arch/arm/xen/enlighten.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <xen/xen.h>
   3 #include <xen/events.h>
   4 #include <xen/grant_table.h>
   5 #include <xen/hvm.h>
   6 #include <xen/interface/vcpu.h>
   7 #include <xen/interface/xen.h>
   8 #include <xen/interface/memory.h>
   9 #include <xen/interface/hvm/params.h>
  10 #include <xen/features.h>
  11 #include <xen/platform_pci.h>
  12 #include <xen/xenbus.h>
  13 #include <xen/page.h>
  14 #include <xen/interface/sched.h>
  15 #include <xen/xen-ops.h>
  16 #include <asm/xen/hypervisor.h>
  17 #include <asm/xen/hypercall.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 static 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(uint32_t, xen_vcpu_id);
  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 uint32_t xen_start_flags;
  63 EXPORT_SYMBOL(xen_start_flags);
  64
  65 int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
  66                                int nr, struct page **pages)
  67 {
  68         return xen_xlate_unmap_gfn_range(vma, nr, pages);
  69 }
  70 EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
  71
  72 static void xen_read_wallclock(struct timespec64 *ts)
  73 {
  74         u32 version;
  75         struct timespec64 now, ts_monotonic;
  76         struct shared_info *s = HYPERVISOR_shared_info;
  77         struct pvclock_wall_clock *wall_clock = &(s->wc);
  78
  79         /* get wallclock at system boot */
  80         do {
  81                 version = wall_clock->version;
  82                 rmb();          /* fetch version before time */
  83                 now.tv_sec  = ((uint64_t)wall_clock->sec_hi << 32) | wall_clock->sec;
  84                 now.tv_nsec = wall_clock->nsec;
  85                 rmb();          /* fetch time before checking version */
  86         } while ((wall_clock->version & 1) || (version != wall_clock->version));
  87
  88         /* time since system boot */
  89         ktime_get_ts64(&ts_monotonic);
  90         *ts = timespec64_add(now, ts_monotonic);
  91 }
  92
  93 static int xen_pvclock_gtod_notify(struct notifier_block *nb,
  94                                    unsigned long was_set, void *priv)
  95 {
  96         /* Protected by the calling core code serialization */
  97         static struct timespec64 next_sync;
  98
  99         struct xen_platform_op op;
 100         struct timespec64 now, system_time;
 101         struct timekeeper *tk = priv;
 102
 103         now.tv_sec = tk->xtime_sec;
 104         now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
 105         system_time = timespec64_add(now, tk->wall_to_monotonic);
 106
 107         /*
 108          * We only take the expensive HV call when the clock was set
 109          * or when the 11 minutes RTC synchronization time elapsed.
 110          */
 111         if (!was_set && timespec64_compare(&now, &next_sync) < 0)
 112                 return NOTIFY_OK;
 113
 114         op.cmd = XENPF_settime64;
 115         op.u.settime64.mbz = 0;
 116         op.u.settime64.secs = now.tv_sec;
 117         op.u.settime64.nsecs = now.tv_nsec;
 118         op.u.settime64.system_time = timespec64_to_ns(&system_time);
 119         (void)HYPERVISOR_platform_op(&op);
 120
 121         /*
 122          * Move the next drift compensation time 11 minutes
 123          * ahead. That's emulating the sync_cmos_clock() update for
 124          * the hardware RTC.
 125          */
 126         next_sync = now;
 127         next_sync.tv_sec += 11 * 60;
 128
 129         return NOTIFY_OK;
 130 }
 131
 132 static struct notifier_block xen_pvclock_gtod_notifier = {
 133         .notifier_call = xen_pvclock_gtod_notify,
 134 };
 135
 136 static int xen_starting_cpu(unsigned int cpu)
 137 {
 138         struct vcpu_register_vcpu_info info;
 139         struct vcpu_info *vcpup;
 140         int err;
 141
 142         /*
 143          * VCPUOP_register_vcpu_info cannot be called twice for the same
 144          * vcpu, so if vcpu_info is already registered, just get out. This
 145          * can happen with cpu-hotplug.
