Currently, the configuration of blkdebug and blkverify is done through
the "filename" alone. There is now way of manually choosing blkdebug or
blkverify as a driver and using a normal image filename.
In the case of blkdebug, the filename starts with the protocol prefix,
follows up with the name of
This patch series introduces a new block driver which acts as a protocol and
whose purpose it is to fail requests. To be more precise, I want it to fail in
configurable places, so that qemu-iotests can be extended with tests for the
error paths (for example for the case when something with metadata
