[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, 3 deletions

diff --git a/include/asm-i386/io.h b/include/asm-i386/io.h
index 68df0dc3ab8..86ff5e83be2 100644
--- a/include/asm-i386/io.h
+++ b/include/asm-i386/io.h
@@ -256,11 +256,11 @@ static inline void flush_write_buffers(void)
 
 #endif /* __KERNEL__ */
 
-#ifdef SLOW_IO_BY_JUMPING
-#define __SLOW_DOWN_IO "jmp 1f; 1: jmp 1f; 1:"
+#if defined(CONFIG_PARAVIRT)
+#include <asm/paravirt.h>
 #else
+
 #define __SLOW_DOWN_IO "outb %%al,$0x80;"
-#endif
 
 static inline void slow_down_io(void) {
 	__asm__ __volatile__(
@@ -271,6 +271,8 @@ static inline void slow_down_io(void) {
 		: : );
 }
 
+#endif
+
 #ifdef CONFIG_X86_NUMAQ
 extern void *xquad_portio;    /* Where the IO area was mapped */
 #define XQUAD_PORT_ADDR(port, quad) (xquad_portio + (XQUAD_PORTIO_QUAD*quad) + port)