Re: [PATCH 00/15] Intel Xe GPU Debug Support (eudebug) v4

["Christian König" <christian.koenig@amd.com>]

On 08.08.25 12:43, Mika Kuoppala wrote:
> Hi,
> 
> This is the v4 patch series for Intel Xe GPU debug support (eudebug).
> 
> This series continues from the following previous submissions:
> - v1: https://lists.freedesktop.org/archives/intel-xe/2024-July/043605.html
> - v2: https://lists.freedesktop.org/archives/intel-xe/2024-October/052260.html
> - v3: https://lists.freedesktop.org/archives/intel-xe/2024-December/061476.html
> 
> This is a major cleanup and rework of eudebug patch series to address the
> feedback for v3. Page fault handling is omitted for until we receive
> ack on core design, as there was no feedback on it on previous iterations.
> 
> ### Major Changes
> 
> #### 1. Elimination of ptrace_may_access() and pid
> 
> In previous series, the connection attempt was made using the process ID
> (PID) as the target. Access was checked using the `ptrace_may_access()`
> helper to achieve security parity with CPU-side debugging.
> 
> In v4, this has been changed to connect to a DRM client, using a file
> descriptor as the target. This approach eliminates the need for the
> `ptrace_may_access()` symbol export, as access control is now managed
> through the debugger process's access to the file descriptor. For example,
> accessing a remote DRM client requires the debugger process to
> successfully call `pidfd_getfd()` to obtain a duplicate of the target
> file descriptor.The 1:1 mapping between DRM clients and their debuggers
> eliminates the need for `EVENT_OPEN` and simplifies overall connection
> tracking.

It would be really nice if we could document that approach under Documentation/gpu.

> 
> #### 2. ELF binaries not held in kernel memory
> 
> In v4, debug data is delivered as a VM bind 'OP_ADD_DEBUG_DATA' extension.
> The ELF binaries are no longer stored within the Xe KMD but are instead
> kept in a file. The file path is passed as part of an extension in
> the newly introduced 'OP_ADD_DEBUG_DATA' VM bind operation. Alternatively
> pseudo-paths can be used to annotate special address ranges similar to
> /proc/<pid>/maps.
> 
> #### 3. Debug metadata not carried in VMA struct
> 
> Instead of attaching debug data to vma created by 'OP_MAP',
> we introduce separate ops for managing the metadata.
> Debug data is no longer held in the VMA struct. xe_vm contains a
> list of all associated debug data.

I need to take a closer look but that sounds like it takes a big step into the right direction.

Regards,
Christian.

