xref: /openbmc/linux/drivers/xen/sys-hypervisor.c (revision 4ecc96cb)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  copyright (c) 2006 IBM Corporation
4  *  Authored by: Mike D. Day <ncmike@us.ibm.com>
5  */
6 
7 #include <linux/slab.h>
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 #include <linux/kobject.h>
11 #include <linux/err.h>
12 
13 #include <asm/xen/hypervisor.h>
14 #include <asm/xen/hypercall.h>
15 
16 #include <xen/xen.h>
17 #include <xen/xenbus.h>
18 #include <xen/interface/xen.h>
19 #include <xen/interface/version.h>
20 #ifdef CONFIG_XEN_HAVE_VPMU
21 #include <xen/interface/xenpmu.h>
22 #endif
23 
24 #define HYPERVISOR_ATTR_RO(_name) \
25 static struct hyp_sysfs_attr _name##_attr = __ATTR_RO(_name)
26 
27 #define HYPERVISOR_ATTR_RW(_name) \
28 static struct hyp_sysfs_attr _name##_attr = __ATTR_RW(_name)
29 
30 struct hyp_sysfs_attr {
31 	struct attribute attr;
32 	ssize_t (*show)(struct hyp_sysfs_attr *, char *);
33 	ssize_t (*store)(struct hyp_sysfs_attr *, const char *, size_t);
34 	union {
35 		void *hyp_attr_data;
36 		unsigned long hyp_attr_value;
37 	};
38 };
39 
type_show(struct hyp_sysfs_attr * attr,char * buffer)40 static ssize_t type_show(struct hyp_sysfs_attr *attr, char *buffer)
41 {
42 	return sprintf(buffer, "xen\n");
43 }
44 
45 HYPERVISOR_ATTR_RO(type);
46 
xen_sysfs_type_init(void)47 static int __init xen_sysfs_type_init(void)
48 {
49 	return sysfs_create_file(hypervisor_kobj, &type_attr.attr);
50 }
51 
guest_type_show(struct hyp_sysfs_attr * attr,char * buffer)52 static ssize_t guest_type_show(struct hyp_sysfs_attr *attr, char *buffer)
53 {
54 	const char *type;
55 
56 	switch (xen_domain_type) {
57 	case XEN_NATIVE:
58 		/* ARM only. */
59 		type = "Xen";
60 		break;
61 	case XEN_PV_DOMAIN:
62 		type = "PV";
63 		break;
64 	case XEN_HVM_DOMAIN:
65 		type = xen_pvh_domain() ? "PVH" : "HVM";
66 		break;
67 	default:
68 		return -EINVAL;
69 	}
70 
71 	return sprintf(buffer, "%s\n", type);
72 }
73 
74 HYPERVISOR_ATTR_RO(guest_type);
75 
xen_sysfs_guest_type_init(void)76 static int __init xen_sysfs_guest_type_init(void)
77 {
78 	return sysfs_create_file(hypervisor_kobj, &guest_type_attr.attr);
79 }
80 
81 /* xen version attributes */
major_show(struct hyp_sysfs_attr * attr,char * buffer)82 static ssize_t major_show(struct hyp_sysfs_attr *attr, char *buffer)
83 {
84 	int version = HYPERVISOR_xen_version(XENVER_version, NULL);
85 	if (version)
86 		return sprintf(buffer, "%d\n", version >> 16);
87 	return -ENODEV;
88 }
89 
90 HYPERVISOR_ATTR_RO(major);
91 
minor_show(struct hyp_sysfs_attr * attr,char * buffer)92 static ssize_t minor_show(struct hyp_sysfs_attr *attr, char *buffer)
93 {
94 	int version = HYPERVISOR_xen_version(XENVER_version, NULL);
95 	if (version)
96 		return sprintf(buffer, "%d\n", version & 0xff);
97 	return -ENODEV;
98 }
99 
100 HYPERVISOR_ATTR_RO(minor);
101 
extra_show(struct hyp_sysfs_attr * attr,char * buffer)102 static ssize_t extra_show(struct hyp_sysfs_attr *attr, char *buffer)
103 {
104 	int ret = -ENOMEM;
105 	char *extra;
