arch/arm/xen/enlighten.c

   1 #include <xen/xen.h>
   2 #include <xen/events.h>
   3 #include <xen/grant_table.h>
   4 #include <xen/hvm.h>
   5 #include <xen/interface/vcpu.h>
   6 #include <xen/interface/xen.h>
   7 #include <xen/interface/memory.h>
   8 #include <xen/interface/hvm/params.h>
   9 #include <xen/features.h>
  10 #include <xen/platform_pci.h>
  11 #include <xen/xenbus.h>
  12 #include <xen/page.h>
  13 #include <xen/interface/sched.h>
  14 #include <xen/xen-ops.h>
  15 #include <asm/xen/hypervisor.h>
  16 #include <asm/xen/hypercall.h>
  17 #include <asm/xen/xen-ops.h>
  18 #include <asm/system_misc.h>
  19 #include <asm/efi.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irqreturn.h>
  22 #include <linux/module.h>
  23 #include <linux/of.h>
  24 #include <linux/of_fdt.h>
  25 #include <linux/of_irq.h>
  26 #include <linux/of_address.h>
  27 #include <linux/cpuidle.h>
  28 #include <linux/cpufreq.h>
  29 #include <linux/cpu.h>
  30 #include <linux/console.h>
  31 #include <linux/pvclock_gtod.h>
  32 #include <linux/time64.h>
  33 #include <linux/timekeeping.h>
  34 #include <linux/timekeeper_internal.h>
  35 #include <linux/acpi.h>
  36
  37 #include <linux/mm.h>
  38
  39 struct start_info _xen_start_info;
  40 struct start_info *xen_start_info = &_xen_start_info;
  41 EXPORT_SYMBOL(xen_start_info);
  42
  43 enum xen_domain_type xen_domain_type = XEN_NATIVE;
  44 EXPORT_SYMBOL(xen_domain_type);
  45
  46 struct shared_info xen_dummy_shared_info;
  47 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
  48
  49 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
  50 static struct vcpu_info __percpu *xen_vcpu_info;
  51
  52 /* These are unused until we support booting "pre-ballooned" */
  53 unsigned long xen_released_pages;
  54 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
  55
  56 static __read_mostly unsigned int xen_events_irq;
  57
  58 int xen_remap_domain_gfn_array(struct vm_area_struct *vma,
  59                                unsigned long addr,
  60                                xen_pfn_t *gfn, int nr,
  61                                int *err_ptr, pgprot_t prot,
  62                                unsigned domid,
  63                                struct page **pages)
  64 {
  65         return xen_xlate_remap_gfn_array(vma, addr, gfn, nr, err_ptr,
  66                                          prot, domid, pages);
  67 }
  68 EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_array);
  69
  70 /* Not used by XENFEAT_auto_translated guests. */
  71 int xen_remap_domain_gfn_range(struct vm_area_struct *vma,
  72                               unsigned long addr,
  73                               xen_pfn_t gfn, int nr,
  74                               pgprot_t prot, unsigned domid,
  75                               struct page **pages)
  76 {
  77         return -ENOSYS;
  78 }
  79 EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_range);
  80
  81 int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
  82                                int nr, struct page **pages)
  83 {
  84         return xen_xlate_unmap_gfn_range(vma, nr, pages);
  85 }
  86 EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
  87
  88 static void xen_read_wallclock(struct timespec64 *ts)
  89 {
  90         u32 version;
  91         struct timespec64 now, ts_monotonic;
  92         struct shared_info *s = HYPERVISOR_shared_info;
  93         struct pvclock_wall_clock *wall_clock = &(s->wc);
  94
  95         /* get wallclock at system boot */
  96         do {
  97                 version = wall_clock->version;
  98                 rmb();          /* fetch version before time */
  99                 now.tv_sec  = ((uint64_t)wall_clock->sec_hi << 32) | wall_clock->sec;
 100                 now.tv_nsec = wall_clock->nsec;
 101                 rmb();          /* fetch time before checking version */
 102         } while ((wall_clock->version & 1) || (version != wall_clock->version));
 103
 104         /* time since system boot */
 105         ktime_get_ts64(&ts_monotonic);
 106         *ts = timespec64_add(now, ts_monotonic);
 107 }
 108
 109 static int xen_pvclock_gtod_notify(struct notifier_block *nb,
 110                                    unsigned long was_set, void *priv)
 111 {
 112         /* Protected by the calling core code serialization */
 113         static struct timespec64 next_sync;
 114
 115         struct xen_platform_op op;
 116         struct timespec64 now, system_time;
 117         struct timekeeper *tk = priv;
 118
 119         now.tv_sec = tk->xtime_sec;
 120         now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
 121         system_time = timespec64_add(now, tk->wall_to_monotonic);
 122
 123         /*
 124          * We only take the expensive HV call when the clock was set
 125          * or when the 11 minutes RTC synchronization time elapsed.
