xref: /openbmc/linux/arch/x86/kvm/hyperv.c (revision 5974565bc26d6a599189db7c0b1f79eaa9af8eb9)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * KVM Microsoft Hyper-V emulation
4  *
5  * derived from arch/x86/kvm/x86.c
6  *
7  * Copyright (C) 2006 Qumranet, Inc.
8  * Copyright (C) 2008 Qumranet, Inc.
9  * Copyright IBM Corporation, 2008
10  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
11  * Copyright (C) 2015 Andrey Smetanin <asmetanin@virtuozzo.com>
12  *
13  * Authors:
14  *   Avi Kivity   <avi@qumranet.com>
15  *   Yaniv Kamay  <yaniv@qumranet.com>
16  *   Amit Shah    <amit.shah@qumranet.com>
17  *   Ben-Ami Yassour <benami@il.ibm.com>
18  *   Andrey Smetanin <asmetanin@virtuozzo.com>
19  */
20 
21 #include "x86.h"
22 #include "lapic.h"
23 #include "ioapic.h"
24 #include "cpuid.h"
25 #include "hyperv.h"
26 #include "xen.h"
27 
28 #include <linux/cpu.h>
29 #include <linux/kvm_host.h>
30 #include <linux/highmem.h>
31 #include <linux/sched/cputime.h>
32 #include <linux/eventfd.h>
33 
34 #include <asm/apicdef.h>
35 #include <trace/events/kvm.h>
36 
37 #include "trace.h"
38 #include "irq.h"
39 #include "fpu.h"
40 
41 /* "Hv#1" signature */
42 #define HYPERV_CPUID_SIGNATURE_EAX 0x31237648
43 
44 #define KVM_HV_MAX_SPARSE_VCPU_SET_BITS DIV_ROUND_UP(KVM_MAX_VCPUS, 64)
45 
46 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
47 				bool vcpu_kick);
48 
49 static inline u64 synic_read_sint(struct kvm_vcpu_hv_synic *synic, int sint)
50 {
51 	return atomic64_read(&synic->sint[sint]);
52 }
53 
54 static inline int synic_get_sint_vector(u64 sint_value)
55 {
56 	if (sint_value & HV_SYNIC_SINT_MASKED)
57 		return -1;
58 	return sint_value & HV_SYNIC_SINT_VECTOR_MASK;
59 }
60 
61 static bool synic_has_vector_connected(struct kvm_vcpu_hv_synic *synic,
62 				      int vector)
63 {
64 	int i;
65 
66 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
67 		if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
68 			return true;
69 	}
70 	return false;
71 }
72 
73 static bool synic_has_vector_auto_eoi(struct kvm_vcpu_hv_synic *synic,
74 				     int vector)
75 {
76 	int i;
77 	u64 sint_value;
78 
79 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
80 		sint_value = synic_read_sint(synic, i);
81 		if (synic_get_sint_vector(sint_value) == vector &&
82 		    sint_value & HV_SYNIC_SINT_AUTO_EOI)
83 			return true;
84 	}
85 	return false;
86 }
87 
88 static void synic_update_vector(struct kvm_vcpu_hv_synic *synic,
89 				int vector)
90 {
91 	if (vector < HV_SYNIC_FIRST_VALID_VECTOR)
92 		return;
93 
94 	if (synic_has_vector_connected(synic, vector))
95 		__set_bit(vector, synic->vec_bitmap);
96 	else
97 		__clear_bit(vector, synic->vec_bitmap);
98 
99 	if (synic_has_vector_auto_eoi(synic, vector))
100 		__set_bit(vector, synic->auto_eoi_bitmap);
101 	else
102 		__clear_bit(vector, synic->auto_eoi_bitmap);
103 }
104 
105 static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint,
106 			  u64 data, bool host)
107 {
108 	int vector, old_vector;
109 	bool masked;
110 
111 	vector = data & HV_SYNIC_SINT_VECTOR_MASK;
112 	masked = data & HV_SYNIC_SINT_MASKED;
113 
114 	/*
115 	 * Valid vectors are 16-255, however, nested Hyper-V attempts to write
116 	 * default '0x10000' value on boot and this should not #GP. We need to
117 	 * allow zero-initing the register from host as well.
118 	 */
119 	if (vector < HV_SYNIC_FIRST_VALID_VECTOR && !host && !masked)
120 		return 1;
121 	/*
122 	 * Guest may configure multiple SINTs to use the same vector, so
123 	 * we maintain a bitmap of vectors handled by synic, and a
124 	 * bitmap of vectors with auto-eoi behavior.  The bitmaps are
125 	 * updated here, and atomically queried on fast paths.
126 	 */
127 	old_vector = synic_read_sint(synic, sint) & HV_SYNIC_SINT_VECTOR_MASK;
128 
129 	atomic64_set(&synic->sint[sint], data);
130 
131 	synic_update_vector(synic, old_vector);
132 
133 	synic_update_vector(synic, vector);
134 
135 	/* Load SynIC vectors into EOI exit bitmap */
136 	kvm_make_request(KVM_REQ_SCAN_IOAPIC, hv_synic_to_vcpu(synic));
137 	return 0;
138 }
139 
140 static struct kvm_vcpu *get_vcpu_by_vpidx(struct kvm *kvm, u32 vpidx)
141 {
142 	struct kvm_vcpu *vcpu = NULL;
143 	int i;
144 
145 	if (vpidx >= KVM_MAX_VCPUS)
146 		return NULL;
147 
148 	vcpu = kvm_get_vcpu(kvm, vpidx);
149 	if (vcpu && kvm_hv_get_vpindex(vcpu) == vpidx)
150 		return vcpu;
151 	kvm_for_each_vcpu(i, vcpu, kvm)
152 		if (kvm_hv_get_vpindex(vcpu) == vpidx)
153 			return vcpu;
154 	return NULL;
155 }
156 
157 static struct kvm_vcpu_hv_synic *synic_get(struct kvm *kvm, u32 vpidx)
158 {
159 	struct kvm_vcpu *vcpu;
160 	struct kvm_vcpu_hv_synic *synic;
161 
162 	vcpu = get_vcpu_by_vpidx(kvm, vpidx);
163 	if (!vcpu || !to_hv_vcpu(vcpu))
164 		return NULL;
165 	synic = to_hv_synic(vcpu);
166 	return (synic->active) ? synic : NULL;
167 }
168 
169 static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
170 {
171 	struct kvm *kvm = vcpu->kvm;
172 	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
173 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
174 	struct kvm_vcpu_hv_stimer *stimer;
175 	int gsi, idx;
176 
177 	trace_kvm_hv_notify_acked_sint(vcpu->vcpu_id, sint);
178 
179 	/* Try to deliver pending Hyper-V SynIC timers messages */
180 	for (idx = 0; idx < ARRAY_SIZE(hv_vcpu->stimer); idx++) {
181 		stimer = &hv_vcpu->stimer[idx];
182 		if (stimer->msg_pending && stimer->config.enable &&
183 		    !stimer->config.direct_mode &&
184 		    stimer->config.sintx == sint)
185 			stimer_mark_pending(stimer, false);
186 	}
187 
188 	idx = srcu_read_lock(&kvm->irq_srcu);
189 	gsi = atomic_read(&synic->sint_to_gsi[sint]);
190 	if (gsi != -1)
191 		kvm_notify_acked_gsi(kvm, gsi);
192 	srcu_read_unlock(&kvm->irq_srcu, idx);
193 }
194 
195 static void synic_exit(struct kvm_vcpu_hv_synic *synic, u32 msr)
196 {
197 	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
198 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
199 
