commit	ed0af21ca6092a7ceb19660b69b76a5c304efcb0	[log] [tgz]
author	Aditya Kurdunkar <akurdunkar@nvidia.com>	Wed Jun 11 04:38:52 2025 +0530
committer	Ed Tanous <ed@tanous.net>	Thu Jul 10 15:01:22 2025 +0000
tree	aa28efd09d908cee935cdb23d964a3c64483fb56
parent	bd815c7f79301fe3932093bfd799122879122680 [diff]

gpu: add support for per EID request queuing

The Nvidia Extension of OCP MCTP VDM Protocol specifies that there
should be only one outstanding request message to a GPU Device
implementing the VDM protocol. This introduces a requirement for request
queuing per EID. This patch implements the same.

This patch renames the MctpRequester to Requester and introduces a new
QueuingRequester that composes on top of the Requester and introduces
per EID queuing. Each call to `sendRecvMsg` now enqueues the request
(instead of sending it immediately). If there is no ongoing request the
requester will send the request out right away. Otherwise the requester
waits for the ongoing request to finish before sending out the
previously enqueued request. This ensures the serialization of the
requests and makes sure that there is only one request "in flight" at a
time. For minimal/no client changes, QueuingRequester is type aliased to
MctpRequester.

Tested.

Build an image for gb200nvl-obmc machine with the following
patches cherry picked. This patches are needed to enable the mctp stack.

https://gerrit.openbmc.org/c/openbmc/openbmc/+/79422

Pick the following changes (in order) that enable multiple GPU sensors:

'''
https://gerrit.openbmc.org/c/openbmc/dbus-sensors/+/79970
https://gerrit.openbmc.org/c/openbmc/dbus-sensors/+/80031
https://gerrit.openbmc.org/c/openbmc/dbus-sensors/+/80078
https://gerrit.openbmc.org/c/openbmc/dbus-sensors/+/80099
https://gerrit.openbmc.org/c/openbmc/dbus-sensors/+/80566
https://gerrit.openbmc.org/c/openbmc/dbus-sensors/+/80567
'''

Check if all sensors are available on redfish.

'''
~ % curl -s -k -u 'root:0penBmc' https://10.137.203.137/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/
{
  "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors",
  "@odata.type": "#SensorCollection.SensorCollection",
  "Description": "Collection of Sensors for this Chassis",
  "Members": [
    {
      "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/energy_NVIDIA_GB200_GPU_0_Energy_0"
    },
    {
      "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/power_NVIDIA_GB200_GPU_0_Power_0"
    },
    {
      "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/temperature_NVIDIA_GB200_GPU_0_TEMP_0"
    },
    {
      "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/temperature_NVIDIA_GB200_GPU_0_TEMP_1"
    },
    {
      "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/voltage_NVIDIA_GB200_GPU_0_Voltage_0"
    }
  ],
  "Members@odata.count": 5,
  "Name": "Sensors"
}
'''

Check Individual Sensor Updates.

'''
curl -s -k -u 'root:0penBmc' https://10.137.203.245/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/temperature_NVIDIA_GB200_GPU_0_TEMP_0
{
  "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/temperature_NVIDIA_GB200_GPU_0_TEMP_0",
  "@odata.type": "#Sensor.v1_2_0.Sensor",
  "Id": "temperature_NVIDIA_GB200_GPU_0_TEMP_0",
  "Name": "NVIDIA GB200 GPU 0 TEMP 0",
  "Reading": 27.71875,
  "ReadingRangeMax": 127.0,
  "ReadingRangeMin": -128.0,
  "ReadingType": "Temperature",
  "ReadingUnits": "Cel",
  "Status": {
    "Health": "OK",
    "State": "Enabled"
  }
}

curl -s -k -u 'root:0penBmc' https://10.137.203.245/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/temperature_NVIDIA_GB200_GPU_0_TEMP_1
{
  "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/temperature_NVIDIA_GB200_GPU_0_TEMP_1",
  "@odata.type": "#Sensor.v1_2_0.Sensor",
  "Id": "temperature_NVIDIA_GB200_GPU_0_TEMP_1",
  "Name": "NVIDIA GB200 GPU 0 TEMP 1",
  "Reading": 57.28125,
  "ReadingRangeMax": 127.0,
  "ReadingRangeMin": -128.0,
  "ReadingType": "Temperature",
  "ReadingUnits": "Cel",
  "Status": {
    "Health": "OK",
    "State": "Enabled"
  }
}

curl -s -k -u 'root:0penBmc' https://10.137.203.245/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/power_NVIDIA_GB200_GPU_0_Power_0
{
  "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/power_NVIDIA_GB200_GPU_0_Power_0",
  "@odata.type": "#Sensor.v1_2_0.Sensor",
  "Id": "power_NVIDIA_GB200_GPU_0_Power_0",
  "Name": "NVIDIA GB200 GPU 0 Power 0",
  "Reading": 27.468,
  "ReadingRangeMax": 4294967.295,
  "ReadingRangeMin": 0.0,
  "ReadingType": "Power",
  "ReadingUnits": "W",
  "Status": {
    "Health": "OK",
    "State": "Enabled"
  }
}

