KVM: PPC: Add CAP to indicate hcall fixes

We worked around some nasty KVM magic page hcall breakages: 1) NX bit not honored, so ignore NX when we detect it 2) LE guests swizzle hypercall instruction Without these fixes in place, there's no way it would make sense to expose kvm hypercalls to a guest. Chances are immensely high it would trip over and break. So add a new CAP that gives user space a hint that we have workarounds for the bugs above in place. It can use those as hint to disable PV hypercalls when the guest CPU is anything POWER7 or higher and the host does not have fixes in place.

AGAlexander Graf committed 12 years ago