linux-stable.git/drivers/gpu/drm/xe/xe_exec_queue.c, branch v6.15 Linux kernel stable tree drm/xe: Add WA BB to capture active context utilization 2025-05-14T16:03:29+00:00 Umesh Nerlige Ramappa umesh.nerlige.ramappa@intel.com 2025-05-09T16:12:03+00:00 617d824c5323b8474b3665ae6c410c98b839e0b0 Context Timestamp (CTX_TIMESTAMP) in the LRC accumulates the run ticks of the context, but only gets updated when the context switches out. In order to check how long a context has been active before it switches out, two things are required: (1) Determine if the context is running: To do so, we program the WA BB to set an initial value for CTX_TIMESTAMP in the LRC. The value chosen is 1 since 0 is the initial value when the LRC is initialized. During a query, we just check for this value to determine if the context is active. If the context switched out, it would overwrite this location with the actual CTX_TIMESTAMP MMIO value. Note that WA BB runs as the last part of the context restore, so reusing this LRC location will not clobber anything. (2) Calculate the time that the context has been active for: The CTX_TIMESTAMP ticks only when the context is active. If a context is active, we just use the CTX_TIMESTAMP MMIO as the new value of utilization. While doing so, we need to read the CTX_TIMESTAMP MMIO for the specific engine instance. Since we do not know which instance the context is running on until it is scheduled, we also read the ENGINE_ID MMIO in the WA BB and store it in the PPHSWP. Using the above 2 instructions in a WA BB, capture active context utilization. v2: (Matt Brost) - This breaks TDR, fix it by saving the CTX_TIMESTAMP register "drm/xe: Save CTX_TIMESTAMP mmio value instead of LRC value" - Drop tile from LRC if using gt "drm/xe: Save the gt pointer in LRC and drop the tile" v3: - Remove helpers for bb_per_ctx_ptr (Matt) - Add define for context active value (Matt) - Use 64 bit CTX TIMESTAMP for platforms that support it. For platforms that don't, live with the rare race. (Matt, Lucas) - Convert engine id to hwe and get the MMIO value (Lucas) - Correct commit message on when WA BB runs (Lucas) v4: - s/GRAPHICS_VER(...)/xe->info.has_64bit_timestamp/ (Matt) - Drop support for active utilization on a VF (CI failure) - In xe_lrc_init ensure the lrc value is 0 to begin with (CI regression) v5: - Minor checkpatch fix - Squash into previous commit and make TDR use 32-bit time - Update code comment to match commit msg Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4532 Cc: <stable@vger.kernel.org> # v6.13+ Suggested-by: Lucas De Marchi <lucas.demarchi@intel.com> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com> Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com> Link: https://lore.kernel.org/r/20250509161159.2173069-8-umesh.nerlige.ramappa@intel.com (cherry picked from commit 82b98cadb01f63cdb159e596ec06866d00f8e8c7) Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> 
Context Timestamp (CTX_TIMESTAMP) in the LRC accumulates the run ticks
of the context, but only gets updated when the context switches out. In
order to check how long a context has been active before it switches
out, two things are required:

(1) Determine if the context is running:

To do so, we program the WA BB to set an initial value for CTX_TIMESTAMP
in the LRC. The value chosen is 1 since 0 is the initial value when the
LRC is initialized. During a query, we just check for this value to
determine if the context is active. If the context switched out, it
would overwrite this location with the actual CTX_TIMESTAMP MMIO value.
Note that WA BB runs as the last part of the context restore, so reusing
this LRC location will not clobber anything.

(2) Calculate the time that the context has been active for:

The CTX_TIMESTAMP ticks only when the context is active. If a context is
active, we just use the CTX_TIMESTAMP MMIO as the new value of
utilization. While doing so, we need to read the CTX_TIMESTAMP MMIO
for the specific engine instance. Since we do not know which instance
the context is running on until it is scheduled, we also read the
ENGINE_ID MMIO in the WA BB and store it in the PPHSWP.

