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

[Christian Borntraeger]

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.