KVM: arm64: vgic-its: Return -ENXIO to invalid KVM_DEV_ARM_VGIC_GRP_CTRL attrs

[Eric Auger]

Hi David,

On 6/24/25 11:01 AM, David Woodhouse wrote:
> On Tue, 2025-06-24 at 09:25 +0200, Eric Auger wrote:
>> Hi David,
>>
>> On 6/23/25 3:22 PM, David Woodhouse wrote:
>>> From: David Woodhouse <dwmw at amazon.co.uk>
>>>
>>> A preliminary version of a hack to invoke unmap_all_vpes() from an ioctl
>>> didn't work very well. We eventually determined this was because we were
>>> invoking it on the wrong file descriptor, but not getting an error.
>>>
>>> Signed-off-by: David Woodhouse <dwmw at amazon.co.uk>
>>
>> In the corresponding doc (virt/kvm/devices/arm-vgic-its.rst)
>> it is said about possible returned values:
>>      -ENXIO  ITS not properly configured as required prior to setting
>>              this attribute
>> which does not exactly match your situation. Shouldn't we also update
>> the doc or change the returned value?
> 
> Hi Eric, thanks for looking at this.
> 
> I think this is OK because the -ENXIO return is covered by the high-
> level description of KVM_[GS]ET_DEVICE_ATTR in virt/kvm/api.rst:
> 
> Errors:
> 
>   =====   =============================================================
>   ENXIO   The group or attribute is unknown/unsupported for this device
>           or hardware support is missing.
> 

Ah OK I missed that. Anyway that's not a big deal I think.

Reviewed-by: Eric Auger <eric.auger at redhat.com>

Eric