On 28.08.2017 21:35, Christian Borntraeger wrote:
>
>
> On 08/28/2017 09:27 PM, David Hildenbrand wrote:
>>
>>> rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
>>> diff --git a/arch/s390/tools/gen_facilities.c b/arch/s390/tools/gen_facilities.c
>>> index 025ea20..181db5b 100644
>>> --- a/arch/s390/tools/gen_facilities.c
>>> +++ b/arch/s390/tools/gen_facilities.c
>>> @@ -80,6 +80,7 @@ static struct facility_def facility_defs[] = {
>>> 78, /* enhanced-DAT 2 */
>>> 130, /* instruction-execution-protection */
>>> 131, /* enhanced-SOP 2 and side-effect */
>>> + 138, /* configuration z/architecture mode (czam) */
>>> 146, /* msa extension 8 */
>>> -1 /* END */
>>> }
>>>
>>
>> Thinking about it, this should be the right thing to do instead of the
>> last hunk:
>>
>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>> index 84c069afc02f..39115f5a38df 100644
>> --- a/arch/s390/kvm/kvm-s390.c
>> +++ b/arch/s390/kvm/kvm-s390.c
>> @@ -1927,6 +1927,10 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned
>> long type)
>> memcpy(kvm->arch.model.fac_list, kvm->arch.model.fac_mask,
>> S390_ARCH_FAC_LIST_SIZE_BYTE);
>>
>> + /* we are always in CZAM mode - even on pre z14 machines */
>> + set_kvm_facility(kvm->arch.model.fac_mask, 138);
>> + set_kvm_facility(kvm->arch.model.fac_list, 138);
>> + /* we emulate STHYI in kvm */
>> set_kvm_facility(kvm->arch.model.fac_mask, 74);
>> set_kvm_facility(kvm->arch.model.fac_list, 74);
>> if (MACHINE_HAS_TLB_GUEST) {
>>
>> That would produce consistent results for very old QEMU.
>>
>
> This should be identical as the initial fac_list is populated from the fac_mask,
> which is populated by the facility_defs structure.
>
> [..]
> /* Populate the facility list initially. */
> kvm->arch.model.fac_list = kvm->arch.sie_page2->fac_list;
> ----> memcpy(kvm->arch.model.fac_list, kvm->arch.model.fac_mask,
> S390_ARCH_FAC_LIST_SIZE_BYTE);
>
> [,..]
>
This would keep it unset on e.g. a z13, no? (that's why I added the
comment regarding z14)
By always enabling it we would behave exactly like QEMU.
--
Thanks,
David
