Re: [PATCH v7 8/8] s390x/s390-virtio-ccw: add zpcii-disable machine property

[Matthew Rosato <mjrosato@linux.ibm.com>]

On 6/22/22 4:50 AM, Pierre Morel wrote:
> 
> 
> On 6/6/22 22:36, Matthew Rosato wrote:
>> The zpcii-disable machine property can be used to force-disable the use
>> of zPCI interpretation facilities for a VM.  By default, this setting
>> will be off for machine 7.1 and newer.
>>
>> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
>> ---
>>   hw/s390x/s390-pci-kvm.c            |  4 +++-
>>   hw/s390x/s390-virtio-ccw.c         | 24 ++++++++++++++++++++++++
>>   include/hw/s390x/s390-virtio-ccw.h |  1 +
>>   qemu-options.hx                    |  8 +++++++-
>>   util/qemu-config.c                 |  4 ++++
>>   5 files changed, 39 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/s390x/s390-pci-kvm.c b/hw/s390x/s390-pci-kvm.c
>> index 9134fe185f..5eb7fd12e2 100644
>> --- a/hw/s390x/s390-pci-kvm.c
>> +++ b/hw/s390x/s390-pci-kvm.c
>> @@ -22,7 +22,9 @@
>>   bool s390_pci_kvm_interp_allowed(void)
>>   {
>> -    return kvm_s390_get_zpci_op() && !s390_is_pv();
>> +    return (kvm_s390_get_zpci_op() && !s390_is_pv() &&
>> +            !object_property_get_bool(OBJECT(qdev_get_machine()),
>> +                                      "zpcii-disable", NULL));
>>   }
> 
> Isn't it a duplication of machine_get_zpcii_disable?
> 

No, this will actually trigger machine_get_zpcii_disable -- it was setup 
as the 'getter' routine in s390_machine_initfn() -- see below:

> Wouldn't it better go to hw/s390x/kvm/ ?
> 
> There get the MachineState *ms = MACHINE(qdev_get_machine()) and return 
> the ms->zpcii_disable
> 
> ?
> 
>>   int s390_pci_kvm_aif_enable(S390PCIBusDevice *pbdev, ZpciFib *fib, 
>> bool assist)
>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>> index cc3097bfee..70229b102b 100644
>> --- a/hw/s390x/s390-virtio-ccw.c
>> +++ b/hw/s390x/s390-virtio-ccw.c
>> @@ -645,6 +645,21 @@ static inline void 
>> machine_set_dea_key_wrap(Object *obj, bool value,
>>       ms->dea_key_wrap = value;
>>   }
>> +static inline bool machine_get_zpcii_disable(Object *obj, Error **errp)
>> +{
>> +    S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
>> +
>> +    return ms->zpcii_disable;
>> +}
>> +
>> +static inline void machine_set_zpcii_disable(Object *obj, bool value,
>> +                                             Error **errp)
>> +{
>> +    S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
>> +
>> +    ms->zpcii_disable = value;
>> +}
>> +
>>   static S390CcwMachineClass *current_mc;
>>   /*
>> @@ -740,6 +755,13 @@ static inline void s390_machine_initfn(Object *obj)
>>               "Up to 8 chars in set of [A-Za-z0-9. ] (lower case chars 
>> converted"
>>               " to upper case) to pass to machine loader, boot manager,"
>>               " and guest kernel");
>> +
>> +    object_property_add_bool(obj, "zpcii-disable",
>> +                             machine_get_zpcii_disable,

^^ Here.