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 = percpu_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         if (!xen_kernel_unmapped_at_usr())
 162                 xen_setup_runstate_info(cpu);
 163
 164 after_register_vcpu_info:
 165         enable_percpu_irq(xen_events_irq, 0);
 166         return 0;
 167 }
 168
 169 static int xen_dying_cpu(unsigned int cpu)
 170 {
 171         disable_percpu_irq(xen_events_irq);
 172         return 0;
 173 }
 174
 175 void xen_reboot(int reason)
 176 {
 177         struct sched_shutdown r = { .reason = reason };
 178         int rc;
 179
 180         rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
 181         BUG_ON(rc);
 182 }
 183
 184 static void xen_restart(enum reboot_mode reboot_mode, const char *cmd)
 185 {
 186         xen_reboot(SHUTDOWN_reboot);
 187 }
 188
 189
 190 static void xen_power_off(void)
 191 {
 192         xen_reboot(SHUTDOWN_poweroff);
 193 }
 194
 195 static irqreturn_t xen_arm_callback(int irq, void *arg)
 196 {
 197         xen_hvm_evtchn_do_upcall();
 198         return IRQ_HANDLED;
 199 }
 200
 201 static __initdata struct {
 202         const char *compat;
 203         const char *prefix;
 204         const char *version;
 205         bool found;
 206 } hyper_node = {"xen,xen", "xen,xen-", NULL, false};
 207
 208 static int __init fdt_find_hyper_node(unsigned long node, const char *uname,
 209                                       int depth, void *data)
 210 {
 211         const void *s = NULL;
 212         int len;
 213
 214         if (depth != 1 || strcmp(uname, "hypervisor") != 0)
 215                 return 0;
 216
 217         if (of_flat_dt_is_compatible(node, hyper_node.compat))
 218                 hyper_node.found = true;
 219
 220         s = of_get_flat_dt_prop(node, "compatible", &len);
 221         if (strlen(hyper_node.prefix) + 3  < len &&
 222             !strncmp(hyper_node.prefix, s, strlen(hyper_node.prefix)))
 223                 hyper_node.version = s + strlen(hyper_node.prefix);
 224
 225         /*
 226          * Check if Xen supports EFI by checking whether there is the
 227          * "/hypervisor/uefi" node in DT. If so, runtime services are available
 228          * through proxy functions (e.g. in case of Xen dom0 EFI implementation
 229          * they call special hypercall which executes relevant EFI functions)
 230          * and that is why they are always enabled.
 231          */
 232         if (IS_ENABLED(CONFIG_XEN_EFI)) {
 233                 if ((of_get_flat_dt_subnode_by_name(node, "uefi") > 0) &&
 234                     !efi_runtime_disabled())
 235                         set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 236         }
 237
 238         return 0;
 239 }
 240
 241 /*
 242  * see Documentation/devicetree/bindings/arm/xen.txt for the
 243  * documentation of the Xen Device Tree format.
 244  */
 245 void __init xen_early_init(void)
 246 {
 247         of_scan_flat_dt(fdt_find_hyper_node, NULL);
 248         if (!hyper_node.found) {
 249                 pr_debug("No Xen support\n");
 250                 return;
 251         }
 252
 253         if (hyper_node.version == NULL) {
 254                 pr_debug("Xen version not found\n");
 255                 return;
 256         }
 257
 258         pr_info("Xen %s support found\n", hyper_node.version);
 259
 260         xen_domain_type = XEN_HVM_DOMAIN;
 261
 262         xen_setup_features();
 263
 264         if (xen_feature(XENFEAT_dom0))
 265                 xen_start_flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
 266
 267         if (!console_set_on_cmdline && !xen_initial_domain())
 268                 add_preferred_console("hvc", 0, NULL);
 269 }
 270
 271 static void __init xen_acpi_guest_init(void)
 272 {
 273 #ifdef CONFIG_ACPI
 274         struct xen_hvm_param a;
 275         int interrupt, trigger, polarity;
 276
 277         a.domid = DOMID_SELF;
 278         a.index = HVM_PARAM_CALLBACK_IRQ;
 279
 280         if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)
 281             || (a.value >> 56) != HVM_PARAM_CALLBACK_TYPE_PPI) {
 282                 xen_events_irq = 0;
 283                 return;
 284         }
 285
 286         interrupt = a.value & 0xff;
 287         trigger = ((a.value >> 8) & 0x1) ? ACPI_EDGE_SENSITIVE
 288                                          : ACPI_LEVEL_SENSITIVE;
 289         polarity = ((a.value >> 8) & 0x2) ? ACPI_ACTIVE_LOW
 290                                           : ACPI_ACTIVE_HIGH;
 291         xen_events_irq = acpi_register_gsi(NULL, interrupt, trigger, polarity);
 292 #endif
 293 }
 294
 295 static void __init xen_dt_guest_init(void)
 296 {
 297         struct device_node *xen_node;
 298
 299         xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
 300         if (!xen_node) {
 301                 pr_err("Xen support was detected before, but it has disappeared\n");
 302                 return;
 303         }
 304
 305         xen_events_irq = irq_of_parse_and_map(xen_node, 0);
 306 }
 307
 308 static int __init xen_guest_init(void)
 309 {
 310         struct xen_add_to_physmap xatp;
 311         struct shared_info *shared_info_page = NULL;
 312         int cpu;
 313
 314         if (!xen_domain())
 315                 return 0;
 316
 317         if (!acpi_disabled)
 318                 xen_acpi_guest_init();
 319         else
 320                 xen_dt_guest_init();
 321
 322         if (!xen_events_irq) {
 323                 pr_err("Xen event channel interrupt not found\n");
 324                 return -ENODEV;
 325         }
 326
 327         /*
 328          * The fdt parsing codes have set EFI_RUNTIME_SERVICES if Xen EFI
 329          * parameters are found. Force enable runtime services.