Using the above 2 instructions in a WA BB, capture active context
utilization.

v2: (Matt Brost)
- This breaks TDR, fix it by saving the CTX_TIMESTAMP register
  "drm/xe: Save CTX_TIMESTAMP mmio value instead of LRC value"
- Drop tile from LRC if using gt
  "drm/xe: Save the gt pointer in LRC and drop the tile"

v3:
- Remove helpers for bb_per_ctx_ptr (Matt)
- Add define for context active value (Matt)
- Use 64 bit CTX TIMESTAMP for platforms that support it. For platforms
  that don't, live with the rare race. (Matt, Lucas)
- Convert engine id to hwe and get the MMIO value (Lucas)
- Correct commit message on when WA BB runs (Lucas)

v4:
- s/GRAPHICS_VER(...)/xe->info.has_64bit_timestamp/ (Matt)
- Drop support for active utilization on a VF (CI failure)
- In xe_lrc_init ensure the lrc value is 0 to begin with (CI regression)

v5:
- Minor checkpatch fix
- Squash into previous commit and make TDR use 32-bit time
- Update code comment to match commit msg

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4532
Cc: <stable@vger.kernel.org> # v6.13+
Suggested-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250509161159.2173069-8-umesh.nerlige.ramappa@intel.com
(cherry picked from commit 82b98cadb01f63cdb159e596ec06866d00f8e8c7)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
drm/xe: Allow fault injection in exec queue IOCTLs 2025-03-06T11:16:35+00:00 Francois Dugast francois.dugast@intel.com 2025-03-05T15:06:59+00:00 5148da09dcd3f00913ddfc5d03901c4de56b61e3 Use fault injection infrastructure to allow specific functions to be configured over debugfs for failing during the execution of xe_exec_queue_create_ioctl(). xe_exec_queue_destroy_ioctl() and xe_exec_queue_get_property_ioctl() are not considered as there is no unwinding code to test with fault injection. This allows more thorough testing from user space by going through code paths for error handling and unwinding which cannot be reached by simply injecting errors in IOCTL arguments. This can help increase code robustness. The corresponding IGT series is: https://patchwork.freedesktop.org/series/144138/ Reviewed-by: Sai Teja Pottumuttu <sai.teja.pottumuttu@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250305150659.46276-1-francois.dugast@intel.com Signed-off-by: Francois Dugast <francois.dugast@intel.com> 
Use fault injection infrastructure to allow specific functions to
be configured over debugfs for failing during the execution of
xe_exec_queue_create_ioctl(). xe_exec_queue_destroy_ioctl() and
xe_exec_queue_get_property_ioctl() are not considered as there is
no unwinding code to test with fault injection.

This allows more thorough testing from user space by going through
code paths for error handling and unwinding which cannot be reached
by simply injecting errors in IOCTL arguments. This can help
increase code robustness.

The corresponding IGT series is:
https://patchwork.freedesktop.org/series/144138/

