>> Yeah, but can this ever trigger without the check? AFAIKs, no. So why
>> add it?
>
> It can. the GPRS can contain stale data and so can operand2.
>
Oh, ok. Makes sense.
>>
>> (rather add a BUG_ON in kvm_s390_inject_program_int() in case we are in
>> PV mode)
>>
>>>>
>>>>>
>>>>> switch (fc) {
>>>>> @@ -893,8 +893,13 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
>>>>> handle_stsi_3_2_2(vcpu, (void *) mem);
>>>>> break;
>>>>> }
>>>>> -
>>>>> - rc = write_guest(vcpu, operand2, ar, (void *)mem, PAGE_SIZE);
>>>>> + if (kvm_s390_pv_is_protected(vcpu->kvm)) {
>>>>> + memcpy((void *)sida_origin(vcpu->arch.sie_block), (void *)mem,
>>>>> + PAGE_SIZE);
>>>>> + rc = 0;
>>>>> + } else {
>>>>> + rc = write_guest(vcpu, operand2, ar, (void *)mem, PAGE_SIZE);
>>>>> + }
>>>>> if (rc) {
>>>>> rc = kvm_s390_inject_prog_cond(vcpu, rc);
>>>>> goto out;
>>>>>
>>>>
>>>> I'd pull the interrupt injection into the else case, makes things clearer.
>>>
>>> Well, no. Thhe else case could set rc to 0.
>>
>> Huh?!
>>
>> if (kvm_s390_pv_is_protected(vcpu->kvm)) {
>> memcpy((void *)sida_origin(vcpu->arch.sie_block), (void *)mem,
>> rc = 0;
>> } else {
>> rc = write_guest(vcpu, operand2, ar, (void *)mem, PAGE_SIZE);
>> if (rc) {
>> rc = kvm_s390_inject_prog_cond(vcpu, rc);
>> goto out;
>> }
>> }
>>
>
> Hmm, I find that one harder to read.
It's clearer that you only inject a program check when not in pv mode
... ;) No strong feelings.
--
Thanks,
David / dhildenb