106 
107 	extra = kmalloc(XEN_EXTRAVERSION_LEN, GFP_KERNEL);
108 	if (extra) {
109 		ret = HYPERVISOR_xen_version(XENVER_extraversion, extra);
110 		if (!ret)
111 			ret = sprintf(buffer, "%s\n", extra);
112 		kfree(extra);
113 	}
114 
115 	return ret;
116 }
117 
118 HYPERVISOR_ATTR_RO(extra);
119 
120 static struct attribute *version_attrs[] = {
121 	&major_attr.attr,
122 	&minor_attr.attr,
123 	&extra_attr.attr,
124 	NULL
125 };
126 
127 static const struct attribute_group version_group = {
128 	.name = "version",
129 	.attrs = version_attrs,
130 };
131 
xen_sysfs_version_init(void)132 static int __init xen_sysfs_version_init(void)
133 {
134 	return sysfs_create_group(hypervisor_kobj, &version_group);
135 }
136 
137 /* UUID */
138 
uuid_show_fallback(struct hyp_sysfs_attr * attr,char * buffer)139 static ssize_t uuid_show_fallback(struct hyp_sysfs_attr *attr, char *buffer)
140 {
141 	char *vm, *val;
142 	int ret;
143 	extern int xenstored_ready;
144 
145 	if (!xenstored_ready)
146 		return -EBUSY;
147 
148 	vm = xenbus_read(XBT_NIL, "vm", "", NULL);
149 	if (IS_ERR(vm))
150 		return PTR_ERR(vm);
151 	val = xenbus_read(XBT_NIL, vm, "uuid", NULL);
152 	kfree(vm);
153 	if (IS_ERR(val))
154 		return PTR_ERR(val);
155 	ret = sprintf(buffer, "%s\n", val);
156 	kfree(val);
157 	return ret;
158 }
159 
uuid_show(struct hyp_sysfs_attr * attr,char * buffer)160 static ssize_t uuid_show(struct hyp_sysfs_attr *attr, char *buffer)
161 {
162 	xen_domain_handle_t uuid;
163 	int ret;
164 	ret = HYPERVISOR_xen_version(XENVER_guest_handle, uuid);
165 	if (ret)
166 		return uuid_show_fallback(attr, buffer);
167 	ret = sprintf(buffer, "%pU\n", uuid);
168 	return ret;
169 }
170 
171 HYPERVISOR_ATTR_RO(uuid);
172 
xen_sysfs_uuid_init(void)173 static int __init xen_sysfs_uuid_init(void)
174 {
175 	return sysfs_create_file(hypervisor_kobj, &uuid_attr.attr);
176 }
177 
178 /* xen compilation attributes */
179 
compiler_show(struct hyp_sysfs_attr * attr,char * buffer)180 static ssize_t compiler_show(struct hyp_sysfs_attr *attr, char *buffer)
181 {
182 	int ret = -ENOMEM;
183 	struct xen_compile_info *info;
184 
185 	info = kmalloc(sizeof(struct xen_compile_info), GFP_KERNEL);
186 	if (info) {
187 		ret = HYPERVISOR_xen_version(XENVER_compile_info, info);
188 		if (!ret)
189 			ret = sprintf(buffer, "%s\n", info->compiler);
190 		kfree(info);
191 	}
192 
193 	return ret;
194 }
195 
196 HYPERVISOR_ATTR_RO(compiler);
197 
compiled_by_show(struct hyp_sysfs_attr * attr,char * buffer)198 static ssize_t compiled_by_show(struct hyp_sysfs_attr *attr, char *buffer)
199 {
200 	int ret = -ENOMEM;
201 	struct xen_compile_info *info;
202 
203 	info = kmalloc(sizeof(struct xen_compile_info), GFP_KERNEL);
204 	if (info) {
205 		ret = HYPERVISOR_xen_version(XENVER_compile_info, info);
206 		if (!ret)
207 			ret = sprintf(buffer, "%s\n", info->compile_by);
208 		kfree(info);
209 	}
210 
211 	return ret;
212 }
213 
214 HYPERVISOR_ATTR_RO(compiled_by);
215 
compile_date_show(struct hyp_sysfs_attr * attr,char * buffer)216 static ssize_t compile_date_show(struct hyp_sysfs_attr *attr, char *buffer)
