[PATCH v12 00/22] gpu: nova-core: Add memory management support

Joel Fernandes
2026-04-25T21:15:13Z

The patches are based on drm-rust-next and work on Ampere, and should work on
Blackwell (with a few more patches) once John's Blackwell patches are merged,
however it does not depend on those patches and can independently go in.

This series depends on Alex Courbot's bitfield series:
https://lore.kernel.org/all/20260409-bitfield-v2-0-23ac400071cb@nvidia.com/

The git tree with all patches can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux.git (tag: nova-mm-v12-20260425)

Change log:

Changes from v11 to v12:
- Make VMM use maple tree for virtual address range management (Danilo)
- Added "rust: maple_tree: implement Send and Sync for MapleTree" sent out before.
- Refactored MMU-version dispatch from wrapper enums (Pte/Pde/DualPde) to
trait-based generics (PteOps, PdeOps, DualPdeOps, MmuConfig). (Eliot, Alex)
- Replaces the previous `try_access()` patterns with access() (Danilo).
- Added Reviewed-by John Hubbard on some GSP patches.
- Removed the `Static GPU information from GSP.` comment that added no
information beyond the field name (John Hubbard).
- Removed Nouveau references from one comment (John Hubbard).
- PRAMIN doc: widened address columns in the ASCII diagrams.
- Logged FB region and total VRAM at boot (Alex).
- Dropped a useless `as_ref()` in PRAMIN run_self_test.

Changes from v10 to v11:
- Rebased on new bitfield! macro infrastructure.
- Squashed Zhi Wang's "Use runtime BAR1 size" fix with Co-develop tag (Eliot)
- Refactored page table walker to generics (PtWalkInner<M: MmuConfig>) (Eliot, Alex)
- Changed first_usable_fb_region() to return Range<u64> with checked_add (Eliot)
- Tightened visibility from pub(crate) to pub(super) across mm submodules (Eliot)
- TLB flush: added ack_globally bit for global engine acknowledgment.

Changes from v9 to v10:
- Rebased and dropped patches already merged in to drm-rust-next.
- GPU_BUDDY select folded into GpuMm patch.
- updated code with new register macro API.
- Refactored fb_regions() to use iterator (Alex Courbot).
- Renamed Pramin::window() to get_window() to make it more clear it is
'acquiring a resource'.
- Converted Bar0WindowTarget to bounded_enum! macro, replacing TryFrom.
Allows to use `with_*` instead of `try_with_*`.

Changes from v8 to v9:
- Added fixes from Zhi Wang for bitfield position changes in virtual address
and larger BAR1 size on some platforms. Tested and working for vGPU usecase!
- Refactored gsp: boot() to return only GspStaticInfo, removing FbLayout (Alex).
- bar1_pde_base and bar2_pde_base are now accessed via GspStaticInfo directly (Alex).
- Added new patch "gsp: Expose total physical VRAM end from FB region info"
introducing total_fb_end() to expose VRAM extent (Alex).
- Consolidated usable VRAM and BarUser setup; removed dedicated
"fb: Add usable_vram field to FbLayout", "mm: Use usable VRAM region for
buddy allocator", and "mm: Add BarUser to struct Gpu and create at boot".

Changes from v7 to v8:
- Incorporated "Select GPU_BUDDY for VRAM allocation" patch from the
dependency series (Alex).
- Significant patch reordering for better logical flow (GSP/FB patches
moved earlier, page table patches, Vmm, Bar1, tests) (Alex).
- Replaced several 'as' usages with into_safe_cast() (Danilo, Alex).
- Updated BAR 1 test cases to include exercising the block size API
(Eliot, Danilo).

Changes from v6 to v7:
- Addressed DMA fence signalling usecase per Danilo's feedback.

Pre v6:
- Simplified PRAMIN code (John Hubbard, Alex Courbot).
- Handled different MMU versions: ver2 versus ver3 (John Hubbard).
- Added BAR1 usecase so we have user of DRM Buddy / VMM (John Hubbard).
- Iterating over clist/buddy bindings.

