Re: [PATCH v2] hw/arm/virt: Fix gic-version=max when CONFIG_ARM_GIC_TCG is unset

[Eric Auger]

On 3/4/22 7:36 PM, Peter Maydell wrote:
> On Fri, 4 Mar 2022 at 17:46, Eric Auger <eric.auger@redhat.com> wrote:
>> In TCG mode, if gic-version=max we always select GICv3 even if
>> CONFIG_ARM_GIC_TCG is unset. We shall rather select GICv2.
>> This also brings the benefit of fixing qos tests errors for tests
>> using gic-version=max with CONFIG_ARM_GIC_TCG unset.
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>> Reviewed-by: Andrew Jones <drjones@redhat.com>
>> Fixes: a8a5546798c3 ("hw/intc/arm_gicv3: Introduce CONFIG_ARM_GIC_TCG 
>> Kconfig selector")
>>
>> ---
>>
>> v1 -> v2:
>> - added Drew's R-b
>> - dropped PATCH 2/2 for the time being (requires more discussions)
>> ---
>>  hw/arm/virt.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
>> index 46bf7ceddf..f29779c951 100644
>> --- a/hw/arm/virt.c
>> +++ b/hw/arm/virt.c
>> @@ -1852,7 +1852,11 @@ static void finalize_gic_version(VirtMachineState 
>> *vms)
>>          vms->gic_version = VIRT_GIC_VERSION_2;
>>          break;
>>      case VIRT_GIC_VERSION_MAX:
>> +#ifdef CONFIG_ARM_GIC_TCG
>>          vms->gic_version = VIRT_GIC_VERSION_3;
>> +#else
>> +        vms->gic_version = VIRT_GIC_VERSION_2;
>> +#endif
>>          break;
>>      case VIRT_GIC_VERSION_HOST:
>>          error_report("gic-version=host requires KVM");
> This doesn't look right, because the correct condition for
> "should 'max' be 2 or 3" is "do we have a GICv2 or a GICv3
> compiled in", which is nothing to do with "is the GIC a TCG
> GIC or the KVM GIC". Indeed at this point in the code we
> know we're dealing with TCG, so the right response to
> "we don't have a TCG GIC" is "give up entirely".
>
> I think fundamentally CONFIG_ARM_GIC_TCG is either misnamed
> or selecting the wrong files to compile.
Yes CONFIG_ARM_GIC_TCG is misnamed and as far as I understand selects
GICV3 TCG specific files. So I will respin and change the name of the
config.

Thanks

Eric
>
> thanks
> -- PMM
>