On PVH there's no ACPI, so the CPU enumeration must be implemented
using Xen hypercalls.
Approved by: gibbs
Sponsored by: Citrix Systems R&D
x86/xen/pvcpu_enum.c:
- Enumerate avaiable vCPUs on PVH by using the VCPUOP_is_up
hypercall.
- Set vcpu_id for PVH guests.
conf/files.amd64:
- Include the PV CPU enumerator in the XENHVM build.