drm/amdgpu: mark A+A VF VRAM mappings as system memory

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On the A+A VF the GPU reaches its HBM over the system memory path at a
system physical address, so page table entries covering VRAM have to
carry AMDGPU_PTE_SYSTEM and the addresses they hold have to be physical
rather than MC addresses.

Set the SYSTEM bit in the PDB0 entries and in amdgpu_ttm_tt_pde_flags(),
and convert the VRAM address in amdgpu_gmc_get_pde_for_bo() with
amdgpu_gmc_vram_mc2pa().

NPA mappings still require VSCT=0011 (PTE.S=0). Clear SYSTEM in
gmc_v12_1_get_npa_flags() and amdgpu_ualink_peer_remote_init() so NPA
PTEs do not inherit the VRAM SYSTEM bit.

v2:
- Use (sriov_vf || passthrough) and amdgpu_virt_vram_is_spm() for
  PDB0/TTM SYSTEM bits and mc2pa.

v3:
- Rely on amdgpu_virt_vram_is_spm() without redundant VF/passthrough
  checks.

v4:
- Explicitly clear AMDGPU_PTE_SYSTEM for NPA (VSCT=0011).

Signed-off-by: Zhigang Luo <zhigang.luo@amd.com>
Signed-off-by: Fangsheng Huang <Fangsheng.Huang@amd.com>
Signed-off-by: YuBiao Wang <YuBiao.Wang@amd.com>
Reviewed-by: Philip Yang <philip.yang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

...

This commit is contained in:

Zhigang Luo 2026-08-31 15:39:03 -04:00 • committed by Alex Deucher

parent 489ee1c344

commit 010e510347

4 changed files with 22 additions and 3 deletions

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9

drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c

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14

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c

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1

drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c

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1

drivers/gpu/drm/amd/amdgpu/gmc_v12_1.c

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