[PATCH] paravirt: header and stubs for paravirtualisation

Create a paravirt.h header for all the critical operations which need to be
replaced with hypervisor calls, and include that instead of defining native
operations, when CONFIG_PARAVIRT.

This patch does the dumbest possible replacement of paravirtualized
instructions: calls through a "paravirt_ops" structure.  Currently these are
function implementations of native hardware: hypervisors will override the ops
structure with their own variants.

All the pv-ops functions are declared "fastcall" so that a specific
register-based ABI is used, to make inlining assember easier.

And:

+From: Andy Whitcroft <apw@shadowen.org>

The paravirt ops introduce a 'weak' attribute onto memory_setup().
Code ordering leads to the following warnings on x86:

    arch/i386/kernel/setup.c:651: warning: weak declaration of
                `memory_setup' after first use results in unspecified behavior

Move memory_setup() to avoid this.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
diff --git a/include/asm-i386/suspend.h b/include/asm-i386/suspend.h
index 08be1e5..3036152 100644
--- a/include/asm-i386/suspend.h
+++ b/include/asm-i386/suspend.h
@@ -23,12 +23,8 @@
 struct saved_context {
   	u16 es, fs, gs, ss;
 	unsigned long cr0, cr2, cr3, cr4;
-	u16 gdt_pad;
-	u16 gdt_limit;
-	unsigned long gdt_base;
-	u16 idt_pad;
-	u16 idt_limit;
-	unsigned long idt_base;
+	struct Xgt_desc_struct gdt;
+	struct Xgt_desc_struct idt;
 	u16 ldt;
 	u16 tss;
 	unsigned long tr;