skiboot-5.1.8 was released on October 19th, 2015.
skiboot-5.1.8 is the 9th stable release of 5.1, it follows skiboot-5.1.7 (which was released October 13th, 2015).
Skiboot 5.1.8 contains all fixes from skiboot-5.1.7 and is a minor bug fix release, with a single fix for recovery from a (rare) error.
Over skiboot-5.1.7, we have the following change:
opal/hmi: Fix a soft lockup issue on Hypervisor Maintenance Interrupt for certain timebase errors.
We also introduce a timeout to handle the worst situation where all other threads are badly stuck without setting a cleanup done bit. Under such situation timeout will help to avoid soft lockups and report failure to kernel.