Cross-subsystem Changes:

- mm: Fix a hmm_range_fault() livelock / starvation problem (Thomas)
 
 Core Changes:
  - Revert "drm/pagemap: Disable device-to-device migration" (Thomas)
 
 Driver Changes:
  - Do not preempt fence signaling CS instructions (Brost)
  - Some leak and finalization fixes (Shuicheng, Tomasz, Varun, Zhanjun)
  - Workaround fix (Roper)
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Merge tag 'drm-xe-fixes-2026-03-05' of https://gitlab.freedesktop.org/drm/xe/kernel into drm-fixes

Cross-subsystem Changes:
 - mm: Fix a hmm_range_fault() livelock / starvation problem (Thomas)

Core Changes:
 - Revert "drm/pagemap: Disable device-to-device migration" (Thomas)

Driver Changes:
 - Do not preempt fence signaling CS instructions (Brost)
 - Some leak and finalization fixes (Shuicheng, Tomasz, Varun, Zhanjun)
 - Workaround fix (Roper)

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patch.msgid.link/aamGvvGRBRtX8-6u@intel.com

drivers/gpu/drm/drm_pagemap.c

@@ -480,18 +480,8 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
 		.start		= start,
 		.end		= end,
 		.pgmap_owner	= pagemap->owner,
-		/*
-		 * FIXME: MIGRATE_VMA_SELECT_DEVICE_PRIVATE intermittently
-		 * causes 'xe_exec_system_allocator --r *race*no*' to trigger aa
-		 * engine reset and a hard hang due to getting stuck on a folio
-		 * lock. This should work and needs to be root-caused. The only
-		 * downside of not selecting MIGRATE_VMA_SELECT_DEVICE_PRIVATE
-		 * is that device-to-device migrations won’t work; instead,
-		 * memory will bounce through system memory. This path should be
-		 * rare and only occur when the madvise attributes of memory are
-		 * changed or atomics are being used.
-		 */
-		.flags		= MIGRATE_VMA_SELECT_SYSTEM | MIGRATE_VMA_SELECT_DEVICE_COHERENT,
+		.flags		= MIGRATE_VMA_SELECT_SYSTEM | MIGRATE_VMA_SELECT_DEVICE_COHERENT |
+		MIGRATE_VMA_SELECT_DEVICE_PRIVATE,
 	};
 	unsigned long i, npages = npages_in_range(start, end);
 	unsigned long own_pages = 0, migrated_pages = 0;

drivers/gpu/drm/xe/xe_configfs.c

@@ -830,6 +830,7 @@ static void xe_config_device_release(struct config_item *item)
 
 	mutex_destroy(&dev->lock);
 
+	kfree(dev->config.ctx_restore_mid_bb[0].cs);
 	kfree(dev->config.ctx_restore_post_bb[0].cs);
 	kfree(dev);
 }

drivers/gpu/drm/xe/xe_exec_queue.c

@@ -266,6 +266,16 @@ static struct xe_exec_queue *__xe_exec_queue_alloc(struct xe_device *xe,
 	return q;
 }
 
+static void __xe_exec_queue_fini(struct xe_exec_queue *q)
+{
+	int i;
+
+	q->ops->fini(q);
+
+	for (i = 0; i < q->width; ++i)
+		xe_lrc_put(q->lrc[i]);
+}
+
 static int __xe_exec_queue_init(struct xe_exec_queue *q, u32 exec_queue_flags)
 {
 	int i, err;
@@ -320,21 +330,10 @@ static int __xe_exec_queue_init(struct xe_exec_queue *q, u32 exec_queue_flags)
 	return 0;
 
 err_lrc:
-	for (i = i - 1; i >= 0; --i)
-		xe_lrc_put(q->lrc[i]);
+	__xe_exec_queue_fini(q);
 	return err;
 }
 
-static void __xe_exec_queue_fini(struct xe_exec_queue *q)
-{
-	int i;
-
-	q->ops->fini(q);
-
-	for (i = 0; i < q->width; ++i)
-		xe_lrc_put(q->lrc[i]);
-}
-
 struct xe_exec_queue *xe_exec_queue_create(struct xe_device *xe, struct xe_vm *vm,
 					   u32 logical_mask, u16 width,
 					   struct xe_hw_engine *hwe, u32 flags,

drivers/gpu/drm/xe/xe_gsc_proxy.c

@@ -435,15 +435,11 @@ static int proxy_channel_alloc(struct xe_gsc *gsc)
 	return 0;
 }
 
