Re: how do the iotests pick a machine model to run on ?

[Kevin Wolf <kwolf@redhat.com>]

Am 19.01.2024 um 13:55 hat Peter Maydell geschrieben:
> If you build QEMU with support for the sh4 target only
> (configure --target-list=sh4-softmmu) then 'make check' fails
> in the iotests, because some iotests, including for instance 040,
> try to create a machine with a virtio-scsi device, but they don't
> do anything to ensure that the machine they create actually
> has a PCI bus to plug the virtio-scsi device into, and so the test
> fails:
> 
> +Traceback (most recent call last):
> +  File "/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/tests/qemu-iotests/040",
> line 94, in setUp
> +    self.vm.launch()
> +  File "/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/python/qemu/machine/machine.py",
> line 455, in launch
> +    raise VMLaunchFailure(
> +qemu.machine.machine.VMLaunchFailure: ConnectError: Failed to
> establish session: EOFError
> +       Exit code: 1
> +       Command:
> /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/sh4/qemu-system-sh4
> -display none -vga none -chardev socket,id=mon,fd=5 -mon
> chardev=mon,mode=control -chardev socket,id=qtest,fd=3 -qtest
> chardev:qtest -accel qtest -nodefaults -display none -accel qtest
> -drive if=none,id=drive0,file=/mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/sh4/scratch/qcow2-file-040/test.img,format=qcow2,cache=writeback,aio=threads,node-name=top,backing.node-name=mid,backing.backing.node-name=base
> -device virtio-scsi -device scsi-hd,id=scsi0,drive=drive0
> +       Output: [I 0.000000] OPENED
> +qemu-system-sh4: -device virtio-scsi: No 'PCI' bus found for device
> 'virtio-scsi-pci'
> 
> (It happens that the default machine type for 'sh4'
> does not have a PCI bus.)
> 
> How are the iotests supposed to select a machine model to run
> on, and how are they intended to mark themselves as requiring
> particular facilities, like PCI? Presumably some of the tests
> are missing the appropriate annotations to ensure they're
> skipped when the facilities required aren't present.

Probably next to nobody builds only sh4 and then runs 'make check'...

I think the following patch should fix this test case (but as nobody
ever tested it, I fully expect other cases to fail, too). The fix could
of course be a lot more fine grained and skip only some individual tests
instead of all of them. I doubt we care, though, as long as it passes.

iotests use machine_map in tests/qemu-iotests/testenv.py to decide which
machine to use for which target (unless the individual test case
overrides that). If the target isn't the list, it gets the default
machine type.

Kevin

diff --git a/tests/qemu-iotests/040 b/tests/qemu-iotests/040
index 5c18e413ec..19f0bb1010 100755
--- a/tests/qemu-iotests/040
+++ b/tests/qemu-iotests/040
@@ -952,5 +952,6 @@ class TestCommitWithOverriddenBacking(iotests.QMPTestCase):
         self.vm.event_wait('BLOCK_JOB_COMPLETED')
 
 if __name__ == '__main__':
+    iotests.verify_virtio_scsi_pci_or_ccw()
     iotests.main(supported_fmts=['qcow2', 'qed'],
                  supported_protocols=['file'])