Document VMA tile_invalidated access rules, use READ_ONCE / WRITE_ONCE
for opportunistic checks of tile_present and tile_invalidated, move
tile_invalidated state change from page fault handler to PT code under
the correct locks, and add lockdep asserts to TLB invalidation paths.
v2:
- Assert VM dma-resv lock rather than BO in zap PTEs
v3:
- Back to BO's dma-resv lock, adjust documentation
v4:
- Add WRITE_ONCE in xe_vm_invalidate_vma (Thomas)
- Change lockdep assert for userptr in xe_vm_invalidate_vma (CI)
- Take userptr notifier lock in read mode in xe_vm_userptr_pin before
calling xe_vm_invalidate_vma (CI)
v5:
- Fix typos (Thomas)
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://lore.kernel.org/r/20250602164412.1912293-1-matthew.brost@intel.com
Add a new entry in stats to for svm page faults. If CONFIG_DEBUG_FS is
enabled, the count can be viewed with per GT stat debugfs file.
This is similar to what is already in place for vma page faults.
Example output:
cat /sys/kernel/debug/dri/0/gt0/stats
svm_pagefault_count: 6
tlb_inval_count: 78
vma_pagefault_count: 0
vma_pagefault_kb: 0
v2: Fix build with CONFIG_DRM_GPUSVM disabled
v3: Update argument in kernel doc
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250312092749.164232-1-francois.dugast@intel.com
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Add SVM range invalidation vfunc which invalidates PTEs. A new PT layer
function which accepts a SVM range is added to support this. In
addition, add the basic page fault handler which allocates a SVM range
which is used by SVM range invalidation vfunc.
v2:
- Don't run invalidation if VM is closed
- Cycle notifier lock in xe_svm_close
- Drop xe_gt_tlb_invalidation_fence_fini
v3:
- Better commit message (Thomas)
- Add lockdep asserts (Thomas)
- Add kernel doc (Thomas)
- s/change/changed (Thomas)
- Use new GPU SVM range / notifier structures
- Ensure PTEs are zapped / dma mappings are unmapped on VM close (Thomas)
v4:
- Fix macro (Checkpatch)
v5:
- Use range start/end helpers (Thomas)
- Use notifier start/end helpers (Thomas)
v6:
- Use min/max helpers (Himal)
- Only compile if CONFIG_DRM_GPUSVM selected (CI, Lucas)
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250306012657.3505757-13-matthew.brost@intel.com
Add new entries in stats for vma page faults. If CONFIG_DEBUG_FS is
enabled, the count and number of bytes can be viewed per GT in the
stat debugfs file. This helps when testing, to confirm page faults
have been triggered as expected. It also helps when looking at the
performance impact of page faults. Data is simply collected when
entering the page fault handler so there is no indication whether
it completed successfully, with or without retries, etc.
Example output:
cat /sys/kernel/debug/dri/0/gt0/stats
tlb_inval_count: 129
vma_pagefault_count: 12
vma_pagefault_bytes: 98304
v2: Rebase
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250206134551.1321265-1-francois.dugast@intel.com
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Backmerge drm-next to get the common APIs and refactors as well as
getting the display changes from i915 in xe so the probe order can be
improved.
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
In effort to make multiple VMA binds operations atomic (1 job), all
device page tables updates will be implemented via a xe_vma_ops (atomic
unit) interface,
Add xe_vma_rebind function which is implemented using xe_vma_ops
interface. Use xe_vma_rebind in GPU page faults for rebinds rather than
directly called deprecated function in PT layer.
v3:
- Update commit message (Oak)
v4:
- Fix tile_mask argument (CI)
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Oak Zeng <oak.zeng@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240425045513.1913039-8-matthew.brost@intel.com
Rebinding might allocate page-table bos, causing evictions.
To support blocking locking during these evictions,
perform the rebinding in the drm_exec locking loop.
Also Reserve fence slots where actually needed rather than trying to
predict how many fence slots will be needed over a complete
wound-wait transaction.
v2:
- Remove a leftover call to xe_vm_rebind() (Matt Brost)
- Add a helper function xe_vm_validate_rebind() (Matt Brost)
v3:
- Add comments and squash with previous patch (Matt Brost)
Fixes: 24f947d58f ("drm/xe: Use DRM GPUVM helpers for external- and evicted objects")
Fixes: 29f424eb87 ("drm/xe/exec: move fence reservation")
Cc: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240327091136.3271-5-thomas.hellstrom@linux.intel.com
Rather than return an error to the user or ban the VM when userptr VMA
page pin fails with -EFAULT, invalidate VMA mappings. This supports the
UMD use case of freeing userptr while still having bindings.
Now that non-faulting VMs can invalidate VMAs, drop the usm prefix for
the tile_invalidated member.
v2:
- Fix build error (CI)
v3:
- Don't invalidate VMA if in fault mode, rather kill VM (Thomas)
- Update commit message with tile_invalidated name chagne (Thomas)
- Wait VM bookkeep slots with VM resv lock (Thomas)
v4:
- Move list_del_init(&userptr.repin_link) after error check (Thomas)
- Assert not in fault mode (Matthew)
Fixes: dd08ebf6c3 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240312183907.933835-1-matthew.brost@intel.com
gcc-13 warns about an array overflow that it sees but that is
prevented by the "asid % NUM_PF_QUEUE" calculation:
drivers/gpu/drm/xe/xe_gt_pagefault.c: In function 'xe_guc_pagefault_handler':
include/linux/fortify-string.h:57:33: error: writing 16 bytes into a region of size 0 [-Werror=stringop-overflow=]
include/linux/fortify-string.h:689:26: note: in expansion of macro '__fortify_memcpy_chk'
689 | #define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \
| ^~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/xe/xe_gt_pagefault.c:341:17: note: in expansion of macro 'memcpy'
341 | memcpy(pf_queue->data + pf_queue->tail, msg, len * sizeof(u32));
| ^~~~~~
drivers/gpu/drm/xe/xe_gt_types.h:102:25: note: at offset [1144, 265324] into destination object 'tile' of size 8
I found that rewriting the assignment using pointer addition rather than the
equivalent array index calculation prevents the warning, so use that instead.
