Re: [Qemu-devel] [PATCH v8 2/6] s390x/cpumodel: Set up CPU model for AP device support

[David Hildenbrand]

Am 12.09.18 um 22:08 schrieb Tony Krowiak:
> A new CPU model feature and two new CPU model facilities are
> introduced to support AP devices for a KVM guest.
> 
> CPU model features:
> 
> 1. The KVM_S390_VM_CPU_FEAT_AP CPU model feature indicates that
>    AP facilities are installed. This feature will be enabled by
>    the kernel only if the AP facilities are installed on the linux
>    host. This feature must be turned on from userspace to access
>    AP devices from the KVM guest. The QEMU command line to turn
>    this feature looks something like this:
> 
>       qemu-system-s390x ... -cpu xxx,ap=on
> 
>    This feature will be supported for zEC12 and newer CPU models.
>    The feature will not be supported for older models due to
>    testability issues.

I think we (me,  Halil and Pierre) agreed that this should not be a
CPU_FEAT but instead some AP_INTERPRETATION toggle, that can be turned
on/off dynamically. (CPU_FEAT cannot be changed after CPUs have been
created).

Can you discuss that with Halil + Pierre?


-- 

Thanks,

David / dhildenb