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/interface/memory.h>
  24 #include <xen/features.h>
  25
  26 #include "xen-ops.h"
  27 #include "vdso.h"
  28
  29 /* These are code, but not functions.  Defined in entry.S */
  30 extern const char xen_hypervisor_callback[];
  31 extern const char xen_failsafe_callback[];
  32 extern void xen_sysenter_target(void);
  33 extern void xen_syscall_target(void);
  34 extern void xen_syscall32_target(void);
  35
  36 static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
  37                                               phys_addr_t end_addr)
  38 {
  39         struct xen_memory_reservation reservation = {
  40                 .address_bits = 0,
  41                 .extent_order = 0,
  42                 .domid        = DOMID_SELF
  43         };
  44         unsigned long start, end;
  45         unsigned long len = 0;
  46         unsigned long pfn;
  47         int ret;
  48
  49         start = PFN_UP(start_addr);
  50         end = PFN_DOWN(end_addr);
  51
  52         if (end <= start)
  53                 return 0;
  54
  55         printk(KERN_INFO "xen_release_chunk: looking at area pfn %lx-%lx: ",
  56                start, end);
  57         for(pfn = start; pfn < end; pfn++) {
  58                 unsigned long mfn = pfn_to_mfn(pfn);
  59
  60                 /* Make sure pfn exists to start with */
  61                 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
  62                         continue;
  63
  64                 set_xen_guest_handle(reservation.extent_start, &mfn);
  65                 reservation.nr_extents = 1;
  66
  67                 ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
  68                                            &reservation);
  69                 WARN(ret != 1, "Failed to release memory %lx-%lx err=%d\n",
  70                      start, end, ret);
  71                 if (ret == 1) {
  72                         set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
  73                         len++;
  74                 }
  75         }
  76         printk(KERN_CONT "%ld pages freed\n", len);
  77
  78         return len;
  79 }
  80
  81 static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
  82                                                      const struct e820map *e820)
  83 {
  84         phys_addr_t max_addr = PFN_PHYS(max_pfn);
  85         phys_addr_t last_end = 0;
  86         unsigned long released = 0;
  87         int i;
  88
  89         for (i = 0; i < e820->nr_map && last_end < max_addr; i++) {
  90                 phys_addr_t end = e820->map[i].addr;
  91                 end = min(max_addr, end);
  92
  93                 released += xen_release_chunk(last_end, end);
  94                 last_end = e820->map[i].addr + e820->map[i].size;
  95         }
  96
  97         if (last_end < max_addr)
  98                 released += xen_release_chunk(last_end, max_addr);
  99
 100         printk(KERN_INFO "released %ld pages of unused memory\n", released);
 101         return released;
 102 }
 103
 104 /**
 105  * machine_specific_memory_setup - Hook for machine specific memory setup.
 106  **/
 107
 108 char * __init xen_memory_setup(void)
 109 {
 110         unsigned long max_pfn = xen_start_info->nr_pages;
 111
 112         max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
 113
 114         e820.nr_map = 0;
 115
 116         e820_add_region(0, PFN_PHYS((u64)max_pfn), E820_RAM);
 117
 118         /*
 119          * Even though this is normal, usable memory under Xen, reserve
 120          * ISA memory anyway because too many things think they can poke
 121          * about in there.
 122          */
 123         e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
 124                         E820_RESERVED);
 125
 126         /*
 127          * Reserve Xen bits:
 128          *  - mfn_list
 129          *  - xen_start_info
 130          * See comment above "struct start_info" in <xen/interface/xen.h>
 131          */
 132         reserve_early(__pa(xen_start_info->mfn_list),
 133                       __pa(xen_start_info->pt_base),
 134                         "XEN START INFO");
 135
 136         sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 137
 138         xen_return_unused_memory(xen_start_info->nr_pages, &e820);
 139
 140         return "Xen";
 141 }
 142
 143 static void xen_idle(void)
 144 {
 145         local_irq_disable();
 146
 147         if (need_resched())
 148                 local_irq_enable();
 149         else {
 150                 current_thread_info()->status &= ~TS_POLLING;
 151                 smp_mb__after_clear_bit();
 152                 safe_halt();
 153                 current_thread_info()->status |= TS_POLLING;
 154         }
 155 }
 156
 157 /*
 158  * Set the bit indicating "nosegneg" library variants should be used.
 159  * We only need to bother in pure 32-bit mode; compat 32-bit processes
 160  * can have un-truncated segments, so wrapping around is allowed.
 161  */
 162 static void __init fiddle_vdso(void)
 163 {
 164 #ifdef CONFIG_X86_32
 165         u32 *mask;
 166         mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK);
 167         *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
 168         mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK);
 169         *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
 170 #endif
 171 }
 172
 173 static __cpuinit int register_callback(unsigned type, const void *func)
 174 {
 175         struct callback_register callback = {
 176                 .type = type,
 177                 .address = XEN_CALLBACK(__KERNEL_CS, func),
 178                 .flags = CALLBACKF_mask_events,
 179         };
 180
 181         return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
 182 }
 183
 184 void __cpuinit xen_enable_sysenter(void)
 185 {
 186         int ret;
 187         unsigned sysenter_feature;
 188
 189 #ifdef CONFIG_X86_32
 190         sysenter_feature = X86_FEATURE_SEP;
 191 #else
 192         sysenter_feature = X86_FEATURE_SYSENTER32;
 193 #endif
 194
 195         if (!boot_cpu_has(sysenter_feature))
 196                 return;
 197
 198         ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
 199         if(ret != 0)
 200                 setup_clear_cpu_cap(sysenter_feature);
 201 }
 202
 203 void __cpuinit xen_enable_syscall(void)
 204 {
 205 #ifdef CONFIG_X86_64
 206         int ret;
 207
 208         ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
 209         if (ret != 0) {
 210                 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
 211                 /* Pretty fatal; 64-bit userspace has no other
 212                    mechanism for syscalls. */
 213         }
 214
 215         if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
 216                 ret = register_callback(CALLBACKTYPE_syscall32,
 217                                         xen_syscall32_target);
 218                 if (ret != 0)
 219                         setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
 220         }
 221 #endif /* CONFIG_X86_64 */
 222 }
 223
 224 void __init xen_arch_setup(void)
 225 {
 226         struct physdev_set_iopl set_iopl;
 227         int rc;
 228
 229         xen_panic_handler_init();
 230
 231         HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
 232         HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
 233
 234         if (!xen_feature(XENFEAT_auto_translated_physmap))
 235                 HYPERVISOR_vm_assist(VMASST_CMD_enable,
 236                                      VMASST_TYPE_pae_extended_cr3);
 237
 238         if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
 239             register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
 240                 BUG();
 241
 242         xen_enable_sysenter();
 243         xen_enable_syscall();
 244
 245         set_iopl.iopl = 1;
 246         rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
 247         if (rc != 0)
 248                 printk(KERN_INFO "physdev_op failed %d\n", rc);
 249
 250 #ifdef CONFIG_ACPI
 251         if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
 252                 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
 253                 disable_acpi();
 254         }
 255 #endif
 256
 257         memcpy(boot_command_line, xen_start_info->cmd_line,
 258                MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
 259                COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
 260
 261         pm_idle = xen_idle;
 262
 263         paravirt_disable_iospace();
 264
 265         fiddle_vdso();
 266 }