 126          */
 127         if (!was_set && timespec64_compare(&now, &next_sync) < 0)
 128                 return NOTIFY_OK;
 129
 130         op.cmd = XENPF_settime64;
 131         op.u.settime64.mbz = 0;
 132         op.u.settime64.secs = now.tv_sec;
 133         op.u.settime64.nsecs = now.tv_nsec;
 134         op.u.settime64.system_time = timespec64_to_ns(&system_time);
 135         (void)HYPERVISOR_platform_op(&op);
 136
 137         /*
 138          * Move the next drift compensation time 11 minutes
 139          * ahead. That's emulating the sync_cmos_clock() update for
 140          * the hardware RTC.
 141          */
 142         next_sync = now;
 143         next_sync.tv_sec += 11 * 60;
 144
 145         return NOTIFY_OK;
 146 }
 147
 148 static struct notifier_block xen_pvclock_gtod_notifier = {
 149         .notifier_call = xen_pvclock_gtod_notify,
 150 };
 151
 152 static void xen_percpu_init(void)
 153 {
 154         struct vcpu_register_vcpu_info info;
 155         struct vcpu_info *vcpup;
 156         int err;
 157         int cpu = get_cpu();
 158
 159         /*
 160          * VCPUOP_register_vcpu_info cannot be called twice for the same
 161          * vcpu, so if vcpu_info is already registered, just get out. This
 162          * can happen with cpu-hotplug.
 163          */
 164         if (per_cpu(xen_vcpu, cpu) != NULL)
 165                 goto after_register_vcpu_info;
 166
 167         pr_info("Xen: initializing cpu%d\n", cpu);
 168         vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
 169
 170         info.mfn = virt_to_gfn(vcpup);
 171         info.offset = xen_offset_in_page(vcpup);
 172
 173         err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
 174         BUG_ON(err);
 175         per_cpu(xen_vcpu, cpu) = vcpup;
 176
 177         xen_setup_runstate_info(cpu);
 178
 179 after_register_vcpu_info:
 180         enable_percpu_irq(xen_events_irq, 0);
 181         put_cpu();
 182 }
 183
 184 static void xen_restart(enum reboot_mode reboot_mode, const char *cmd)
 185 {
 186         struct sched_shutdown r = { .reason = SHUTDOWN_reboot };
 187         int rc;
 188         rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
 189         BUG_ON(rc);
 190 }
 191
 192 static void xen_power_off(void)
 193 {
 194         struct sched_shutdown r = { .reason = SHUTDOWN_poweroff };
 195         int rc;
 196         rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
 197         BUG_ON(rc);
 198 }
 199
 200 static int xen_cpu_notification(struct notifier_block *self,
 201                                 unsigned long action,
 202                                 void *hcpu)
 203 {
 204         switch (action) {
 205         case CPU_STARTING:
 206                 xen_percpu_init();
 207                 break;
 208         case CPU_DYING:
 209                 disable_percpu_irq(xen_events_irq);
 210                 break;
 211         default:
 212                 break;
 213         }
 214
 215         return NOTIFY_OK;
 216 }
 217
 218 static struct notifier_block xen_cpu_notifier = {
 219         .notifier_call = xen_cpu_notification,
 220 };
 221
 222 static irqreturn_t xen_arm_callback(int irq, void *arg)
 223 {
 224         xen_hvm_evtchn_do_upcall();
 225         return IRQ_HANDLED;
 226 }
 227
 228 static __initdata struct {
 229         const char *compat;
 230         const char *prefix;
 231         const char *version;
 232         bool found;
 233 } hyper_node = {"xen,xen", "xen,xen-", NULL, false};
 234
 235 static int __init fdt_find_hyper_node(unsigned long node, const char *uname,
 236                                       int depth, void *data)
 237 {
 238         const void *s = NULL;
 239         int len;
 240
 241         if (depth != 1 || strcmp(uname, "hypervisor") != 0)
 242                 return 0;
 243
 244         if (of_flat_dt_is_compatible(node, hyper_node.compat))
 245                 hyper_node.found = true;
 246
 247         s = of_get_flat_dt_prop(node, "compatible", &len);
