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linux-next/arch/x86/xen/setup.c
Jeremy Fitzhardinge e2a81baf66 xen: support sysenter/sysexit if hypervisor does
64-bit Xen supports sysenter for 32-bit guests, so support its
use.  (sysenter is faster than int $0x80 in 32-on-64.)

sysexit is still not supported, so we fake it up using iret.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:31 +02:00

133 lines
3.2 KiB
C

/*
* Machine specific setup for xen
*
* Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/pm.h>
#include <asm/elf.h>
#include <asm/vdso.h>
#include <asm/e820.h>
#include <asm/setup.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
#include <xen/interface/callback.h>
#include <xen/interface/physdev.h>
#include <xen/features.h>
#include "xen-ops.h"
#include "vdso.h"
/* These are code, but not functions. Defined in entry.S */
extern const char xen_hypervisor_callback[];
extern const char xen_failsafe_callback[];
unsigned long *phys_to_machine_mapping;
EXPORT_SYMBOL(phys_to_machine_mapping);
/**
* machine_specific_memory_setup - Hook for machine specific memory setup.
**/
char * __init xen_memory_setup(void)
{
unsigned long max_pfn = xen_start_info->nr_pages;
e820.nr_map = 0;
add_memory_region(0, LOWMEMSIZE(), E820_RAM);
add_memory_region(HIGH_MEMORY, PFN_PHYS(max_pfn)-HIGH_MEMORY, E820_RAM);
return "Xen";
}
static void xen_idle(void)
{
local_irq_disable();
if (need_resched())
local_irq_enable();
else {
current_thread_info()->status &= ~TS_POLLING;
smp_mb__after_clear_bit();
safe_halt();
current_thread_info()->status |= TS_POLLING;
}
}
/*
* Set the bit indicating "nosegneg" library variants should be used.
*/
static void __init fiddle_vdso(void)
{
extern const char vdso32_default_start;
u32 *mask = VDSO32_SYMBOL(&vdso32_default_start, NOTE_MASK);
*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
}
void xen_enable_sysenter(void)
{
int cpu = smp_processor_id();
extern void xen_sysenter_target(void);
/* Mask events on entry, even though they get enabled immediately */
static struct callback_register sysenter = {
.type = CALLBACKTYPE_sysenter,
.address = { __KERNEL_CS, (unsigned long)xen_sysenter_target },
.flags = CALLBACKF_mask_events,
};
if (!boot_cpu_has(X86_FEATURE_SEP) ||
HYPERVISOR_callback_op(CALLBACKOP_register, &sysenter) != 0) {
clear_cpu_cap(&cpu_data(cpu), X86_FEATURE_SEP);
clear_cpu_cap(&boot_cpu_data, X86_FEATURE_SEP);
}
}
void __init xen_arch_setup(void)
{
struct physdev_set_iopl set_iopl;
int rc;
HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
if (!xen_feature(XENFEAT_auto_translated_physmap))
HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_pae_extended_cr3);
HYPERVISOR_set_callbacks(__KERNEL_CS, (unsigned long)xen_hypervisor_callback,
__KERNEL_CS, (unsigned long)xen_failsafe_callback);
xen_enable_sysenter();
set_iopl.iopl = 1;
rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
if (rc != 0)
printk(KERN_INFO "physdev_op failed %d\n", rc);
#ifdef CONFIG_ACPI
if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
disable_acpi();
}
#endif
memcpy(boot_command_line, xen_start_info->cmd_line,
MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
pm_idle = xen_idle;
#ifdef CONFIG_SMP
/* fill cpus_possible with all available cpus */
xen_fill_possible_map();
#endif
paravirt_disable_iospace();
fiddle_vdso();
}