217 {
218 	int ret = -ENOMEM;
219 	struct xen_compile_info *info;
220 
221 	info = kmalloc(sizeof(struct xen_compile_info), GFP_KERNEL);
222 	if (info) {
223 		ret = HYPERVISOR_xen_version(XENVER_compile_info, info);
224 		if (!ret)
225 			ret = sprintf(buffer, "%s\n", info->compile_date);
226 		kfree(info);
227 	}
228 
229 	return ret;
230 }
231 
232 HYPERVISOR_ATTR_RO(compile_date);
233 
234 static struct attribute *xen_compile_attrs[] = {
235 	&compiler_attr.attr,
236 	&compiled_by_attr.attr,
237 	&compile_date_attr.attr,
238 	NULL
239 };
240 
241 static const struct attribute_group xen_compilation_group = {
242 	.name = "compilation",
243 	.attrs = xen_compile_attrs,
244 };
245 
xen_sysfs_compilation_init(void)246 static int __init xen_sysfs_compilation_init(void)
247 {
248 	return sysfs_create_group(hypervisor_kobj, &xen_compilation_group);
249 }
250 
251 /* xen properties info */
252 
capabilities_show(struct hyp_sysfs_attr * attr,char * buffer)253 static ssize_t capabilities_show(struct hyp_sysfs_attr *attr, char *buffer)
254 {
255 	int ret = -ENOMEM;
256 	char *caps;
257 
258 	caps = kmalloc(XEN_CAPABILITIES_INFO_LEN, GFP_KERNEL);
259 	if (caps) {
260 		ret = HYPERVISOR_xen_version(XENVER_capabilities, caps);
261 		if (!ret)
262 			ret = sprintf(buffer, "%s\n", caps);
263 		kfree(caps);
264 	}
265 
266 	return ret;
267 }
268 
269 HYPERVISOR_ATTR_RO(capabilities);
270 
changeset_show(struct hyp_sysfs_attr * attr,char * buffer)271 static ssize_t changeset_show(struct hyp_sysfs_attr *attr, char *buffer)
272 {
273 	int ret = -ENOMEM;
274 	char *cset;
275 
276 	cset = kmalloc(XEN_CHANGESET_INFO_LEN, GFP_KERNEL);
277 	if (cset) {
278 		ret = HYPERVISOR_xen_version(XENVER_changeset, cset);
279 		if (!ret)
280 			ret = sprintf(buffer, "%s\n", cset);
281 		kfree(cset);
282 	}
283 
284 	return ret;
285 }
286 
287 HYPERVISOR_ATTR_RO(changeset);
288 
virtual_start_show(struct hyp_sysfs_attr * attr,char * buffer)289 static ssize_t virtual_start_show(struct hyp_sysfs_attr *attr, char *buffer)
290 {
291 	int ret = -ENOMEM;
292 	struct xen_platform_parameters *parms;
293 
294 	parms = kmalloc(sizeof(struct xen_platform_parameters), GFP_KERNEL);
295 	if (parms) {
296 		ret = HYPERVISOR_xen_version(XENVER_platform_parameters,
297 					     parms);
298 		if (!ret)
299 			ret = sprintf(buffer, "%"PRI_xen_ulong"\n",
300 				      parms->virt_start);
301 		kfree(parms);
302 	}
303 
304 	return ret;
305 }
306 
307 HYPERVISOR_ATTR_RO(virtual_start);
308 
pagesize_show(struct hyp_sysfs_attr * attr,char * buffer)309 static ssize_t pagesize_show(struct hyp_sysfs_attr *attr, char *buffer)
310 {
311 	int ret;
312 
313 	ret = HYPERVISOR_xen_version(XENVER_pagesize, NULL);
314 	if (ret > 0)
315 		ret = sprintf(buffer, "%x\n", ret);
316 
317 	return ret;
318 }
319 
320 HYPERVISOR_ATTR_RO(pagesize);
321 
xen_feature_show(int index,char * buffer)322 static ssize_t xen_feature_show(int index, char *buffer)
323 {
324 	ssize_t ret;
325 	struct xen_feature_info info;
