drm/xe: Convert existing drm_exec transactions for exhaustive eviction

Convert existing drm_exec transactions, like GT pagefault validation,
non-LR exec() IOCTL and the rebind worker to support
exhaustive eviction using the xe_validation_guard().

v2:
- Adapt to signature change in xe_validation_guard() (Matt Brost)
- Avoid gotos from within xe_validation_guard() (Matt Brost)
- Check error return from xe_validation_guard()

v3:
- Rebase on gpu_madvise()

Signed-off-by: Thomas Hellström <[e-mail]>
Reviewed-by: Matthew Brost <[e-mail]> #v1
Link: https://lore.kernel.org/r/[e-mail]

drivers/gpu/drm/xe/xe_exec.c

···
 	struct drm_gpuvm_exec vm_exec = {.extra.fn = xe_exec_fn};
 	struct drm_exec *exec = &vm_exec.exec;
 	u32 i, num_syncs, num_ufence = 0;
+	struct xe_validation_ctx ctx;
 	struct xe_sched_job *job;
 	struct xe_vm *vm;
 	bool write_locked, skip_retry = false;
-	ktime_t end = 0;
 	int err = 0;
 	struct xe_hw_engine_group *group;
 	enum xe_hw_engine_group_execution_mode mode, previous_mode;
···
 	if (err)
 		goto err_unlock_list;
 
-	vm_exec.vm = &vm->gpuvm;
-	vm_exec.flags = DRM_EXEC_INTERRUPTIBLE_WAIT;
-	if (xe_vm_in_lr_mode(vm)) {
-		drm_exec_init(exec, vm_exec.flags, 0);
-	} else {
-		err = drm_gpuvm_exec_lock(&vm_exec);
-		if (err) {
-			if (xe_vm_validate_should_retry(exec, err, &end))
-				err = -EAGAIN;
+	if (!xe_vm_in_lr_mode(vm)) {
+		vm_exec.vm = &vm->gpuvm;
+		vm_exec.flags = DRM_EXEC_INTERRUPTIBLE_WAIT;
+		err = xe_validation_exec_lock(&ctx, &vm_exec, &xe->val);
+		if (err)
 			goto err_unlock_list;
-		}
 	}
 
 	if (xe_vm_is_closed_or_banned(q->vm)) {
···
 	if (err)
 		xe_sched_job_put(job);
 err_exec:
-	drm_exec_fini(exec);
+	if (!xe_vm_in_lr_mode(vm))
+		xe_validation_ctx_fini(&ctx);
 err_unlock_list:
 	up_read(&vm->lock);
 	if (err == -EAGAIN && !skip_retry)

drivers/gpu/drm/xe/xe_gt_pagefault.c

···
 {
 	struct xe_vm *vm = xe_vma_vm(vma);
 	struct xe_tile *tile = gt_to_tile(gt);
+	struct xe_validation_ctx ctx;
 	struct drm_exec exec;
 	struct dma_fence *fence;
-	ktime_t end = 0;
 	int err, needs_vram;
 
 	lockdep_assert_held_write(&vm->lock);
···
 	}
 
 	/* Lock VM and BOs dma-resv */
-	drm_exec_init(&exec, 0, 0);
+	xe_validation_ctx_init(&ctx, &vm->xe->val, &exec, (struct xe_val_flags) {});
 	drm_exec_until_all_locked(&exec) {
 		err = xe_pf_begin(&exec, vma, needs_vram == 1, tile->mem.vram);
 		drm_exec_retry_on_contention(&exec);
-		if (xe_vm_validate_should_retry(&exec, err, &end))
-			err = -EAGAIN;
+		xe_validation_retry_on_oom(&ctx, &err);
 		if (err)
 			goto unlock_dma_resv;
 
···
 		xe_vm_set_validation_exec(vm, NULL);
 		if (IS_ERR(fence)) {
 			err = PTR_ERR(fence);
-			if (xe_vm_validate_should_retry(&exec, err, &end))
-				err = -EAGAIN;
+			xe_validation_retry_on_oom(&ctx, &err);
 			goto unlock_dma_resv;
 		}
 	}
···
 	dma_fence_put(fence);
 
 unlock_dma_resv:
-	drm_exec_fini(&exec);
+	xe_validation_ctx_fini(&ctx);
 	if (err == -EAGAIN)
 		goto retry_userptr;
 
···
 {
 	struct xe_device *xe = gt_to_xe(gt);
 	struct xe_tile *tile = gt_to_tile(gt);
+	struct xe_validation_ctx ctx;
 	struct drm_exec exec;
 	struct xe_vm *vm;
 	struct xe_vma *vma;
···
 		goto unlock_vm;
 
 	/* Lock VM and BOs dma-resv */
-	drm_exec_init(&exec, 0, 0);
+	xe_validation_ctx_init(&ctx, &vm->xe->val, &exec, (struct xe_val_flags) {});
 	drm_exec_until_all_locked(&exec) {
 		ret = xe_pf_begin(&exec, vma, IS_DGFX(vm->xe), tile->mem.vram);
 		drm_exec_retry_on_contention(&exec);
-		if (ret)
-			break;
+		xe_validation_retry_on_oom(&ctx, &ret);
 	}
 