-static void xe_gsc_proxy_remove(void *arg)
+static void xe_gsc_proxy_stop(struct xe_gsc *gsc)
 {
-	struct xe_gsc *gsc = arg;
 	struct xe_gt *gt = gsc_to_gt(gsc);
 	struct xe_device *xe = gt_to_xe(gt);
 
-	if (!gsc->proxy.component_added)
-		return;
-
 	/* disable HECI2 IRQs */
 	scoped_guard(xe_pm_runtime, xe) {
 		CLASS(xe_force_wake, fw_ref)(gt_to_fw(gt), XE_FW_GSC);
@@ -455,6 +451,30 @@ static void xe_gsc_proxy_remove(void *arg)
 	}
 
 	xe_gsc_wait_for_worker_completion(gsc);
+	gsc->proxy.started = false;
+}
+
+static void xe_gsc_proxy_remove(void *arg)
+{
+	struct xe_gsc *gsc = arg;
+	struct xe_gt *gt = gsc_to_gt(gsc);
+	struct xe_device *xe = gt_to_xe(gt);
+
+	if (!gsc->proxy.component_added)
+		return;
+
+	/*
+	 * GSC proxy start is an async process that can be ongoing during
+	 * Xe module load/unload. Using devm managed action to register
+	 * xe_gsc_proxy_stop could cause issues if Xe module unload has
+	 * already started when the action is registered, potentially leading
+	 * to the cleanup being called at the wrong time. Therefore, instead
+	 * of registering a separate devm action to undo what is done in
+	 * proxy start, we call it from here, but only if the start has
+	 * completed successfully (tracked with the 'started' flag).
+	 */
+	if (gsc->proxy.started)
+		xe_gsc_proxy_stop(gsc);
 
 	component_del(xe->drm.dev, &xe_gsc_proxy_component_ops);
 	gsc->proxy.component_added = false;
@@ -510,6 +530,7 @@ int xe_gsc_proxy_init(struct xe_gsc *gsc)
  */
 int xe_gsc_proxy_start(struct xe_gsc *gsc)
 {
+	struct xe_gt *gt = gsc_to_gt(gsc);
 	int err;
 
 	/* enable the proxy interrupt in the GSC shim layer */
@@ -521,12 +542,18 @@ int xe_gsc_proxy_start(struct xe_gsc *gsc)
 	 */
 	err = xe_gsc_proxy_request_handler(gsc);
 	if (err)
-		return err;
+		goto err_irq_disable;
 
 	if (!xe_gsc_proxy_init_done(gsc)) {
-		xe_gt_err(gsc_to_gt(gsc), "GSC FW reports proxy init not completed\n");
-		return -EIO;
+		xe_gt_err(gt, "GSC FW reports proxy init not completed\n");
+		err = -EIO;
+		goto err_irq_disable;
 	}
 
+	gsc->proxy.started = true;
 	return 0;
+
+err_irq_disable:
+	gsc_proxy_irq_toggle(gsc, false);
+	return err;
 }

drivers/gpu/drm/xe/xe_gsc_types.h

@@ -58,6 +58,8 @@ struct xe_gsc {
 		struct mutex mutex;
 		/** @proxy.component_added: whether the component has been added */
 		bool component_added;
+		/** @proxy.started: whether the proxy has been started */
+		bool started;
 		/** @proxy.bo: object to store message to and from the GSC */
 		struct xe_bo *bo;
 		/** @proxy.to_gsc: map of the memory used to send messages to the GSC */

drivers/gpu/drm/xe/xe_lrc.h

@@ -75,7 +75,8 @@ static inline struct xe_lrc *xe_lrc_get(struct xe_lrc *lrc)
  */
 static inline void xe_lrc_put(struct xe_lrc *lrc)
 {
-	kref_put(&lrc->refcount, xe_lrc_destroy);
+	if (lrc)
+		kref_put(&lrc->refcount, xe_lrc_destroy);
 }
 
 /**

drivers/gpu/drm/xe/xe_reg_sr.c

@@ -98,10 +98,12 @@ int xe_reg_sr_add(struct xe_reg_sr *sr,
 	*pentry = *e;
 	ret = xa_err(xa_store(&sr->xa, idx, pentry, GFP_KERNEL));
 	if (ret)
-		goto fail;
+		goto fail_free;
 
 	return 0;
 
