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/reboot.h>
  33 #include <linux/time64.h>
  34 #include <linux/timekeeping.h>
  35 #include <linux/timekeeper_internal.h>
  36 #include <linux/acpi.h>
  37
  38 #include <linux/mm.h>
  39
  40 static struct start_info _xen_start_info;
  41 struct start_info *xen_start_info = &_xen_start_info;
  42 EXPORT_SYMBOL(xen_start_info);
  43
  44 enum xen_domain_type xen_domain_type = XEN_NATIVE;
  45 EXPORT_SYMBOL(xen_domain_type);
  46
  47 struct shared_info xen_dummy_shared_info;
  48 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
  49
  50 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
  51 static struct vcpu_info __percpu *xen_vcpu_info;
  52
  53 /* Linux <-> Xen vCPU id mapping */
  54 DEFINE_PER_CPU(uint32_t, xen_vcpu_id);
  55 EXPORT_PER_CPU_SYMBOL(xen_vcpu_id);
  56
  57 /* These are unused until we support booting "pre-ballooned" */
  58 unsigned long xen_released_pages;
  59 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
  60
  61 static __read_mostly unsigned int xen_events_irq;
  62
  63 uint32_t xen_start_flags;
  64 EXPORT_SYMBOL(xen_start_flags);
  65
  66 int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
  67                                int nr, struct page **pages)
  68 {
  69         return xen_xlate_unmap_gfn_range(vma, nr, pages);
  70 }
  71 EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
  72
  73 static void xen_read_wallclock(struct timespec64 *ts)
  74 {
  75         u32 version;
  76         struct timespec64 now, ts_monotonic;
  77         struct shared_info *s = HYPERVISOR_shared_info;
  78         struct pvclock_wall_clock *wall_clock = &(s->wc);
  79
  80         /* get wallclock at system boot */
  81         do {
  82                 version = wall_clock->version;
  83                 rmb();          /* fetch version before time */
  84                 now.tv_sec  = ((uint64_t)wall_clock->sec_hi << 32) | wall_clock->sec;
  85                 now.tv_nsec = wall_clock->nsec;
  86                 rmb();          /* fetch time before checking version */
  87         } while ((wall_clock->version & 1) || (version != wall_clock->version));
  88
  89         /* time since system boot */
  90         ktime_get_ts64(&ts_monotonic);
  91         *ts = timespec64_add(now, ts_monotonic);
  92 }
  93
  94 static int xen_pvclock_gtod_notify(struct notifier_block *nb,
  95                                    unsigned long was_set, void *priv)
  96 {
  97         /* Protected by the calling core code serialization */
  98         static struct timespec64 next_sync;
  99
 100         struct xen_platform_op op;
 101         struct timespec64 now, system_time;
 102         struct timekeeper *tk = priv;
 103
 104         now.tv_sec = tk->xtime_sec;
 105         now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
 106         system_time = timespec64_add(now, tk->wall_to_monotonic);
 107
 108         /*
 109          * We only take the expensive HV call when the clock was set
 110          * or when the 11 minutes RTC synchronization time elapsed.
 111          */
 112         if (!was_set && timespec64_compare(&now, &next_sync) < 0)
 113                 return NOTIFY_OK;
 114
 115         op.cmd = XENPF_settime64;
 116         op.u.settime64.mbz = 0;
 117         op.u.settime64.secs = now.tv_sec;
 118         op.u.settime64.nsecs = now.tv_nsec;
 119         op.u.settime64.system_time = timespec64_to_ns(&system_time);
 120         (void)HYPERVISOR_platform_op(&op);
 121
 122         /*
 123          * Move the next drift compensation time 11 minutes
 124          * ahead. That's emulating the sync_cmos_clock() update for
 125          * the hardware RTC.
 126          */
 127         next_sync = now;
 128         next_sync.tv_sec += 11 * 60;
 129
 130         return NOTIFY_OK;
 131 }
 132
 133 static struct notifier_block xen_pvclock_gtod_notifier = {
 134         .notifier_call = xen_pvclock_gtod_notify,
 135 };
 136
 137 static int xen_starting_cpu(unsigned int cpu)
 138 {
 139         struct vcpu_register_vcpu_info info;
 140         struct vcpu_info *vcpup;
 141         int err;
 142
 143         /*
 144          * VCPUOP_register_vcpu_info cannot be called twice for the same
 145          * vcpu, so if vcpu_info is already registered, just get out. This
 146          * can happen with cpu-hotplug.
