On 11/05/2018 04:14 PM, Michael Mueller wrote:
>
>
> On 05.11.18 15:51, Pierre Morel wrote:
>> On 25/10/2018 14:37, Michael Mueller wrote:
[..]
>>> +
>>> +void kvm_s390_gib_init(u8 nisc)
>>> +{
>>> + int rc;
>>> +
>>> + if (gib)
>>> + return;
>>> +
>>> + if (!css_general_characteristics.aiv) {
>>> + KVM_EVENT(3, "%s", "gib not initialized, no AIV facility");
>>> + return;
>>> + }
>>> +
>>> + gib = (struct kvm_s390_gib *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
>>> + if (!gib) {
>>> + KVM_EVENT(3, "%s", "gib memory allocation failed");
>>> + return;
>>> + }
>>
>> Why should we survive this error?
>
> Design question.
>
I'm with Pierre on this one. We should fail starting the guest
if this allocation fails.
>>
>>
>>> +
>>> + gib->nisc = nisc;
>>> + rc = chsc_sgib((u32)(u64)gib);
>>> + if (rc) {
>>> + KVM_EVENT(3, "gib 0x%pK AIV association failed rc: %d",
>>> + gib, rc);
>>> + free_page((unsigned long)gib);
>>> + gib = NULL;
>>> + return;
>>> + }
>>
>> or this failure ?
>>
>> shouldn't we better return an error and abort loading KVM?
>
> Design question.
>
Same here I guess. This would be only either due to a guest or
a host bug, or?
I would prefer being fairly deterministic about whether we do have
a gib or not.
Regards,
Halil