200 	hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNIC;
201 	hv_vcpu->exit.u.synic.msr = msr;
202 	hv_vcpu->exit.u.synic.control = synic->control;
203 	hv_vcpu->exit.u.synic.evt_page = synic->evt_page;
204 	hv_vcpu->exit.u.synic.msg_page = synic->msg_page;
205 
206 	kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
207 }
208 
209 static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
210 			 u32 msr, u64 data, bool host)
211 {
212 	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
213 	int ret;
214 
215 	if (!synic->active && !host)
216 		return 1;
217 
218 	trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host);
219 
220 	ret = 0;
221 	switch (msr) {
222 	case HV_X64_MSR_SCONTROL:
223 		synic->control = data;
224 		if (!host)
225 			synic_exit(synic, msr);
226 		break;
227 	case HV_X64_MSR_SVERSION:
228 		if (!host) {
229 			ret = 1;
230 			break;
231 		}
232 		synic->version = data;
233 		break;
234 	case HV_X64_MSR_SIEFP:
235 		if ((data & HV_SYNIC_SIEFP_ENABLE) && !host &&
236 		    !synic->dont_zero_synic_pages)
237 			if (kvm_clear_guest(vcpu->kvm,
238 					    data & PAGE_MASK, PAGE_SIZE)) {
239 				ret = 1;
240 				break;
241 			}
242 		synic->evt_page = data;
243 		if (!host)
244 			synic_exit(synic, msr);
245 		break;
246 	case HV_X64_MSR_SIMP:
247 		if ((data & HV_SYNIC_SIMP_ENABLE) && !host &&
248 		    !synic->dont_zero_synic_pages)
249 			if (kvm_clear_guest(vcpu->kvm,
250 					    data & PAGE_MASK, PAGE_SIZE)) {
251 				ret = 1;
252 				break;
253 			}
254 		synic->msg_page = data;
255 		if (!host)
256 			synic_exit(synic, msr);
257 		break;
258 	case HV_X64_MSR_EOM: {
259 		int i;
260 
261 		for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
262 			kvm_hv_notify_acked_sint(vcpu, i);
263 		break;
264 	}
265 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
266 		ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data, host);
267 		break;
268 	default:
269 		ret = 1;
270 		break;
271 	}
272 	return ret;
273 }
274 
275 static bool kvm_hv_is_syndbg_enabled(struct kvm_vcpu *vcpu)
276 {
277 	struct kvm_cpuid_entry2 *entry;
278 
279 	entry = kvm_find_cpuid_entry(vcpu,
280 				     HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES,
281 				     0);
282 	if (!entry)
283 		return false;
284 
285 	return entry->eax & HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
286 }
287 
288 static int kvm_hv_syndbg_complete_userspace(struct kvm_vcpu *vcpu)
289 {
290 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
291 
292 	if (vcpu->run->hyperv.u.syndbg.msr == HV_X64_MSR_SYNDBG_CONTROL)
293 		hv->hv_syndbg.control.status =
294 			vcpu->run->hyperv.u.syndbg.status;
295 	return 1;
296 }
297 
298 static void syndbg_exit(struct kvm_vcpu *vcpu, u32 msr)
299 {
300 	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
301 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
302 
303 	hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNDBG;
304 	hv_vcpu->exit.u.syndbg.msr = msr;
305 	hv_vcpu->exit.u.syndbg.control = syndbg->control.control;
306 	hv_vcpu->exit.u.syndbg.send_page = syndbg->control.send_page;
307 	hv_vcpu->exit.u.syndbg.recv_page = syndbg->control.recv_page;
308 	hv_vcpu->exit.u.syndbg.pending_page = syndbg->control.pending_page;
309 	vcpu->arch.complete_userspace_io =
310 			kvm_hv_syndbg_complete_userspace;
311 
312 	kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
313 }
314 
315 static int syndbg_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
316 {
317 	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
318 
319 	if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
320 		return 1;
321 
322 	trace_kvm_hv_syndbg_set_msr(vcpu->vcpu_id,
323 				    to_hv_vcpu(vcpu)->vp_index, msr, data);
324 	switch (msr) {
325 	case HV_X64_MSR_SYNDBG_CONTROL:
326 		syndbg->control.control = data;
327 		if (!host)
328 			syndbg_exit(vcpu, msr);
329 		break;
330 	case HV_X64_MSR_SYNDBG_STATUS:
331 		syndbg->control.status = data;
332 		break;
333 	case HV_X64_MSR_SYNDBG_SEND_BUFFER:
334 		syndbg->control.send_page = data;
335 		break;
336 	case HV_X64_MSR_SYNDBG_RECV_BUFFER:
337 		syndbg->control.recv_page = data;
338 		break;
339 	case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
340 		syndbg->control.pending_page = data;
341 		if (!host)
342 			syndbg_exit(vcpu, msr);
343 		break;
344 	case HV_X64_MSR_SYNDBG_OPTIONS:
345 		syndbg->options = data;
346 		break;
347 	default:
348 		break;
349 	}
350 
351 	return 0;
352 }
353 
354 static int syndbg_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
355 {
356 	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
357 
358 	if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
359 		return 1;
360 
361 	switch (msr) {
362 	case HV_X64_MSR_SYNDBG_CONTROL:
363 		*pdata = syndbg->control.control;
364 		break;
365 	case HV_X64_MSR_SYNDBG_STATUS:
366 		*pdata = syndbg->control.status;
367 		break;
368 	case HV_X64_MSR_SYNDBG_SEND_BUFFER:
369 		*pdata = syndbg->control.send_page;
370 		break;
371 	case HV_X64_MSR_SYNDBG_RECV_BUFFER:
372 		*pdata = syndbg->control.recv_page;
373 		break;
374 	case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
375 		*pdata = syndbg->control.pending_page;
376 		break;
377 	case HV_X64_MSR_SYNDBG_OPTIONS:
378 		*pdata = syndbg->options;
379 		break;
380 	default:
381 		break;
382 	}
383 
384 	trace_kvm_hv_syndbg_get_msr(vcpu->vcpu_id, kvm_hv_get_vpindex(vcpu), msr, *pdata);
385 
386 	return 0;
387 }
388 
389 static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata,
390 			 bool host)
391 {
392 	int ret;
393 
394 	if (!synic->active && !host)
395 		return 1;
396 
397 	ret = 0;
398 	switch (msr) {
399 	case HV_X64_MSR_SCONTROL:
400 		*pdata = synic->control;
401 		break;
402 	case HV_X64_MSR_SVERSION:
403 		*pdata = synic->version;
404 		break;
405 	case HV_X64_MSR_SIEFP:
406 		*pdata = synic->evt_page;
407 		break;
408 	case HV_X64_MSR_SIMP:
409 		*pdata = synic->msg_page;
410 		break;
411 	case HV_X64_MSR_EOM:
412 		*pdata = 0;
