Kevin Wolf <kw...@redhat.com> writes:
> 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.
Makes sense, but I'm quite pretty much a noob there. Perhaps I can copy
an existing test and hack it up. Which one would you recommend?