326 
327 	info.submap_idx = index;
328 	ret = HYPERVISOR_xen_version(XENVER_get_features, &info);
329 	if (!ret)
330 		ret = sprintf(buffer, "%08x", info.submap);
331 
332 	return ret;
333 }
334 
features_show(struct hyp_sysfs_attr * attr,char * buffer)335 static ssize_t features_show(struct hyp_sysfs_attr *attr, char *buffer)
336 {
337 	ssize_t len;
338 	int i;
339 
340 	len = 0;
341 	for (i = XENFEAT_NR_SUBMAPS-1; i >= 0; i--) {
342 		int ret = xen_feature_show(i, buffer + len);
343 		if (ret < 0) {
344 			if (len == 0)
345 				len = ret;
346 			break;
347 		}
348 		len += ret;
349 	}
350 	if (len > 0)
351 		buffer[len++] = '\n';
352 
353 	return len;
354 }
355 
356 HYPERVISOR_ATTR_RO(features);
357 
buildid_show(struct hyp_sysfs_attr * attr,char * buffer)358 static ssize_t buildid_show(struct hyp_sysfs_attr *attr, char *buffer)
359 {
360 	ssize_t ret;
361 	struct xen_build_id *buildid;
362 
363 	ret = HYPERVISOR_xen_version(XENVER_build_id, NULL);
364 	if (ret < 0) {
365 		if (ret == -EPERM)
366 			ret = sprintf(buffer, "<denied>");
367 		return ret;
368 	}
369 
370 	buildid = kmalloc(sizeof(*buildid) + ret, GFP_KERNEL);
371 	if (!buildid)
372 		return -ENOMEM;
373 
374 	buildid->len = ret;
375 	ret = HYPERVISOR_xen_version(XENVER_build_id, buildid);
376 	if (ret > 0)
377 		ret = sprintf(buffer, "%s", buildid->buf);
378 	kfree(buildid);
379 
380 	return ret;
381 }
382 
383 HYPERVISOR_ATTR_RO(buildid);
384 
385 static struct attribute *xen_properties_attrs[] = {
386 	&capabilities_attr.attr,
387 	&changeset_attr.attr,
388 	&virtual_start_attr.attr,
389 	&pagesize_attr.attr,
390 	&features_attr.attr,
391 	&buildid_attr.attr,
392 	NULL
393 };
394 
395 static const struct attribute_group xen_properties_group = {
396 	.name = "properties",
397 	.attrs = xen_properties_attrs,
398 };
399 
xen_sysfs_properties_init(void)400 static int __init xen_sysfs_properties_init(void)
401 {
402 	return sysfs_create_group(hypervisor_kobj, &xen_properties_group);
403 }
404 
405 #define FLAG_UNAME "unknown"
406 #define FLAG_UNAME_FMT FLAG_UNAME "%02u"
407 #define FLAG_UNAME_MAX sizeof(FLAG_UNAME "XX")
408 #define FLAG_COUNT (sizeof(xen_start_flags) * BITS_PER_BYTE)
409 static_assert(sizeof(xen_start_flags) <=
410 	      sizeof_field(struct hyp_sysfs_attr, hyp_attr_value));
411 
flag_show(struct hyp_sysfs_attr * attr,char * buffer)412 static ssize_t flag_show(struct hyp_sysfs_attr *attr, char *buffer)
413 {
414 	char *p = buffer;
415 
416 	*p++ = '0' + ((xen_start_flags & attr->hyp_attr_value) != 0);
417 	*p++ = '\n';
418 	return p - buffer;
419 }
420 
421 #define FLAG_NODE(flag, node)				\
422 	[ilog2(flag)] = {				\
423 		.attr = { .name = #node, .mode = 0444 },\
424 		.show = flag_show,			\
425 		.hyp_attr_value = flag			\
426 	}
427 
428 /*
429  * Add new, known flags here.  No other changes are required, but
430  * note that each known flag wastes one entry in flag_unames[].
431  * The code/complexity machinations to avoid this isn't worth it
432  * for a few entries, but keep it in mind.
