x86: Make Linux guest support optional

Put all config options needed to run Linux as a guest behind a
CONFIG_HYPERVISOR_GUEST menu so that they don't get built-in by default
but be selectable by the user. Also, make all units which depend on
x86_hyper, depend on this new symbol so that compilation doesn't fail
when CONFIG_HYPERVISOR_GUEST is disabled but those units assume its
presence.

Sort options in the new HYPERVISOR_GUEST menu, adapt config text and
drop redundant select.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1362428421-9244-3-git-send-email-bp@alien8.de
Cc: Dmitry Torokhov <dtor@vmware.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/include/asm/hypervisor.h b/arch/x86/include/asm/hypervisor.h
index 86095ed..2d4b5e6 100644
--- a/arch/x86/include/asm/hypervisor.h
+++ b/arch/x86/include/asm/hypervisor.h
@@ -20,13 +20,11 @@
 #ifndef _ASM_X86_HYPERVISOR_H
 #define _ASM_X86_HYPERVISOR_H
 
+#ifdef CONFIG_HYPERVISOR_GUEST
+
 #include <asm/kvm_para.h>
 #include <asm/xen/hypervisor.h>
 
-extern void init_hypervisor(struct cpuinfo_x86 *c);
-extern void init_hypervisor_platform(void);
-extern bool hypervisor_x2apic_available(void);
-
 /*
  * x86 hypervisor information
  */
@@ -55,4 +53,12 @@
 extern const struct hypervisor_x86 x86_hyper_xen_hvm;
 extern const struct hypervisor_x86 x86_hyper_kvm;
 
-#endif
+extern void init_hypervisor(struct cpuinfo_x86 *c);
+extern void init_hypervisor_platform(void);
+extern bool hypervisor_x2apic_available(void);
+#else
+static inline void init_hypervisor(struct cpuinfo_x86 *c) { }
+static inline void init_hypervisor_platform(void) { }
+static inline bool hypervisor_x2apic_available(void) { return false; }
+#endif /* CONFIG_HYPERVISOR_GUEST */
+#endif /* _ASM_X86_HYPERVISOR_H */