Re: [PATCH i-g-t 0/2] test/intel/xe_vm: Add overcommit and no‑overcommit handling tests

["Hellstrom, Thomas" <thomas.hellstrom@intel.com>]

Hi, Thomas,

On Thu, 2026-02-12 at 19:03 +0000, Sobin Thomas wrote:
> This series adds coverage to xe_vm test by adding over commit test in
> fault mode and
> non fault mode.
> Also added support to test the no overcommit flag
> (DRM_XE_VM_CREATE_NO_VM_OVERCOMMIT)
> 
> Sobin Thomas (2):
>   tests/intel/xe_vm: overcommit tests for fault-mode and non-fault-
> mode
>     VMs
>   test/intel/xe_vm: Test to check no overcommit flag in fault mode
> 
>  include/drm-uapi/xe_drm.h |   1 +
>  tests/intel/xe_vm.c       | 634
> +++++++++++++++++++++++++++++++++++++-
>  2 files changed, 630 insertions(+), 5 deletions(-)

I wonder, is it possible to create a single test for the different
modes and select the different modes with flags? The following should
hold for bos in VRAM:

1. DRM_XE_VM_CREATE_FLAG_LR_MODE:
a) If bos are created in VRAM only and either local to the VM or
created with the flag DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING, then
overcommit is not allowed. Compute is relying on this and this is what
"test_oom" tests.
b) If bos are created external and without the flag
DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING, overcommit is allowed but will
error on first exec.

2. DRM_XE_VM_CREATE_FLAG_LR_MODE | DRM_XE_VM_CREATE_FLAG_FAULT_MODE:
Overcommit is always allowed. Should not error on exec.

3. !DRM_XE_VM_CREATE_FLAG_LR_MODE:
Overcommit is always allowed. Should error on exec if overcommited.

4. DRM_XE_VM_CREATE_FLAG_LR_MODE | DRM_XE_VM_CREATE_FLAG_FAULT_MODE:
   DRM_XE_VM_CREATE_FLAG_NO_VM_OVERCOMMIT.
Should behave just like 1.)

So it should be possible to create an array with VM create flags, bo
create mode and expected results and use a single test?

For bos in system memory the above should also hold but with the
additional problem that it is likely that the oom killer is hit. In
particular with systems without swap.

Thanks,
Thomas