@@ -99,6 +99,9 @@ struct virtio_mem {
/* Id of the next memory bock to prepare when needed. */
unsigned long next_mb_id;
+ /* The parent resource for all memory added via this device. */
+ struct resource *parent_resource;
+
/* Summary of all memory block states. */
unsigned long nb_mb_state[VIRTIO_MEM_MB_STATE_COUNT];
#define VIRTIO_MEM_NB_OFFLINE_THRESHOLD 10
@@ -1741,6 +1744,44 @@ static int virtio_mem_init(struct virtio_mem *vm)
return 0;
}
+static int virtio_mem_create_resource(struct virtio_mem *vm)
+{
+ /*
+ * When force-unloading the driver and removing the device, we
+ * could have a garbage pointer. Duplicate the string.
+ */
+ const char *name = kstrdup(dev_name(&vm->vdev->dev), GFP_KERNEL);
+
+ if (!name)
+ return -ENOMEM;
+
+ vm->parent_resource = __request_mem_region(vm->addr, vm->region_size,
+ name, IORESOURCE_SYSTEM_RAM);
+ if (!vm->parent_resource) {
+ kfree(name);
+ dev_warn(&vm->vdev->dev, "could not reserve device region\n");
+ return -EBUSY;
+ }
+
+ /* The memory is not actually busy - make add_memory() work. */
+ vm->parent_resource->flags &= ~IORESOURCE_BUSY;
+ return 0;
+}
+
+static void virtio_mem_delete_resource(struct virtio_mem *vm)
+{
+ const char *name;
+
+ if (!vm->parent_resource)
+ return;
+
+ name = vm->parent_resource->name;
+ release_resource(vm->parent_resource);
+ kfree(vm->parent_resource);
+ kfree(name);
+ vm->parent_resource = NULL;
+}
+
static int virtio_mem_probe(struct virtio_device *vdev)
{
struct virtio_mem *vm;
@@ -1770,11 +1811,16 @@ static int virtio_mem_probe(struct virtio_device *vdev)
if (rc)
goto out_del_vq;
+ /* create the parent resource for all memory */
+ rc = virtio_mem_create_resource(vm);
+ if (rc)
+ goto out_del_vq;
+
/* register callbacks */
vm->memory_notifier.notifier_call = virtio_mem_memory_notifier_cb;
rc = register_memory_notifier(&vm->memory_notifier);
if (rc)
- goto out_del_vq;
+ goto out_del_resource;
rc = register_virtio_mem_device(vm);
if (rc)
goto out_unreg_mem;
@@ -1788,6 +1834,8 @@ static int virtio_mem_probe(struct virtio_device *vdev)
return 0;
out_unreg_mem:
unregister_memory_notifier(&vm->memory_notifier);
+out_del_resource:
+ virtio_mem_delete_resource(vm);
out_del_vq:
vdev->config->del_vqs(vdev);
out_free_vm:
@@ -1848,6 +1896,8 @@ static void virtio_mem_remove(struct virtio_device *vdev)
vm->nb_mb_state[VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL] ||
vm->nb_mb_state[VIRTIO_MEM_MB_STATE_ONLINE_MOVABLE])
dev_warn(&vdev->dev, "device still has system memory added\n");
+ else
+ virtio_mem_delete_resource(vm);
/* remove all tracking data - no locking needed */
vfree(vm->mb_state);
Let's add a parent resource, named after the virtio device (inspired by drivers/dax/kmem.c). This allows user space to identify which memory belongs to which virtio-mem device. With this change and two virtio-mem devices: :/# cat /proc/iomem 00000000-00000fff : Reserved 00001000-0009fbff : System RAM [...] 140000000-333ffffff : virtio0 140000000-147ffffff : System RAM 148000000-14fffffff : System RAM 150000000-157ffffff : System RAM [...] 334000000-3033ffffff : virtio1 338000000-33fffffff : System RAM 340000000-347ffffff : System RAM 348000000-34fffffff : System RAM [...] Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> --- drivers/virtio/virtio_mem.c | 52 ++++++++++++++++++++++++++++++++++++- 1 file changed, 51 insertions(+), 1 deletion(-)