 146          */
 147         if (per_cpu(xen_vcpu, cpu) != NULL)
 148                 goto after_register_vcpu_info;
 149
 150         pr_info("Xen: initializing cpu%d\n", cpu);
 151         vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
 152
 153         info.mfn = virt_to_gfn(vcpup);
 154         info.offset = xen_offset_in_page(vcpup);
 155
 156         err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
 157                                  &info);
 158         BUG_ON(err);
 159         per_cpu(xen_vcpu, cpu) = vcpup;
 160
 161         xen_setup_runstate_info(cpu);
 162
 163 after_register_vcpu_info:
 164         enable_percpu_irq(xen_events_irq, 0);
 165         return 0;
 166 }
 167
 168 static int xen_dying_cpu(unsigned int cpu)
 169 {
 170         disable_percpu_irq(xen_events_irq);
 171         return 0;
 172 }
 173
 174 void xen_reboot(int reason)
 175 {
 176         struct sched_shutdown r = { .reason = reason };
 177         int rc;
 178
 179         rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
 180         BUG_ON(rc);
 181 }
 182
 183 static void xen_restart(enum reboot_mode reboot_mode, const char *cmd)
 184 {
 185         xen_reboot(SHUTDOWN_reboot);
 186 }
 187
 188
 189 static void xen_power_off(void)
 190 {
 191         xen_reboot(SHUTDOWN_poweroff);
 192 }
 193
 194 static irqreturn_t xen_arm_callback(int irq, void *arg)
 195 {
 196         xen_hvm_evtchn_do_upcall();
 197         return IRQ_HANDLED;
 198 }
 199
 200 static __initdata struct {
 201         const char *compat;
 202         const char *prefix;
 203         const char *version;
 204         bool found;
 205 } hyper_node = {"xen,xen", "xen,xen-", NULL, false};
 206
 207 static int __init fdt_find_hyper_node(unsigned long node, const char *uname,
 208                                       int depth, void *data)
 209 {
 210         const void *s = NULL;
 211         int len;
 212
 213         if (depth != 1 || strcmp(uname, "hypervisor") != 0)
 214                 return 0;
 215
 216         if (of_flat_dt_is_compatible(node, hyper_node.compat))
 217                 hyper_node.found = true;
 218
 219         s = of_get_flat_dt_prop(node, "compatible", &len);
 220         if (strlen(hyper_node.prefix) + 3  < len &&
 221             !strncmp(hyper_node.prefix, s, strlen(hyper_node.prefix)))
 222                 hyper_node.version = s + strlen(hyper_node.prefix);
 223
 224         /*
 225          * Check if Xen supports EFI by checking whether there is the
 226          * "/hypervisor/uefi" node in DT. If so, runtime services are available
 227          * through proxy functions (e.g. in case of Xen dom0 EFI implementation
 228          * they call special hypercall which executes relevant EFI functions)
 229          * and that is why they are always enabled.
 230          */
 231         if (IS_ENABLED(CONFIG_XEN_EFI)) {
 232                 if ((of_get_flat_dt_subnode_by_name(node, "uefi") > 0) &&
 233                     !efi_runtime_disabled())
 234                         set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 235         }
 236
 237         return 0;
 238 }
 239
 240 /*
 241  * see Documentation/devicetree/bindings/arm/xen.txt for the
 242  * documentation of the Xen Device Tree format.
 243  */
 244 void __init xen_early_init(void)
 245 {
 246         of_scan_flat_dt(fdt_find_hyper_node, NULL);
 247         if (!hyper_node.found) {
 248                 pr_debug("No Xen support\n");
 249                 return;
 250         }
 251
 252         if (hyper_node.version == NULL) {
 253                 pr_debug("Xen version not found\n");
 254                 return;
 255         }
 256
 257         pr_info("Xen %s support found\n", hyper_node.version);
 258
 259         xen_domain_type = XEN_HVM_DOMAIN;
 260
 261         xen_setup_features();
 262
 263         if (xen_feature(XENFEAT_dom0))
 264                 xen_start_flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
 265
 266         if (!console_set_on_cmdline && !xen_initial_domain())
 267                 add_preferred_console("hvc", 0, NULL);
 268 }
 269
 270 static void __init xen_acpi_guest_init(void)
 271 {
 272 #ifdef CONFIG_ACPI
 273         struct xen_hvm_param a;
 274         int interrupt, trigger, polarity;
 275
 276         a.domid = DOMID_SELF;
 277         a.index = HVM_PARAM_CALLBACK_IRQ;
 278
 279         if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)
 280             || (a.value >> 56) != HVM_PARAM_CALLBACK_TYPE_PPI) {
 281                 xen_events_irq = 0;
 282                 return;
 283         }
 284
 285         interrupt = a.value & 0xff;
 286         trigger = ((a.value >> 8) & 0x1) ? ACPI_EDGE_SENSITIVE
 287                                          : ACPI_LEVEL_SENSITIVE;
 288         polarity = ((a.value >> 8) & 0x2) ? ACPI_ACTIVE_LOW
 289                                           : ACPI_ACTIVE_HIGH;
 290         xen_events_irq = acpi_register_gsi(NULL, interrupt, trigger, polarity);
 291 #endif
 292 }
 293
 294 static void __init xen_dt_guest_init(void)
 295 {
 296         struct device_node *xen_node;
 297
 298         xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
 299         if (!xen_node) {
 300                 pr_err("Xen support was detected before, but it has disappeared\n");
 301                 return;
 302         }
 303
 304         xen_events_irq = irq_of_parse_and_map(xen_node, 0);
 305 }
 306
 307 static int __init xen_guest_init(void)
 308 {
 309         struct xen_add_to_physmap xatp;
 310         struct shared_info *shared_info_page = NULL;
 311         int cpu;
 312
 313         if (!xen_domain())
 314                 return 0;
 315
 316         if (!acpi_disabled)
 317                 xen_acpi_guest_init();
 318         else
 319                 xen_dt_guest_init();
 320
 321         if (!xen_events_irq) {
 322                 pr_err("Xen event channel interrupt not found\n");
 323                 return -ENODEV;
 324         }
 325
 326         /*
 327          * The fdt parsing codes have set EFI_RUNTIME_SERVICES if Xen EFI
 328          * parameters are found. Force enable runtime services.