I sent a bug report against gcc for the false positive warning.
Fixes: dd08ebf6c3 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113214
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240103114819.2913937-1-arnd@kernel.org
Convention for queues in Linux is the producer moves the head and
consumer moves the tail. Fix the access counter queue to conform to
this convention.
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
If ACC_QUEUE_NUM_DW % ACC_MSG_LEN_DW != 0 then the access counter queue
logic does not work when wrapping occurs. Add a build bug on to assert
ACC_QUEUE_NUM_DW % ACC_MSG_LEN_DW == 0 to enforce this restriction and
document the code.
v2:
- s/NUM_ACC_QUEUE/ACC_QUEUE_NUM_DW (Brian)
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Convention for queues in Linux is the producer moves the head and
consumer moves the tail. Fix the page fault queue to conform to this
convention.
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
If PF_QUEUE_NUM_DW % PF_MSG_LEN_DW != 0 then the page fault queue logic
does not work when wrapping occurs. Add a build bug on to assert
PF_QUEUE_NUM_DW % PF_MSG_LEN_DW == 0 to enforce this restriction and
document the code.
v2:
- s/NUM_PF_QUEUE/PF_QUEUE_NUM_DW (Brian)
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Introduce a new DRM driver for Intel GPUs
Xe, is a new driver for Intel GPUs that supports both integrated and
discrete platforms. The experimental support starts with Tiger Lake.
i915 will continue be the main production driver for the platforms
up to Meteor Lake and Alchemist. Then the goal is to make this Intel
Xe driver the primary driver for Lunar Lake and newer platforms.
It uses most, if not all, of the key drm concepts, in special: TTM,
drm-scheduler, drm-exec, drm-gpuvm/gpuva and others.
Signed-off-by: Dave Airlie <airlied@redhat.com>
[airlied: add an extra X86 check, fix a typo, fix drm_exec_init interface
change].
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/ZYSwLgXZUZ57qGPQ@intel.com
SW is not expected to handle TRTT faults and should report these as
unsuccessful page fault in the reply, such that HW can respond by
raising a CAT error.
Signed-off-by: Brian Welty <brian.welty@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Update xe_migrate_prepare_vm() to use the usm batch buffer even for
servicing device page faults on integrated platforms. And as we have
no VRAM on integrated platforms, device pagefault handler should not
attempt to migrate into VRAM.
LNL is first integrated platform to support device pagefaults.
Signed-off-by: Brian Welty <brian.welty@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
When processing G2H messages for pagefault or access counters, we queue a
work item and call queue_work(). This fails if the worker thread is already
queued to run.
The expectation is that the worker function will do more than process a
single item and return. It needs to either process all pending items or
requeue itself if items are pending. But requeuing will add latency and
potential context switch can occur.
We don't want to add unnecessary latency and so the worker should process
as many faults as it can within a reasonable duration of time.
We also do not want to hog the cpu core, so here we execute in a loop
and requeue if still running after more than 20 ms.
This seems reasonable framework and easy to tune this futher if needed.
This resolves issues seen with several igt@xe_exec_fault_mode subtests
where the GPU will hang when KMD ignores a pending pagefault.
v2: requeue the worker instead of having an internal processing loop.
v3: implement hybrid model of v1 and v2
now, run for 20 msec before we will requeue if still running
v4: only requeue in worker if queue is non-empty (Matt B)
Signed-off-by: Brian Welty <brian.welty@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
The access counters worker function is fixed to advance the head pointer
when dequeuing from the acc_queue. This now matches the similar logic in
get_pagefault().
Signed-off-by: Bruce Chang <yu.bruce.chang@intel.com>
Signed-off-by: Brian Welty <brian.welty@intel.com>
Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Use the generic drm_warn instead of the driver-specific XE_WARN_ON
in cases where XE_WARN_ON is used to unconditionally print a debug
message.
v2: Rebase
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Rather than open coding VM binds and VMA tracking, use the GPUVA
library. GPUVA provides a common infrastructure for VM binds to use mmap
/ munmap semantics and support for VK sparse bindings.
The concepts are:
1) xe_vm inherits from drm_gpuva_manager
2) xe_vma inherits from drm_gpuva
3) xe_vma_op inherits from drm_gpuva_op
4) VM bind operations (MAP, UNMAP, PREFETCH, UNMAP_ALL) call into the
GPUVA code to generate an VMA operations list which is parsed, committed,
and executed.
v2 (CI): Add break after default in case statement.
v3: Rebase
v4: Fix some error handling
v5: Use unlocked version VMA in error paths
v6: Rebase, address some review feedback mainly Thomas H
v7: Fix compile error in xe_vma_op_unwind, address checkpatch
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