413 		break;
414 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
415 		*pdata = atomic64_read(&synic->sint[msr - HV_X64_MSR_SINT0]);
416 		break;
417 	default:
418 		ret = 1;
419 		break;
420 	}
421 	return ret;
422 }
423 
424 static int synic_set_irq(struct kvm_vcpu_hv_synic *synic, u32 sint)
425 {
426 	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
427 	struct kvm_lapic_irq irq;
428 	int ret, vector;
429 
430 	if (sint >= ARRAY_SIZE(synic->sint))
431 		return -EINVAL;
432 
433 	vector = synic_get_sint_vector(synic_read_sint(synic, sint));
434 	if (vector < 0)
435 		return -ENOENT;
436 
437 	memset(&irq, 0, sizeof(irq));
438 	irq.shorthand = APIC_DEST_SELF;
439 	irq.dest_mode = APIC_DEST_PHYSICAL;
440 	irq.delivery_mode = APIC_DM_FIXED;
441 	irq.vector = vector;
442 	irq.level = 1;
443 
444 	ret = kvm_irq_delivery_to_apic(vcpu->kvm, vcpu->arch.apic, &irq, NULL);
445 	trace_kvm_hv_synic_set_irq(vcpu->vcpu_id, sint, irq.vector, ret);
446 	return ret;
447 }
448 
449 int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vpidx, u32 sint)
450 {
451 	struct kvm_vcpu_hv_synic *synic;
452 
453 	synic = synic_get(kvm, vpidx);
454 	if (!synic)
455 		return -EINVAL;
456 
457 	return synic_set_irq(synic, sint);
458 }
459 
460 void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
461 {
462 	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
463 	int i;
464 
465 	trace_kvm_hv_synic_send_eoi(vcpu->vcpu_id, vector);
466 
467 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
468 		if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
469 			kvm_hv_notify_acked_sint(vcpu, i);
470 }
471 
472 static int kvm_hv_set_sint_gsi(struct kvm *kvm, u32 vpidx, u32 sint, int gsi)
473 {
474 	struct kvm_vcpu_hv_synic *synic;
475 
476 	synic = synic_get(kvm, vpidx);
477 	if (!synic)
478 		return -EINVAL;
479 
480 	if (sint >= ARRAY_SIZE(synic->sint_to_gsi))
481 		return -EINVAL;
482 
483 	atomic_set(&synic->sint_to_gsi[sint], gsi);
484 	return 0;
485 }
486 
487 void kvm_hv_irq_routing_update(struct kvm *kvm)
488 {
489 	struct kvm_irq_routing_table *irq_rt;
490 	struct kvm_kernel_irq_routing_entry *e;
491 	u32 gsi;
492 
493 	irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
494 					lockdep_is_held(&kvm->irq_lock));
495 
496 	for (gsi = 0; gsi < irq_rt->nr_rt_entries; gsi++) {
497 		hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
498 			if (e->type == KVM_IRQ_ROUTING_HV_SINT)
499 				kvm_hv_set_sint_gsi(kvm, e->hv_sint.vcpu,
500 						    e->hv_sint.sint, gsi);
501 		}
502 	}
503 }
504 
505 static void synic_init(struct kvm_vcpu_hv_synic *synic)
506 {
507 	int i;
508 
509 	memset(synic, 0, sizeof(*synic));
510 	synic->version = HV_SYNIC_VERSION_1;
511 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
512 		atomic64_set(&synic->sint[i], HV_SYNIC_SINT_MASKED);
513 		atomic_set(&synic->sint_to_gsi[i], -1);
514 	}
515 }
516 
517 static u64 get_time_ref_counter(struct kvm *kvm)
518 {
519 	struct kvm_hv *hv = to_kvm_hv(kvm);
520 	struct kvm_vcpu *vcpu;
521 	u64 tsc;
522 
523 	/*
524 	 * Fall back to get_kvmclock_ns() when TSC page hasn't been set up,
525 	 * is broken, disabled or being updated.
526 	 */
527 	if (hv->hv_tsc_page_status != HV_TSC_PAGE_SET)
528 		return div_u64(get_kvmclock_ns(kvm), 100);
529 
530 	vcpu = kvm_get_vcpu(kvm, 0);
531 	tsc = kvm_read_l1_tsc(vcpu, rdtsc());
532 	return mul_u64_u64_shr(tsc, hv->tsc_ref.tsc_scale, 64)
533 		+ hv->tsc_ref.tsc_offset;
534 }
535 
536 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
537 				bool vcpu_kick)
538 {
539 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
540 
541 	set_bit(stimer->index,
542 		to_hv_vcpu(vcpu)->stimer_pending_bitmap);
543 	kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
544 	if (vcpu_kick)
545 		kvm_vcpu_kick(vcpu);
546 }
547 
548 static void stimer_cleanup(struct kvm_vcpu_hv_stimer *stimer)
549 {
550 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
551 
552 	trace_kvm_hv_stimer_cleanup(hv_stimer_to_vcpu(stimer)->vcpu_id,
553 				    stimer->index);
554 
555 	hrtimer_cancel(&stimer->timer);
556 	clear_bit(stimer->index,
557 		  to_hv_vcpu(vcpu)->stimer_pending_bitmap);
558 	stimer->msg_pending = false;
559 	stimer->exp_time = 0;
560 }
561 
562 static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer)
563 {
564 	struct kvm_vcpu_hv_stimer *stimer;
565 
566 	stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer);
567 	trace_kvm_hv_stimer_callback(hv_stimer_to_vcpu(stimer)->vcpu_id,
568 				     stimer->index);
569 	stimer_mark_pending(stimer, true);
570 
571 	return HRTIMER_NORESTART;
572 }
573 
574 /*
575  * stimer_start() assumptions:
576  * a) stimer->count is not equal to 0
577  * b) stimer->config has HV_STIMER_ENABLE flag
578  */
579 static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
580 {
581 	u64 time_now;
582 	ktime_t ktime_now;
583 
584 	time_now = get_time_ref_counter(hv_stimer_to_vcpu(stimer)->kvm);
585 	ktime_now = ktime_get();
586 
587 	if (stimer->config.periodic) {
588 		if (stimer->exp_time) {
589 			if (time_now >= stimer->exp_time) {
590 				u64 remainder;
591 
592 				div64_u64_rem(time_now - stimer->exp_time,
593 					      stimer->count, &remainder);
594 				stimer->exp_time =
595 					time_now + (stimer->count - remainder);
596 			}
597 		} else
598 			stimer->exp_time = time_now + stimer->count;
599 
600 		trace_kvm_hv_stimer_start_periodic(
601 					hv_stimer_to_vcpu(stimer)->vcpu_id,
602 					stimer->index,
603 					time_now, stimer->exp_time);
604 
605 		hrtimer_start(&stimer->timer,
606 			      ktime_add_ns(ktime_now,
607 					   100 * (stimer->exp_time - time_now)),
608 			      HRTIMER_MODE_ABS);
609 		return 0;
610 	}
611 	stimer->exp_time = stimer->count;
612 	if (time_now >= stimer->count) {
613 		/*
614 		 * Expire timer according to Hypervisor Top-Level Functional
615 		 * specification v4(15.3.1):
616 		 * "If a one shot is enabled and the specified count is in
617 		 * the past, it will expire immediately."
