[PATCH v8 23/29] KVM: s390: Add basic arm64 kvm module

[Hendrik Brueckner]

On Fri, Sep 18, 2026 at 03:31:00PM +0200, Steffen Eiden wrote:
> Add basic code for the new arm64 on s390 KVM implementation.
> Add kernel module boilerplate code and trivial functions.
> Add tracing scaffolding.
> 
> Signed-off-by: Steffen Eiden <seiden at linux.ibm.com>
> ---
>  arch/s390/kvm/arm64/arm.c   | 147 ++++++++++++++++++++++++++++++++++++
>  arch/s390/kvm/arm64/arm.h   |  44 +++++++++++
>  arch/s390/kvm/arm64/guest.c |  92 ++++++++++++++++++++++
>  arch/s390/kvm/arm64/trace.h |  18 +++++
>  4 files changed, 301 insertions(+)
>  create mode 100644 arch/s390/kvm/arm64/arm.c
>  create mode 100644 arch/s390/kvm/arm64/arm.h
>  create mode 100644 arch/s390/kvm/arm64/guest.c
>  create mode 100644 arch/s390/kvm/arm64/trace.h
> 
> diff --git a/arch/s390/kvm/arm64/arm.c b/arch/s390/kvm/arm64/arm.c
> new file mode 100644
> index 000000000000..8b056fc836d7
> --- /dev/null
> +++ b/arch/s390/kvm/arm64/arm.c

[..]

> +static int __init kvm_s390_arm64_init(void)
> +{
> +	if (!sclp.has_aef)
> +		return -ENXIO;

I suggest to use -ENODEV here to be consistent with s390 kvm module.
The arm64 module also return -ENODEV when not available.