Re: [PATCH v4 24/27] KVM: s390: arm64: Implement vm/vcpu create destroy.

[Marc Zyngier <maz@kernel.org>]

On Mon, 06 Jul 2026 09:52:24 +0100,
Steffen Eiden <seiden@linux.ibm.com> wrote:
> 
> Implement init and destroy IOCTLS for vcpu and vm.
> Implement arch vm IOCTL. Use s390 gmap.
> 
> Co-developed-by: Janosch Frank <frankja@linux.ibm.com>
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> Co-developed-by: Andreas Grapentin <gra@linux.ibm.com>
> Signed-off-by: Andreas Grapentin <gra@linux.ibm.com>
> Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
> Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
> ---
>  arch/s390/kvm/arm64/arm.c       | 190 ++++++++++++++++++++++++++++++++
>  arch/s390/kvm/arm64/arm.h       |  56 ++++++++++
>  arch/s390/kvm/gmap/faultin.c    |   5 +
>  arch/s390/kvm/gmap/gmap.c       |   4 +
>  arch/s390/kvm/gmap/trace-gmap.h |  13 +++
>  5 files changed, 268 insertions(+)
> 
> diff --git a/arch/s390/kvm/arm64/arm.c b/arch/s390/kvm/arm64/arm.c
> index 19249ec5c539..3a4092698fae 100644
> --- a/arch/s390/kvm/arm64/arm.c
> +++ b/arch/s390/kvm/arm64/arm.c
> @@ -8,6 +8,10 @@
>  #include <linux/kvm_types.h>
>  #include <linux/kvm_host.h>
>  
> +#include <arm64/kvm_mmu.h>
> +
> +#include <gmap.h>
> +
>  #include "arm.h"
>  
>  static unsigned long system_supported_vcpu_features(void);
> @@ -31,6 +35,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>  		break;
>  	case KVM_CAP_IOEVENTFD:
>  	case KVM_CAP_ARM_USER_IRQ:
> +	case KVM_CAP_PRE_FAULT_MEMORY:

arm64 *doesn't* support this yet. Please make sure you don't deviate
from what arm64 currently supports.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.