433  */
434 static struct hyp_sysfs_attr flag_attrs[FLAG_COUNT] = {
435 	FLAG_NODE(SIF_PRIVILEGED, privileged),
436 	FLAG_NODE(SIF_INITDOMAIN, initdomain)
437 };
438 static struct attribute_group xen_flags_group = {
439 	.name = "start_flags",
440 	.attrs = (struct attribute *[FLAG_COUNT + 1]){}
441 };
442 static char flag_unames[FLAG_COUNT][FLAG_UNAME_MAX];
443 
xen_sysfs_flags_init(void)444 static int __init xen_sysfs_flags_init(void)
445 {
446 	for (unsigned fnum = 0; fnum != FLAG_COUNT; fnum++) {
447 		if (likely(flag_attrs[fnum].attr.name == NULL)) {
448 			sprintf(flag_unames[fnum], FLAG_UNAME_FMT, fnum);
449 			flag_attrs[fnum].attr.name = flag_unames[fnum];
450 			flag_attrs[fnum].attr.mode = 0444;
451 			flag_attrs[fnum].show = flag_show;
452 			flag_attrs[fnum].hyp_attr_value = 1 << fnum;
453 		}
454 		xen_flags_group.attrs[fnum] = &flag_attrs[fnum].attr;
455 	}
456 	return sysfs_create_group(hypervisor_kobj, &xen_flags_group);
457 }
458 
459 #ifdef CONFIG_XEN_HAVE_VPMU
460 struct pmu_mode {
461 	const char *name;
462 	uint32_t mode;
463 };
464 
465 static struct pmu_mode pmu_modes[] = {
466 	{"off", XENPMU_MODE_OFF},
467 	{"self", XENPMU_MODE_SELF},
468 	{"hv", XENPMU_MODE_HV},
469 	{"all", XENPMU_MODE_ALL}
470 };
471 
pmu_mode_store(struct hyp_sysfs_attr * attr,const char * buffer,size_t len)472 static ssize_t pmu_mode_store(struct hyp_sysfs_attr *attr,
473 			      const char *buffer, size_t len)
474 {
475 	int ret;
476 	struct xen_pmu_params xp;
477 	int i;
478 
479 	for (i = 0; i < ARRAY_SIZE(pmu_modes); i++) {
480 		if (strncmp(buffer, pmu_modes[i].name, len - 1) == 0) {
481 			xp.val = pmu_modes[i].mode;
482 			break;
483 		}
484 	}
485 
486 	if (i == ARRAY_SIZE(pmu_modes))
487 		return -EINVAL;
488 
489 	xp.version.maj = XENPMU_VER_MAJ;
490 	xp.version.min = XENPMU_VER_MIN;
491 	ret = HYPERVISOR_xenpmu_op(XENPMU_mode_set, &xp);
492 	if (ret)
493 		return ret;
494 
495 	return len;
496 }
497 
pmu_mode_show(struct hyp_sysfs_attr * attr,char * buffer)498 static ssize_t pmu_mode_show(struct hyp_sysfs_attr *attr, char *buffer)
499 {
500 	int ret;
501 	struct xen_pmu_params xp;
502 	int i;
503 	uint32_t mode;
504 
505 	xp.version.maj = XENPMU_VER_MAJ;
506 	xp.version.min = XENPMU_VER_MIN;
507 	ret = HYPERVISOR_xenpmu_op(XENPMU_mode_get, &xp);
508 	if (ret)
509 		return ret;
510 
511 	mode = (uint32_t)xp.val;
512 	for (i = 0; i < ARRAY_SIZE(pmu_modes); i++) {
513 		if (mode == pmu_modes[i].mode)
514 			return sprintf(buffer, "%s\n", pmu_modes[i].name);
515 	}
516 
517 	return -EINVAL;
518 }
519 HYPERVISOR_ATTR_RW(pmu_mode);
520 
pmu_features_store(struct hyp_sysfs_attr * attr,const char * buffer,size_t len)521 static ssize_t pmu_features_store(struct hyp_sysfs_attr *attr,
522 				  const char *buffer, size_t len)
523 {
524 	int ret;
525 	uint32_t features;
526 	struct xen_pmu_params xp;
527 
528 	ret = kstrtou32(buffer, 0, &features);
529 	if (ret)
530 		return ret;
531 
532 	xp.val = features;
533 	xp.version.maj = XENPMU_VER_MAJ;
534 	xp.version.min = XENPMU_VER_MIN;
535 	ret = HYPERVISOR_xenpmu_op(XENPMU_feature_set, &xp);
536 	if (ret)
537 		return ret;
538 
539 	return len;
540 }
541 
pmu_features_show(struct hyp_sysfs_attr * attr,char * buffer)542 static ssize_t pmu_features_show(struct hyp_sysfs_attr *attr, char *buffer)
543 {
544 	int ret;
545 	struct xen_pmu_params xp;
546 
547 	xp.version.maj = XENPMU_VER_MAJ;
548 	xp.version.min = XENPMU_VER_MIN;