Link to v11: https://lore.kernel.org/all/20260415210548.3776595-21-joelagnelf@nvidia.com/
Link to v10: https://lore.kernel.org/all/20260331212048.2229260-1-joelagnelf@nvidia.com/
Link to v9: https://lore.kernel.org/all/20260311004008.2208806-1-joelagnelf@nvidia.com/
Link to v8: https://lore.kernel.org/all/20260224225323.3312204-1-joelagnelf@nvidia.com/
Link to v7: https://lore.kernel.org/all/20260218212020.800836-1-joelagnelf@nvidia.com/

Joel Fernandes (22):
gpu: nova-core: gsp: Return GspStaticInfo from boot()
gpu: nova-core: gsp: Extract usable FB region from GSP
gpu: nova-core: gsp: Expose total physical VRAM end from FB region
info
gpu: nova-core: mm: Add support to use PRAMIN windows to write to VRAM
docs: gpu: nova-core: Document the PRAMIN aperture mechanism
gpu: nova-core: mm: Add common memory management types
gpu: nova-core: mm: Add TLB flush support
gpu: nova-core: mm: Add GpuMm centralized memory manager
gpu: nova-core: mm: Add common types for all page table formats
gpu: nova-core: mm: Add MMU v2 page table types
gpu: nova-core: mm: Add MMU v3 page table types
gpu: nova-core: mm: Add page table entry operation traits
gpu: nova-core: mm: Add page table walker for MMU v2/v3
gpu: nova-core: mm: Add Virtual Memory Manager
gpu: nova-core: mm: Add virtual address range tracking to VMM
gpu: nova-core: mm: Add multi-page mapping API to VMM
gpu: nova-core: Add BAR1 aperture type and size constant
gpu: nova-core: mm: Add BAR1 user interface
gpu: nova-core: mm: Add BAR1 memory management self-tests
gpu: nova-core: mm: Add PRAMIN aperture self-tests
gpu: nova-core: mm: pramin: drop useless as_ref() in run_self_test
rust: maple_tree: implement Send and Sync for MapleTree

Documentation/gpu/nova/core/pramin.rst | 123 +++++
Documentation/gpu/nova/index.rst | 1 +
drivers/gpu/nova-core/Kconfig | 11 +
drivers/gpu/nova-core/driver.rs | 3 +
drivers/gpu/nova-core/gpu.rs | 99 +++-
drivers/gpu/nova-core/gsp/boot.rs | 12 +-
drivers/gpu/nova-core/gsp/commands.rs | 18 +-
drivers/gpu/nova-core/gsp/fw/commands.rs | 60 ++-
drivers/gpu/nova-core/mm.rs | 267 +++++++++++
drivers/gpu/nova-core/mm/bar_user.rs | 400 ++++++++++++++++
drivers/gpu/nova-core/mm/pagetable.rs | 418 +++++++++++++++++
drivers/gpu/nova-core/mm/pagetable/map.rs | 355 ++++++++++++++
drivers/gpu/nova-core/mm/pagetable/ver2.rs | 306 ++++++++++++
drivers/gpu/nova-core/mm/pagetable/ver3.rs | 431 +++++++++++++++++
drivers/gpu/nova-core/mm/pagetable/walk.rs | 258 +++++++++++
drivers/gpu/nova-core/mm/pramin.rs | 515 +++++++++++++++++++++
drivers/gpu/nova-core/mm/tlb.rs | 130 ++++++
drivers/gpu/nova-core/mm/vmm.rs | 370 +++++++++++++++
drivers/gpu/nova-core/nova_core.rs | 1 +
drivers/gpu/nova-core/regs.rs | 77 +++
rust/kernel/maple_tree.rs | 29 +-
21 files changed, 3868 insertions(+), 16 deletions(-)
create mode 100644 Documentation/gpu/nova/core/pramin.rst
create mode 100644 drivers/gpu/nova-core/mm.rs
create mode 100644 drivers/gpu/nova-core/mm/bar_user.rs
create mode 100644 drivers/gpu/nova-core/mm/pagetable.rs
create mode 100644 drivers/gpu/nova-core/mm/pagetable/map.rs
create mode 100644 drivers/gpu/nova-core/mm/pagetable/ver2.rs
create mode 100644 drivers/gpu/nova-core/mm/pagetable/ver3.rs
create mode 100644 drivers/gpu/nova-core/mm/pagetable/walk.rs
create mode 100644 drivers/gpu/nova-core/mm/pramin.rs
create mode 100644 drivers/gpu/nova-core/mm/tlb.rs
create mode 100644 drivers/gpu/nova-core/mm/vmm.rs

base-commit: 74a720e00dfbb3ab92934660b4692b90331623ac
--
2.34.1