virtio-mem: use a single dynamic memory group for a single virtio-mem device

Let's use a single dynamic memory group.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Hui Zhu <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Marek Kedzierski <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Pankaj Gupta <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Wei Yang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 19 insertions, 3 deletions

diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index 7e83ed373e00..bef8ad6bf466 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c
@@ -143,6 +143,8 @@ struct virtio_mem {
 	 * add_memory_driver_managed().
 	 */
 	const char *resource_name;
+	/* Memory group identification. */
+	int mgid;
 
 	/*
 	 * We don't want to add too much memory if it's not getting onlined,
@@ -626,8 +628,8 @@ static int virtio_mem_add_memory(struct virtio_mem *vm, uint64_t addr,
 		addr + size - 1);
 	/* Memory might get onlined immediately. */
 	atomic64_add(size, &vm->offline_size);
-	rc = add_memory_driver_managed(vm->nid, addr, size, vm->resource_name,
-				       MHP_MERGE_RESOURCE);
+	rc = add_memory_driver_managed(vm->mgid, addr, size, vm->resource_name,
+				       MHP_MERGE_RESOURCE | MHP_NID_IS_MGID);
 	if (rc) {
 		atomic64_sub(size, &vm->offline_size);
 		dev_warn(&vm->vdev->dev, "adding memory failed: %d\n", rc);
@@ -2569,6 +2571,7 @@ static bool virtio_mem_has_memory_added(struct virtio_mem *vm)
 static int virtio_mem_probe(struct virtio_device *vdev)
 {
 	struct virtio_mem *vm;
+	uint64_t unit_pages;
 	int rc;
 
 	BUILD_BUG_ON(sizeof(struct virtio_mem_req) != 24);
@@ -2603,6 +2606,16 @@ static int virtio_mem_probe(struct virtio_device *vdev)
 	if (rc)
 		goto out_del_vq;
 
+	/* use a single dynamic memory group to cover the whole memory device */
+	if (vm->in_sbm)
+		unit_pages = PHYS_PFN(memory_block_size_bytes());
+	else
+		unit_pages = PHYS_PFN(vm->bbm.bb_size);
+	rc = memory_group_register_dynamic(vm->nid, unit_pages);
+	if (rc < 0)
+		goto out_del_resource;
+	vm->mgid = rc;
+
 	/*
 	 * If we still have memory plugged, we have to unplug all memory first.
 	 * Registering our parent resource makes sure that this memory isn't
@@ -2617,7 +2630,7 @@ static int virtio_mem_probe(struct virtio_device *vdev)
 	vm->memory_notifier.notifier_call = virtio_mem_memory_notifier_cb;
 	rc = register_memory_notifier(&vm->memory_notifier);
 	if (rc)
-		goto out_del_resource;
+		goto out_unreg_group;
 	rc = register_virtio_mem_device(vm);
 	if (rc)
 		goto out_unreg_mem;
@@ -2631,6 +2644,8 @@ static int virtio_mem_probe(struct virtio_device *vdev)
 	return 0;
 out_unreg_mem:
 	unregister_memory_notifier(&vm->memory_notifier);
+out_unreg_group:
+	memory_group_unregister(vm->mgid);
 out_del_resource:
 	virtio_mem_delete_resource(vm);
 out_del_vq:
@@ -2695,6 +2710,7 @@ static void virtio_mem_remove(struct virtio_device *vdev)
 	} else {
 		virtio_mem_delete_resource(vm);
 		kfree_const(vm->resource_name);
+		memory_group_unregister(vm->mgid);
 	}
 
 	/* remove all tracking data - no locking needed */