Il 03/06/2013 16:58, Stefan Hajnoczi ha scritto:
> 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));
> }
>
Reviewed-by: Paolo Bonzini <pbonz...@redhat.com>
Paolo