618 		 */
619 		stimer_mark_pending(stimer, false);
620 		return 0;
621 	}
622 
623 	trace_kvm_hv_stimer_start_one_shot(hv_stimer_to_vcpu(stimer)->vcpu_id,
624 					   stimer->index,
625 					   time_now, stimer->count);
626 
627 	hrtimer_start(&stimer->timer,
628 		      ktime_add_ns(ktime_now, 100 * (stimer->count - time_now)),
629 		      HRTIMER_MODE_ABS);
630 	return 0;
631 }
632 
633 static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
634 			     bool host)
635 {
636 	union hv_stimer_config new_config = {.as_uint64 = config},
637 		old_config = {.as_uint64 = stimer->config.as_uint64};
638 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
639 	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
640 
641 	if (!synic->active && !host)
642 		return 1;
643 
644 	trace_kvm_hv_stimer_set_config(hv_stimer_to_vcpu(stimer)->vcpu_id,
645 				       stimer->index, config, host);
646 
647 	stimer_cleanup(stimer);
648 	if (old_config.enable &&
649 	    !new_config.direct_mode && new_config.sintx == 0)
650 		new_config.enable = 0;
651 	stimer->config.as_uint64 = new_config.as_uint64;
652 
653 	if (stimer->config.enable)
654 		stimer_mark_pending(stimer, false);
655 
656 	return 0;
657 }
658 
659 static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,
660 			    bool host)
661 {
662 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
663 	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
664 
665 	if (!synic->active && !host)
666 		return 1;
667 
668 	trace_kvm_hv_stimer_set_count(hv_stimer_to_vcpu(stimer)->vcpu_id,
669 				      stimer->index, count, host);
670 
671 	stimer_cleanup(stimer);
672 	stimer->count = count;
673 	if (stimer->count == 0)
674 		stimer->config.enable = 0;
675 	else if (stimer->config.auto_enable)
676 		stimer->config.enable = 1;
677 
678 	if (stimer->config.enable)
679 		stimer_mark_pending(stimer, false);
680 
681 	return 0;
682 }
683 
684 static int stimer_get_config(struct kvm_vcpu_hv_stimer *stimer, u64 *pconfig)
685 {
686 	*pconfig = stimer->config.as_uint64;
687 	return 0;
688 }
689 
690 static int stimer_get_count(struct kvm_vcpu_hv_stimer *stimer, u64 *pcount)
691 {
692 	*pcount = stimer->count;
693 	return 0;
694 }
695 
696 static int synic_deliver_msg(struct kvm_vcpu_hv_synic *synic, u32 sint,
697 			     struct hv_message *src_msg, bool no_retry)
698 {
699 	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
700 	int msg_off = offsetof(struct hv_message_page, sint_message[sint]);
701 	gfn_t msg_page_gfn;
702 	struct hv_message_header hv_hdr;
703 	int r;
704 
705 	if (!(synic->msg_page & HV_SYNIC_SIMP_ENABLE))
706 		return -ENOENT;
707 
708 	msg_page_gfn = synic->msg_page >> PAGE_SHIFT;
709 
710 	/*
711 	 * Strictly following the spec-mandated ordering would assume setting
712 	 * .msg_pending before checking .message_type.  However, this function
713 	 * is only called in vcpu context so the entire update is atomic from
714 	 * guest POV and thus the exact order here doesn't matter.
715 	 */
716 	r = kvm_vcpu_read_guest_page(vcpu, msg_page_gfn, &hv_hdr.message_type,
717 				     msg_off + offsetof(struct hv_message,
718 							header.message_type),
719 				     sizeof(hv_hdr.message_type));
720 	if (r < 0)
721 		return r;
722 
723 	if (hv_hdr.message_type != HVMSG_NONE) {
724 		if (no_retry)
725 			return 0;
726 
727 		hv_hdr.message_flags.msg_pending = 1;
728 		r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn,
729 					      &hv_hdr.message_flags,
730 					      msg_off +
731 					      offsetof(struct hv_message,
732 						       header.message_flags),
733 					      sizeof(hv_hdr.message_flags));
734 		if (r < 0)
735 			return r;
736 		return -EAGAIN;
737 	}
738 
739 	r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn, src_msg, msg_off,
740 				      sizeof(src_msg->header) +
741 				      src_msg->header.payload_size);
742 	if (r < 0)
743 		return r;
744 
745 	r = synic_set_irq(synic, sint);
746 	if (r < 0)
747 		return r;
748 	if (r == 0)
749 		return -EFAULT;
750 	return 0;
751 }
752 
753 static int stimer_send_msg(struct kvm_vcpu_hv_stimer *stimer)
754 {
755 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
756 	struct hv_message *msg = &stimer->msg;
757 	struct hv_timer_message_payload *payload =
758 			(struct hv_timer_message_payload *)&msg->u.payload;
759 
760 	/*
761 	 * To avoid piling up periodic ticks, don't retry message
762 	 * delivery for them (within "lazy" lost ticks policy).