 330          */
 331         if (efi_enabled(EFI_RUNTIME_SERVICES))
 332                 xen_efi_runtime_setup();
 333
 334         shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
 335
 336         if (!shared_info_page) {
 337                 pr_err("not enough memory\n");
 338                 return -ENOMEM;
 339         }
 340         xatp.domid = DOMID_SELF;
 341         xatp.idx = 0;
 342         xatp.space = XENMAPSPACE_shared_info;
 343         xatp.gpfn = virt_to_gfn(shared_info_page);
 344         if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
 345                 BUG();
 346
 347         HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
 348
 349         /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
 350          * page, we use it in the event channel upcall and in some pvclock
 351          * related functions.
 352          * The shared info contains exactly 1 CPU (the boot CPU). The guest
 353          * is required to use VCPUOP_register_vcpu_info to place vcpu info
 354          * for secondary CPUs as they are brought up.
 355          * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
 356          */
 357         xen_vcpu_info = alloc_percpu(struct vcpu_info);
 358         if (xen_vcpu_info == NULL)
 359                 return -ENOMEM;
 360
 361         /* Direct vCPU id mapping for ARM guests. */
 362         for_each_possible_cpu(cpu)
 363                 per_cpu(xen_vcpu_id, cpu) = cpu;
 364
 365         xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
 366         if (xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
 367                                           &xen_auto_xlat_grant_frames.vaddr,
 368                                           xen_auto_xlat_grant_frames.count)) {
 369                 free_percpu(xen_vcpu_info);
 370                 return -ENOMEM;
 371         }
 372         gnttab_init();
 373         if (!xen_initial_domain())
 374                 xenbus_probe(NULL);
 375
 376         /*
 377          * Making sure board specific code will not set up ops for
 378          * cpu idle and cpu freq.
 379          */
 380         disable_cpuidle();
 381         disable_cpufreq();
 382
 383         xen_init_IRQ();
 384
 385         if (request_percpu_irq(xen_events_irq, xen_arm_callback,
 386                                "events", &xen_vcpu)) {
 387                 pr_err("Error request IRQ %d\n", xen_events_irq);
 388                 return -EINVAL;
 389         }
 390
 391         if (!xen_kernel_unmapped_at_usr())
 392                 xen_time_setup_guest();
 393
 394         if (xen_initial_domain())
 395                 pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
 396
 397         return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING,
 398                                  "arm/xen:starting", xen_starting_cpu,
 399                                  xen_dying_cpu);
 400 }
 401 early_initcall(xen_guest_init);
 402
 403 static int __init xen_pm_init(void)
 404 {
 405         if (!xen_domain())
 406                 return -ENODEV;
 407
 408         pm_power_off = xen_power_off;
 409         arm_pm_restart = xen_restart;
 410         if (!xen_initial_domain()) {
 411                 struct timespec64 ts;
 412                 xen_read_wallclock(&ts);
 413                 do_settimeofday64(&ts);
 414         }
 415
 416         return 0;
 417 }
 418 late_initcall(xen_pm_init);
 419
 420
 421 /* empty stubs */
 422 void xen_arch_pre_suspend(void) { }
 423 void xen_arch_post_suspend(int suspend_cancelled) { }
 424 void xen_timer_resume(void) { }
 425 void xen_arch_resume(void) { }
 426 void xen_arch_suspend(void) { }
 427
 428
 429 /* In the hypercall.S file. */
 430 EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
 431 EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
 432 EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
 433 EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
 434 EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
 435 EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
 436 EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
 437 EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
 438 EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
 439 EXPORT_SYMBOL_GPL(HYPERVISOR_tmem_op);
 440 EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op_raw);
 441 EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
 442 EXPORT_SYMBOL_GPL(HYPERVISOR_vm_assist);
 443 EXPORT_SYMBOL_GPL(HYPERVISOR_dm_op);
 444 EXPORT_SYMBOL_GPL(privcmd_call);