|author||Stefan Hajnoczi <email@example.com>||2013-06-05 10:33:14 +0200|
|committer||Stefan Hajnoczi <firstname.lastname@example.org>||2013-06-05 16:39:59 +0200|
blockdev: reset werror/rerror on drive_del
Paolo Bonzini <email@example.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. The guest is stuck in a continuous pause loop since the I/O request is retried and fails immediately again when the guest is resumed. With this patch the error is reported to the guest. 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 <firstname.lastname@example.org> Signed-off-by: Stefan Hajnoczi <email@example.com> Reviewed-by: Kevin Wolf <firstname.lastname@example.org>
Diffstat (limited to 'hmp-commands.hx')
1 files changed, 2 insertions, 0 deletions
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 9cea4151b9..4f5a3fd7d5 100644
@@ -185,6 +185,8 @@ Remove host block device. The result is that guest generated IO is no longer
submitted against the host device underlying the disk. Once a drive has
been deleted, the QEMU Block layer returns -EIO which results in IO
errors in the guest for applications that are reading/writing to the device.
+These errors are always reported to the guest, regardless of the drive's error
+actions (drive options rerror, werror).