drm/xe: Add vm to exec queues association

Maintain a list of exec queues per vm which will be used by TLB
invalidation code to do context-ID based tlb invalidations.

v4:
 - More asserts (Stuart)
 - Per GT list (CI)
 - Skip adding / removal if context TLB invalidatiions not supported
   (Stuart)

Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Tested-by: Stuart Summers <stuart.summers@intel.com>
Link: https://patch.msgid.link/20260116221731.868657-6-matthew.brost@intel.com

drivers/gpu/drm/xe/xe_device.h

@@ -62,13 +62,6 @@ static inline struct xe_tile *xe_device_get_root_tile(struct xe_device *xe)
 	return &xe->tiles[0];
 }
 
-/*
- * Highest GT/tile count for any platform.  Used only for memory allocation
- * sizing.  Any logic looping over GTs or mapping userspace GT IDs into GT
- * structures should use the per-platform xe->info.max_gt_per_tile instead.
- */
-#define XE_MAX_GT_PER_TILE 2
-
 static inline struct xe_gt *xe_device_get_gt(struct xe_device *xe, u8 gt_id)
 {
 	struct xe_tile *tile;

drivers/gpu/drm/xe/xe_device_types.h

@@ -79,6 +79,13 @@ enum xe_wedged_mode {
 #define XE_GT1		1
 #define XE_MAX_TILES_PER_DEVICE	(XE_GT1 + 1)
 
+/*
+ * Highest GT/tile count for any platform.  Used only for memory allocation
+ * sizing.  Any logic looping over GTs or mapping userspace GT IDs into GT
+ * structures should use the per-platform xe->info.max_gt_per_tile instead.
+ */
+#define XE_MAX_GT_PER_TILE 2
+
 #define XE_MAX_ASID	(BIT(20))
 
 #define IS_PLATFORM_STEP(_xe, _platform, min_step, max_step)	\

drivers/gpu/drm/xe/xe_exec_queue.c

@@ -152,8 +152,10 @@ static void __xe_exec_queue_free(struct xe_exec_queue *q)
 	if (xe_exec_queue_is_multi_queue(q))
 		xe_exec_queue_group_cleanup(q);
 
-	if (q->vm)
+	if (q->vm) {
+		xe_vm_remove_exec_queue(q->vm, q);
 		xe_vm_put(q->vm);
+	}
 
 	if (q->xef)
 		xe_file_put(q->xef);
@@ -224,6 +226,7 @@ static struct xe_exec_queue *__xe_exec_queue_alloc(struct xe_device *xe,
 	q->ring_ops = gt->ring_ops[hwe->class];
 	q->ops = gt->exec_queue_ops;
 	INIT_LIST_HEAD(&q->lr.link);
+	INIT_LIST_HEAD(&q->vm_exec_queue_link);
 	INIT_LIST_HEAD(&q->multi_gt_link);
 	INIT_LIST_HEAD(&q->hw_engine_group_link);
 	INIT_LIST_HEAD(&q->pxp.link);
@@ -1203,6 +1206,8 @@ int xe_exec_queue_create_ioctl(struct drm_device *dev, void *data,
 	}
 
 	q->xef = xe_file_get(xef);
+	if (eci[0].engine_class != DRM_XE_ENGINE_CLASS_VM_BIND)
+		xe_vm_add_exec_queue(vm, q);
 
 	/* user id alloc must always be last in ioctl to prevent UAF */
 	err = xa_alloc(&xef->exec_queue.xa, &id, q, xa_limit_32b, GFP_KERNEL);

drivers/gpu/drm/xe/xe_exec_queue_types.h

@@ -207,6 +207,9 @@ struct xe_exec_queue {
 		struct dma_fence *last_fence;
 	} tlb_inval[XE_EXEC_QUEUE_TLB_INVAL_COUNT];
 
+	/** @vm_exec_queue_link: Link to track exec queue within a VM's list of exec queues. */
+	struct list_head vm_exec_queue_link;
+
 	/** @pxp: PXP info tracking */
 	struct {
 		/** @pxp.type: PXP session type used by this queue */

drivers/gpu/drm/xe/xe_vm.c

@@ -1529,11 +1529,24 @@ struct xe_vm *xe_vm_create(struct xe_device *xe, u32 flags, struct xe_file *xef)
 	INIT_WORK(&vm->destroy_work, vm_destroy_work_func);
 
 	INIT_LIST_HEAD(&vm->preempt.exec_queues);
+	for (id = 0; id < XE_MAX_TILES_PER_DEVICE * XE_MAX_GT_PER_TILE; ++id)
+		INIT_LIST_HEAD(&vm->exec_queues.list[id]);
 	if (flags & XE_VM_FLAG_FAULT_MODE)
 		vm->preempt.min_run_period_ms = xe->min_run_period_pf_ms;
 	else
 		vm->preempt.min_run_period_ms = xe->min_run_period_lr_ms;
 
