From 04e1f683cd28dc9407b238543871a6e09a570dc0 Mon Sep 17 00:00:00 2001 From: Zbigniew Kempczyński Date: Wed, 20 Aug 2025 10:39:04 +0200 Subject: drm/xe/xe_sync: avoid race during ufence signaling MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Marking ufence as signalled after copy_to_user() is too late. Worker thread which signals ufence by memory write might be raced with another userspace vm-bind call. In map/unmap scenario unmap may still see ufence is not signalled causing -EBUSY. Change the order of marking / write to user-fence fixes this issue. Fixes: 977e5b82e090 ("drm/xe: Expose user fence from xe_sync_entry") Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/5536 Signed-off-by: Zbigniew Kempczyński Cc: Matthew Brost Cc: Matthew Auld Reviewed-by: Matthew Brost Signed-off-by: Matthew Brost Link: https://lore.kernel.org/r/20250820083903.2109891-2-zbigniew.kempczynski@intel.com (cherry picked from commit 8ae04fe9ffc93d6bc3bc63ac08375427d69cee06) Signed-off-by: Rodrigo Vivi --- drivers/gpu/drm/xe/xe_sync.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/xe/xe_sync.c b/drivers/gpu/drm/xe/xe_sync.c index f87276df18f2..82872a51f098 100644 --- a/drivers/gpu/drm/xe/xe_sync.c +++ b/drivers/gpu/drm/xe/xe_sync.c @@ -77,6 +77,7 @@ static void user_fence_worker(struct work_struct *w) { struct xe_user_fence *ufence = container_of(w, struct xe_user_fence, worker); + WRITE_ONCE(ufence->signalled, 1); if (mmget_not_zero(ufence->mm)) { kthread_use_mm(ufence->mm); if (copy_to_user(ufence->addr, &ufence->value, sizeof(ufence->value))) @@ -91,7 +92,6 @@ static void user_fence_worker(struct work_struct *w) * Wake up waiters only after updating the ufence state, allowing the UMD * to safely reuse the same ufence without encountering -EBUSY errors. */ - WRITE_ONCE(ufence->signalled, 1); wake_up_all(&ufence->xe->ufence_wq); user_fence_put(ufence); } -- cgit v1.2.3 From 7551865cd12af2dc47e5a174eebcfb0b94b5449b Mon Sep 17 00:00:00 2001 From: Thomas Hellström Date: Thu, 21 Aug 2025 16:30:43 +0200 Subject: drm/xe/vm: Don't pin the vm_resv during validation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The pinning has the odd side-effect that unlocking *any* resv during validation triggers an "unlocking pinned lock" warning. Cc: Matthew Brost Fixes: 5cc3325584c4 ("drm/xe: Rework eviction rejection of bound external bos") Signed-off-by: Thomas Hellström Reviewed-by: Matthew Brost Link: https://lore.kernel.org/r/20250821143045.106005-2-thomas.hellstrom@linux.intel.com (cherry picked from commit 0a51bf3e54dd8b77e6f1febbbb66def0660862d2) Signed-off-by: Rodrigo Vivi --- drivers/gpu/drm/xe/xe_bo.c | 5 ++--- drivers/gpu/drm/xe/xe_vm.h | 15 ++------------- 2 files changed, 4 insertions(+), 16 deletions(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c index 18f27da47a36..d3ef79ebceee 100644 --- a/drivers/gpu/drm/xe/xe_bo.c +++ b/drivers/gpu/drm/xe/xe_bo.c @@ -2438,7 +2438,6 @@ int xe_bo_validate(struct xe_bo *bo, struct xe_vm *vm, bool allow_res_evict) .no_wait_gpu = false, .gfp_retry_mayfail = true, }; - struct pin_cookie cookie; int ret; if (vm) { @@ -2449,10 +2448,10 @@ int xe_bo_validate(struct xe_bo *bo, struct xe_vm *vm, bool allow_res_evict) ctx.resv = xe_vm_resv(vm); } - cookie = xe_vm_set_validating(vm, allow_res_evict); + xe_vm_set_validating(vm, allow_res_evict); trace_xe_bo_validate(bo); ret = ttm_bo_validate(&bo->ttm, &bo->placement, &ctx); - xe_vm_clear_validating(vm, allow_res_evict, cookie); + xe_vm_clear_validating(vm, allow_res_evict); return ret; } diff --git a/drivers/gpu/drm/xe/xe_vm.h b/drivers/gpu/drm/xe/xe_vm.h index 2f213737c7e5..2ecb417c19a2 100644 --- a/drivers/gpu/drm/xe/xe_vm.h +++ b/drivers/gpu/drm/xe/xe_vm.h @@ -315,22 +315,14 @@ void xe_vm_snapshot_free(struct xe_vm_snapshot *snap); * Register this task as currently making bos resident for the vm. Intended * to avoid eviction by the same task of shared bos bound to the vm. * Call with the vm's resv lock held. - * - * Return: A pin cookie that should be used for xe_vm_clear_validating(). */ -static inline struct pin_cookie xe_vm_set_validating(struct xe_vm *vm, - bool allow_res_evict) +static inline void xe_vm_set_validating(struct xe_vm *vm, bool allow_res_evict) { - struct pin_cookie cookie = {}; - if (vm && !allow_res_evict) { xe_vm_assert_held(vm); - cookie = lockdep_pin_lock(&xe_vm_resv(vm)->lock.base); /* Pairs with READ_ONCE in xe_vm_is_validating() */ WRITE_ONCE(vm->validating, current); } - - return cookie; } /** @@ -338,17 +330,14 @@ static inline struct pin_cookie xe_vm_set_validating(struct xe_vm *vm, * @vm: Pointer to the vm or NULL * @allow_res_evict: Eviction from @vm was allowed. Must be set to the same * value as for xe_vm_set_validation(). - * @cookie: Cookie obtained from xe_vm_set_validating(). * * Register this task as currently making bos resident for the vm. Intended * to avoid eviction by the same task of shared bos bound to the vm. * Call with the vm's resv lock held. */ -static inline void xe_vm_clear_validating(struct xe_vm *vm, bool allow_res_evict, - struct pin_cookie cookie) +static inline void xe_vm_clear_validating(struct xe_vm *vm, bool allow_res_evict) { if (vm && !allow_res_evict) { - lockdep_unpin_lock(&xe_vm_resv(vm)->lock.base, cookie); /* Pairs with READ_ONCE in xe_vm_is_validating() */ WRITE_ONCE(vm->validating, NULL); } -- cgit v1.2.3 From 2b55ddf36229e0278c956215784ab1feeff510aa Mon Sep 17 00:00:00 2001 From: Thomas Hellström Date: Thu, 21 Aug 2025 16:30:45 +0200 Subject: drm/xe/vm: Clear the scratch_pt pointer on error MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Avoid triggering a dereference of an error pointer on cleanup in xe_vm_free_scratch() by clearing any scratch_pt error pointer. Signed-off-by: Thomas Hellström Fixes: 06951c2ee72d ("drm/xe: Use NULL PTEs as scratch PTEs") Cc: Brian Welty Cc: Rodrigo Vivi Cc: Lucas De Marchi Cc: # v6.8+ Reviewed-by: Matthew Brost Link: https://lore.kernel.org/r/20250821143045.106005-4-thomas.hellstrom@linux.intel.com (cherry picked from commit 358ee50ab565f3c8ea32480e9d03127a81ba32f8) Signed-off-by: Rodrigo Vivi --- drivers/gpu/drm/xe/xe_vm.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c index ec04bef8ae40..d60c4b115304 100644 --- a/drivers/gpu/drm/xe/xe_vm.c +++ b/drivers/gpu/drm/xe/xe_vm.c @@ -1610,8 +1610,12 @@ static int xe_vm_create_scratch(struct xe_device *xe, struct xe_tile *tile, for (i = MAX_HUGEPTE_LEVEL; i < vm->pt_root[id]->level; i++) { vm->scratch_pt[id][i] = xe_pt_create(vm, tile, i); - if (IS_ERR(vm->scratch_pt[id][i])) - return PTR_ERR(vm->scratch_pt[id][i]); + if (IS_ERR(vm->scratch_pt[id][i])) { + int err = PTR_ERR(vm->scratch_pt[id][i]); + + vm->scratch_pt[id][i] = NULL; + return err; + } xe_pt_populate_empty(tile, vm, vm->scratch_pt[id][i]); } -- cgit v1.2.3 From 16ca06aa2c2218cb21907c0c45a746958c944def