docs: Add page for device tests

Add a page with a brief overview of device tests and how to enable them
with pointers to the relevant documentation.

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

kernelci.org/content/en/kernel-community/_index.md

@@ -14,4 +14,6 @@ This section of the documentation shares instructions to:
 * [enable specific tests](../maestro/pipeline/developer-documentation/#enabling-a-new-test)
 * [visualize the results](view-results)
 
+For suggestions of device tests, see [device kselftests](device-tests).
+
 We know that the documentation above may not answer all your questions. We are working to improve it. We ask you to reach out to our mailing list at [kernelci@lists.linux.dev](mailto:kernelci@lists.linux.dev)  with questions and feedback. We are eager to hear from you!

kernelci.org/content/en/kernel-community/device-tests.md

@@ -0,0 +1,30 @@
+---
+title: "Device kselftests"
+date: 2024-10-01
+description: Overview of the process of enabling device kselftests on new platforms
+---
+
+Device kselftests provide a good starting point to validate basic kernel
+functionality. There are a few of them upstream, with varying coverage and
+requirements. See this documentation page for more information:
+https://lore.kernel.org/all/20241001-kselftest-device-docs-v1-1-be28b70dd855@collabora.com
+
+After deciding which test to run and satisfying its requirement (if any),
+enabling the test on a new platform in KernelCI is a matter of adding the
+platform to the test's scheduler entry. For example, for the DT kselftest on
+ARM64, that would be adding the platform here:
+
+https://github.com/kernelci/kernelci-pipeline/blob/08e7bce8044d04faa79028273384d9c30a1f5d9e/config/pipeline.yaml#L2495
+
+For the other tests, just look for the entry in the ``scheduler`` that has
+``collections`` set to the kselftest path as per the upstream documentation (for
+example, for the error logs test, look for ``collections: devices/error_logs``).
+To enable the test on a different architecture, look for the entry that has the
+build corresponding to that architecture, or create it if there's none. See
+https://docs.kernelci.org/maestro/pipeline/developer-documentation/#an-example-of-enabling-a-new-job
+for more details on enabling tests in KernelCI.
+
+Note: In addition to the tests described in the upstream documentation, there is
+also an alternative to the DT kselftest for ACPI platforms: the ``acpi``
+kselftest. It is not described there as it hasn't been merged upstream, but it
+is already being run in KernelCI.