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

[Steffen Eiden <seiden@linux.ibm.com>]

On Mon, Sep 28, 2026 at 04:15:58PM +0200, Hendrik Brueckner wrote:
> 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@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.

Makes sense. Thanks

	Steffen