 147          */
 148         if (per_cpu(xen_vcpu, cpu) != NULL)
 149                 goto after_register_vcpu_info;
 150
 151         pr_info("Xen: initializing cpu%d\n", cpu);
 152         vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
 153
 154         info.mfn = percpu_to_gfn(vcpup);
 155         info.offset = xen_offset_in_page(vcpup);
 156
 157         err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
 158                                  &info);
 159         BUG_ON(err);
 160         per_cpu(xen_vcpu, cpu) = vcpup;
 161
 162         if (!xen_kernel_unmapped_at_usr())
 163                 xen_setup_runstate_info(cpu);
 164
 165 after_register_vcpu_info:
 166         enable_percpu_irq(xen_events_irq, 0);
 167         return 0;
 168 }
 169
 170 static int xen_dying_cpu(unsigned int cpu)
 171 {
 172         disable_percpu_irq(xen_events_irq);
 173         return 0;
 174 }
 175
 176 void xen_reboot(int reason)
 177 {
 178         struct sched_shutdown r = { .reason = reason };
 179         int rc;
 180
 181         rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
 182         BUG_ON(rc);
 183 }
 184
 185 static int xen_restart(struct notifier_block *nb, unsigned long action,
 186                        void *data)
 187 {
 188         xen_reboot(SHUTDOWN_reboot);
 189
 190         return NOTIFY_DONE;
 191 }
 192
 193 static struct notifier_block xen_restart_nb = {
 194         .notifier_call = xen_restart,
 195         .priority = 192,
 196 };
 197
 198 static void xen_power_off(void)
 199 {
 200         xen_reboot(SHUTDOWN_poweroff);
 201 }
 202
 203 static irqreturn_t xen_arm_callback(int irq, void *arg)
 204 {
 205         xen_hvm_evtchn_do_upcall();
 206         return IRQ_HANDLED;
 207 }
 208
 209 static __initdata struct {
 210         const char *compat;
 211         const char *prefix;
 212         const char *version;
 213         bool found;
 214 } hyper_node = {"xen,xen", "xen,xen-", NULL, false};
 215
 216 static int __init fdt_find_hyper_node(unsigned long node, const char *uname,
 217                                       int depth, void *data)
 218 {
 219         const void *s = NULL;
 220         int len;
 221
 222         if (depth != 1 || strcmp(uname, "hypervisor") != 0)
 223                 return 0;
 224
 225         if (of_flat_dt_is_compatible(node, hyper_node.compat))
 226                 hyper_node.found = true;
 227
 228         s = of_get_flat_dt_prop(node, "compatible", &len);
 229         if (strlen(hyper_node.prefix) + 3  < len &&
 230             !strncmp(hyper_node.prefix, s, strlen(hyper_node.prefix)))
 231                 hyper_node.version = s + strlen(hyper_node.prefix);
 232
 233         /*
 234          * Check if Xen supports EFI by checking whether there is the
 235          * "/hypervisor/uefi" node in DT. If so, runtime services are available
 236          * through proxy functions (e.g. in case of Xen dom0 EFI implementation
 237          * they call special hypercall which executes relevant EFI functions)
 238          * and that is why they are always enabled.
 239          */
 240         if (IS_ENABLED(CONFIG_XEN_EFI)) {
 241                 if ((of_get_flat_dt_subnode_by_name(node, "uefi") > 0) &&
 242                     !efi_runtime_disabled())
 243                         set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 244         }
 245
 246         return 0;
 247 }
 248
 249 /*
 250  * see Documentation/devicetree/bindings/arm/xen.txt for the
 251  * documentation of the Xen Device Tree format.
 252  */
 253 void __init xen_early_init(void)
 254 {
 255         of_scan_flat_dt(fdt_find_hyper_node, NULL);
 256         if (!hyper_node.found) {
 257                 pr_debug("No Xen support\n");
 258                 return;
 259         }
 260
 261         if (hyper_node.version == NULL) {
 262                 pr_debug("Xen version not found\n");
 263                 return;
 264         }
 265
 266         pr_info("Xen %s support found\n", hyper_node.version);
 267
 268         xen_domain_type = XEN_HVM_DOMAIN;
 269
 270         xen_setup_features();
 271
 272         if (xen_feature(XENFEAT_dom0))
 273                 xen_start_flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
 274
 275         if (!console_set_on_cmdline && !xen_initial_domain())
 276                 add_preferred_console("hvc", 0, NULL);
 277 }
 278
 279 static void __init xen_acpi_guest_init(void)
 280 {
 281 #ifdef CONFIG_ACPI
 282         struct xen_hvm_param a;
 283         int interrupt, trigger, polarity;
 284
 285         a.domid = DOMID_SELF;
 286         a.index = HVM_PARAM_CALLBACK_IRQ;
 287
 288         if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)
 289             || (a.value >> 56) != HVM_PARAM_CALLBACK_TYPE_PPI) {
 290                 xen_events_irq = 0;
 291                 return;
 292         }
 293
 294         interrupt = a.value & 0xff;
 295         trigger = ((a.value >> 8) & 0x1) ? ACPI_EDGE_SENSITIVE
 296                                          : ACPI_LEVEL_SENSITIVE;
 297         polarity = ((a.value >> 8) & 0x2) ? ACPI_ACTIVE_LOW
 298                                           : ACPI_ACTIVE_HIGH;
 299         xen_events_irq = acpi_register_gsi(NULL, interrupt, trigger, polarity);
 300 #endif
 301 }
 302
 303 static void __init xen_dt_guest_init(void)
 304 {
 305         struct device_node *xen_node;
 306
 307         xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
 308         if (!xen_node) {
 309                 pr_err("Xen support was detected before, but it has disappeared\n");
 310                 return;
 311         }
 312
 313         xen_events_irq = irq_of_parse_and_map(xen_node, 0);
 314 }
 315
 316 static int __init xen_guest_init(void)
 317 {
 318         struct xen_add_to_physmap xatp;
 319         struct shared_info *shared_info_page = NULL;
 320         int cpu;
 321
 322         if (!xen_domain())
 323                 return 0;
 324
 325         if (!acpi_disabled)
 326                 xen_acpi_guest_init();
 327         else
 328                 xen_dt_guest_init();
 329
 330         if (!xen_events_irq) {
 331                 pr_err("Xen event channel interrupt not found\n");
 332                 return -ENODEV;
 333         }
 334
 335         /*
 336          * The fdt parsing codes have set EFI_RUNTIME_SERVICES if Xen EFI
 337          * parameters are found. Force enable runtime services.
