Intel
processors to communicate with management controllers.

This series of patches simulate some PECI subsystem functionality. This
work is currently used against Nuvoton 7xx BMC, but it can easily be
extended to support Aspeed BMCs. Most of the functionality is derived
from PECI support in openbmc. See https://github.com/openbmc/libpeci

The main consumer of this work is openbmc, so functionality not
exercised by the openbmc/libpeci is unlikely to be present here.

peci-core.c is an attempt to split out functionality defined by the
spec. Anything that is not expected to change between BMC vendors.

The following commands have some support:
    Ping()
    GetDIB()
    GetTemp()
    ~RdPkgConfig()
    ~RdEndPtConfig()

To be implemented:
    RdIAMSR()
    RdPCIConfig()
    RdPCIConfigLocal()

Currently, in the board file during bmc_init() one may specify defaults
as follows:

static void my_machine_peci_init(NPCM7xxState *soc)
{
    PECIBus *peci_bus = npcm7xx_peci_get_bus(soc);
    DeviceState *dev;

    /* per socket properties - both sockets are identical in this case */
    PECIClientProperties peci_props = {
        .cpu_family = FAM6_SAPPHIRE_RAPIDS_X,
        .cpus = 56,
        .dimms = 16
    };

    /* socket 0 - with example setting a few of the cpu and dimm temperatures in millidegrees */
    dev = DEVICE(peci_add_client(peci_bus, 0x30, &peci_props));
    object_property_set_uint(OBJECT(dev), "cpu_temp[0]", 30000, &error_abort);
    object_property_set_uint(OBJECT(dev), "cpu_temp[2]", 35000, &error_abort);
    object_property_set_uint(OBJECT(dev), "dimm_temp[1]", 40000, &error_abort);
    object_property_set_uint(OBJECT(dev), "dimm_temp[8]", 36000, &error_abort);

    /* socket 1 */
    dev = DEVICE(peci_add_client(peci_bus, 0x31, &peci_props));
    object_property_set_uint(OBJECT(dev), "cpu_temp[9]", 50000, &error_abort);
    object_property_set_uint(OBJECT(dev), "dimm_temp[0]", 31000, &error_abort);
    object_property_set_uint(OBJECT(dev), "dimm_temp[14]", 36000, &error_abort);
    ...
}

This is something that can also be extended as other parameters arise that need
to differ between platforms. So far you can have have different CPUs, DIMM counts,
DIMM temperatures here. These fields can also be adjusted at runtime through qmp.

A lot of the registers are hard coded, see hw/peci/peci-client.c. I'd like to
gauge interest in what potential users would like to be adjustable at runtime.
I've not written QEMU models that read config files at runtime, something I'd
appreciate guidance on.

Thanks all

Changes in v2:
- rename EndPt to EndPoint

Titus Rwantare (3):
  hw/peci: add initial support for PECI
  hw/peci: add PECI support for NPCM7xx BMCs
  hw/peci: add support for EndPointConfig reads

 MAINTAINERS                    |   8 +
 hw/Kconfig                     |   1 +
 hw/arm/Kconfig                 |   1 +
 hw/arm/npcm7xx.c               |   9 +
 hw/meson.build                 |   1 +
 hw/peci/Kconfig                |   2 +
 hw/peci/meson.build            |   2 +
 hw/peci/npcm7xx_peci.c         | 204 +++++++++++++++++++++++
 hw/peci/peci-client.c          | 293 +++++++++++++++++++++++++++++++++
 hw/peci/peci-core.c            | 222 +++++++++++++++++++++++++
 hw/peci/trace-events           |  10 ++
 hw/peci/trace.h                |   1 +
 include/hw/arm/npcm7xx.h       |   2 +
 include/hw/peci/npcm7xx_peci.h |  37 +++++
 include/hw/peci/peci.h         | 217 ++++++++++++++++++++++++
 meson.build                    |   1 +
 16 files changed, 1011 insertions(+)
 create mode 100644 hw/peci/Kconfig
 create mode 100644 hw/peci/meson.build
 create mode 100644 hw/peci/npcm7xx_peci.c
 create mode 100644 hw/peci/peci-client.c
 create mode 100644 hw/peci/peci-core.c
 create mode 100644 hw/peci/trace-events
 create mode 100644 hw/peci/trace.h
 create mode 100644 include/hw/peci/npcm7xx_peci.h
 create mode 100644 include/hw/peci/peci.h

Comments

Peter Maydell Sept. 22, 2022, 3:09 p.m. UTC | #1

On Tue, 13 Sept 2022 at 19:26, Titus Rwantare <[e-mail]> wrote:
> A lot of the registers are hard coded, see hw/peci/peci-client.c. I'd like to
> gauge interest in what potential users would like to be adjustable at runtime.
> I've not written QEMU models that read config files at runtime, something I'd
> appreciate guidance on.

From upstream's point of view: please don't do that... Ad-hoc
config-file-reading code inside device models sounds like it
would be very confusing, and wouldn't work if the system is being
run inside a sandbox.

-- PMM