549 	ret = HYPERVISOR_xenpmu_op(XENPMU_feature_get, &xp);
550 	if (ret)
551 		return ret;
552 
553 	return sprintf(buffer, "0x%x\n", (uint32_t)xp.val);
554 }
555 HYPERVISOR_ATTR_RW(pmu_features);
556 
557 static struct attribute *xen_pmu_attrs[] = {
558 	&pmu_mode_attr.attr,
559 	&pmu_features_attr.attr,
560 	NULL
561 };
562 
563 static const struct attribute_group xen_pmu_group = {
564 	.name = "pmu",
565 	.attrs = xen_pmu_attrs,
566 };
567 
xen_sysfs_pmu_init(void)568 static int __init xen_sysfs_pmu_init(void)
569 {
570 	return sysfs_create_group(hypervisor_kobj, &xen_pmu_group);
571 }
572 #endif
573 
hyper_sysfs_init(void)574 static int __init hyper_sysfs_init(void)
575 {
576 	int ret;
577 
578 	if (!xen_domain())
579 		return -ENODEV;
580 
581 	ret = xen_sysfs_type_init();
582 	if (ret)
583 		goto out;
584 	ret = xen_sysfs_guest_type_init();
585 	if (ret)
586 		goto guest_type_out;
587 	ret = xen_sysfs_version_init();
588 	if (ret)
589 		goto version_out;
590 	ret = xen_sysfs_compilation_init();
591 	if (ret)
592 		goto comp_out;
593 	ret = xen_sysfs_uuid_init();
594 	if (ret)
595 		goto uuid_out;
596 	ret = xen_sysfs_properties_init();
597 	if (ret)
598 		goto prop_out;
599 	ret = xen_sysfs_flags_init();
600 	if (ret)
601 		goto flags_out;
602 #ifdef CONFIG_XEN_HAVE_VPMU
603 	if (xen_initial_domain()) {
604 		ret = xen_sysfs_pmu_init();
605 		if (ret) {
606 			sysfs_remove_group(hypervisor_kobj, &xen_flags_group);
607 			goto flags_out;
608 		}
609 	}
610 #endif
611 	goto out;
612 
613 flags_out:
614 	sysfs_remove_group(hypervisor_kobj, &xen_properties_group);
615 prop_out:
616 	sysfs_remove_file(hypervisor_kobj, &uuid_attr.attr);
617 uuid_out:
618 	sysfs_remove_group(hypervisor_kobj, &xen_compilation_group);
619 comp_out:
620 	sysfs_remove_group(hypervisor_kobj, &version_group);
621 version_out:
622 	sysfs_remove_file(hypervisor_kobj, &guest_type_attr.attr);
623 guest_type_out:
624 	sysfs_remove_file(hypervisor_kobj, &type_attr.attr);
625 out:
626 	return ret;
627 }
628 device_initcall(hyper_sysfs_init);
629 
hyp_sysfs_show(struct kobject * kobj,struct attribute * attr,char * buffer)630 static ssize_t hyp_sysfs_show(struct kobject *kobj,
631 			      struct attribute *attr,
632 			      char *buffer)
633 {
634 	struct hyp_sysfs_attr *hyp_attr;
635 	hyp_attr = container_of(attr, struct hyp_sysfs_attr, attr);
636 	if (hyp_attr->show)
637 		return hyp_attr->show(hyp_attr, buffer);
638 	return 0;
639 }
640 
hyp_sysfs_store(struct kobject * kobj,struct attribute * attr,const char * buffer,size_t len)641 static ssize_t hyp_sysfs_store(struct kobject *kobj,
642 			       struct attribute *attr,
643 			       const char *buffer,
644 			       size_t len)
645 {
646 	struct hyp_sysfs_attr *hyp_attr;
647 	hyp_attr = container_of(attr, struct hyp_sysfs_attr, attr);
648 	if (hyp_attr->store)
649 		return hyp_attr->store(hyp_attr, buffer, len);
650 	return 0;
651 }
652 
653 static const struct sysfs_ops hyp_sysfs_ops = {
654 	.show = hyp_sysfs_show,
655 	.store = hyp_sysfs_store,
656 };
657 
658 static const struct kobj_type hyp_sysfs_kobj_type = {
659 	.sysfs_ops = &hyp_sysfs_ops,
660 };
661 
hypervisor_subsys_init(void)662 static int __init hypervisor_subsys_init(void)
663 {
664 	if (!xen_domain())
665 		return -ENODEV;
666 
667 	hypervisor_kobj->ktype = &hyp_sysfs_kobj_type;
668 	return 0;
669 }
670 device_initcall(hypervisor_subsys_init);
671