Reviewed-by: Sai Teja Pottumuttu <sai.teja.pottumuttu@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250305150659.46276-1-francois.dugast@intel.com
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
drm/xe/uapi: Use hint for guc to set GT frequency 2025-03-05T04:24:24+00:00 Tejas Upadhyay tejas.upadhyay@intel.com 2025-02-28T07:02:24+00:00 5488bec96bccbd87335921338f8dc38b87db7d2c Allow user to provide a low latency hint. When set, KMD sends a hint to GuC which results in special handling for that process. SLPC will ramp the GT frequency aggressively every time it switches to this process. We need to enable the use of SLPC Compute strategy during init, but it will apply only to processes that set this bit during process creation. Improvement with this approach as below: Before, :~$ NEOReadDebugKeys=1 EnableDirectSubmission=0 clpeak --kernel-latency Platform: Intel(R) OpenCL Graphics Device: Intel(R) Graphics [0xe20b] Driver version : 24.52.0 (Linux x64) Compute units : 160 Clock frequency : 2850 MHz Kernel launch latency : 283.16 us After, :~$ NEOReadDebugKeys=1 EnableDirectSubmission=0 clpeak --kernel-latency Platform: Intel(R) OpenCL Graphics Device: Intel(R) Graphics [0xe20b] Driver version : 24.52.0 (Linux x64) Compute units : 160 Clock frequency : 2850 MHz Kernel launch latency : 63.38 us Compute PR: https://github.com/intel/compute-runtime/pull/794 Mesa PR: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33214 IGT PR: https://patchwork.freedesktop.org/patch/639989/ V10(Lucas): - Remove doc from drm-uapi.rst v9(Vinay): - remove extra line, align commit message v8(Vinay): - Add separate example for using low latency hint v7(Jose): - Update UMD PR - applicable to all gpus V6: - init flags, remove redundant flags check (MAuld) V5: - Move uapi doc to documentation and GuC ABI specific change (Rodrigo) - Modify logic to restrict exec queue flags (MAuld) V4: - To make it clear, dont use exec queue word (Vinay) - Correct typo in description of flag (Jose/Vinay) - rename set_strategy api and replace ctx with exec queue(Vinay) - Start with 0th bit to indentify user flags (Jose) V3: - Conver user flag to kernel internal flag and use (Oak) - Support query config for use to check kernel support (Jose) - Dont need to take runtime pm (Vinay) V2: - DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT 1 planned for other hint(Szymon) - Add motivation to description (Lucas) Acked-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250228070224.739295-2-tejas.upadhyay@intel.com Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com> 
Allow user to provide a low latency hint. When set, KMD sends a hint
to GuC which results in special handling for that process. SLPC will
ramp the GT frequency aggressively every time it switches to this
process.

We need to enable the use of SLPC Compute strategy during init, but
it will apply only to processes that set this bit during process
creation.

Improvement with this approach as below:

Before,

:~$ NEOReadDebugKeys=1 EnableDirectSubmission=0 clpeak --kernel-latency
Platform: Intel(R) OpenCL Graphics
  Device: Intel(R) Graphics [0xe20b]
    Driver version  : 24.52.0 (Linux x64)
    Compute units   : 160
    Clock frequency : 2850 MHz
    Kernel launch latency : 283.16 us

After,

:~$ NEOReadDebugKeys=1 EnableDirectSubmission=0 clpeak --kernel-latency
Platform: Intel(R) OpenCL Graphics
  Device: Intel(R) Graphics [0xe20b]
    Driver version  : 24.52.0 (Linux x64)
    Compute units   : 160
    Clock frequency : 2850 MHz

    Kernel launch latency : 63.38 us

Compute PR: https://github.com/intel/compute-runtime/pull/794
Mesa PR: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33214
IGT PR: https://patchwork.freedesktop.org/patch/639989/

V10(Lucas):
  - Remove doc from drm-uapi.rst
v9(Vinay):
  - remove extra line, align commit message
v8(Vinay):
  - Add separate example for using low latency hint
v7(Jose):
  - Update UMD PR
  - applicable to all gpus
V6:
  - init flags, remove redundant flags check (MAuld)
V5:
  - Move uapi doc to documentation and GuC ABI specific change (Rodrigo)
  - Modify logic to restrict exec queue flags (MAuld)
V4:
  - To make it clear, dont use exec queue word (Vinay)
  - Correct typo in description of flag (Jose/Vinay)
  - rename set_strategy api and replace ctx with exec queue(Vinay)
  - Start with 0th bit to indentify user flags (Jose)
V3:
  - Conver user flag to kernel internal flag and use (Oak)
  - Support query config for use to check kernel support (Jose)
  - Dont need to take runtime pm (Vinay)
V2:
  - DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT 1 planned for other hint(Szymon)
  - Add motivation to description (Lucas)

