Re: [PATCH v2 09/20] KVM: s390: KVM page table management functions: clear and replace

[Heiko Carstens <hca@linux.ibm.com>]

On Wed, Sep 10, 2025 at 08:07:35PM +0200, Claudio Imbrenda wrote:
> Add page table management functions to be used for KVM guest (gmap)
> page tables.
> 
> This patch adds functions to clear, replace or exchange DAT table
> entries.
> 
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
>  arch/s390/kvm/dat.c | 120 ++++++++++++++++++++++++++++++++++++++++++++
>  arch/s390/kvm/dat.h |  40 +++++++++++++++
>  2 files changed, 160 insertions(+)

...

> +bool dat_crstep_xchg_atomic(union crste *crstep, union crste old, union crste new, gfn_t gfn,
> +			    union asce asce)
> +{
> +	if (old.h.i)
> +		return arch_try_cmpxchg((long *)crstep, &old.val, new.val);
> +	if (cpu_has_edat2())
> +		return crdte_crste(crstep, old, new, gfn, asce);
> +	if (cpu_has_idte())
> +		return cspg_crste(crstep, old, new);

FWIW, CSPG is present if EDAT1 is installed. So this should be
cpu_has_edat1() instead, I would guess.