[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>

1 files changed, 41 insertions, 0 deletions

diff --git a/include/asm-i386/time.h b/include/asm-i386/time.h
new file mode 100644
index 000000000000..ea8065af825a
--- /dev/null
+++ b/include/asm-i386/time.h
@@ -0,0 +1,41 @@
+#ifndef _ASMi386_TIME_H
+#define _ASMi386_TIME_H
+
+#include <linux/efi.h>
+#include "mach_time.h"
+
+static inline unsigned long native_get_wallclock(void)
+{
+        unsigned long retval;
+
+        if (efi_enabled)
+                retval = efi_get_time();
+        else
+                retval = mach_get_cmos_time();
+
+        return retval;
+}
+
+static inline int native_set_wallclock(unsigned long nowtime)
+{
+        int retval;
+
+        if (efi_enabled)
+                retval = efi_set_rtc_mmss(nowtime);
+        else
+                retval = mach_set_rtc_mmss(nowtime);
+
+        return retval;
+}
+
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else /* !CONFIG_PARAVIRT */
+
+#define get_wallclock() native_get_wallclock()
+#define set_wallclock(x) native_set_wallclock(x)
+#define do_time_init() time_init_hook()
+
+#endif /* CONFIG_PARAVIRT */
+
+#endif