kernel-hacking-2024-linux-s.../arch/i386/xen/setup.c
Jeremy Fitzhardinge f87e4cac4f xen: SMP guest support
This is a fairly straightforward Xen implementation of smp_ops.

Xen has its own IPI mechanisms, and has no dependency on any
APIC-based IPI.  The smp_ops hooks and the flush_tlb_others pv_op
allow a Xen guest to avoid all APIC code in arch/i386 (the only apic
operation is a single apic_read for the apic version number).

One subtle point which needs to be addressed is unpinning pagetables
when another cpu may have a lazy tlb reference to the pagetable. Xen
will not allow an in-use pagetable to be unpinned, so we must find any
other cpus with a reference to the pagetable and get them to shoot
down their references.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andi Kleen <ak@suse.de>
2007-07-18 08:47:44 -07:00

102 lines
2.4 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/e820.h>
#include <asm/setup.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
#include <xen/interface/physdev.h>
#include <xen/features.h>
#include "xen-ops.h"
/* These are code, but not functions. Defined in entry.S */
extern const char xen_hypervisor_callback[];
extern const char xen_failsafe_callback[];
static __initdata struct shared_info init_shared;
/*
* Point at some empty memory to start with. We map the real shared_info
* page as soon as fixmap is up and running.
*/
struct shared_info *HYPERVISOR_shared_info = &init_shared;
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, PFN_PHYS(max_pfn), 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;
}
}
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);
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
}