763 	 */
764 	bool no_retry = stimer->config.periodic;
765 
766 	payload->expiration_time = stimer->exp_time;
767 	payload->delivery_time = get_time_ref_counter(vcpu->kvm);
768 	return synic_deliver_msg(to_hv_synic(vcpu),
769 				 stimer->config.sintx, msg,
770 				 no_retry);
771 }
772 
773 static int stimer_notify_direct(struct kvm_vcpu_hv_stimer *stimer)
774 {
775 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
776 	struct kvm_lapic_irq irq = {
777 		.delivery_mode = APIC_DM_FIXED,
778 		.vector = stimer->config.apic_vector
779 	};
780 
781 	if (lapic_in_kernel(vcpu))
782 		return !kvm_apic_set_irq(vcpu, &irq, NULL);
783 	return 0;
784 }
785 
786 static void stimer_expiration(struct kvm_vcpu_hv_stimer *stimer)
787 {
788 	int r, direct = stimer->config.direct_mode;
789 
790 	stimer->msg_pending = true;
791 	if (!direct)
792 		r = stimer_send_msg(stimer);
793 	else
794 		r = stimer_notify_direct(stimer);
795 	trace_kvm_hv_stimer_expiration(hv_stimer_to_vcpu(stimer)->vcpu_id,
796 				       stimer->index, direct, r);
797 	if (!r) {
798 		stimer->msg_pending = false;
799 		if (!(stimer->config.periodic))
800 			stimer->config.enable = 0;
801 	}
802 }
803 
804 void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
805 {
806 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
807 	struct kvm_vcpu_hv_stimer *stimer;
808 	u64 time_now, exp_time;
809 	int i;
810 
811 	if (!hv_vcpu)
812 		return;
813 
814 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
815 		if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) {
816 			stimer = &hv_vcpu->stimer[i];
817 			if (stimer->config.enable) {
818 				exp_time = stimer->exp_time;
819 
820 				if (exp_time) {
821 					time_now =
822 						get_time_ref_counter(vcpu->kvm);
823 					if (time_now >= exp_time)
824 						stimer_expiration(stimer);
825 				}
826 
827 				if ((stimer->config.enable) &&
828 				    stimer->count) {
829 					if (!stimer->msg_pending)
830 						stimer_start(stimer);
831 				} else
832 					stimer_cleanup(stimer);
833 			}
834 		}
835 }
836 
837 void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu)
838 {
839 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
840 	int i;
841 
842 	if (!hv_vcpu)
843 		return;
844 
845 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
846 		stimer_cleanup(&hv_vcpu->stimer[i]);
847 
848 	kfree(hv_vcpu);
849 	vcpu->arch.hyperv = NULL;
850 }
851 
852 bool kvm_hv_assist_page_enabled(struct kvm_vcpu *vcpu)
853 {
854 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
855 
856 	if (!hv_vcpu)
857 		return false;
858 
859 	if (!(hv_vcpu->hv_vapic & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE))
860 		return false;
861 	return vcpu->arch.pv_eoi.msr_val & KVM_MSR_ENABLED;
862 }
863 EXPORT_SYMBOL_GPL(kvm_hv_assist_page_enabled);
864 
865 bool kvm_hv_get_assist_page(struct kvm_vcpu *vcpu,
866 			    struct hv_vp_assist_page *assist_page)
867 {
868 	if (!kvm_hv_assist_page_enabled(vcpu))
869 		return false;
870 	return !kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data,
871 				      assist_page, sizeof(*assist_page));
872 }
873 EXPORT_SYMBOL_GPL(kvm_hv_get_assist_page);
874 
875 static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
876 {
877 	struct hv_message *msg = &stimer->msg;
878 	struct hv_timer_message_payload *payload =
879 			(struct hv_timer_message_payload *)&msg->u.payload;
880 
881 	memset(&msg->header, 0, sizeof(msg->header));
882 	msg->header.message_type = HVMSG_TIMER_EXPIRED;
883 	msg->header.payload_size = sizeof(*payload);
884 
885 	payload->timer_index = stimer->index;
886 	payload->expiration_time = 0;
887 	payload->delivery_time = 0;
888 }
889 
890 static void stimer_init(struct kvm_vcpu_hv_stimer *stimer, int timer_index)
891 {
892 	memset(stimer, 0, sizeof(*stimer));
893 	stimer->index = timer_index;
894 	hrtimer_init(&stimer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
895 	stimer->timer.function = stimer_timer_callback;
896 	stimer_prepare_msg(stimer);
897 }
898 
899 static int kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
900 {
901 	struct kvm_vcpu_hv *hv_vcpu;
902 	int i;
903 
904 	hv_vcpu = kzalloc(sizeof(struct kvm_vcpu_hv), GFP_KERNEL_ACCOUNT);
905 	if (!hv_vcpu)
906 		return -ENOMEM;
907 
908 	vcpu->arch.hyperv = hv_vcpu;
909 	hv_vcpu->vcpu = vcpu;
910 
911 	synic_init(&hv_vcpu->synic);
912 
913 	bitmap_zero(hv_vcpu->stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
914 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
915 		stimer_init(&hv_vcpu->stimer[i], i);
916 
917 	hv_vcpu->vp_index = kvm_vcpu_get_idx(vcpu);
918 
919 	return 0;
920 }
921 
922 int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages)
923 {
924 	struct kvm_vcpu_hv_synic *synic;
925 	int r;
926 
927 	if (!to_hv_vcpu(vcpu)) {
928 		r = kvm_hv_vcpu_init(vcpu);
929 		if (r)
930 			return r;
931 	}
932 
933 	synic = to_hv_synic(vcpu);
934 
935 	/*
936 	 * Hyper-V SynIC auto EOI SINT's are
937 	 * not compatible with APICV, so request
938 	 * to deactivate APICV permanently.
