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