[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, 5 insertions, 0 deletions

diff --git a/include/asm-i386/msr.h b/include/asm-i386/msr.h
index 1820d9d73af3..5679d4993072 100644
--- a/include/asm-i386/msr.h
+++ b/include/asm-i386/msr.h
@@ -1,6 +1,10 @@
 #ifndef __ASM_MSR_H
 #define __ASM_MSR_H
 
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
+
 /*
  * Access to machine-specific registers (available on 586 and better only)
  * Note: the rd* operations modify the parameters directly (without using
@@ -77,6 +81,7 @@ static inline void wrmsrl (unsigned long msr, unsigned long long val)
      __asm__ __volatile__("rdpmc" \
                           : "=a" (low), "=d" (high) \
                           : "c" (counter))
+#endif  /* !CONFIG_PARAVIRT */
 
 /* symbolic names for some interesting MSRs */
 /* Intel defined MSRs. */