+	init_rwsem(&vm->exec_queues.lock);
+	if (IS_ENABLED(CONFIG_PROVE_LOCKING)) {
+		fs_reclaim_acquire(GFP_KERNEL);
+		might_lock(&vm->exec_queues.lock);
+		fs_reclaim_release(GFP_KERNEL);
+
+		down_read(&vm->exec_queues.lock);
+		might_lock(&xe_root_mmio_gt(xe)->uc.guc.ct.lock);
+		up_read(&vm->exec_queues.lock);
+	}
+
 	for_each_tile(tile, xe, id)
 		xe_range_fence_tree_init(&vm->rftree[id]);
 
@@ -4569,3 +4582,52 @@ int xe_vm_alloc_cpu_addr_mirror_vma(struct xe_vm *vm, uint64_t start, uint64_t r
 	return xe_vm_alloc_vma(vm, &map_req, false);
 }
 
+/**
+ * xe_vm_add_exec_queue() - Add exec queue to VM
+ * @vm: The VM.
+ * @q: The exec_queue
+ *
+ * Add exec queue to VM, skipped if the device does not have context based TLB
+ * invalidations.
+ */
+void xe_vm_add_exec_queue(struct xe_vm *vm, struct xe_exec_queue *q)
+{
+	struct xe_device *xe = vm->xe;
+
+	/* User VMs and queues only */
+	xe_assert(xe, !(q->flags & EXEC_QUEUE_FLAG_KERNEL));
+	xe_assert(xe, !(q->flags & EXEC_QUEUE_FLAG_PERMANENT));
+	xe_assert(xe, !(q->flags & EXEC_QUEUE_FLAG_VM));
+	xe_assert(xe, !(q->flags & EXEC_QUEUE_FLAG_MIGRATE));
+	xe_assert(xe, vm->xef);
+	xe_assert(xe, vm == q->vm);
+
+	if (!xe->info.has_ctx_tlb_inval)
+		return;
+
+	down_write(&vm->exec_queues.lock);
+	list_add(&q->vm_exec_queue_link, &vm->exec_queues.list[q->gt->info.id]);
+	++vm->exec_queues.count[q->gt->info.id];
+	up_write(&vm->exec_queues.lock);
+}
+
+/**
+ * xe_vm_remove_exec_queue() - Remove exec queue from VM
+ * @vm: The VM.
+ * @q: The exec_queue
+ *
+ * Remove exec queue from VM, skipped if the device does not have context based
+ * TLB invalidations.
+ */
+void xe_vm_remove_exec_queue(struct xe_vm *vm, struct xe_exec_queue *q)
+{
+	if (!vm->xe->info.has_ctx_tlb_inval)
+		return;
+
+	down_write(&vm->exec_queues.lock);
+	if (!list_empty(&q->vm_exec_queue_link)) {
+		list_del(&q->vm_exec_queue_link);
+		--vm->exec_queues.count[q->gt->info.id];
+	}
+	up_write(&vm->exec_queues.lock);
+}

drivers/gpu/drm/xe/xe_vm.h

@@ -287,6 +287,9 @@ static inline struct dma_resv *xe_vm_resv(struct xe_vm *vm)
 
 void xe_vm_kill(struct xe_vm *vm, bool unlocked);
 
+void xe_vm_add_exec_queue(struct xe_vm *vm, struct xe_exec_queue *q);
+void xe_vm_remove_exec_queue(struct xe_vm *vm, struct xe_exec_queue *q);
+
 /**
  * xe_vm_assert_held(vm) - Assert that the vm's reservation object is held.
  * @vm: The vm

drivers/gpu/drm/xe/xe_vm_types.h

@@ -298,6 +298,22 @@ struct xe_vm {
 		struct list_head pm_activate_link;
 	} preempt;
 
+	/** @exec_queues: Manages list of exec queues attached to this VM, protected by lock. */
+	struct {
+		/**
+		 * @exec_queues.list: list of exec queues attached to this VM,
+		 * per GT
+		 */
+		struct list_head list[XE_MAX_TILES_PER_DEVICE * XE_MAX_GT_PER_TILE];
+		/**
+		 * @exec_queues.count: count of exec queues attached to this VM,
+		 * per GT
+		 */
+		int count[XE_MAX_TILES_PER_DEVICE * XE_MAX_GT_PER_TILE];
+		/** @exec_queues.lock: lock to protect exec_queues list */
+		struct rw_semaphore lock;
+	} exec_queues;
+
 	/** @um: unified memory state */
 	struct {
 		/** @asid: address space ID, unique to each VM */