 248         if (strlen(hyper_node.prefix) + 3  < len &&
 249             !strncmp(hyper_node.prefix, s, strlen(hyper_node.prefix)))
 250                 hyper_node.version = s + strlen(hyper_node.prefix);
 251
 252         /*
 253          * Check if Xen supports EFI by checking whether there is the
 254          * "/hypervisor/uefi" node in DT. If so, runtime services are available
 255          * through proxy functions (e.g. in case of Xen dom0 EFI implementation
 256          * they call special hypercall which executes relevant EFI functions)
 257          * and that is why they are always enabled.
 258          */
 259         if (IS_ENABLED(CONFIG_XEN_EFI)) {
 260                 if ((of_get_flat_dt_subnode_by_name(node, "uefi") > 0) &&
 261                     !efi_runtime_disabled())
 262                         set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 263         }
 264
 265         return 0;
 266 }
 267
 268 /*
 269  * see Documentation/devicetree/bindings/arm/xen.txt for the
 270  * documentation of the Xen Device Tree format.
 271  */
 272 #define GRANT_TABLE_PHYSADDR 0
 273 void __init xen_early_init(void)
 274 {
 275         of_scan_flat_dt(fdt_find_hyper_node, NULL);
 276         if (!hyper_node.found) {
 277                 pr_debug("No Xen support\n");
 278                 return;
 279         }
 280
 281         if (hyper_node.version == NULL) {
 282                 pr_debug("Xen version not found\n");
 283                 return;
 284         }
 285
 286         pr_info("Xen %s support found\n", hyper_node.version);
 287
 288         xen_domain_type = XEN_HVM_DOMAIN;
 289
 290         xen_setup_features();
 291
 292         if (xen_feature(XENFEAT_dom0))
 293                 xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
 294         else
 295                 xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED);
 296
 297         if (!console_set_on_cmdline && !xen_initial_domain())
 298                 add_preferred_console("hvc", 0, NULL);
 299 }
 300
 301 static void __init xen_acpi_guest_init(void)
 302 {
 303 #ifdef CONFIG_ACPI
 304         struct xen_hvm_param a;
 305         int interrupt, trigger, polarity;
 306
 307         a.domid = DOMID_SELF;
 308         a.index = HVM_PARAM_CALLBACK_IRQ;
 309
 310         if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)
 311             || (a.value >> 56) != HVM_PARAM_CALLBACK_TYPE_PPI) {
 312                 xen_events_irq = 0;
 313                 return;
 314         }
 315
 316         interrupt = a.value & 0xff;
 317         trigger = ((a.value >> 8) & 0x1) ? ACPI_EDGE_SENSITIVE
 318                                          : ACPI_LEVEL_SENSITIVE;
 319         polarity = ((a.value >> 8) & 0x2) ? ACPI_ACTIVE_LOW
 320                                           : ACPI_ACTIVE_HIGH;
 321         xen_events_irq = acpi_register_gsi(NULL, interrupt, trigger, polarity);
 322 #endif
 323 }
 324
 325 static void __init xen_dt_guest_init(void)
 326 {
 327         struct device_node *xen_node;
 328
 329         xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
 330         if (!xen_node) {
 331                 pr_err("Xen support was detected before, but it has disappeared\n");
 332                 return;
 333         }
 334
 335         xen_events_irq = irq_of_parse_and_map(xen_node, 0);
 336 }
 337
 338 static int __init xen_guest_init(void)
 339 {
 340         struct xen_add_to_physmap xatp;
 341         struct shared_info *shared_info_page = NULL;
 342
 343         if (!xen_domain())
 344                 return 0;
 345
 346         if (!acpi_disabled)
 347                 xen_acpi_guest_init();
 348         else
 349                 xen_dt_guest_init();
 350
 351         if (!xen_events_irq) {
 352                 pr_err("Xen event channel interrupt not found\n");
 353                 return -ENODEV;
 354         }
 355
 356         /*
 357          * The fdt parsing codes have set EFI_RUNTIME_SERVICES if Xen EFI
 358          * parameters are found. Force enable runtime services.
