drm/xe: Nuke VM's mapping upon close

Clear root PT entry and invalidate entire VM's address space when
closing the VM. Will prevent the GPU from accessing any of the VM's
memory after closing.

v2:
 - s/vma/vm in kernel doc (CI)
 - Don't nuke migration VM as this occur at driver unload (CI)
v3:
 - Rebase and pull into SVM series (Thomas)
 - Wait for pending binds (Thomas)
v5:
 - Remove xe_gt_tlb_invalidation_fence_fini in error case (Matt Auld)
 - Drop local migration bool (Thomas)
v7:
 - Add drm_dev_enter/exit protecting invalidation (CI, Matt Auld)

Signed-off-by: Matthew Brost <[email protected]>
Reviewed-by: Thomas Hellström <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

Author: mbrost05

drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c

@@ -410,6 +410,28 @@ int xe_gt_tlb_invalidation_range(struct xe_gt *gt,
 	return send_tlb_invalidation(&gt->uc.guc, fence, action, len);
 }
 
+/**
+ * xe_gt_tlb_invalidation_vm - Issue a TLB invalidation on this GT for a VM
+ * @gt: graphics tile
+ * @vm: VM to invalidate
+ *
+ * Invalidate entire VM's address space
+ */
+void xe_gt_tlb_invalidation_vm(struct xe_gt *gt, struct xe_vm *vm)
+{
+	struct xe_gt_tlb_invalidation_fence fence;
+	u64 range = 1ull << vm->xe->info.va_bits;
+	int ret;
+
+	xe_gt_tlb_invalidation_fence_init(gt, &fence, true);
+
+	ret = xe_gt_tlb_invalidation_range(gt, &fence, 0, range, vm->usm.asid);
+	if (ret < 0)
+		return;
+
+	xe_gt_tlb_invalidation_fence_wait(&fence);
+}
+
 /**
  * xe_gt_tlb_invalidation_vma - Issue a TLB invalidation on this GT for a VMA
  * @gt: GT structure

drivers/gpu/drm/xe/xe_gt_tlb_invalidation.h

@@ -12,6 +12,7 @@
 
 struct xe_gt;
 struct xe_guc;
+struct xe_vm;
 struct xe_vma;
 
 int xe_gt_tlb_invalidation_init_early(struct xe_gt *gt);
@@ -21,6 +22,7 @@ int xe_gt_tlb_invalidation_ggtt(struct xe_gt *gt);
 int xe_gt_tlb_invalidation_vma(struct xe_gt *gt,
 			       struct xe_gt_tlb_invalidation_fence *fence,
 			       struct xe_vma *vma);
+void xe_gt_tlb_invalidation_vm(struct xe_gt *gt, struct xe_vm *vm);
 int xe_gt_tlb_invalidation_range(struct xe_gt *gt,
 				 struct xe_gt_tlb_invalidation_fence *fence,
 				 u64 start, u64 end, u32 asid);

drivers/gpu/drm/xe/xe_pt.c

@@ -218,6 +218,20 @@ void xe_pt_destroy(struct xe_pt *pt, u32 flags, struct llist_head *deferred)
 	xe_pt_free(pt);
 }
 
+/**
+ * xe_pt_clear() - Clear a page-table.
+ * @xe: xe device.
+ * @pt: The page-table.
+ *
+ * Clears page-table by setting to zero.
+ */
+void xe_pt_clear(struct xe_device *xe, struct xe_pt *pt)
+{
+	struct iosys_map *map = &pt->bo->vmap;
+
+	xe_map_memset(xe, map, 0, 0, SZ_4K);
+}
+
 /**
  * DOC: Pagetable building
  *

drivers/gpu/drm/xe/xe_pt.h

@@ -13,6 +13,7 @@ struct dma_fence;
 struct xe_bo;
 struct xe_device;
 struct xe_exec_queue;
+struct xe_svm_range;
 struct xe_sync_entry;
 struct xe_tile;
 struct xe_vm;
@@ -35,6 +36,8 @@ void xe_pt_populate_empty(struct xe_tile *tile, struct xe_vm *vm,
 
 void xe_pt_destroy(struct xe_pt *pt, u32 flags, struct llist_head *deferred);
 
+void xe_pt_clear(struct xe_device *xe, struct xe_pt *pt);
+
 int xe_pt_update_ops_prepare(struct xe_tile *tile, struct xe_vma_ops *vops);
 struct dma_fence *xe_pt_update_ops_run(struct xe_tile *tile,
 				       struct xe_vma_ops *vops);

drivers/gpu/drm/xe/xe_vm.c

@@ -8,6 +8,7 @@
 #include <linux/dma-fence-array.h>
 #include <linux/nospec.h>
 
+#include <drm/drm_drv.h>
 #include <drm/drm_exec.h>
 #include <drm/drm_print.h>
 #include <drm/ttm/ttm_tt.h>
@@ -1615,9 +1616,40 @@ struct xe_vm *xe_vm_create(struct xe_device *xe, u32 flags)
 
 static void xe_vm_close(struct xe_vm *vm)
 {
+	struct xe_device *xe = vm->xe;
+	bool bound;
+	int idx;
+
+	bound = drm_dev_enter(&xe->drm, &idx);
+
 	down_write(&vm->lock);
+
 	vm->size = 0;
+
+	if (!((vm->flags & XE_VM_FLAG_MIGRATION))) {
+		struct xe_tile *tile;
+		struct xe_gt *gt;
+		u8 id;
+
+		/* Wait for pending binds */
+		dma_resv_wait_timeout(xe_vm_resv(vm),
+				      DMA_RESV_USAGE_BOOKKEEP,
+				      false, MAX_SCHEDULE_TIMEOUT);
+
+		if (bound) {
+			for_each_tile(tile, xe, id)
+				if (vm->pt_root[id])
+					xe_pt_clear(xe, vm->pt_root[id]);
+
+			for_each_gt(gt, xe, id)
+				xe_gt_tlb_invalidation_vm(gt, vm);
+		}
+	}
+
 	up_write(&vm->lock);
+
+	if (bound)
+		drm_dev_exit(idx);
 }
 
 void xe_vm_close_and_put(struct xe_vm *vm)