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 #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
  90         extern const char vdso32_default_start;
  91         u32 *mask = VDSO32_SYMBOL(&vdso32_default_start, NOTE_MASK);
  92         *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
  93 #endif
  94 }
  95
  96 static __cpuinit int register_callback(unsigned type, const void *func)
  97 {
  98         struct callback_register callback = {
  99                 .type = type,
 100                 .address = XEN_CALLBACK(__KERNEL_CS, func),
 101                 .flags = CALLBACKF_mask_events,
 102         };
 103
 104         return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
 105 }
 106
 107 void __cpuinit xen_enable_sysenter(void)
 108 {
 109         extern void xen_sysenter_target(void);
 110         int ret;
 111         unsigned sysenter_feature;
 112
 113 #ifdef CONFIG_X86_32
 114         sysenter_feature = X86_FEATURE_SEP;
 115 #else
 116         sysenter_feature = X86_FEATURE_SYSENTER32;
 117 #endif
 118
 119         if (!boot_cpu_has(sysenter_feature))
 120                 return;
 121
 122         ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
 123         if(ret != 0)
 124                 setup_clear_cpu_cap(sysenter_feature);
 125 }
 126
 127 void __cpuinit xen_enable_syscall(void)
 128 {
 129 #ifdef CONFIG_X86_64
 130         int ret;
 131         extern void xen_syscall_target(void);
 132         extern void xen_syscall32_target(void);
 133
 134         ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
 135         if (ret != 0) {
 136                 printk(KERN_ERR "Failed to set syscall: %d\n", ret);
 137                 /* Pretty fatal; 64-bit userspace has no other
 138                    mechanism for syscalls. */
 139         }
 140
 141         if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
 142                 ret = register_callback(CALLBACKTYPE_syscall32,
 143                                         xen_syscall32_target);
 144                 if (ret != 0) {
 145                         printk(KERN_INFO "Xen: 32-bit syscall not supported: disabling vdso\n");
 146                         setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
 147                         sysctl_vsyscall32 = 0;
 148                 }
 149         }
 150 #endif /* CONFIG_X86_64 */
 151 }
 152
 153 void __init xen_arch_setup(void)
 154 {
 155         struct physdev_set_iopl set_iopl;
 156         int rc;
 157
 158         HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
 159         HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
 160
 161         if (!xen_feature(XENFEAT_auto_translated_physmap))
 162                 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_pae_extended_cr3);
 163
 164         if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
 165             register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
 166                 BUG();
 167
 168         xen_enable_sysenter();
 169         xen_enable_syscall();
 170
 171         set_iopl.iopl = 1;
 172         rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
 173         if (rc != 0)
 174                 printk(KERN_INFO "physdev_op failed %d\n", rc);
 175
 176 #ifdef CONFIG_ACPI
 177         if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
 178                 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
 179                 disable_acpi();
 180         }
 181 #endif
 182
 183         memcpy(boot_command_line, xen_start_info->cmd_line,
 184                MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
 185                COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
 186
 187         pm_idle = xen_idle;
 188
 189         paravirt_disable_iospace();
 190
 191         fiddle_vdso();
 192 }