 359          */
 360         if (efi_enabled(EFI_RUNTIME_SERVICES))
 361                 xen_efi_runtime_setup();
 362
 363         shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
 364
 365         if (!shared_info_page) {
 366                 pr_err("not enough memory\n");
 367                 return -ENOMEM;
 368         }
 369         xatp.domid = DOMID_SELF;
 370         xatp.idx = 0;
 371         xatp.space = XENMAPSPACE_shared_info;
 372         xatp.gpfn = virt_to_gfn(shared_info_page);
 373         if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
 374                 BUG();
 375
 376         HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
 377
 378         /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
 379          * page, we use it in the event channel upcall and in some pvclock
 380          * related functions.
 381          * The shared info contains exactly 1 CPU (the boot CPU). The guest
 382          * is required to use VCPUOP_register_vcpu_info to place vcpu info
 383          * for secondary CPUs as they are brought up.
 384          * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
 385          */
 386         xen_vcpu_info = __alloc_percpu(sizeof(struct vcpu_info),
 387                                                sizeof(struct vcpu_info));
 388         if (xen_vcpu_info == NULL)
 389                 return -ENOMEM;
 390
 391         xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
 392         if (xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
 393                                           &xen_auto_xlat_grant_frames.vaddr,
 394                                           xen_auto_xlat_grant_frames.count)) {
 395                 free_percpu(xen_vcpu_info);
 396                 return -ENOMEM;
 397         }
 398         gnttab_init();
 399         if (!xen_initial_domain())
 400                 xenbus_probe(NULL);
 401
 402         /*
 403          * Making sure board specific code will not set up ops for
 404          * cpu idle and cpu freq.
 405          */
 406         disable_cpuidle();
 407         disable_cpufreq();
 408
 409         xen_init_IRQ();
 410
 411         if (request_percpu_irq(xen_events_irq, xen_arm_callback,
 412                                "events", &xen_vcpu)) {
 413                 pr_err("Error request IRQ %d\n", xen_events_irq);
 414                 return -EINVAL;
 415         }
 416
 417         xen_percpu_init();
 418
 419         register_cpu_notifier(&xen_cpu_notifier);
 420
 421         xen_time_setup_guest();
 422
 423         if (xen_initial_domain())
 424                 pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
 425
 426         return 0;
 427 }
 428 early_initcall(xen_guest_init);
 429
 430 static int __init xen_pm_init(void)
 431 {
 432         if (!xen_domain())
 433                 return -ENODEV;
 434
 435         pm_power_off = xen_power_off;
 436         arm_pm_restart = xen_restart;
 437         if (!xen_initial_domain()) {
 438                 struct timespec64 ts;
 439                 xen_read_wallclock(&ts);
 440                 do_settimeofday64(&ts);
 441         }
 442
 443         return 0;
 444 }
 445 late_initcall(xen_pm_init);
 446
 447
 448 /* empty stubs */
 449 void xen_arch_pre_suspend(void) { }
 450 void xen_arch_post_suspend(int suspend_cancelled) { }
 451 void xen_timer_resume(void) { }
 452 void xen_arch_resume(void) { }
 453 void xen_arch_suspend(void) { }
 454
 455
 456 /* In the hypercall.S file. */
 457 EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
 458 EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
 459 EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
 460 EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
 461 EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
 462 EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
 463 EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
 464 EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
 465 EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
 466 EXPORT_SYMBOL_GPL(HYPERVISOR_tmem_op);
 467 EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op);
 468 EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
 469 EXPORT_SYMBOL_GPL(privcmd_call);