Leonardo, since you seem to have a reliable reproducer now, could you give this test kernel [1] a try? It just contains commit c066fafc595e ("KVM: PPC: Book3S HV: Use correct pagesize in kvm_unmap_radix()") and is basically what Joe gave you (comment #5) but at that time you weren't able to reproduce the issue.
Leonardo, since you seem to have a reliable reproducer now, could you give this test kernel [1] a try? It just contains commit c066fafc595e ("KVM: PPC: Book3S HV: Use correct pagesize in kvm_unmap_radix()") and is basically what Joe gave you (comment #5) but at that time you weren't able to reproduce the issue.
[1] https:/ /kernel. ubuntu. com/~juergh/ lp1788098/