Re: [Qemu-devel] [PATCH v4 7/9] s390x/pci: fence off instructions for non-pci

[David Hildenbrand <david@redhat.com>]

On 07.08.2017 11:52, Cornelia Huck wrote:
> On Fri, 4 Aug 2017 15:17:25 +0200
> David Hildenbrand <david@redhat.com> wrote:
> 
>> On 04.08.2017 13:29, Cornelia Huck wrote:
>>> If a guest running on a machine without zpci issues a pci instruction,
>>> throw them an exception.
>>>
>>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>>> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
>>> ---
>>>  target/s390x/kvm.c | 54 +++++++++++++++++++++++++++++++++++++++++-------------
>>>  1 file changed, 41 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
>>> index bc62bba5b7..9de165d8b1 100644
>>> --- a/target/s390x/kvm.c
>>> +++ b/target/s390x/kvm.c
>>> @@ -1191,7 +1191,11 @@ static int kvm_clp_service_call(S390CPU *cpu, struct kvm_run *run)
>>>  {
>>>      uint8_t r2 = (run->s390_sieic.ipb & 0x000f0000) >> 16;
>>>  
>>> -    return clp_service_call(cpu, r2);
>>> +    if (s390_has_feat(S390_FEAT_ZPCI)) {
>>> +        return clp_service_call(cpu, r2);
>>> +    } else {
>>> +        return -1;
>>> +    }  
>>
>> I am a fan of dropping these else case and returning directly. But that
>> is just my opinion.
>>
>> (applies to all changes in this patch)
>>
>>
> 
> You are not the first to say that :)

so ... at least 2 vs. 1? ;)

Nevermind, doesn't really matter.

> 
> I do prefer this way around, though, and if there aren't strong
> objections, I'll keep it like this.
> 


-- 

Thanks,

David