-	drm_exec_fini(&exec);
+	xe_validation_ctx_fini(&ctx);
 unlock_vm:
 	up_read(&vm->lock);
 	xe_vm_put(vm);

drivers/gpu/drm/xe/xe_vm.c

···
 		.num_fences = 1,
 	};
 	struct drm_exec *exec = &vm_exec.exec;
+	struct xe_validation_ctx ctx;
 	struct dma_fence *pfence;
 	int err;
 	bool wait;
···
 	xe_assert(vm->xe, xe_vm_in_preempt_fence_mode(vm));
 
 	down_write(&vm->lock);
-	err = drm_gpuvm_exec_lock(&vm_exec);
+	err = xe_validation_exec_lock(&ctx, &vm_exec, &vm->xe->val);
 	if (err)
 		goto out_up_write;
 
···
 	xe_svm_notifier_unlock(vm);
 
 out_fini:
-	drm_exec_fini(exec);
+	xe_validation_ctx_fini(&ctx);
 out_up_write:
 	up_write(&vm->lock);
 
···
 		xe_vm_unlock(vm);
 
 	/* TODO: Inform user the VM is banned */
-}
-
-/**
- * xe_vm_validate_should_retry() - Whether to retry after a validate error.
- * @exec: The drm_exec object used for locking before validation.
- * @err: The error returned from ttm_bo_validate().
- * @end: A ktime_t cookie that should be set to 0 before first use and
- * that should be reused on subsequent calls.
- *
- * With multiple active VMs, under memory pressure, it is possible that
- * ttm_bo_validate() run into -EDEADLK and in such case returns -ENOMEM.
- * Until ttm properly handles locking in such scenarios, best thing the
- * driver can do is retry with a timeout. Check if that is necessary, and
- * if so unlock the drm_exec's objects while keeping the ticket to prepare
- * for a rerun.
- *
- * Return: true if a retry after drm_exec_init() is recommended;
- * false otherwise.
- */
-bool xe_vm_validate_should_retry(struct drm_exec *exec, int err, ktime_t *end)
-{
-	ktime_t cur;
-
-	if (err != -ENOMEM)
-		return false;
-
-	cur = ktime_get();
-	*end = *end ? : ktime_add_ms(cur, XE_VM_REBIND_RETRY_TIMEOUT_MS);
-	if (!ktime_before(cur, *end))
-		return false;
-
-	msleep(20);
-	return true;
 }
 
 static int xe_gpuvm_validate(struct drm_gpuvm_bo *vm_bo, struct drm_exec *exec)
···
 static void preempt_rebind_work_func(struct work_struct *w)
 {
 	struct xe_vm *vm = container_of(w, struct xe_vm, preempt.rebind_work);
+	struct xe_validation_ctx ctx;
 	struct drm_exec exec;
 	unsigned int fence_count = 0;
 	LIST_HEAD(preempt_fences);
-	ktime_t end = 0;
 	int err = 0;
 	long wait;
 	int __maybe_unused tries = 0;
···
 			goto out_unlock_outer;
 	}
 
-	drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT, 0);
+	err = xe_validation_ctx_init(&ctx, &vm->xe->val, &exec,
+				     (struct xe_val_flags) {.interruptible = true});
+	if (err)
+		goto out_unlock_outer;
 
 	drm_exec_until_all_locked(&exec) {
 		bool done = false;
 
 		err = xe_preempt_work_begin(&exec, vm, &done);
 		drm_exec_retry_on_contention(&exec);
+		xe_validation_retry_on_oom(&ctx, &err);
 		if (err || done) {
-			drm_exec_fini(&exec);
-			if (err && xe_vm_validate_should_retry(&exec, err, &end))
-				err = -EAGAIN;
-
+			xe_validation_ctx_fini(&ctx);
 			goto out_unlock_outer;
 		}
 	}
···
 	xe_svm_notifier_unlock(vm);
 
 out_unlock:
-	drm_exec_fini(&exec);
+	xe_validation_ctx_fini(&ctx);
 out_unlock_outer:
 	if (err == -EAGAIN) {
 		trace_xe_vm_rebind_worker_retry(vm);
···
 
 static void xe_vma_destroy_unlocked(struct xe_vma *vma)
 {
+	struct xe_device *xe = xe_vma_vm(vma)->xe;
+	struct xe_validation_ctx ctx;
 	struct drm_exec exec;
-	int err;
+	int err = 0;
 
