[PATCH v3 5/6] vduse-blk: Add vduse-blk resize support

[Xie Yongji <xieyongji@bytedance.com>]

To support block resize, this uses vduse_dev_update_config()
to update the capacity field in configuration space and inject
config interrupt on the block resize callback.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/export/vduse-blk.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/block/export/vduse-blk.c b/block/export/vduse-blk.c
index 3f4e0df34b..e027b2e5ff 100644
--- a/block/export/vduse-blk.c
+++ b/block/export/vduse-blk.c
@@ -310,6 +310,23 @@ static void blk_aio_detach(void *opaque)
     vblk_exp->export.ctx = NULL;
 }
 
+static void vduse_blk_resize(void *opaque)
+{
+    BlockExport *exp = opaque;
+    VduseBlkExport *vblk_exp = container_of(exp, VduseBlkExport, export);
+    struct virtio_blk_config config;
+
+    config.capacity =
+            cpu_to_le64(blk_getlength(exp->blk) >> VIRTIO_BLK_SECTOR_BITS);
+    vduse_dev_update_config(vblk_exp->dev, sizeof(config.capacity),
+                            offsetof(struct virtio_blk_config, capacity),
+                            (char *)&config.capacity);
+}
+
+static const BlockDevOps vduse_block_ops = {
+    .resize_cb = vduse_blk_resize,
+};
+
 static int vduse_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
                                 Error **errp)
 {
@@ -397,6 +414,8 @@ static int vduse_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
     blk_add_aio_context_notifier(exp->blk, blk_aio_attached, blk_aio_detach,
                                  vblk_exp);
 
+    blk_set_dev_ops(exp->blk, &vduse_block_ops, exp);
+
     return 0;
 }
 
@@ -406,6 +425,7 @@ static void vduse_blk_exp_delete(BlockExport *exp)
 
     blk_remove_aio_context_notifier(exp->blk, blk_aio_attached, blk_aio_detach,
                                     vblk_exp);
+    blk_set_dev_ops(exp->blk, NULL, NULL);
     vduse_dev_destroy(vblk_exp->dev);
 }
 
-- 
2.20.1