powerpc: Ultravisor: Add PPC_UV config option

CONFIG_PPC_UV adds support for ultravisor.

Signed-off-by: Anshuman Khandual <[email protected]>
Signed-off-by: Bharata B Rao <[email protected]>
Signed-off-by: Ram Pai <[email protected]>
[ Update config help and commit message ]
Signed-off-by: Claudio Carvalho <[email protected]>
Reviewed-by: Sukadev Bhattiprolu <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>

Author: Anshuman Khandual

arch/powerpc/Kconfig

@@ -451,6 +451,23 @@ config PPC_TRANSACTIONAL_MEM
 	help
 	  Support user-mode Transactional Memory on POWERPC.
 
+config PPC_UV
+	bool "Ultravisor support"
+	depends on KVM_BOOK3S_HV_POSSIBLE
+	select ZONE_DEVICE
+	select DEV_PAGEMAP_OPS
+	select DEVICE_PRIVATE
+	select MEMORY_HOTPLUG
+	select MEMORY_HOTREMOVE
+	default n
+	help
+	  This option paravirtualizes the kernel to run in POWER platforms that
+	  supports the Protected Execution Facility (PEF). On such platforms,
+	  the ultravisor firmware runs at a privilege level above the
+	  hypervisor.
+
+	  If unsure, say "N".
+
 config LD_HEAD_STUB_CATCH
 	bool "Reserve 256 bytes to cope with linker stubs in HEAD text" if EXPERT
 	depends on PPC64