i386: Allow disabling legacy power

From: Rusty Russell <rusty@rustcorp.com.au>
Two legacy power management modes are much easier to just explicitly disable
when running in paravirtualized mode - neither APM nor PnP is still relevant.
The status of ACPI is still debatable, and noacpi is still a common enough
boot parameter that it is not necessary to explicitly disable ACPI.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>

===================================================================
---
 arch/i386/kernel/apm.c     |    3 ++-
 drivers/pnp/pnpbios/core.c |    3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

Index: linux/arch/i386/kernel/apm.c
===================================================================
--- linux.orig/arch/i386/kernel/apm.c
+++ linux/arch/i386/kernel/apm.c
@@ -231,6 +231,7 @@
 #include <asm/uaccess.h>
 #include <asm/desc.h>
 #include <asm/i8253.h>
+#include <asm/paravirt.h>
 
 #include "io_ports.h"
 
@@ -2235,7 +2236,7 @@ static int __init apm_init(void)
 
 	dmi_check_system(apm_dmi_table);
 
-	if (apm_info.bios.version == 0) {
+	if (apm_info.bios.version == 0 || paravirt_enabled()) {
 		printk(KERN_INFO "apm: BIOS not found.\n");
 		return -ENODEV;
 	}
Index: linux/drivers/pnp/pnpbios/core.c
===================================================================
--- linux.orig/drivers/pnp/pnpbios/core.c
+++ linux/drivers/pnp/pnpbios/core.c
@@ -530,7 +530,8 @@ static int __init pnpbios_init(void)
 	if (check_legacy_ioport(PNPBIOS_BASE))
 		return -ENODEV;
 #endif
-	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table)) {
+	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
+	    paravirt_enabled()) {
 		printk(KERN_INFO "PnPBIOS: Disabled\n");
 		return -ENODEV;
 	}