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

[Eric Auger]

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?

Thanks

Eric

> ---
>  arch/arm64/kvm/vgic/vgic-its.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
> index 534049c7c94b..b34f8976c9cc 100644
> --- a/arch/arm64/kvm/vgic/vgic-its.c
> +++ b/arch/arm64/kvm/vgic/vgic-its.c
> @@ -2694,6 +2694,9 @@ static int vgic_its_ctrl(struct kvm *kvm, struct vgic_its *its, u64 attr)
>  	case KVM_DEV_ARM_ITS_RESTORE_TABLES:
>  		ret = abi->restore_tables(its);
>  		break;
> +	default:
> +		ret = -ENXIO;
> +		break;
>  	}
>  
>  	mutex_unlock(&its->its_lock);