Hello,

0: The QEMU steps:
https://staging.validation.linaro.org/static/docs/v2/first-devices.html#adding-a-dictionary-to-the-first-qemu-device

I do the following:
lava-server manage device-types add qemu

This is expected if the corresponding device-type (qemu) was already added.

Which is the case in your instance.

It says that qemu device type is already added (python exception).

I sent a patch to print an error message instead of the python exception.

Then I do:
lava-server manage device-types add qemu01

You are mixing "device-types" and "devices". You should add a device here.

There I see the qemu.jinja2. So I have created the new device, called
qemu01.jinja2 as:

{% extends 'qemu.jinja2' %}
{% set mac_addr = '52:54:00:12:34:59' %}
{% set memory = '1024' %}

Same here, this is a device configuration that should go into /etc/lava-server/dispatcher-config/devices/

So then, if I do:
root@stretch:/etc/lava-server/dispatcher-config/device-types#
lava-server manage device-types list -a

I see the device qemu01 there. Newly created. But I do NOT see qemu device.

This command will only list the device-types not the devices.

To list the devices, use

lava-server manage devices list

It says:
On the command line, you can add device types (for instance a QEMU
type device with a hostname qemu01) using:
lava-server manage devices add --device-type qemu --worker <worker> qemu01

The worker (or dispatcher) is the name of the machine that will run the qemu or (for boards) which is connected to the device you are creating.

You can see the workers that are actually active in your instance with

lava-server manage workers list

Rgds

Rémi Duraffort