From: Andrew Cooper <andrew.cooper3@citrix.com>
Date: Mon, 1 Feb 2016 12:54:46 +0000 (+0100)
Subject: x86: convert shadow-paging to Kconfig
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=54da55fda7e4be7454ac9b19a8e84b1e8b4079e5;p=people%2Fliuw%2Flibxenctrl-split%2Fxen.git

x86: convert shadow-paging to Kconfig

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Doug Goldstein <cardoe@cardoe.com>
Acked-by: Tim Deegan <tim@xen.org>
---

diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index 4781b34f78..1fd72fab63 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -27,6 +27,24 @@ menu "Architecture Features"
 
 source "arch/Kconfig"
 
+config SHADOW_PAGING
+        bool "Shadow Paging"
+        default y
+        ---help---
+
+          Shadow paging is a software alternative to hardware paging support
+          (Intel EPT, AMD NPT).
+
+          It is required for:
+            * Running HVM guests on hardware lacking hardware paging support
+              (First-generation Intel VT-x or AMD SVM).
+            * Live migration of PV guests.
+
+          Under a small number of specific workloads, shadow paging may be
+          deliberately used as a performance optimisation.
+
+          If unsure, say Y.
+
 config BIGMEM
 	bool "big memory support"
 	default n
diff --git a/xen/arch/x86/Rules.mk b/xen/arch/x86/Rules.mk
index a108d24a35..a1cdae04e8 100644
--- a/xen/arch/x86/Rules.mk
+++ b/xen/arch/x86/Rules.mk
@@ -22,13 +22,9 @@ $(call as-insn-check,CFLAGS,CC,".equ \"x\"$$(comma)1", \
                      -U__OBJECT_LABEL__ -DHAVE_GAS_QUOTED_SYM \
                      '-D__OBJECT_LABEL__=$(subst $(BASEDIR)/,,$(CURDIR))/$$@')
 
-shadow-paging ?= y
-
 CFLAGS += -mno-red-zone -mno-sse -fpic
 CFLAGS += -fno-asynchronous-unwind-tables
 # -fvisibility=hidden reduces -fpic cost, if it's available
 ifneq ($(call cc-option,$(CC),-fvisibility=hidden,n),n)
 CFLAGS += -DGCC_HAS_VISIBILITY_ATTRIBUTE
 endif
-
-CFLAGS-$(shadow-paging) += -DCONFIG_SHADOW_PAGING
diff --git a/xen/arch/x86/mm/shadow/Makefile b/xen/arch/x86/mm/shadow/Makefile
index a07bc0cf4a..cd4ec8a36b 100644
--- a/xen/arch/x86/mm/shadow/Makefile
+++ b/xen/arch/x86/mm/shadow/Makefile
@@ -1,4 +1,4 @@
-ifeq ($(shadow-paging),y)
+ifeq ($(CONFIG_SHADOW_PAGING),y)
 obj-y += common.o guest_2.o guest_3.o guest_4.o
 else
 obj-y += none.o