The SLB shadow buffer is a pure software construct recording the required
segment translations. Registering a the shadow buffer informs the
hypervisor which entries are required when switching partitions, and may
allow it to recover the partition from a hardware error.
What Milton said. It's a high availability feature.
We can register volatile and persistent SLBs with PHYP. PHYP will
invalidate volatile entries and replace persistent entries if it sees a
problem with them.
Here I've only registered the 3 persistent (bolted) SLBs, as the
volatile SLBs can be handled with SLB faults in the kernel.
Mikey