Paolo Bonzini <pbonz...@redhat.com> suggested the following test case:
1. Launch a guest and wait at the GRUB boot menu:
qemu-system-x86_64 -enable-kvm -m 1024 \
-drive if=none,cache=none,file=test.img,id=foo,werror=stop,rerror=stop
-device virtio-blk-pci,drive=foo,id=virtio0,addr=4
2. Hot unplug the device:
(qemu) drive_del foo
3. Select the first boot menu entry
Without this patch the guest pauses due to ENOMEDIUM. But it is not
possible to resolve this situation - the drive has become anonymous.
With this patch the guest the guest gets the ENOMEDIUM error.
Note that this scenario actually happens sometimes during libvirt disk
hot unplug, where device_del is followed by drive_del. I/O may still be
submitted to the drive after drive_del if the guest does not process the
PCI hot unplug notification.
Reported-by: Dafna Ron <d...@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
blockdev.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/blockdev.c b/blockdev.c
index d1ec99a..6eb81a3 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1180,6 +1180,10 @@ int do_drive_del(Monitor *mon, const QDict *qdict,
QObject **ret_data)
*/
if (bdrv_get_attached_dev(bs)) {
bdrv_make_anon(bs);
+
+ /* Further I/O must not pause the guest */
+ bdrv_set_on_error(bs, BLOCKDEV_ON_ERROR_REPORT,
+ BLOCKDEV_ON_ERROR_REPORT);
} else {
drive_uninit(drive_get_by_blockdev(bs));
}
--
1.8.1.4