939 	 */
940 	kvm_request_apicv_update(vcpu->kvm, false, APICV_INHIBIT_REASON_HYPERV);
941 	synic->active = true;
942 	synic->dont_zero_synic_pages = dont_zero_synic_pages;
943 	synic->control = HV_SYNIC_CONTROL_ENABLE;
944 	return 0;
945 }
946 
947 static bool kvm_hv_msr_partition_wide(u32 msr)
948 {
949 	bool r = false;
950 
951 	switch (msr) {
952 	case HV_X64_MSR_GUEST_OS_ID:
953 	case HV_X64_MSR_HYPERCALL:
954 	case HV_X64_MSR_REFERENCE_TSC:
955 	case HV_X64_MSR_TIME_REF_COUNT:
956 	case HV_X64_MSR_CRASH_CTL:
957 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
958 	case HV_X64_MSR_RESET:
959 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
960 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
961 	case HV_X64_MSR_TSC_EMULATION_STATUS:
962 	case HV_X64_MSR_SYNDBG_OPTIONS:
963 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
964 		r = true;
965 		break;
966 	}
967 
968 	return r;
969 }
970 
971 static int kvm_hv_msr_get_crash_data(struct kvm *kvm, u32 index, u64 *pdata)
972 {
973 	struct kvm_hv *hv = to_kvm_hv(kvm);
974 	size_t size = ARRAY_SIZE(hv->hv_crash_param);
975 
976 	if (WARN_ON_ONCE(index >= size))
977 		return -EINVAL;
978 
979 	*pdata = hv->hv_crash_param[array_index_nospec(index, size)];
980 	return 0;
981 }
982 
983 static int kvm_hv_msr_get_crash_ctl(struct kvm *kvm, u64 *pdata)
984 {
985 	struct kvm_hv *hv = to_kvm_hv(kvm);
986 
987 	*pdata = hv->hv_crash_ctl;
988 	return 0;
989 }
990 
991 static int kvm_hv_msr_set_crash_ctl(struct kvm *kvm, u64 data)
992 {
993 	struct kvm_hv *hv = to_kvm_hv(kvm);
994 
995 	hv->hv_crash_ctl = data & HV_CRASH_CTL_CRASH_NOTIFY;
996 
997 	return 0;
998 }
999 
1000 static int kvm_hv_msr_set_crash_data(struct kvm *kvm, u32 index, u64 data)
1001 {
1002 	struct kvm_hv *hv = to_kvm_hv(kvm);
1003 	size_t size = ARRAY_SIZE(hv->hv_crash_param);
1004 
1005 	if (WARN_ON_ONCE(index >= size))
1006 		return -EINVAL;
1007 
1008 	hv->hv_crash_param[array_index_nospec(index, size)] = data;
1009 	return 0;
1010 }
1011 
1012 /*
1013  * The kvmclock and Hyper-V TSC page use similar formulas, and converting
1014  * between them is possible:
1015  *
1016  * kvmclock formula:
1017  *    nsec = (ticks - tsc_timestamp) * tsc_to_system_mul * 2^(tsc_shift-32)
1018  *           + system_time
1019  *
1020  * Hyper-V formula:
1021  *    nsec/100 = ticks * scale / 2^64 + offset
1022  *
1023  * When tsc_timestamp = system_time = 0, offset is zero in the Hyper-V formula.
1024  * By dividing the kvmclock formula by 100 and equating what's left we get:
1025  *    ticks * scale / 2^64 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1026  *            scale / 2^64 =         tsc_to_system_mul * 2^(tsc_shift-32) / 100
1027  *            scale        =         tsc_to_system_mul * 2^(32+tsc_shift) / 100
1028  *
1029  * Now expand the kvmclock formula and divide by 100:
1030  *    nsec = ticks * tsc_to_system_mul * 2^(tsc_shift-32)
1031  *           - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32)
1032  *           + system_time
1033  *    nsec/100 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1034  *               - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1035  *               + system_time / 100
1036  *
1037  * Replace tsc_to_system_mul * 2^(tsc_shift-32) / 100 by scale / 2^64:
1038  *    nsec/100 = ticks * scale / 2^64
1039  *               - tsc_timestamp * scale / 2^64
1040  *               + system_time / 100
1041  *
1042  * Equate with the Hyper-V formula so that ticks * scale / 2^64 cancels out:
1043  *    offset = system_time / 100 - tsc_timestamp * scale / 2^64
1044  *
1045  * These two equivalencies are implemented in this function.
1046  */
1047 static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
1048 					struct ms_hyperv_tsc_page *tsc_ref)
1049 {
1050 	u64 max_mul;
1051 
1052 	if (!(hv_clock->flags & PVCLOCK_TSC_STABLE_BIT))
1053 		return false;
1054 
1055 	/*
1056 	 * check if scale would overflow, if so we use the time ref counter
1057 	 *    tsc_to_system_mul * 2^(tsc_shift+32) / 100 >= 2^64
1058 	 *    tsc_to_system_mul / 100 >= 2^(32-tsc_shift)
1059 	 *    tsc_to_system_mul >= 100 * 2^(32-tsc_shift)
1060 	 */
1061 	max_mul = 100ull << (32 - hv_clock->tsc_shift);
1062 	if (hv_clock->tsc_to_system_mul >= max_mul)
1063 		return false;
1064 
1065 	/*
1066 	 * Otherwise compute the scale and offset according to the formulas
1067 	 * derived above.
1068 	 */
1069 	tsc_ref->tsc_scale =
1070 		mul_u64_u32_div(1ULL << (32 + hv_clock->tsc_shift),
1071 				hv_clock->tsc_to_system_mul,
1072 				100);
1073 
1074 	tsc_ref->tsc_offset = hv_clock->system_time;
1075 	do_div(tsc_ref->tsc_offset, 100);
1076 	tsc_ref->tsc_offset -=
1077 		mul_u64_u64_shr(hv_clock->tsc_timestamp, tsc_ref->tsc_scale, 64);
1078 	return true;
1079 }
1080 
1081 /*
1082  * Don't touch TSC page values if the guest has opted for TSC emulation after
1083  * migration. KVM doesn't fully support reenlightenment notifications and TSC
1084  * access emulation and Hyper-V is known to expect the values in TSC page to
1085  * stay constant before TSC access emulation is disabled from guest side
1086  * (HV_X64_MSR_TSC_EMULATION_STATUS). KVM userspace is expected to preserve TSC
1087  * frequency and guest visible TSC value across migration (and prevent it when
1088  * TSC scaling is unsupported).
1089  */
1090 static inline bool tsc_page_update_unsafe(struct kvm_hv *hv)
1091 {
1092 	return (hv->hv_tsc_page_status != HV_TSC_PAGE_GUEST_CHANGED) &&
1093 		hv->hv_tsc_emulation_control;
1094 }
1095 
1096 void kvm_hv_setup_tsc_page(struct kvm *kvm,
1097 			   struct pvclock_vcpu_time_info *hv_clock)
1098 {
1099 	struct kvm_hv *hv = to_kvm_hv(kvm);
1100 	u32 tsc_seq;
1101 	u64 gfn;
1102 
1103 	BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
1104 	BUILD_BUG_ON(offsetof(struct ms_hyperv_tsc_page, tsc_sequence) != 0);
1105 
1106 	if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN ||
1107 	    hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET)
1108 		return;
1109 
1110 	mutex_lock(&hv->hv_lock);
1111 	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
1112 		goto out_unlock;
1113 
1114 	gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
1115 	/*
1116 	 * Because the TSC parameters only vary when there is a
1117 	 * change in the master clock, do not bother with caching.
1118 	 */
1119 	if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
1120 				    &tsc_seq, sizeof(tsc_seq))))
1121 		goto out_err;
1122 
1123 	if (tsc_seq && tsc_page_update_unsafe(hv)) {
1124 		if (kvm_read_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1125 			goto out_err;
1126 
1127 		hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1128 		goto out_unlock;
1129 	}
1130 
1131 	/*
1132 	 * While we're computing and writing the parameters, force the
1133 	 * guest to use the time reference count MSR.
