Hi Mike, On Thu, Jul 30, 2020 at 01:27:48AM +0000, Mike Stunes wrote: > Thanks for the updated patches! I applied this patch-set onto commit > 01634f2bd42e ("Merge branch 'x86/urgent’”) from your tree. It boots, > but CPU 1 (on a two-CPU VM) is offline at boot, and `chcpu -e 1` returns: > > chcpu: CPU 1 enable failed: Input/output error > > with nothing in dmesg to indicate why it failed. The first thing I thought > of was anything relating to the AP jump table, but I haven’t changed > anything there on the hypervisor side. Let me know what other data I can > provide for you. Hard to tell, have you enabled FSGSBASE in the guest? If yes, can you try to disable it? Regards, Joerg