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

[Igor Mammedov]

On Thu, 17 Jun 2021 18:49:17 +0200
Claudio Fontana <cfontana@suse.de> wrote:

> On 6/16/21 5:24 PM, 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.  
> 
> Hello,
> 
> It seems to me that we are constantly re-implementing the same feature with 
> slight variations?
> 
> Didn't we have a generic series to introduce qtest_has_accel() from Philippe 
> before?
It's mentioned in cover letter (PS: part) and in [1/3] with rationale
why this was posted.

> Does this series work with --disable-kvm builds? (TCG-only builds?)
I'll test. But on the first glance it should work without issues.
(i.e. kvm only tests will be skipped).

> 
> Thanks,
> 
> CLaudio
> 
> 
> > 
> > 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.
> > 
> > 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.
> > But it's more complex and what I dislike about it most,
> > it requires execution of 'probing' QEMU instance to find
> > execute 'query-accels' QMP command, which is rather resource
> > consuming. So I'd use query-accels approach only when it's
> > the only possible option to minimize load on CI systems.
> > 
> > Igor Mammedov (2):
> >   tests: acpi: q35: test for x2APIC entries in SRAT
> >   tests: acpi: update expected tables blobs
> > 
> > root (1):
> >   tests: qtest: add qtest_has_kvm() to check if tested bynary supports
> >     KVM
> > 
> >  tests/qtest/libqos/libqtest.h    |   7 +++++++
> >  meson.build                      |   1 +
> >  tests/data/acpi/q35/APIC.numamem | Bin 0 -> 2686 bytes
> >  tests/data/acpi/q35/DSDT.numamem | Bin 7865 -> 35222 bytes
> >  tests/data/acpi/q35/FACP.numamem | Bin 0 -> 244 bytes
> >  tests/data/acpi/q35/SRAT.numamem | Bin 224 -> 5080 bytes
> >  tests/qtest/bios-tables-test.c   |  10 +++++++---
> >  tests/qtest/libqtest.c           |  20 ++++++++++++++++++++
> >  8 files changed, 35 insertions(+), 3 deletions(-)
> >  create mode 100644 tests/data/acpi/q35/APIC.numamem
> >  create mode 100644 tests/data/acpi/q35/FACP.numamem
> >   
>