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

Christian Borntraeger
2018-09-26T07:28:15Z

On 09/26/2018 09:15 AM, David Hildenbrand wrote:
> On 26/09/2018 01:16, Tony Krowiak wrote:
>> From: Tony Krowiak <akrowiak@linux.ibm.com>
>>
>> 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@linux.ibm.com>
>> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
>> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
>> Reviewed-by: David Hildenbrand <david@redhat.com>
>> Tested-by: Michael Mueller <mimu@linux.ibm.com>
>> Tested-by: Farhan Ali <alifm@linux.ibm.com>
>> ---
>> 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.

I can fixup when applying.

>
> (can maybe be fixed when applying)
>
> Apart from that looks good!
>