> 
> ### Supported Hardware with v4
> - Lunarlake (LNL)
> - Battlemage (BMG)
> - Pantherlake (PTL)
> 
> The code for this submission can be found at:
> https://gitlab.freedesktop.org/miku/kernel/-/tree/eudebug-v4
> 
> Christoph Manszewski (5):
>   drm/xe: Introduce ADD_DEBUG_DATA and REMOVE_DEBUG_DATA vm bind ops
>   drm/xe/eudebug: Introduce vm bind and vm bind debug data events
>   drm/xe/eudebug_test: Introduce xe_eudebug wa kunit test
>   drm/xe: Implement SR-IOV and eudebug exclusivity
>   drm/xe: Add xe_client_debugfs and introduce debug_data file
> 
> Dominik Grzegorzek (5):
>   drm/xe/eudebug: Introduce exec_queue events
>   drm/xe: Add EUDEBUG_ENABLE exec queue property
>   drm/xe/eudebug: hw enablement for eudebug
>   drm/xe/eudebug: Introduce EU control interface
>   drm/xe/eudebug: Introduce per device attention scan worker
> 
> Mika Kuoppala (5):
>   drm/xe/eudebug: Introduce eudebug interface
>   drm/xe/eudebug: Introduce discovery for resources
>   drm/xe/eudebug: Add UFENCE events with acks
>   drm/xe/eudebug: vm open/pread/pwrite
>   drm/xe/eudebug: userptr vm pread/pwrite
> 
>  drivers/gpu/drm/xe/Kconfig                  |   10 +
>  drivers/gpu/drm/xe/Makefile                 |    7 +-
>  drivers/gpu/drm/xe/regs/xe_engine_regs.h    |    7 +
>  drivers/gpu/drm/xe/regs/xe_gt_regs.h        |   43 +
>  drivers/gpu/drm/xe/tests/xe_eudebug.c       |  189 ++
>  drivers/gpu/drm/xe/tests/xe_live_test_mod.c |    5 +
>  drivers/gpu/drm/xe/xe_client_debugfs.c      |  118 +
>  drivers/gpu/drm/xe/xe_client_debugfs.h      |   19 +
>  drivers/gpu/drm/xe/xe_debug_data.c          |  279 +++
>  drivers/gpu/drm/xe/xe_debug_data.h          |   22 +
>  drivers/gpu/drm/xe/xe_debug_data_types.h    |   25 +
>  drivers/gpu/drm/xe/xe_device.c              |   30 +-
>  drivers/gpu/drm/xe/xe_device.h              |   42 +
>  drivers/gpu/drm/xe/xe_device_types.h        |   40 +
>  drivers/gpu/drm/xe/xe_eudebug.c             | 2309 +++++++++++++++++++
>  drivers/gpu/drm/xe/xe_eudebug.h             |  116 +
>  drivers/gpu/drm/xe/xe_eudebug_hw.c          |  730 ++++++
>  drivers/gpu/drm/xe/xe_eudebug_hw.h          |   32 +
>  drivers/gpu/drm/xe/xe_eudebug_types.h       |  174 ++
>  drivers/gpu/drm/xe/xe_eudebug_vm.c          |  434 ++++
>  drivers/gpu/drm/xe/xe_eudebug_vm.h          |    8 +
>  drivers/gpu/drm/xe/xe_exec.c                |    2 +-
>  drivers/gpu/drm/xe/xe_exec_queue.c          |   51 +-
>  drivers/gpu/drm/xe/xe_exec_queue.h          |    2 +
>  drivers/gpu/drm/xe/xe_exec_queue_types.h    |    7 +
>  drivers/gpu/drm/xe/xe_gt.c                  |    1 +
>  drivers/gpu/drm/xe/xe_gt_debug.c            |  179 ++
>  drivers/gpu/drm/xe/xe_gt_debug.h            |   41 +
>  drivers/gpu/drm/xe/xe_hw_engine.h           |   14 +
>  drivers/gpu/drm/xe/xe_lrc.c                 |   10 +
>  drivers/gpu/drm/xe/xe_oa.c                  |    3 +-
>  drivers/gpu/drm/xe/xe_pci_sriov.c           |   10 +
>  drivers/gpu/drm/xe/xe_reg_sr.c              |   21 +-
>  drivers/gpu/drm/xe/xe_reg_sr.h              |    4 +-
>  drivers/gpu/drm/xe/xe_reg_whitelist.c       |    2 +-
>  drivers/gpu/drm/xe/xe_rtp.c                 |    2 +-
>  drivers/gpu/drm/xe/xe_sync.c                |   45 +-
>  drivers/gpu/drm/xe/xe_sync.h                |    8 +-
>  drivers/gpu/drm/xe/xe_sync_types.h          |   28 +-
>  drivers/gpu/drm/xe/xe_vm.c                  |  186 +-
>  drivers/gpu/drm/xe/xe_vm.h                  |   26 +
>  drivers/gpu/drm/xe/xe_vm_types.h            |   38 +
>  drivers/gpu/drm/xe/xe_wa_oob.rules          |    4 +
>  include/uapi/drm/xe_drm.h                   |   59 +
>  include/uapi/drm/xe_drm_eudebug.h           |  217 ++
>  45 files changed, 5552 insertions(+), 47 deletions(-)
>  create mode 100644 drivers/gpu/drm/xe/tests/xe_eudebug.c
>  create mode 100644 drivers/gpu/drm/xe/xe_client_debugfs.c
>  create mode 100644 drivers/gpu/drm/xe/xe_client_debugfs.h
>  create mode 100644 drivers/gpu/drm/xe/xe_debug_data.c
>  create mode 100644 drivers/gpu/drm/xe/xe_debug_data.h
>  create mode 100644 drivers/gpu/drm/xe/xe_debug_data_types.h
>  create mode 100644 drivers/gpu/drm/xe/xe_eudebug.c
>  create mode 100644 drivers/gpu/drm/xe/xe_eudebug.h
>  create mode 100644 drivers/gpu/drm/xe/xe_eudebug_hw.c
>  create mode 100644 drivers/gpu/drm/xe/xe_eudebug_hw.h
>  create mode 100644 drivers/gpu/drm/xe/xe_eudebug_types.h
>  create mode 100644 drivers/gpu/drm/xe/xe_eudebug_vm.c
>  create mode 100644 drivers/gpu/drm/xe/xe_eudebug_vm.h
>  create mode 100644 drivers/gpu/drm/xe/xe_gt_debug.c
>  create mode 100644 drivers/gpu/drm/xe/xe_gt_debug.h
>  create mode 100644 include/uapi/drm/xe_drm_eudebug.h
>