-	drm_exec_init(&exec, 0, 0);
-	drm_exec_until_all_locked(&exec) {
+	xe_validation_guard(&ctx, &xe->val, &exec, (struct xe_val_flags) {}, err) {
 		err = xe_vm_lock_vma(&exec, vma);
 		drm_exec_retry_on_contention(&exec);
 		if (XE_WARN_ON(err))
 			break;
+		xe_vma_destroy(vma, NULL);
 	}
-
-	xe_vma_destroy(vma, NULL);
-
-	drm_exec_fini(&exec);
+	xe_assert(xe, !err);
 }
 
 struct xe_vma *
···
 			      struct xe_vma_mem_attr *attr, unsigned int flags)
 {
 	struct xe_bo *bo = op->gem.obj ? gem_to_xe_bo(op->gem.obj) : NULL;
+	struct xe_validation_ctx ctx;
 	struct drm_exec exec;
 	struct xe_vma *vma;
 	int err = 0;
···
 	lockdep_assert_held_write(&vm->lock);
 
 	if (bo) {
-		drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT, 0);
-		drm_exec_until_all_locked(&exec) {
-			err = 0;
+		err = 0;
+		xe_validation_guard(&ctx, &vm->xe->val, &exec,
+				    (struct xe_val_flags) {.interruptible = true}, err) {
 			if (!bo->vm) {
 				err = drm_exec_lock_obj(&exec, xe_vm_obj(vm));
 				drm_exec_retry_on_contention(&exec);
···
 				err = drm_exec_lock_obj(&exec, &bo->ttm.base);
 				drm_exec_retry_on_contention(&exec);
 			}
-			if (err) {
-				drm_exec_fini(&exec);
+			if (err)
 				return ERR_PTR(err);
+
+			vma = xe_vma_create(vm, bo, op->gem.offset,
+					    op->va.addr, op->va.addr +
+					    op->va.range - 1, attr, flags);
+			if (IS_ERR(vma))
+				return vma;
+
+			if (!bo->vm) {
+				err = add_preempt_fences(vm, bo);
+				if (err) {
+					prep_vma_destroy(vm, vma, false);
+					xe_vma_destroy(vma, NULL);
+				}
 			}
 		}
+		if (err)
+			return ERR_PTR(err);
+	} else {
+		vma = xe_vma_create(vm, NULL, op->gem.offset,
+				    op->va.addr, op->va.addr +
+				    op->va.range - 1, attr, flags);
+		if (IS_ERR(vma))
+			return vma;
+
+		if (xe_vma_is_userptr(vma))
+			err = xe_vma_userptr_pin_pages(to_userptr_vma(vma));
 	}
-	vma = xe_vma_create(vm, bo, op->gem.offset,
-			    op->va.addr, op->va.addr +
-			    op->va.range - 1, attr, flags);
-	if (IS_ERR(vma))
-		goto err_unlock;
-
-	if (xe_vma_is_userptr(vma))
-		err = xe_vma_userptr_pin_pages(to_userptr_vma(vma));
-	else if (!xe_vma_has_no_bo(vma) && !bo->vm)
-		err = add_preempt_fences(vm, bo);
-
-err_unlock:
-	if (bo)
-		drm_exec_fini(&exec);
-
 	if (err) {
 		prep_vma_destroy(vm, vma, false);
 		xe_vma_destroy_unlocked(vma);
···
 static struct dma_fence *vm_bind_ioctl_ops_execute(struct xe_vm *vm,
 						   struct xe_vma_ops *vops)
 {
+	struct xe_validation_ctx ctx;
 	struct drm_exec exec;
 	struct dma_fence *fence;
-	int err;
+	int err = 0;
 
 	lockdep_assert_held_write(&vm->lock);
 
-	drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT |
-		      DRM_EXEC_IGNORE_DUPLICATES, 0);
-	drm_exec_until_all_locked(&exec) {
+	xe_validation_guard(&ctx, &vm->xe->val, &exec,
+			    ((struct xe_val_flags) {
+				    .interruptible = true,
+				    .exec_ignore_duplicates = true,
+			    }), err) {
 		err = vm_bind_ioctl_ops_lock_and_prep(&exec, vm, vops);
 		drm_exec_retry_on_contention(&exec);
-		if (err) {
-			fence = ERR_PTR(err);
-			goto unlock;
-		}
+		xe_validation_retry_on_oom(&ctx, &err);
+		if (err)
+			return ERR_PTR(err);
 
 		xe_vm_set_validation_exec(vm, &exec);
 		fence = ops_execute(vm, vops);
···
 		if (IS_ERR(fence)) {
 			if (PTR_ERR(fence) == -ENODATA)
 				vm_bind_ioctl_ops_fini(vm, vops, NULL);
-			goto unlock;
+			return fence;
 		}
 
 		vm_bind_ioctl_ops_fini(vm, vops, fence);
 	}
 
-unlock:
-	drm_exec_fini(&exec);
-	return fence;
+	return err ? ERR_PTR(err) : fence;
 }
 ALLOW_ERROR_INJECTION(vm_bind_ioctl_ops_execute, ERRNO);
 

drivers/gpu/drm/xe/xe_vm.h

···
 	}
 }
 
-bool xe_vm_validate_should_retry(struct drm_exec *exec, int err, ktime_t *end);
-
 int xe_vm_lock_vma(struct drm_exec *exec, struct xe_vma *vma);
 
 int xe_vm_validate_rebind(struct xe_vm *vm, struct drm_exec *exec,