Re: [PATCH v1 4/8] KVM: s390: Fix return value of kvm_s390_set_cmma_bits()

[Christian Borntraeger <borntraeger@de.ibm.com>]

Am 02.07.26 um 17:24 schrieb Claudio Imbrenda:
> If kvm_s390_set_cmma_bits() is asked to set CMMA values outside of a
> memslot, PGM_ADDRESSING (5) is returned, instead of a negative error
> value.
> 
> Fix by returning -EFAULT whenever the return value would be > 0, which
> is consistent with the behaviour before the gmap rewrite.
> 
> Fixes: e38c884df921 ("KVM: s390: Switch to new gmap")
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

Not wrong, but should we fix the documentation for dat_set_cmma_bits which says
  * Return: %0 in case of success, a negative error value otherwise.
  */

or should be handle PGM_ADDRESSING there instead of here?

> ---
>   arch/s390/kvm/kvm-s390.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 784f7d9c79c7..512c81eee068 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -2384,7 +2384,7 @@ static int kvm_s390_set_cmma_bits(struct kvm *kvm,
>   
>   	set_bit(GMAP_FLAG_USES_CMM, &kvm->arch.gmap->flags);
>   
> -	return r;
> +	return r <= 0 ? r : -EFAULT;
>   }
>   
>   /**