Mon Sep 17 00:00:00 2001 From: Matthew Brost Date: Mon, 25 Aug 2025 08:28:41 -0700 Subject: drm/xe: Don't trigger rebind on initial dma-buf validation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On the first validate of an imported dma-buf (initial bind), the device has no GPU mappings, so a rebind is unnecessary. Rebinding here is harmful in multi-GPU setups and for VMs using preempt-fence mode, as it would evict in-flight GPU work. v2: - Drop dma_buf_validated, check for XE_PL_SYSTEM (Thomas) Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs") Signed-off-by: Matthew Brost Reviewed-by: Thomas Hellström Link: https://lore.kernel.org/r/20250825152841.3837378-1-matthew.brost@intel.com (cherry picked from commit ffdf968762e4fb3cdae54e811ec3525e67440a60) Signed-off-by: Rodrigo Vivi --- drivers/gpu/drm/xe/xe_bo.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c index d3ef79ebceee..1be2415966df 100644 --- a/drivers/gpu/drm/xe/xe_bo.c +++ b/drivers/gpu/drm/xe/xe_bo.c @@ -812,7 +812,8 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict, } if (ttm_bo->type == ttm_bo_type_sg) { - ret = xe_bo_move_notify(bo, ctx); + if (new_mem->mem_type == XE_PL_SYSTEM) + ret = xe_bo_move_notify(bo, ctx); if (!ret) ret = xe_bo_move_dmabuf(ttm_bo, new_mem); return ret; -- cgit v1.2.3 From 75671d90fde8c78e940e15a1366a50ece56c6b69 Mon Sep 17 00:00:00 2001 From: Carlos Llamas Date: Mon, 25 Aug 2025 15:57:42 +0000 Subject: drm/xe: switch to local xbasename() helper MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit b0a2ee5567ab ("drm/xe: prepare xe_gen_wa_oob to be multi-use") introduced a call to basename(). The GNU version of this function is not portable and fails to build with alternative libc implementations like musl or bionic. This causes the following build error: drivers/gpu/drm/xe/xe_gen_wa_oob.c:130:12: error: assignment to ‘const char *’ from ‘int’ makes pointer from integer without a cast [-Wint-conversion] 130 | fn = basename(fn); | ^ While a POSIX version of basename() could be used, it would require a separate header plus the behavior differs from GNU version in that it might modify its argument. Not great. Instead, implement a local xbasename() helper based on strrchr() that provides the same functionality and avoids portability issues. Fixes: b0a2ee5567ab ("drm/xe: prepare xe_gen_wa_oob to be multi-use") Suggested-by: Lucas De Marchi Reviewed-by: Tiffany Yang Signed-off-by: Carlos Llamas Reviewed-by: Lucas De Marchi Link: https://lore.kernel.org/r/20250825155743.1132433-1-cmllamas@google.com Signed-off-by: Lucas De Marchi (cherry picked from commit 41be792f5baaf90d744a9a9e82994ce560ca9582) Signed-off-by: Rodrigo Vivi --- drivers/gpu/drm/xe/xe_gen_wa_oob.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/xe/xe_gen_wa_oob.c b/drivers/gpu/drm/xe/xe_gen_wa_oob.c index 6581cb0f0e59..247e41c1c48d 100644 --- a/drivers/gpu/drm/xe/xe_gen_wa_oob.c +++ b/drivers/gpu/drm/xe/xe_gen_wa_oob.c @@ -123,11 +123,19 @@ static int parse(FILE *input, FILE *csource, FILE *cheader, char *prefix) return 0; } +/* Avoid GNU vs POSIX basename() discrepancy, just use our own */ +static const char *xbasename(const char *s) +{ + const char *p = strrchr(s, '/'); + + return p ? p + 1 : s; +} + static int fn_to_prefix(const char *fn, char *prefix, size_t size) { size_t len; - fn = basename(fn); + fn = xbasename(fn); len = strlen(fn); if (len > size - 1) -- cgit v1.2.3