Re: [PATCH v11 25/26] KVM: s390: CPU model support for AP virtualization

[David Hildenbrand]

On 26/09/2018 01:16, Tony Krowiak wrote:
> From: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
> 
> Introduces two new CPU model facilities to support
> AP virtualization for KVM guests:
> 
> 1. AP Query Configuration Information (QCI) facility is installed.
> 
>    This is indicated by setting facilities bit 12 for
>    the guest. The kernel will not enable this facility
>    for the guest if it is not set on the host.
> 
>    If this facility is not set for the KVM guest, then only
>    APQNs with an APQI less than 16 will be used by a Linux
>    guest regardless of the matrix configuration for the virtual
>    machine. This is a limitation of the Linux AP bus.
> 
> 2. AP Facilities Test facility (APFT) is installed.
> 
>    This is indicated by setting facilities bit 15 for
>    the guest. The kernel will not enable this facility for
>    the guest if it is not set on the host.
> 
>    If this facility is not set for the KVM guest, then no
>    AP devices will be available to the guest regardless of
>    the guest's matrix configuration for the virtual
>    machine. This is a limitation of the Linux AP bus.
> 
> Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
> Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
> Tested-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
> Tested-by: Farhan Ali <alifm@xxxxxxxxxxxxx>
> ---
>  arch/s390/kvm/kvm-s390.c         | 1 +
>  arch/s390/tools/gen_facilities.c | 2 ++
>  2 files changed, 3 insertions(+)
> 
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 81fd82f7626d..444965e78010 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -371,6 +371,7 @@ static void kvm_s390_cpu_feat_init(void)
>  
>  	if (MACHINE_HAS_ESOP)
>  		allow_cpu_feat(KVM_S390_VM_CPU_FEAT_ESOP);
> +

This unrelated change should be dropped.

(can maybe be fixed when applying)

Apart from that looks good!

-- 

Thanks,

David / dhildenb