Re: [PATCH v7 23/23] KVM: s390: arm64: Add KVM_S390_ARM64 Kconfig and Makefile

[Sean Christopherson <seanjc@google.com>]

On Mon, Aug 31, 2026, Steffen Eiden wrote:
> diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
> index 8d3ee17a1bcb..9c69ea16031e 100644
> --- a/arch/s390/kvm/Kconfig
> +++ b/arch/s390/kvm/Kconfig
> @@ -53,4 +53,33 @@ config KVM_S390_UCONTROL
>  
>  	  If unsure, say N.
>  
> +config KVM_S390_ARM64
> +	def_tristate y
> +	prompt "KVM support for hardware accelerated arm64 guests"
> +	depends on HAS_IOMEM
> +	depends on KVM

Is this actually necessary?  I.e. does kvm.ko need to be *loaded* in order for
kvm-arm64.ko to be loaded?

If kvm-arm64.ko does indeed have a hard dependency on kvm.ko, then I think it
makes sense to not have redundant "select" statements below.  As an outsider,
it's super confusing because the KVM_S390_ARM64 are incomplete, e.g. are lacking
things like VIRT_XFER_TO_GUEST_WORK (at least, I assume those are lacking), and
makes it hard to see what is actually unique to kvm-arm64.ko.

If kvm-arm64.ko doesn't have a dependency on kvm.ko, e.g. to initialize hardware
or something, then this "depends on" should go away.