+fail_free:
+	kfree(pentry);
 fail:
 	xe_gt_err(gt,
 		  "discarding save-restore reg %04lx (clear: %08x, set: %08x, masked: %s, mcr: %s): ret=%d\n",

drivers/gpu/drm/xe/xe_ring_ops.c

@@ -280,6 +280,9 @@ static void __emit_job_gen12_simple(struct xe_sched_job *job, struct xe_lrc *lrc
 
 	i = emit_bb_start(batch_addr, ppgtt_flag, dw, i);
 
+	/* Don't preempt fence signaling */
+	dw[i++] = MI_ARB_ON_OFF | MI_ARB_DISABLE;
+
 	if (job->user_fence.used) {
 		i = emit_flush_dw(dw, i);
 		i = emit_store_imm_ppgtt_posted(job->user_fence.addr,
@@ -345,6 +348,9 @@ static void __emit_job_gen12_video(struct xe_sched_job *job, struct xe_lrc *lrc,
 
 	i = emit_bb_start(batch_addr, ppgtt_flag, dw, i);
 
+	/* Don't preempt fence signaling */
+	dw[i++] = MI_ARB_ON_OFF | MI_ARB_DISABLE;
+
 	if (job->user_fence.used) {
 		i = emit_flush_dw(dw, i);
 		i = emit_store_imm_ppgtt_posted(job->user_fence.addr,
@@ -397,6 +403,9 @@ static void __emit_job_gen12_render_compute(struct xe_sched_job *job,
 
 	i = emit_bb_start(batch_addr, ppgtt_flag, dw, i);
 
+	/* Don't preempt fence signaling */
+	dw[i++] = MI_ARB_ON_OFF | MI_ARB_DISABLE;
+
 	i = emit_render_cache_flush(job, dw, i);
 
 	if (job->user_fence.used)

drivers/gpu/drm/xe/xe_vm_madvise.c

@@ -453,7 +453,7 @@ int xe_vm_madvise_ioctl(struct drm_device *dev, void *data, struct drm_file *fil
 						    madvise_range.num_vmas,
 						    args->atomic.val)) {
 				err = -EINVAL;
-				goto madv_fini;
+				goto free_vmas;
 			}
 		}
 
@@ -490,6 +490,7 @@ int xe_vm_madvise_ioctl(struct drm_device *dev, void *data, struct drm_file *fil
 err_fini:
 	if (madvise_range.has_bo_vmas)
 		drm_exec_fini(&exec);
+free_vmas:
 	kfree(madvise_range.vmas);
 	madvise_range.vmas = NULL;
 madv_fini:

drivers/gpu/drm/xe/xe_wa.c

@@ -241,12 +241,13 @@ static const struct xe_rtp_entry_sr gt_was[] = {
 
 	{ XE_RTP_NAME("16025250150"),
 	  XE_RTP_RULES(GRAPHICS_VERSION(2001)),
-	  XE_RTP_ACTIONS(SET(LSN_VC_REG2,
-			     LSN_LNI_WGT(1) |
-			     LSN_LNE_WGT(1) |
-			     LSN_DIM_X_WGT(1) |
-			     LSN_DIM_Y_WGT(1) |
-			     LSN_DIM_Z_WGT(1)))
+	  XE_RTP_ACTIONS(FIELD_SET(LSN_VC_REG2,
+				   LSN_LNI_WGT_MASK | LSN_LNE_WGT_MASK |
+				   LSN_DIM_X_WGT_MASK | LSN_DIM_Y_WGT_MASK |
+				   LSN_DIM_Z_WGT_MASK,
+				   LSN_LNI_WGT(1) | LSN_LNE_WGT(1) |
+				   LSN_DIM_X_WGT(1) | LSN_DIM_Y_WGT(1) |
+				   LSN_DIM_Z_WGT(1)))
 	},
 
 	/* Xe2_HPM */

include/linux/migrate.h

@@ -65,7 +65,7 @@ bool isolate_folio_to_list(struct folio *folio, struct list_head *list);
 
 int migrate_huge_page_move_mapping(struct address_space *mapping,
 		struct folio *dst, struct folio *src);
-void migration_entry_wait_on_locked(softleaf_t entry, spinlock_t *ptl)
+void softleaf_entry_wait_on_locked(softleaf_t entry, spinlock_t *ptl)
 		__releases(ptl);
 void folio_migrate_flags(struct folio *newfolio, struct folio *folio);
 int folio_migrate_mapping(struct address_space *mapping,
@@ -97,6 +97,14 @@ static inline int set_movable_ops(const struct movable_operations *ops, enum pag
 	return -ENOSYS;
 }
 