Acked-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250228070224.739295-2-tejas.upadhyay@intel.com
Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
drm/xe: Drop unnecessary GT lookup in xe_exec_queue_create_ioctl() 2025-02-19T15:14:59+00:00 Matt Roper matthew.d.roper@intel.com 2025-02-18T20:05:12+00:00 a1e5b6d83e03d60d15ba393cbbd7d5c13e5cf0b3 xe_exec_queue_create_ioctl() performs a lookup of the xe_gt for the GT ID passed from userspace, but the result is never actually used. Since there's already a separate (and earlier) check that the ID passed from userspace is valid, the unnecessary lookup can be removed. Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com> Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250218200511.4050060-2-matthew.d.roper@intel.com Signed-off-by: Matt Roper <matthew.d.roper@intel.com> 
xe_exec_queue_create_ioctl() performs a lookup of the xe_gt for the GT
ID passed from userspace, but the result is never actually used.  Since
there's already a separate (and earlier) check that the ID passed from
userspace is valid, the unnecessary lookup can be removed.

Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250218200511.4050060-2-matthew.d.roper@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
drm/xe/pxp/uapi: Add userspace and LRC support for PXP-using queues 2025-02-03T19:51:18+00:00 Daniele Ceraolo Spurio daniele.ceraolospurio@intel.com 2025-01-29T17:41:32+00:00 72d479601d67026c4fafaad21762a777cf41f906 Userspace is required to mark a queue as using PXP to guarantee that the PXP instructions will work. In addition to managing the PXP sessions, when a PXP queue is created the driver will set the relevant bits in its context control register. On submission of a valid PXP queue, the driver will validate all encrypted objects mapped to the VM to ensured they were encrypted with the current key. v2: Remove pxp_types include outside of PXP code (Jani), better comments and code cleanup (John) v3: split the internal PXP management to a separate patch for ease of review. re-order ioctl checks to always return -EINVAL if parameters are invalid, rebase on msix changes. Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> Cc: John Harrison <John.C.Harrison@Intel.com> Reviewed-by: John Harrison <John.C.Harrison@Intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250129174140.948829-9-daniele.ceraolospurio@intel.com 
Userspace is required to mark a queue as using PXP to guarantee that the
PXP instructions will work. In addition to managing the PXP sessions,
when a PXP queue is created the driver will set the relevant bits in
its context control register.

On submission of a valid PXP queue, the driver will validate all
encrypted objects mapped to the VM to ensured they were encrypted with
the current key.

v2: Remove pxp_types include outside of PXP code (Jani), better comments
and code cleanup (John)

v3: split the internal PXP management to a separate patch for ease of
review. re-order ioctl checks to always return -EINVAL if parameters are
invalid, rebase on msix changes.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250129174140.948829-9-daniele.ceraolospurio@intel.com
drm/xe/pxp: Add PXP queue tracking and session start 2025-02-03T19:51:16+00:00 Daniele Ceraolo Spurio daniele.ceraolospurio@intel.com 2025-01-29T17:41:31+00:00 f8caa80154c4b5481476d1aad8bef335b5f90e6d We expect every queue that uses PXP to be marked as doing so, to allow the driver to correctly manage the encryption status. The API for doing this from userspace is coming in the next patch, while this patch implement the management side of things. When a PXP queue is created, the driver will do the following: - Start the default PXP session if it is not already running; - assign an rpm ref to the queue to keep for its lifetime (this is required because PXP HWDRM sessions are killed by the HW suspend flow). Since PXP start and termination can race each other, this patch also introduces locking and a state machine to keep track of the pending operations. Note that since we'll need to take the lock from the suspend/resume paths as well, we can't do submissions while holding it, which means we need a slightly more complicated state machine to keep track of intermediate steps. v4: new patch in the series, split from the following interface patch to keep review manageable. Lock and status rework to not do submissions under lock. v5: Improve comments and error logs (John) Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> Cc: John Harrison <John.C.Harrison@Intel.com> Reviewed-by: John Harrison <John.C.Harrison@Intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250129174140.948829-8-daniele.ceraolospurio@intel.com 
We expect every queue that uses PXP to be marked as doing so, to allow
the driver to correctly manage the encryption status. The API for doing
this from userspace is coming in the next patch, while this patch
implement the management side of things. When a PXP queue is created,
the driver will do the following:

- Start the default PXP session if it is not already running;
- assign an rpm ref to the queue to keep for its lifetime (this is
  required because PXP HWDRM sessions are killed by the HW suspend flow).