1134 	 */
1135 	hv->tsc_ref.tsc_sequence = 0;
1136 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1137 			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1138 		goto out_err;
1139 
1140 	if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
1141 		goto out_err;
1142 
1143 	/* Ensure sequence is zero before writing the rest of the struct.  */
1144 	smp_wmb();
1145 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1146 		goto out_err;
1147 
1148 	/*
1149 	 * Now switch to the TSC page mechanism by writing the sequence.
1150 	 */
1151 	tsc_seq++;
1152 	if (tsc_seq == 0xFFFFFFFF || tsc_seq == 0)
1153 		tsc_seq = 1;
1154 
1155 	/* Write the struct entirely before the non-zero sequence.  */
1156 	smp_wmb();
1157 
1158 	hv->tsc_ref.tsc_sequence = tsc_seq;
1159 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1160 			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1161 		goto out_err;
1162 
1163 	hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1164 	goto out_unlock;
1165 
1166 out_err:
1167 	hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN;
1168 out_unlock:
1169 	mutex_unlock(&hv->hv_lock);
1170 }
1171 
1172 void kvm_hv_invalidate_tsc_page(struct kvm *kvm)
1173 {
1174 	struct kvm_hv *hv = to_kvm_hv(kvm);
1175 	u64 gfn;
1176 	int idx;
1177 
1178 	if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN ||
1179 	    hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET ||
1180 	    tsc_page_update_unsafe(hv))
1181 		return;
1182 
1183 	mutex_lock(&hv->hv_lock);
1184 
1185 	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
1186 		goto out_unlock;
1187 
1188 	/* Preserve HV_TSC_PAGE_GUEST_CHANGED/HV_TSC_PAGE_HOST_CHANGED states */
1189 	if (hv->hv_tsc_page_status == HV_TSC_PAGE_SET)
1190 		hv->hv_tsc_page_status = HV_TSC_PAGE_UPDATING;
1191 
1192 	gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
1193 
1194 	hv->tsc_ref.tsc_sequence = 0;
1195 
1196 	/*
1197 	 * Take the srcu lock as memslots will be accessed to check the gfn
1198 	 * cache generation against the memslots generation.
1199 	 */
1200 	idx = srcu_read_lock(&kvm->srcu);
1201 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1202 			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1203 		hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN;
1204 	srcu_read_unlock(&kvm->srcu, idx);
1205 
1206 out_unlock:
1207 	mutex_unlock(&hv->hv_lock);
1208 }
1209 
1210 static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
1211 			     bool host)
1212 {
1213 	struct kvm *kvm = vcpu->kvm;
1214 	struct kvm_hv *hv = to_kvm_hv(kvm);
1215 
1216 	switch (msr) {
1217 	case HV_X64_MSR_GUEST_OS_ID:
1218 		hv->hv_guest_os_id = data;
1219 		/* setting guest os id to zero disables hypercall page */
1220 		if (!hv->hv_guest_os_id)
1221 			hv->hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
1222 		break;
1223 	case HV_X64_MSR_HYPERCALL: {
1224 		u8 instructions[9];
1225 		int i = 0;
1226 		u64 addr;
1227 
1228 		/* if guest os id is not set hypercall should remain disabled */
1229 		if (!hv->hv_guest_os_id)
1230 			break;
1231 		if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
1232 			hv->hv_hypercall = data;
1233 			break;
1234 		}
1235 
1236 		/*
1237 		 * If Xen and Hyper-V hypercalls are both enabled, disambiguate
1238 		 * the same way Xen itself does, by setting the bit 31 of EAX
1239 		 * which is RsvdZ in the 32-bit Hyper-V hypercall ABI and just
1240 		 * going to be clobbered on 64-bit.
1241 		 */
1242 		if (kvm_xen_hypercall_enabled(kvm)) {
1243 			/* orl $0x80000000, %eax */
1244 			instructions[i++] = 0x0d;
1245 			instructions[i++] = 0x00;
1246 			instructions[i++] = 0x00;
1247 			instructions[i++] = 0x00;
1248 			instructions[i++] = 0x80;
1249 		}
1250 
1251 		/* vmcall/vmmcall */
1252 		static_call(kvm_x86_patch_hypercall)(vcpu, instructions + i);
1253 		i += 3;
1254 
1255 		/* ret */
1256 		((unsigned char *)instructions)[i++] = 0xc3;
1257 
1258 		addr = data & HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_MASK;
1259 		if (kvm_vcpu_write_guest(vcpu, addr, instructions, i))
1260 			return 1;
1261 		hv->hv_hypercall = data;
1262 		break;
1263 	}
1264 	case HV_X64_MSR_REFERENCE_TSC:
1265 		hv->hv_tsc_page = data;
1266 		if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE) {
1267 			if (!host)
1268 				hv->hv_tsc_page_status = HV_TSC_PAGE_GUEST_CHANGED;
1269 			else
1270 				hv->hv_tsc_page_status = HV_TSC_PAGE_HOST_CHANGED;
1271 			kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
1272 		} else {
1273 			hv->hv_tsc_page_status = HV_TSC_PAGE_UNSET;
1274 		}
1275 		break;
1276 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1277 		return kvm_hv_msr_set_crash_data(kvm,
1278 						 msr - HV_X64_MSR_CRASH_P0,
1279 						 data);
1280 	case HV_X64_MSR_CRASH_CTL:
1281 		if (host)
1282 			return kvm_hv_msr_set_crash_ctl(kvm, data);
1283 
1284 		if (data & HV_CRASH_CTL_CRASH_NOTIFY) {
1285 			vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx 0x%llx)\n",
1286 				   hv->hv_crash_param[0],
1287 				   hv->hv_crash_param[1],
1288 				   hv->hv_crash_param[2],
1289 				   hv->hv_crash_param[3],
1290 				   hv->hv_crash_param[4]);
1291 
1292 			/* Send notification about crash to user space */
1293 			kvm_make_request(KVM_REQ_HV_CRASH, vcpu);
1294 		}
1295 		break;
1296 	case HV_X64_MSR_RESET:
1297 		if (data == 1) {
1298 			vcpu_debug(vcpu, "hyper-v reset requested\n");
1299 			kvm_make_request(KVM_REQ_HV_RESET, vcpu);
1300 		}
1301 		break;
1302 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1303 		hv->hv_reenlightenment_control = data;
1304 		break;
1305 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1306 		hv->hv_tsc_emulation_control = data;
1307 		break;
1308 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1309 		if (data && !host)
1310 			return 1;
1311 
1312 		hv->hv_tsc_emulation_status = data;
1313 		break;
1314 	case HV_X64_MSR_TIME_REF_COUNT:
1315 		/* read-only, but still ignore it if host-initiated */
1316 		if (!host)
1317 			return 1;
1318 		break;
1319 	case HV_X64_MSR_SYNDBG_OPTIONS:
1320 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1321 		return syndbg_set_msr(vcpu, msr, data, host);
1322 	default:
1323 		vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
1324 			    msr, data);
1325 		return 1;
1326 	}
1327 	return 0;
1328 }
1329 
1330 /* Calculate cpu time spent by current task in 100ns units */
1331 static u64 current_task_runtime_100ns(void)
1332 {
1333 	u64 utime, stime;
1334 
1335 	task_cputime_adjusted(current, &utime, &stime);
1336 
1337 	return div_u64(utime + stime, 100);
1338 }
1339 
1340 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1341 {
1342 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1343 
1344 	switch (msr) {
1345 	case HV_X64_MSR_VP_INDEX: {
1346 		struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1347 		int vcpu_idx = kvm_vcpu_get_idx(vcpu);
1348 		u32 new_vp_index = (u32)data;
1349 
1350 		if (!host || new_vp_index >= KVM_MAX_VCPUS)
1351 			return 1;
1352 
1353 		if (new_vp_index == hv_vcpu->vp_index)
1354 			return 0;
1355 
1356 		/*
1357 		 * The VP index is initialized to vcpu_index by
1358 		 * kvm_hv_vcpu_postcreate so they initially match.  Now the
1359 		 * VP index is changing, adjust num_mismatched_vp_indexes if
1360 		 * it now matches or no longer matches vcpu_idx.
