Re: [PATCH v2 04/15] tests: acpi: q35: test for x2APIC entries in SRAT

[Thomas Huth]

On 20/10/2021 10.53, Igor Mammedov wrote:
> On Wed, 20 Oct 2021 04:18:07 -0400
> "Michael S. Tsirkin" <mst@redhat.com> wrote:
>
> > On Wed, Oct 20, 2021 at 10:16:07AM +0200, Igor Mammedov wrote:
> > > On Tue, 19 Oct 2021 07:44:38 -0400
> > > "Michael S. Tsirkin" <mst@redhat.com> wrote:
> > >    
> > > > On Tue, Oct 19, 2021 at 01:36:24PM +0200, Igor Mammedov wrote:
> > > > > On Tue, 19 Oct 2021 06:23:40 -0400
> > > > > "Michael S. Tsirkin" <mst@redhat.com> wrote:
> > > > >      
> > > > > > On Tue, Oct 19, 2021 at 11:48:25AM +0200, Igor Mammedov wrote:
> > > > > > > On Mon, 18 Oct 2021 17:31:33 -0400
> > > > > > > "Michael S. Tsirkin" <mst@redhat.com> wrote:
> > > > > > >        
> > > > > > > > On Thu, Sep 02, 2021 at 07:35:40AM -0400, Igor Mammedov wrote:
> > > > > > > > > Set -smp 1,maxcpus=288 to test for ACPI code that
> > > > > > > > > deal with CPUs with large APIC ID (>255).
> > > > > > > > >
> > > > > > > > > PS:
> > > > > > > > > Test requires KVM and in-kernel irqchip support,
> > > > > > > > > so skip test if KVM is not available.
> > > > > > > > >
> > > > > > > > > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > > > > > > > > ---
> > > > > > > > > v3:
> > > > > > > > >    - add dedicated test instead of abusing 'numamem' one
> > > > > > > > >    - add 'kvm' prefix to the test name
> > > > > > > > >        ("Michael S. Tsirkin" <mst@redhat.com>)
> > > > > > > > > v2:
> > > > > > > > >    - switch to qtest_has_accel() API
> > > > > > > > >
> > > > > > > > > CC: thuth@redhat.com
> > > > > > > > > CC: lvivier@redhat.com
> > > > > > > > > ---
> > > > > > > > >   tests/qtest/bios-tables-test.c | 17 +++++++++++++++++
> > > > > > > > >   1 file changed, 17 insertions(+)
> > > > > > > > >
> > > > > > > > > diff --git a/tests/qtest/bios-tables-test.c b/tests/qtest/bios-tables-test.c
> > > > > > > > > index 51d3a4e239..1f6779da87 100644
> > > > > > > > > --- a/tests/qtest/bios-tables-test.c
> > > > > > > > > +++ b/tests/qtest/bios-tables-test.c
> > > > > > > > > @@ -1033,6 +1033,19 @@ static void test_acpi_q35_tcg_numamem(void)
> > > > > > > > >       free_test_data(&data);
> > > > > > > > >   }
> > > > > > > > >   
> > > > > > > > > +static void test_acpi_q35_kvm_xapic(void)
> > > > > > > > > +{
> > > > > > > > > +    test_data data;
> > > > > > > > > +
> > > > > > > > > +    memset(&data, 0, sizeof(data));
> > > > > > > > > +    data.machine = MACHINE_Q35;
> > > > > > > > > +    data.variant = ".xapic";
> > > > > > > > > +    test_acpi_one(" -object memory-backend-ram,id=ram0,size=128M"
> > > > > > > > > +                  " -numa node -numa node,memdev=ram0"
> > > > > > > > > +                  " -machine kernel-irqchip=on -smp 1,maxcpus=288", &data);
> > > > > > > > > +    free_test_data(&data);
> > > > > > > > > +}
> > > > > > > > > +
> > > > > > > > >   static void test_acpi_q35_tcg_nosmm(void)
> > > > > > > > >   {
> > > > > > > > >       test_data data;
> > > > > > > >
> > > > > > > >
> > > > > > > > This causes an annoying message each time I run it:
> > > > > > > >
> > > > > > > > qemu-system-x86_64: -accel kvm: warning: Number of hotpluggable cpus requested 
> > > > > > > > (288) exceeds the recommended cpus supported by KVM (240)
> > > > > > > >
> > > > > > > > what gives?
> > > > > > >
> > > > > > > it depends on kernel, see kvm_recommended_vcpus().
> > > > > > >
> > > > > > > We probably should bump it on upstream kernel side
> > > > > > > (it's much more than that in RHEL8).
> > > > > > >
> > > > > > > Is there anything that prevents bumping upstream kernel limits?
> > > > > >
> > > > > > what should we do with the annoying warning though?
> > > > >
> > > > > I'd leave it alone.
> > > > > What do you suggest?
> > > > >       
> > > >
> > > > reduce the value so a typical system does not trigger it?
> > >
> > > it won't work, test needs as minimum 255 vcpus to trigger X2APIC logic
> > > and 288 value additionally tests max limits
> >
> > Add a flag to disable the warning while running this specific test?
>
> if it were qtest accel, it would be trivial but
> I'm not aware of something similar for tcg/kvm mode.
> Do you suggest to add to QEMU a CLI option for that?

I think you can still use qtest_enabled(), even if -accel kvm has been 
specified on top?

 Thomas