 338          */
 339         if (efi_enabled(EFI_RUNTIME_SERVICES))
 340                 xen_efi_runtime_setup();
 341
 342         shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
 343
 344         if (!shared_info_page) {
 345                 pr_err("not enough memory\n");
 346                 return -ENOMEM;
 347         }
 348         xatp.domid = DOMID_SELF;
 349         xatp.idx = 0;
 350         xatp.space = XENMAPSPACE_shared_info;
 351         xatp.gpfn = virt_to_gfn(shared_info_page);
 352         if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
 353                 BUG();
 354
 355         HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
 356
 357         /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
 358          * page, we use it in the event channel upcall and in some pvclock
 359          * related functions.
 360          * The shared info contains exactly 1 CPU (the boot CPU). The guest
 361          * is required to use VCPUOP_register_vcpu_info to place vcpu info
 362          * for secondary CPUs as they are brought up.
 363          * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
 364          */
 365         xen_vcpu_info = alloc_percpu(struct vcpu_info);
 366         if (xen_vcpu_info == NULL)
 367                 return -ENOMEM;
 368
 369         /* Direct vCPU id mapping for ARM guests. */
 370         for_each_possible_cpu(cpu)
 371                 per_cpu(xen_vcpu_id, cpu) = cpu;
 372
 373         xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
 374         if (xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
 375                                           &xen_auto_xlat_grant_frames.vaddr,
 376                                           xen_auto_xlat_grant_frames.count)) {
 377                 free_percpu(xen_vcpu_info);
 378                 return -ENOMEM;
 379         }
 380         gnttab_init();
 381
 382         /*
 383          * Making sure board specific code will not set up ops for
 384          * cpu idle and cpu freq.
 385          */
 386         disable_cpuidle();
 387         disable_cpufreq();
 388
 389         xen_init_IRQ();
 390
 391         if (request_percpu_irq(xen_events_irq, xen_arm_callback,
 392                                "events", &xen_vcpu)) {
 393                 pr_err("Error request IRQ %d\n", xen_events_irq);
 394                 return -EINVAL;
 395         }
 396
 397         if (!xen_kernel_unmapped_at_usr())
 398                 xen_time_setup_guest();
 399
 400         if (xen_initial_domain())
 401                 pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
 402
 403         return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING,
 404                                  "arm/xen:starting", xen_starting_cpu,
 405                                  xen_dying_cpu);
 406 }
 407 early_initcall(xen_guest_init);
 408
 409 static int __init xen_pm_init(void)
 410 {
 411         if (!xen_domain())
 412                 return -ENODEV;
 413
 414         pm_power_off = xen_power_off;
 415         register_restart_handler(&xen_restart_nb);
 416         if (!xen_initial_domain()) {
 417                 struct timespec64 ts;
 418                 xen_read_wallclock(&ts);
 419                 do_settimeofday64(&ts);
 420         }
 421
 422         return 0;
 423 }
 424 late_initcall(xen_pm_init);
 425
 426
 427 /* empty stubs */
 428 void xen_arch_pre_suspend(void) { }
 429 void xen_arch_post_suspend(int suspend_cancelled) { }
 430 void xen_timer_resume(void) { }
 431 void xen_arch_resume(void) { }
 432 void xen_arch_suspend(void) { }
 433
 434
 435 /* In the hypercall.S file. */
 436 EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
 437 EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
 438 EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
 439 EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
 440 EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
 441 EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
 442 EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
 443 EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
 444 EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
 445 EXPORT_SYMBOL_GPL(HYPERVISOR_tmem_op);
 446 EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op_raw);
 447 EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
 448 EXPORT_SYMBOL_GPL(HYPERVISOR_vm_assist);
 449 EXPORT_SYMBOL_GPL(HYPERVISOR_dm_op);
 450 EXPORT_SYMBOL_GPL(privcmd_call);