Re: [PATCH RFC 2/5] s390x: implement diag260

[Christian Borntraeger]

On 13.07.20 14:11, Cornelia Huck wrote:
> On Mon, 13 Jul 2020 13:54:41 +0200
> Christian Borntraeger <borntraeger@de.ibm.com> wrote:
> 
>> On 10.07.20 10:32, David Hildenbrand wrote:
>>
>>>>> --- a/target/s390x/misc_helper.c
>>>>> +++ b/target/s390x/misc_helper.c
>>>>> @@ -116,6 +116,12 @@ void HELPER(diag)(CPUS390XState *env, uint32_t r1, 
>>>>> uint32_t r3, uint32_t num)
>>>>>      uint64_t r;
>>>>>  
>>>>>      switch (num) {
>>>>> +    case 0x260:
>>>>> +        qemu_mutex_lock_iothread();
>>>>> +        handle_diag_260(env, r1, r3, GETPC());
>>>>> +        qemu_mutex_unlock_iothread();
>>>>> +        r = 0;
>>>>> +        break;
>>>>>      case 0x500:
>>>>>          /* KVM hypercall */
>>>>>          qemu_mutex_lock_iothread();  
>>>>
>>>> Looking at the doc referenced above, it seems that we treat every diag
>>>> call as privileged under tcg; but it seems that 0x44 isn't? (Unrelated
>>>> to your patch; maybe I'm misreading.)  
>>>
>>> That's also a BUG in kvm then?
>>>
>>> int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
>>> {
>>> ...
>>>     if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
>>>             return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
>>> ...
>>> }  
>>
>> diag 44 gives a PRIVOP on LPAR, so I think this is fine. 
>>
> 
> Seems like a bug/inconsistency in CP (or its documentation), then.

Yes. 

.globl main
main:
        diag 0,0,0x44
        svc 1



also crashes under z/VM with an illegal op.