Re: [PATCH v3 10/11] tests/qtest/migration: Support more than one QEMU binary

[Juan Quintela <quintela@redhat.com>]

Fabiano Rosas <farosas@suse.de> wrote:
D> We have strict rules around migration compatibility between different
> QEMU versions but no test to validate the migration state between
> different binaries.
>
> Add infrastructure to allow running the migration tests with two
> different QEMU binaries as migration source and destination.
>
> The code now recognizes two new environment variables
> QTEST_QEMU_BINARY_SRC and QTEST_QEMU_BINARY_DST. In the absence of
> either of them, the test will use the QTEST_QEMU_BINARY variable. If
> both are missing then the tests are run with single binary as
> previously.
>
> The machine type is selected automatically as the latest machine type
> version that works with both binaries.
>
> Usage:
> QTEST_QEMU_BINARY_SRC=../build-8.2.0/qemu-system-x86_64 \
> QTEST_QEMU_BINARY_DST=../build-8.1.0/qemu-system-x86_64 \
> ./tests/qtest/migration-test
>
> Reviewed-by: Juan Quintela <quintela@redhat.com>
> Signed-off-by: Fabiano Rosas <farosas@suse.de>

The test works for me.  But I would really like to be able to specify
the machine type for which I have to test.  I.e. right now, we can test:

qemu-8.2 <-> qemu-8.1

and it is going to use q35-8.1

But in the case that I want to test that two binaries with q35-8.0,
there is no way to setup that.

So basically what I need is

QTEST_QEMU_MACHINE_TYPE var, and if that exist, just use that instead of
the value of "machine"

What do you think?

Later, Juan.