xref: /linux/arch/arm/xen/enlighten.c (revision 63307d015b91e626c97bb82e88054af3d0b74643)
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/xen/xen-ops.h>
19 #include <asm/system_misc.h>
20 #include <asm/efi.h>
21 #include <linux/interrupt.h>
22 #include <linux/irqreturn.h>
23 #include <linux/module.h>
24 #include <linux/of.h>
25 #include <linux/of_fdt.h>
26 #include <linux/of_irq.h>
27 #include <linux/of_address.h>
28 #include <linux/cpuidle.h>
29 #include <linux/cpufreq.h>
30 #include <linux/cpu.h>
31 #include <linux/console.h>
32 #include <linux/pvclock_gtod.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 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 = virt_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 	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 #define GRANT_TABLE_PHYSADDR 0
246 void __init xen_early_init(void)
247 {
248 	of_scan_flat_dt(fdt_find_hyper_node, NULL);
249 	if (!hyper_node.found) {
250 		pr_debug("No Xen support\n");
251 		return;
252 	}
253 
254 	if (hyper_node.version == NULL) {
255 		pr_debug("Xen version not found\n");
256 		return;
257 	}
258 
259 	pr_info("Xen %s support found\n", hyper_node.version);
260 
261 	xen_domain_type = XEN_HVM_DOMAIN;
262 
263 	xen_setup_features();
264 
265 	if (xen_feature(XENFEAT_dom0))
266 		xen_start_flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
267 
268 	if (!console_set_on_cmdline && !xen_initial_domain())
269 		add_preferred_console("hvc", 0, NULL);
270 }
271 
272 static void __init xen_acpi_guest_init(void)
273 {
274 #ifdef CONFIG_ACPI
275 	struct xen_hvm_param a;
276 	int interrupt, trigger, polarity;
277 
278 	a.domid = DOMID_SELF;
279 	a.index = HVM_PARAM_CALLBACK_IRQ;
280 
281 	if (HYPERVISOR_hvm_op(HVMOP_get_param, &a)
282 	    || (a.value >> 56) != HVM_PARAM_CALLBACK_TYPE_PPI) {
283 		xen_events_irq = 0;
284 		return;
285 	}
286 
287 	interrupt = a.value & 0xff;
288 	trigger = ((a.value >> 8) & 0x1) ? ACPI_EDGE_SENSITIVE
289 					 : ACPI_LEVEL_SENSITIVE;
290 	polarity = ((a.value >> 8) & 0x2) ? ACPI_ACTIVE_LOW
291 					  : ACPI_ACTIVE_HIGH;
292 	xen_events_irq = acpi_register_gsi(NULL, interrupt, trigger, polarity);
293 #endif
294 }
295 
296 static void __init xen_dt_guest_init(void)
297 {
298 	struct device_node *xen_node;
299 
300 	xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
301 	if (!xen_node) {
302 		pr_err("Xen support was detected before, but it has disappeared\n");
303 		return;
304 	}
305 
306 	xen_events_irq = irq_of_parse_and_map(xen_node, 0);
307 }
308 
309 static int __init xen_guest_init(void)
310 {
311 	struct xen_add_to_physmap xatp;
312 	struct shared_info *shared_info_page = NULL;
313 	int cpu;
314 
315 	if (!xen_domain())
316 		return 0;
317 
318 	if (!acpi_disabled)
319 		xen_acpi_guest_init();
320 	else
321 		xen_dt_guest_init();
322 
323 	if (!xen_events_irq) {
324 		pr_err("Xen event channel interrupt not found\n");
325 		return -ENODEV;
326 	}
327 
328 	/*
329 	 * The fdt parsing codes have set EFI_RUNTIME_SERVICES if Xen EFI
330 	 * parameters are found. Force enable runtime services.
331 	 */
332 	if (efi_enabled(EFI_RUNTIME_SERVICES))
333 		xen_efi_runtime_setup();
334 
335 	shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
336 
337 	if (!shared_info_page) {
338 		pr_err("not enough memory\n");
339 		return -ENOMEM;
340 	}
341 	xatp.domid = DOMID_SELF;
342 	xatp.idx = 0;
343 	xatp.space = XENMAPSPACE_shared_info;
344 	xatp.gpfn = virt_to_gfn(shared_info_page);
345 	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
346 		BUG();
347 
348 	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
349 
350 	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
351 	 * page, we use it in the event channel upcall and in some pvclock
352 	 * related functions.
353 	 * The shared info contains exactly 1 CPU (the boot CPU). The guest
354 	 * is required to use VCPUOP_register_vcpu_info to place vcpu info
355 	 * for secondary CPUs as they are brought up.
356 	 * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
357 	 */
358 	xen_vcpu_info = alloc_percpu(struct vcpu_info);
359 	if (xen_vcpu_info == NULL)
360 		return -ENOMEM;
361 
362 	/* Direct vCPU id mapping for ARM guests. */
363 	for_each_possible_cpu(cpu)
364 		per_cpu(xen_vcpu_id, cpu) = cpu;
365 
366 	xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
367 	if (xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
368 					  &xen_auto_xlat_grant_frames.vaddr,
369 					  xen_auto_xlat_grant_frames.count)) {
370 		free_percpu(xen_vcpu_info);
371 		return -ENOMEM;
372 	}
373 	gnttab_init();
374 	if (!xen_initial_domain())
375 		xenbus_probe(NULL);
376 
377 	/*
378 	 * Making sure board specific code will not set up ops for
379 	 * cpu idle and cpu freq.
380 	 */
381 	disable_cpuidle();
382 	disable_cpufreq();
383 
384 	xen_init_IRQ();
385 
386 	if (request_percpu_irq(xen_events_irq, xen_arm_callback,
387 			       "events", &xen_vcpu)) {
388 		pr_err("Error request IRQ %d\n", xen_events_irq);
389 		return -EINVAL;
390 	}
391 
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);
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);
445