Am 23.04.2018 um 10:45 hat Markus Armbruster geschrieben:
> When resume of a stopped guest immediately runs into block device
> errors, the BLOCK_IO_ERROR event is sent before the RESUME event.
>
> Reproducer:
>
> 1. Create a scratch image
> $ dd if=/dev/zero of=scratch.img bs=1M count=100
>
> Size doesn't actually matter.
>
> 2. Prepare blkdebug configuration:
>
> $ cat >blkdebug.conf <<EOF
> [inject-error]
> event = "write_aio"
> errno = "5"
> EOF
>
> Note that errno 5 is EIO.
>
> 3. Run a guest with an additional scratch disk, i.e. with additional
> arguments
> -drive
> if=none,id=scratch-drive,format=raw,werror=stop,file=blkdebug:blkdebug.conf:scratch.img
> -device virtio-blk-pci,id=scratch,drive=scratch-drive
>
> The blkdebug part makes all writes to the scratch drive fail with
> EIO. The werror=stop pauses the guest on write errors.
>
> 4. Connect to the QMP socket e.g. like this:
> $ socat UNIX:/your/qmp/socket
> READLINE,history=$HOME/.qmp_history,prompt='QMP> '
>
> Issue QMP command 'qmp_capabilities':
> QMP> { "execute": "qmp_capabilities" }
>
> 5. Boot the guest.
>
> 6. In the guest, write to the scratch disk, e.g. like this:
>
> # dd if=/dev/zero of=/dev/vdb count=1
>
> Do double-check the device specified with of= is actually the
> scratch device!
>
> 7. Issue QMP command 'cont':
> QMP> { "execute": "cont" }
>
> After step 6, I get a BLOCK_IO_ERROR event followed by a STOP event. Good.
>
> After step 7, I get BLOCK_IO_ERROR, then RESUME, then STOP. Not so
> good; I'd expect RESUME, then BLOCK_IO_ERROR, then STOP.
Do you want to rephrase this in the form of a script for qemu-iotests?
I suppose the 'dd' line can be replaced by a 'qemu-io' monitor command.
Kevin
