qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [RFC 0/3] qtest: pick tests that require KVM at runtime


From: Thomas Huth
Subject: Re: [RFC 0/3] qtest: pick tests that require KVM at runtime
Date: Tue, 22 Jun 2021 09:59:48 +0200
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0

On 22/06/2021 09.26, Philippe Mathieu-Daudé wrote:
On 6/22/21 9:20 AM, Thomas Huth wrote:
On 16/06/2021 17.24, Igor Mammedov wrote:

Sometimes it's necessary to execute a test that depends on KVM,
however qtest is not aware if tested QEMU binary supports KVM
on the host it the test is executed.

For an example:
   test q35 machine with intel_iommu
   This test will run only is KVM is available and fail
   to start QEMU if it fallsback to TCG, thus failing whole test.
   So if test is executed in VM where nested KVM is not enabled
   or on other than x86 host, it will break 'make check-qtest'

Series adds a lightweight qtest_has_kvm() check, which abuses
build system and should help to avoid running KVM only tests
on hosts that do not support it.

You also might want to update the check in tests/qtest/migration-test.c
while you're at it.

PS:
there is an alternative 'query-accels' QMP command proposal
https://patchwork.kernel.org/project/qemu-devel/patch/20210503211020.894589-3-philmd@redhat.com/

which I think is more robust compared to qtest_has_kvm() and
could be extended to take into account machine type.

Could you please get in touch with Philippe directly and discuss which
way to go? We certainly don't need two approaches in the end...

I'm certainly fine if Igor wants to restart this effort :)

Maybe doing as Claudio suggested, start have qtest_has_accel()
tests accel with Igor's shortpath first, then fallback to
'query-accels' QMP command?

Yeah, that's maybe a good idea ...
But I'm currently wondering whether we need query-accels at all? For detecting kvm, we already have "query-kvm" ... and we don't have tests for any other accelerators yet (hax, hvf, etc.) ... so it's likely just about having a way to detect whether TCG is compiled into the binary? Is there already another command that could be used to check for the availability of TCG?

 Thomas




reply via email to

[Prev in Thread] Current Thread [Next in Thread]