Patchwork [3/3] virtio-blk: tell the guest about size changes

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Submitter Christoph Hellwig
Date Jan. 19, 2011, 5:03 p.m.
Message ID <20110119170305.GC9819@lst.de>
Download mbox | patch
Permalink /patch/79497/
State New
Headers show

Comments

Christoph Hellwig - Jan. 19, 2011, 5:03 p.m.
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>

Patch

Index: qemu/hw/virtio-blk.c
===================================================================
--- qemu.orig/hw/virtio-blk.c	2011-01-19 17:47:10.335004828 +0100
+++ qemu/hw/virtio-blk.c	2011-01-19 17:50:10.748272881 +0100
@@ -504,6 +504,15 @@  static int virtio_blk_load(QEMUFile *f,
     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;
@@ -546,6 +555,7 @@  VirtIODevice *virtio_blk_init(DeviceStat
     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");