+static inline void softleaf_entry_wait_on_locked(softleaf_t entry, spinlock_t *ptl)
+	__releases(ptl)
+{
+	WARN_ON_ONCE(1);
+
+	spin_unlock(ptl);
+}
+
 #endif /* CONFIG_MIGRATION */
 
 #ifdef CONFIG_NUMA_BALANCING

mm/filemap.c

@@ -1379,14 +1379,16 @@ repeat:
 
 #ifdef CONFIG_MIGRATION
 /**
- * migration_entry_wait_on_locked - Wait for a migration entry to be removed
- * @entry: migration swap entry.
+ * softleaf_entry_wait_on_locked - Wait for a migration entry or
+ * device_private entry to be removed.
+ * @entry: migration or device_private swap entry.
  * @ptl: already locked ptl. This function will drop the lock.
  *
- * Wait for a migration entry referencing the given page to be removed. This is
+ * Wait for a migration entry referencing the given page, or device_private
+ * entry referencing a dvice_private page to be unlocked. This is
  * equivalent to folio_put_wait_locked(folio, TASK_UNINTERRUPTIBLE) except
  * this can be called without taking a reference on the page. Instead this
- * should be called while holding the ptl for the migration entry referencing
+ * should be called while holding the ptl for @entry referencing
  * the page.
  *
  * Returns after unlocking the ptl.
@@ -1394,7 +1396,7 @@ repeat:
  * This follows the same logic as folio_wait_bit_common() so see the comments
  * there.
  */
-void migration_entry_wait_on_locked(softleaf_t entry, spinlock_t *ptl)
+void softleaf_entry_wait_on_locked(softleaf_t entry, spinlock_t *ptl)
 	__releases(ptl)
 {
 	struct wait_page_queue wait_page;
@@ -1428,6 +1430,9 @@ void migration_entry_wait_on_locked(softleaf_t entry, spinlock_t *ptl)
 	 * If a migration entry exists for the page the migration path must hold
 	 * a valid reference to the page, and it must take the ptl to remove the
 	 * migration entry. So the page is valid until the ptl is dropped.
+	 * Similarly any path attempting to drop the last reference to a
+	 * device-private page needs to grab the ptl to remove the device-private
+	 * entry.
 	 */
 	spin_unlock(ptl);
 

mm/memory.c

@@ -4763,7 +4763,8 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
 				unlock_page(vmf->page);
 				put_page(vmf->page);
 			} else {
-				pte_unmap_unlock(vmf->pte, vmf->ptl);
+				pte_unmap(vmf->pte);
+				softleaf_entry_wait_on_locked(entry, vmf->ptl);
 			}
 		} else if (softleaf_is_hwpoison(entry)) {
 			ret = VM_FAULT_HWPOISON;

mm/migrate.c

@@ -500,7 +500,7 @@ void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
 	if (!softleaf_is_migration(entry))
 		goto out;
 
-	migration_entry_wait_on_locked(entry, ptl);
+	softleaf_entry_wait_on_locked(entry, ptl);
 	return;
 out:
 	spin_unlock(ptl);
@@ -532,10 +532,10 @@ void migration_entry_wait_huge(struct vm_area_struct *vma, unsigned long addr, p
 		 * If migration entry existed, safe to release vma lock
 		 * here because the pgtable page won't be freed without the
 		 * pgtable lock released.  See comment right above pgtable
-		 * lock release in migration_entry_wait_on_locked().
+		 * lock release in softleaf_entry_wait_on_locked().
 		 */
 		hugetlb_vma_unlock_read(vma);
-		migration_entry_wait_on_locked(entry, ptl);
+		softleaf_entry_wait_on_locked(entry, ptl);
 		return;
 	}
 
@@ -553,7 +553,7 @@ void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd)
 	ptl = pmd_lock(mm, pmd);
 	if (!pmd_is_migration_entry(*pmd))
 		goto unlock;
-	migration_entry_wait_on_locked(softleaf_from_pmd(*pmd), ptl);
+	softleaf_entry_wait_on_locked(softleaf_from_pmd(*pmd), ptl);
 	return;
 unlock:
 	spin_unlock(ptl);

mm/migrate_device.c

@@ -176,7 +176,7 @@ static int migrate_vma_collect_huge_pmd(pmd_t *pmdp, unsigned long start,
 		}
 
 		if (softleaf_is_migration(entry)) {
-			migration_entry_wait_on_locked(entry, ptl);
+			softleaf_entry_wait_on_locked(entry, ptl);
 			spin_unlock(ptl);
 			return -EAGAIN;
 		}