arch/x86/xen/setup.c

   1 /*
   2  * Machine specific setup for xen
   3  *
   4  * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/sched.h>
   9 #include <linux/mm.h>
  10 #include <linux/pm.h>
  11
  12 #include <asm/elf.h>
  13 #include <asm/vdso.h>
  14 #include <asm/e820.h>
  15 #include <asm/setup.h>
  16 #include <asm/acpi.h>
  17 #include <asm/xen/hypervisor.h>
  18 #include <asm/xen/hypercall.h>
  19
  20 #include <xen/page.h>
  21 #include <xen/interface/callback.h>
  22 #include <xen/interface/physdev.h>
  23 #include <xen/features.h>
  24
  25 #include "xen-ops.h"
  26 #include "vdso.h"
  27
  28 /* These are code, but not functions.  Defined in entry.S */
  29 extern const char xen_hypervisor_callback[];
  30 extern const char xen_failsafe_callback[];
  31
  32
  33 /**
  34  * machine_specific_memory_setup - Hook for machine specific memory setup.
  35  **/
  36
  37 char * __init xen_memory_setup(void)
  38 {
  39         unsigned long max_pfn = xen_start_info->nr_pages;
  40
  41         max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
  42
  43         e820.nr_map = 0;
  44
  45         e820_add_region(0, PFN_PHYS(max_pfn), E820_RAM);
  46
  47         /*
  48          * Even though this is normal, usable memory under Xen, reserve
  49          * ISA memory anyway because too many things think they can poke
  50          * about in there.
  51          */
  52         e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
  53                         E820_RESERVED);
  54
  55         /*
  56          * Reserve Xen bits:
  57          *  - mfn_list
  58          *  - xen_start_info
  59          * See comment above "struct start_info" in <xen/interface/xen.h>
  60          */
  61         e820_add_region(__pa(xen_start_info->mfn_list),
  62                         xen_start_info->pt_base - xen_start_info->mfn_list,
  63                         E820_RESERVED);
  64
  65         sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
  66
  67         return "Xen";
  68 }
  69
  70 static void xen_idle(void)
  71 {
  72         local_irq_disable();
  73
  74         if (need_resched())
  75                 local_irq_enable();
  76         else {
  77                 current_thread_info()->status &= ~TS_POLLING;
  78                 smp_mb__after_clear_bit();
  79                 safe_halt();
  80                 current_thread_info()->status |= TS_POLLING;
  81         }
  82 }
  83
  84 /*
  85  * Set the bit indicating "nosegneg" library variants should be used.
  86  */
  87 static void __init fiddle_vdso(void)
  88 {
  89         extern const char vdso32_default_start;
  90         u32 *mask = VDSO32_SYMBOL(&vdso32_default_start, NOTE_MASK);
  91         *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
  92 }
  93
  94 void xen_enable_sysenter(void)
  95 {
  96         int cpu = smp_processor_id();
  97         extern void xen_sysenter_target(void);
  98         /* Mask events on entry, even though they get enabled immediately */
  99         static struct callback_register sysenter = {
 100                 .type = CALLBACKTYPE_sysenter,
 101                 .address = { __KERNEL_CS, (unsigned long)xen_sysenter_target },
 102                 .flags = CALLBACKF_mask_events,
 103         };
 104
 105         if (!boot_cpu_has(X86_FEATURE_SEP) ||
 106             HYPERVISOR_callback_op(CALLBACKOP_register, &sysenter) != 0) {
 107                 clear_cpu_cap(&cpu_data(cpu), X86_FEATURE_SEP);
 108                 clear_cpu_cap(&boot_cpu_data, X86_FEATURE_SEP);
 109         }
 110 }
 111
 112 void __init xen_arch_setup(void)
 113 {
 114         struct physdev_set_iopl set_iopl;
 115         int rc;
 116
 117         HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
 118         HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
 119
 120         if (!xen_feature(XENFEAT_auto_translated_physmap))
 121                 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_pae_extended_cr3);
 122
 123         HYPERVISOR_set_callbacks(__KERNEL_CS, (unsigned long)xen_hypervisor_callback,
 124                                  __KERNEL_CS, (unsigned long)xen_failsafe_callback);
 125
 126         xen_enable_sysenter();
 127
 128         set_iopl.iopl = 1;
 129         rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
 130         if (rc != 0)
 131                 printk(KERN_INFO "physdev_op failed %d\n", rc);
 132
 133 #ifdef CONFIG_ACPI
 134         if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
 135                 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
 136                 disable_acpi();
 137         }
 138 #endif
 139
 140         memcpy(boot_command_line, xen_start_info->cmd_line,
 141                MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
 142                COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
 143
 144         pm_idle = xen_idle;
 145
 146 #ifdef CONFIG_SMP
 147         /* fill cpus_possible with all available cpus */
 148         xen_fill_possible_map();
 149 #endif
 150
 151         paravirt_disable_iospace();
 152
 153         fiddle_vdso();
 154 }