On Wed, Aug 14, 2024 at 03:48:32PM +0200, Andi Shyti wrote:
> Hi,
>
> I am resending this patch series, not to disregard the previous
> discussions, but to ensure it gets tested with the IGTs that
> Krzysztof has provided.
>
> This patch series finalizes the memory mapping fixes and
> improvements by enabling partial memory mapping for CPU memory as
> well.
>
> The concept of partial memory mapping, achieved by adding an
> object offset, was implicitly introduced in commit 8bdd9ef7e9b1
> ("drm/i915/gem: Fix Virtual Memory mapping boundaries
> calculation") for GTT memory.
>
> To address a previous discussion with Sima and Matt, this feature
> is used by Mesa and is required across all platforms utilizing
> Mesa. Although Nirmoy suggested using the Fixes tag to backport
Other vendors than Intel too?
> this to previous kernels, I view this as a new feature rather
> than a fix.
>
> Lionel, please let me know if you have a different perspective
> and believe this should be treated as a bug fix, requiring it
> to be backported to stable kernels.
>
> The IGTs have been developed in collaboration with the Mesa team
> to replicate the exact Mesa use case[*].
>
> Thanks Chris for the support, thanks Krzysztof for taking care of
> the IGT tests, thanks Nirmoy for your reviews and thanks Sima and
> Matt for the discussion on this series.
>
> Andi
>
> [*] https://patchwork.freedesktop.org/patch/608232/?series=137303&rev=1
So here is really quick test [1] which I put together in Xe to test
partial mmaps, not as complete as the i915 one though.
It fails on the Xe baseline.
It pass if with [2] in drm_gem.c:drm_gem_mmap. Blindly changing that
function might not be the correct solution but thought I'd share as a
reference.
Matt
[1] https://patchwork.freedesktop.org/patch/608268/?series=137313&rev=1
[2] s/drm_vma_offset_exact_lookup_locked/drm_vma_offset_lookup_locked
>
> Test-with: 20240814132404.18392-1-krzysztof.niemiec@xxxxxxxxx
>
> Changelog:
> ==========
> v1 -> v2
> - Added Nirmoy's tags.
>
> Andi Shyti (2):
> drm/i915/gem: Do not look for the exact address in node
> drm/i915/gem: Calculate object page offset for partial memory mapping
>
> drivers/gpu/drm/i915/gem/i915_gem_mman.c | 10 ++++++----
> drivers/gpu/drm/i915/i915_mm.c | 12 +++++++++++-
> drivers/gpu/drm/i915/i915_mm.h | 3 ++-
> 3 files changed, 19 insertions(+), 6 deletions(-)
>
> --
> 2.45.2
>
