Re: [Qemu-devel] PVFS2 Block Driver Support

[Stefan Hajnoczi]

On Thu, Jun 27, 2013 at 4:43 PM, Stefan Hajnoczi <address@hidden> wrote:
> On Thu, Jun 27, 2013 at 4:25 PM, Timothy Scott <address@hidden> wrote:
>>   - Is there currently a testing suite/procedure for verifying new block
>> drivers?
>
> There is a test suite in tests/qemu-iotests/.  You will need to add
> support for PVFS2, see how NBD and other protocols were added.

I realized I should give a bit more info to help you get started.

tests/qemu-iotests/check is the script to run tests.  There are
currently around 55 tests which exercise operations using qemu-img(1),
qemu-io(1), and sometimes by running QEMU.

You can launch it like this:
cd tests/qemu-iotests
QEMU_PROG=path/to/qemu-system-x86_64 PATH=path/to/qemu-dir:$PATH ./check -qcow2

You can simplify this by putting 'qemu', 'qemu-img', and 'qemu-io'
into your PATH.  You may wish to symlink 'qemu' to your
qemu-system-x86_64 binary.  That saves you from typing out the
environment variables every time.  See the qemu-iotests code for
details on how paths are detected.

Once you've added PVFS2 support you should be able to do:
check -pvfs2

Tests are grouped by specific areas (read-only, read-write, backing
file, etc) in tests/qemu-iotests/group.  New tests must be added to
this file before they become available in check.

Tests themselves can restrict themselves to certain formats or host
operating systems.  This is useful for ensuring that a test is only
run against, say qcow2, vmdk, and qed.  See the actual test code.

Most tests are written in bash.  The qemu-iotests framework is also
written in bash.  The framework is pretty simple: it runs a test and
compares the output against a "golden master" output file.  If the
output matches then the test passes (this requires filtering output in
some cases to eliminate parts that differ between runs, from system to
system, etc).

Some tests are written in Python and use iotests.py, which provides
the necessary environment and useful functions.  These tests mainly
launch QEMU and interact with the QMP monitor (JSON), which is hard to
do easily in bash.

Stefan