[Qemu-devel] [PATCH 07/28] virtio-blk: tell the guest about size changes

[Kevin Wolf <kwolf@redhat.com>]

From: Christoph Hellwig <hch@lst.de>

Raise a config change interrupt when the size changed.  This allows
virtio-blk guest drivers to read-read the information from the
config space once it got the config chaged interrupt.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 hw/virtio-blk.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index 9f2a9c0..ffac5a4 100644
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -514,6 +514,15 @@ static int virtio_blk_load(QEMUFile *f, void *opaque, int version_id)
     return 0;
 }
 
+static void virtio_blk_change_cb(void *opaque, int reason)
+{
+    VirtIOBlock *s = opaque;
+
+    if (reason & CHANGE_SIZE) {
+        virtio_notify_config(&s->vdev);
+    }
+}
+
 VirtIODevice *virtio_blk_init(DeviceState *dev, BlockConf *conf)
 {
     VirtIOBlock *s;
@@ -556,6 +565,7 @@ VirtIODevice *virtio_blk_init(DeviceState *dev, BlockConf *conf)
     register_savevm(dev, "virtio-blk", virtio_blk_id++, 2,
                     virtio_blk_save, virtio_blk_load, s);
     bdrv_set_removable(s->bs, 0);
+    bdrv_set_change_cb(s->bs, virtio_blk_change_cb, s);
     s->bs->buffer_alignment = conf->logical_block_size;
 
     add_boot_device_path(conf->bootindex, dev, "/disk@0,0");
-- 
1.7.2.3