Since PXP start and termination can race each other, this patch also
introduces locking and a state machine to keep track of the pending
operations. Note that since we'll need to take the lock from the
suspend/resume paths as well, we can't do submissions while holding it,
which means we need a slightly more complicated state machine to keep
track of intermediate steps.

v4: new patch in the series, split from the following interface patch to
keep review manageable. Lock and status rework to not do submissions
under lock.

v5: Improve comments and error logs (John)

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250129174140.948829-8-daniele.ceraolospurio@intel.com
drm/xe/pxp: Allocate PXP execution resources 2025-02-03T19:51:05+00:00 Daniele Ceraolo Spurio daniele.ceraolospurio@intel.com 2025-01-29T17:41:26+00:00 dcdd6b84d9acaa0794c29de7024cfdb20cfd7b92 PXP requires submissions to the HW for the following operations 1) Key invalidation, done via the VCS engine 2) Communication with the GSC FW for session management, done via the GSCCS. Key invalidation submissions are serialized (only 1 termination can be serviced at a given time) and done via GGTT, so we can allocate a simple BO and a kernel queue for it. Submissions for session management are tied to a PXP client (identified by a unique host_session_id); from the GSC POV this is a user-accessible construct, so all related submission must be done via PPGTT. The driver does not currently support PPGTT submission from within the kernel, so to add this support, the following changes have been included: - a new type of kernel-owned VM (marked as GSC), required to ensure we don't use fault mode on the engine and to mark the different lock usage with lockdep. - a new function to map a BO into a VM from within the kernel. v2: improve comments and function name, remove unneeded include (John) v3: fix variable/function names in documentation Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: John Harrison <John.C.Harrison@Intel.com> Reviewed-by: John Harrison <John.C.Harrison@Intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250129174140.948829-3-daniele.ceraolospurio@intel.com 
PXP requires submissions to the HW for the following operations

1) Key invalidation, done via the VCS engine
2) Communication with the GSC FW for session management, done via the
   GSCCS.

Key invalidation submissions are serialized (only 1 termination can be
serviced at a given time) and done via GGTT, so we can allocate a simple
BO and a kernel queue for it.

Submissions for session management are tied to a PXP client (identified
by a unique host_session_id); from the GSC POV this is a user-accessible
construct, so all related submission must be done via PPGTT. The driver
does not currently support PPGTT submission from within the kernel, so
to add this support, the following changes have been included:

- a new type of kernel-owned VM (marked as GSC), required to ensure we
  don't use fault mode on the engine and to mark the different lock
  usage with lockdep.
- a new function to map a BO into a VM from within the kernel.

v2: improve comments and function name, remove unneeded include (John)
v3: fix variable/function names in documentation

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250129174140.948829-3-daniele.ceraolospurio@intel.com
Merge tag 'v6.13-rc6' into drm-next 2025-01-10T04:24:17+00:00 Dave Airlie airlied@redhat.com 2025-01-10T04:24:17+00:00 f6001870edeabf0f7bc0460303d0cdbb9f0b3bc4 This backmerges Linux 6.13-rc6 this is need for the newer pulls. Signed-off-by: Dave Airlie <airlied@redhat.com> 
This backmerges Linux 6.13-rc6 this is need for the newer pulls.

