Commit 6f91f44d authored by Gabriela Bittencourt's avatar Gabriela Bittencourt Committed by Rodrigo Siqueira
Browse files

drm/doc: Add VKMS module description and use to "Testing and Validation" 



Add a description on VKMS module and the cases in which it should be used.
There's a brief explanation on how to set it and use it in a VM, along with
an example of running an igt-test.

Changes since V3:
 Rodrigo:
 - Change the log message to imperative
 - Fix some bad spelling/writing
 - Add a blank line before enumeration

Changes since V2:
 Andre:
 - Avoid repetition of words in the same sentence;
 - Make the explanation on 'setting the kernel' shorter, eliminate the
   'make menuconfig' command;
 - Add tab on enumeration to have one line per item;
 - Clarify from each machine igt-tests commands should be ran on.

Reviewed-by: default avatarRodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Signed-off-by: default avatarGabriela Bittencourt <gabrielabittencourt00@gmail.com>
Signed-off-by: default avatarRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191104162705.19735-1-gabrielabittencourt00@gmail.com
parent f7948907

Documentation/gpu/drm-uapi.rst

+37 −0
Original line number Diff line number Diff line
@@ -257,6 +257,43 @@ core don't regress existing functionality. This test suite is called IGT and 
its code and instructions to build and run can be found in

https://gitlab.freedesktop.org/drm/igt-gpu-tools/.



Using VKMS to test DRM API

--------------------------



VKMS is a software-only model of a KMS driver that is useful for testing

and for running compositors. VKMS aims to enable a virtual display without

the need for a hardware display capability. These characteristics made VKMS

a perfect tool for validating the DRM core behavior and also support the

compositor developer. VKMS makes it possible to test DRM functions in a

virtual machine without display, simplifying the validation of some of the

core changes.



To Validate changes in DRM API with VKMS, start setting the kernel: make

sure to enable VKMS module; compile the kernel with the VKMS enabled and

install it in the target machine. VKMS can be run in a Virtual Machine

(QEMU, virtme or similar). It's recommended the use of KVM with the minimum

of 1GB of RAM and four cores.



It's possible to run the IGT-tests in a VM in two ways:



	1. Use IGT inside a VM

	2. Use IGT from the host machine and write the results in a shared directory.



As follow, there is an example of using a VM with a shared directory with

the host machine to run igt-tests. As an example it's used virtme::



	$ virtme-run --rwdir /path/for/shared_dir --kdir=path/for/kernel/directory --mods=auto



Run the igt-tests in the guest machine, as example it's ran the 'kms_flip'

tests::



	$ /path/for/igt-gpu-tools/scripts/run-tests.sh -p -s -t "kms_flip.*" -v



In this example, instead of build the igt_runner, Piglit is used

(-p option); it's created html summary of the tests results and it's saved

in the folder "igt-gpu-tools/results"; it's executed only the igt-tests

matching the -t option.



Display CRC Support

-------------------

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