Re: [PATCH v7 16/17] KVM: s390: pv: add KVM_CAP_S390_PROT_REBOOT_ASYNC

[Janosch Frank]

On 2/4/22 16:53, Claudio Imbrenda wrote:
> Add KVM_CAP_S390_PROT_REBOOT_ASYNC to signal that the
> KVM_PV_ASYNC_DISABLE and KVM_PV_ASYNC_DISABLE_PREPARE commands for the
> KVM_S390_PV_COMMAND ioctl are available.
>
> Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
> ---
>   arch/s390/kvm/kvm-s390.c | 3 +++
>   include/uapi/linux/kvm.h | 1 +
>   2 files changed, 4 insertions(+)
>
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index f7952cef1309..1e696202a569 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -608,6 +608,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>   	case KVM_CAP_S390_BPB:
>   		r = test_facility(82);
>   		break;
> +	case KVM_CAP_S390_PROT_REBOOT_ASYNC:
> +		r = lazy_destroy && is_prot_virt_host();

While reboot might be the best use-case for the async disable I don't 
think we should name the capability this way.

KVM_CAP_S390_PROTECTED_ASYNC_DESTR ?

It's a bit long but the initial capability didn't abbreviate the 
protected part so it is what it is.


> +		break;
>   	case KVM_CAP_S390_PROTECTED:
>   		r = is_prot_virt_host();
>   		break;
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 7f574c87a6ba..c41c108f6b14 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -1134,6 +1134,7 @@ struct kvm_ppc_resize_hpt {
>   #define KVM_CAP_VM_GPA_BITS 207
>   #define KVM_CAP_XSAVE2 208
>   #define KVM_CAP_SYS_ATTRIBUTES 209
> +#define KVM_CAP_S390_PROT_REBOOT_ASYNC 215
>   
>   #ifdef KVM_CAP_IRQ_ROUTING
>