Hi Greg,
Please backport the following commit to v5.4 and v5.10:
73287caa9210ded6066833195f4335f7f688a46b
("powerpc64/idle: Fix SP offsets when saving GPRs")
And please backport the following commits to v5.4, v5.10 and v5.14:
9b4416c5095c20e110c82ae602c254099b83b72f
("KVM: PPC: Book3S HV: Fix stack handling in idle_kvm_start_guest()")
cdeb5d7d890e14f3b70e8087e745c4a6a7d9f337
("KVM: PPC: Book3S HV: Make idle_kvm_start_guest() return 0 if it went to guest")
496c5fe25c377ddb7815c4ce8ecfb676f051e9b6
("powerpc/idle: Don't corrupt back chain when going idle")
cheers
