[Intel-gfx] [PATCH v4] drm/i915/gvt: return the correct usable aperture size under gvt environment

[Joonas Lahtinen]

On ke, 2017-05-10 at 10:59 +0800, Weinan Li wrote:
> I915_GEM_GET_APERTURE ioctl is used to probe aperture size from userspace.
> In gvt environment, each vm only use the ballooned part of aperture, so we
> should return the correct available aperture size exclude the reserved part
> by balloon.
> 
> v2: add 'reserved' in struct i915_address_space to record the reserved size
> in ggtt.
> 
> v3: remain aper_size as total, adjust aper_available_size exclude reserved
> and pinned. UMD driver need to adjust the max allocation size according to
> the available aperture size but not total size. KMD return the correct
> usable aperture size any time.
> 
> v4: add onion teardown to balloon and deballoon to make sure the reserved
> stays correct. Code style refine.

There's no onion teardown seen yet, please read:

https://www.kernel.org/doc/html/v4.10/process/coding-style.html#central
ized-exiting-of-functions

Please incorporate the addition to vgt_balloon_space function to reduce
code duplication.

Once the proper teardown is implemented, intel_vgt_deballoon function
should unconditionally remove the drm_mm nodes as there's no condition
when only one of them would be allocated. And intel_vgt_balloon
definitely should not call intel_vgt_deballoon in error path as per the
coding style above.

Regards, Joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation