On 06/11/2018 13:06, Michael Mueller wrote:
On 05.11.18 16:44, Janosch Frank wrote:
On 05.11.18 16:36, Halil Pasic wrote:
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.
Halil, the GIB is global to KVM, we would need to fail loading/init of
KVM, which I'd like to avoid.
Neither GIB nor gisa is necessary for a VM to run, so we shouldn't stop
on an error.
I changed the design such that kvm_s390_gib_init() fails and thus
kvm_arch_init() as well
in all error cases except facility AIV is *not* available. This is also
a success case but no GIB
is initialized.
OK, seems right.
+
+ 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.
Same as above
see above
Regards,
Halil
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