curl -s -k -u 'root:0penBmc' https://10.137.203.245/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/energy_NVIDIA_GB200_GPU_0_Energy_0
{
  "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/energy_NVIDIA_GB200_GPU_0_Energy_0",
  "@odata.type": "#Sensor.v1_2_0.Sensor",
  "Id": "energy_NVIDIA_GB200_GPU_0_Energy_0",
  "Name": "NVIDIA GB200 GPU 0 Energy 0",
  "Reading": 45058.545,
  "ReadingRangeMax": 1.8446744073709552e+16,
  "ReadingRangeMin": 0.0,
  "ReadingType": "EnergyJoules",
  "ReadingUnits": "J",
  "Status": {
    "Health": "OK",
    "State": "Enabled"
  }
}

curl -s -k -u 'root:0penBmc' https://10.137.203.245/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/voltage_NVIDIA_GB200_GPU_0_Voltage_0
{
  "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/voltage_NVIDIA_GB200_GPU_0_Voltage_0",
  "@odata.type": "#Sensor.v1_2_0.Sensor",
  "Id": "voltage_NVIDIA_GB200_GPU_0_Voltage_0",
  "Name": "NVIDIA GB200 GPU 0 Voltage 0",
  "Reading": 0.735,
  "ReadingRangeMax": 4294.967295,
  "ReadingRangeMin": 0.0,
  "ReadingType": "Voltage",
  "ReadingUnits": "V",
  "Status": {
    "Health": "OK",
    "State": "Enabled"
  }
}
'''

Change-Id: Ic3b892ef2c76c4c703aa55f5b2a66c22a5d71bdf
Signed-off-by: Aditya Kurdunkar <akurdunkar@nvidia.com>

2 files changed

tree: aa28efd09d908cee935cdb23d964a3c64483fb56

README.md

dbus-sensors

dbus-sensors is a collection of sensor applications that provide the xyz.openbmc_project.Sensor collection of interfaces. They read sensor values from hwmon, d-bus, or direct driver access to provide readings. Some advance non-sensor features such as fan presence, pwm control, and automatic cpu detection (x86) are also supported.

key features

runtime re-configurable from d-bus (entity-manager or the like)
isolated: each sensor type is isolated into its own daemon, so a bug in one sensor is unlikely to affect another, and single sensor modifications are possible
async single-threaded: uses sdbusplus/asio bindings
multiple data inputs: hwmon, d-bus, direct driver access

dbus interfaces

A typical dbus-sensors object support the following dbus interfaces:

Path        /xyz/openbmc_project/sensors/<type>/<sensor_name>

Interfaces  xyz.openbmc_project.Sensor.Value
            xyz.openbmc_project.Sensor.Threshold.Critical
            xyz.openbmc_project.Sensor.Threshold.Warning
            xyz.openbmc_project.State.Decorator.Availability
            xyz.openbmc_project.State.Decorator.OperationalStatus
            xyz.openbmc_project.Association.Definitions

Sensor interfaces collection are described in phosphor-dbus-interfaces.

Consumer examples of these interfaces are Redfish, Phosphor-Pid-Control, IPMI SDR.

Reactor

dbus-sensor daemons are reactors that dynamically create and update sensors configuration when system configuration gets updated.

Using asio timers and async calls, dbus-sensor daemons read sensor values and check thresholds periodically. PropertiesChanged signals will be broadcasted for other services to consume when value or threshold status change. OperationStatus is set to false if the sensor is determined to be faulty.

A simple sensor example can be found in entity-manager examples.

configuration

Sensor devices are described using Exposes records in configuration file. Name and Type fields are required. Different sensor types have different fields. Refer to entity manager schema for complete list.

sensor documentation

ExternalSensor virtual sensor

Sensor Type Documentation

ADC Sensors

ADC sensors are sensors based on an Analog to Digital Converter. They are read via the Linux kernel Industrial I/O subsystem (IIO).

One of the more common use cases within OpenBMC is for reading these sensors from the ADC on the Aspeed ASTXX cards.

To utilize ADC sensors feature within OpenBMC you must first define and enable it within the kernel device tree.

When using a common OpenBMC device like the AST2600 you will find a "adc0" and "adc1" section in the aspeed-g6.dtsi file. These are disabled by default so in your system-specific dts you would enable and configure what you want with something like this:

iio-hwmon {
    compatible = "iio-hwmon";
    io-channels = <&adc0 0>;
    ...
}

&adc0 {
    status = "okay";
    ...
};

&adc1 {
    status = "okay";
    ...
};

Note that this is not meant to be an exhaustive list on the nuances of configuring a device tree but really to point users in the general direction.

You will then create an entity-manager configuration file that is of type "ADC" A very simple example would like look this:

            "Index": 0,
            "Name": "P12V",
            "PowerState": "Always",
            "ScaleFactor": 1.0,
            "Type": "ADC"

When your system is booted, a "in0_input" file will be created within the hwmon subsystem (/sys/class/hwmon/hwmonX). The adcsensor application will scan d-bus for any ADC entity-manager objects, look up their "Index" value, and try to match that with the hwmon inY_input files. When it finds a match it will create a d-bus sensor under the xyz.openbmc_project.ADCSensor service. The sensor will be periodically updated based on readings from the hwmon file.