 329          */
 330         if (efi_enabled(EFI_RUNTIME_SERVICES))
 331                 xen_efi_runtime_setup();
 332
 333         shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
 334
 335         if (!shared_info_page) {
 336                 pr_err("not enough memory\n");
 337                 return -ENOMEM;
 338         }
 339         xatp.domid = DOMID_SELF;
 340         xatp.idx = 0;
 341         xatp.space = XENMAPSPACE_shared_info;
 342         xatp.gpfn = virt_to_gfn(shared_info_page);
 343         if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
 344                 BUG();
 345
 346         HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
 347
 348         /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
 349          * page, we use it in the event channel upcall and in some pvclock
 350          * related functions.
 351          * The shared info contains exactly 1 CPU (the boot CPU). The guest
 352          * is required to use VCPUOP_register_vcpu_info to place vcpu info
 353          * for secondary CPUs as they are brought up.
 354          * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
 355          */
 356         xen_vcpu_info = alloc_percpu(struct vcpu_info);
 357         if (xen_vcpu_info == NULL)
 358                 return -ENOMEM;
 359
 360         /* Direct vCPU id mapping for ARM guests. */
 361         for_each_possible_cpu(cpu)
 362                 per_cpu(xen_vcpu_id, cpu) = cpu;
 363
 364         xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
 365         if (xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
 366                                           &xen_auto_xlat_grant_frames.vaddr,
 367                                           xen_auto_xlat_grant_frames.count)) {
 368                 free_percpu(xen_vcpu_info);
 369                 return -ENOMEM;
 370         }
 371         gnttab_init();
 372         if (!xen_initial_domain())
 373                 xenbus_probe(NULL);
 374
 375         /*
 376          * Making sure board specific code will not set up ops for
 377          * cpu idle and cpu freq.
 378          */
 379         disable_cpuidle();
 380         disable_cpufreq();
 381
 382         xen_init_IRQ();
 383
 384         if (request_percpu_irq(xen_events_irq, xen_arm_callback,
 385                                "events", &xen_vcpu)) {
 386                 pr_err("Error request IRQ %d\n", xen_events_irq);
 387                 return -EINVAL;
 388         }
 389
 390         xen_time_setup_guest();
 391
 392         if (xen_initial_domain())
 393                 pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
 394
 395         return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING,
 396                                  "arm/xen:starting", xen_starting_cpu,
 397                                  xen_dying_cpu);
 398 }
 399 early_initcall(xen_guest_init);
 400
 401 static int __init xen_pm_init(void)
 402 {
 403         if (!xen_domain())
 404                 return -ENODEV;
 405
 406         pm_power_off = xen_power_off;
 407         arm_pm_restart = xen_restart;
 408         if (!xen_initial_domain()) {
 409                 struct timespec64 ts;
 410                 xen_read_wallclock(&ts);
 411                 do_settimeofday64(&ts);
 412         }
 413
 414         return 0;
 415 }
 416 late_initcall(xen_pm_init);
 417
 418
 419 /* empty stubs */
 420 void xen_arch_pre_suspend(void) { }
 421 void xen_arch_post_suspend(int suspend_cancelled) { }
 422 void xen_timer_resume(void) { }
 423 void xen_arch_resume(void) { }
 424 void xen_arch_suspend(void) { }
 425
 426
 427 /* In the hypercall.S file. */
 428 EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
 429 EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
 430 EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
 431 EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
 432 EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
 433 EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
 434 EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
 435 EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
 436 EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
 437 EXPORT_SYMBOL_GPL(HYPERVISOR_tmem_op);
 438 EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op_raw);
 439 EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
 440 EXPORT_SYMBOL_GPL(HYPERVISOR_vm_assist);
 441 EXPORT_SYMBOL_GPL(HYPERVISOR_dm_op);
 442 EXPORT_SYMBOL_GPL(privcmd_call);