Signed-off-by: Dave Airlie <airlied@redhat.com>
drm/xe: Fix fault on fd close after unbind 2024-12-23T15:19:52+00:00 Lucas De Marchi lucas.demarchi@intel.com 2024-12-18T05:31:21+00:00 fe39b222a4139354d32ff9d46b88757f63f71d63 If userspace holds an fd open, unbinds the device and then closes it, the driver shouldn't try to access the hardware. Protect it by using drm_dev_enter()/drm_dev_exit(). This fixes the following page fault: <6> [IGT] xe_wedged: exiting, ret=98 <1> BUG: unable to handle page fault for address: ffffc901bc5e508c <1> #PF: supervisor read access in kernel mode <1> #PF: error_code(0x0000) - not-present page ... <4> xe_lrc_update_timestamp+0x1c/0xd0 [xe] <4> xe_exec_queue_update_run_ticks+0x50/0xb0 [xe] <4> xe_exec_queue_fini+0x16/0xb0 [xe] <4> __guc_exec_queue_fini_async+0xc4/0x190 [xe] <4> guc_exec_queue_fini_async+0xa0/0xe0 [xe] <4> guc_exec_queue_fini+0x23/0x40 [xe] <4> xe_exec_queue_destroy+0xb3/0xf0 [xe] <4> xe_file_close+0xd4/0x1a0 [xe] <4> drm_file_free+0x210/0x280 [drm] <4> drm_close_helper.isra.0+0x6d/0x80 [drm] <4> drm_release_noglobal+0x20/0x90 [drm] Fixes: 514447a12190 ("drm/xe: Stop accumulating LRC timestamp on job_free") Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/3421 Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241218053122.2730195-1-lucas.demarchi@intel.com Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> (cherry picked from commit 4ca1fd418338d4d135428a0eb1e16e3b3ce17ee8) Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> 
If userspace holds an fd open, unbinds the device and then closes it,
the driver shouldn't try to access the hardware. Protect it by using
drm_dev_enter()/drm_dev_exit(). This fixes the following page fault:

<6> [IGT] xe_wedged: exiting, ret=98
<1> BUG: unable to handle page fault for address: ffffc901bc5e508c
<1> #PF: supervisor read access in kernel mode
<1> #PF: error_code(0x0000) - not-present page
...
<4>   xe_lrc_update_timestamp+0x1c/0xd0 [xe]
<4>   xe_exec_queue_update_run_ticks+0x50/0xb0 [xe]
<4>   xe_exec_queue_fini+0x16/0xb0 [xe]
<4>   __guc_exec_queue_fini_async+0xc4/0x190 [xe]
<4>   guc_exec_queue_fini_async+0xa0/0xe0 [xe]
<4>   guc_exec_queue_fini+0x23/0x40 [xe]
<4>   xe_exec_queue_destroy+0xb3/0xf0 [xe]
<4>   xe_file_close+0xd4/0x1a0 [xe]
<4>   drm_file_free+0x210/0x280 [drm]
<4>   drm_close_helper.isra.0+0x6d/0x80 [drm]
<4>   drm_release_noglobal+0x20/0x90 [drm]

Fixes: 514447a12190 ("drm/xe: Stop accumulating LRC timestamp on job_free")
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/3421
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241218053122.2730195-1-lucas.demarchi@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
(cherry picked from commit 4ca1fd418338d4d135428a0eb1e16e3b3ce17ee8)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
drm/xe: Use q->xef for accessing xe file 2024-12-21T00:44:34+00:00 Lucas De Marchi lucas.demarchi@intel.com 2024-12-18T05:31:22+00:00 2054d38ccf708e1add482c6345f7f349059b56e0 No need to traverse through the vm object as each exec queue maintains a reference to xe_file. Also improve/simplify the comment on why xef is checked. Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241218053122.2730195-2-lucas.demarchi@intel.com Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> 
No need to traverse through the vm object as each exec queue maintains a
reference to xe_file. Also improve/simplify the comment on why xef is
checked.

Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241218053122.2730195-2-lucas.demarchi@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>