1361 		 */
1362 		if (hv_vcpu->vp_index == vcpu_idx)
1363 			atomic_inc(&hv->num_mismatched_vp_indexes);
1364 		else if (new_vp_index == vcpu_idx)
1365 			atomic_dec(&hv->num_mismatched_vp_indexes);
1366 
1367 		hv_vcpu->vp_index = new_vp_index;
1368 		break;
1369 	}
1370 	case HV_X64_MSR_VP_ASSIST_PAGE: {
1371 		u64 gfn;
1372 		unsigned long addr;
1373 
1374 		if (!(data & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE)) {
1375 			hv_vcpu->hv_vapic = data;
1376 			if (kvm_lapic_enable_pv_eoi(vcpu, 0, 0))
1377 				return 1;
1378 			break;
1379 		}
1380 		gfn = data >> HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT;
1381 		addr = kvm_vcpu_gfn_to_hva(vcpu, gfn);
1382 		if (kvm_is_error_hva(addr))
1383 			return 1;
1384 
1385 		/*
1386 		 * Clear apic_assist portion of struct hv_vp_assist_page
1387 		 * only, there can be valuable data in the rest which needs
1388 		 * to be preserved e.g. on migration.
1389 		 */
1390 		if (__put_user(0, (u32 __user *)addr))
1391 			return 1;
1392 		hv_vcpu->hv_vapic = data;
1393 		kvm_vcpu_mark_page_dirty(vcpu, gfn);
1394 		if (kvm_lapic_enable_pv_eoi(vcpu,
1395 					    gfn_to_gpa(gfn) | KVM_MSR_ENABLED,
1396 					    sizeof(struct hv_vp_assist_page)))
1397 			return 1;
1398 		break;
1399 	}
1400 	case HV_X64_MSR_EOI:
1401 		return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
1402 	case HV_X64_MSR_ICR:
1403 		return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
1404 	case HV_X64_MSR_TPR:
1405 		return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
1406 	case HV_X64_MSR_VP_RUNTIME:
1407 		if (!host)
1408 			return 1;
1409 		hv_vcpu->runtime_offset = data - current_task_runtime_100ns();
1410 		break;
1411 	case HV_X64_MSR_SCONTROL:
1412 	case HV_X64_MSR_SVERSION:
1413 	case HV_X64_MSR_SIEFP:
1414 	case HV_X64_MSR_SIMP:
1415 	case HV_X64_MSR_EOM:
1416 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1417 		return synic_set_msr(to_hv_synic(vcpu), msr, data, host);
1418 	case HV_X64_MSR_STIMER0_CONFIG:
1419 	case HV_X64_MSR_STIMER1_CONFIG:
1420 	case HV_X64_MSR_STIMER2_CONFIG:
1421 	case HV_X64_MSR_STIMER3_CONFIG: {
1422 		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1423 
1424 		return stimer_set_config(to_hv_stimer(vcpu, timer_index),
1425 					 data, host);
1426 	}
1427 	case HV_X64_MSR_STIMER0_COUNT:
1428 	case HV_X64_MSR_STIMER1_COUNT:
1429 	case HV_X64_MSR_STIMER2_COUNT:
1430 	case HV_X64_MSR_STIMER3_COUNT: {
1431 		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1432 
1433 		return stimer_set_count(to_hv_stimer(vcpu, timer_index),
1434 					data, host);
1435 	}
1436 	case HV_X64_MSR_TSC_FREQUENCY:
1437 	case HV_X64_MSR_APIC_FREQUENCY:
1438 		/* read-only, but still ignore it if host-initiated */
1439 		if (!host)
1440 			return 1;
1441 		break;
1442 	default:
1443 		vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
1444 			    msr, data);
1445 		return 1;
1446 	}
1447 
1448 	return 0;
1449 }
1450 
1451 static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1452 			     bool host)
1453 {
1454 	u64 data = 0;
1455 	struct kvm *kvm = vcpu->kvm;
1456 	struct kvm_hv *hv = to_kvm_hv(kvm);
1457 
1458 	switch (msr) {
1459 	case HV_X64_MSR_GUEST_OS_ID:
1460 		data = hv->hv_guest_os_id;
1461 		break;
1462 	case HV_X64_MSR_HYPERCALL:
1463 		data = hv->hv_hypercall;
1464 		break;
1465 	case HV_X64_MSR_TIME_REF_COUNT:
1466 		data = get_time_ref_counter(kvm);
1467 		break;
1468 	case HV_X64_MSR_REFERENCE_TSC:
1469 		data = hv->hv_tsc_page;
1470 		break;
1471 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1472 		return kvm_hv_msr_get_crash_data(kvm,
1473 						 msr - HV_X64_MSR_CRASH_P0,
1474 						 pdata);
1475 	case HV_X64_MSR_CRASH_CTL:
1476 		return kvm_hv_msr_get_crash_ctl(kvm, pdata);
1477 	case HV_X64_MSR_RESET:
1478 		data = 0;
1479 		break;
1480 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1481 		data = hv->hv_reenlightenment_control;
1482 		break;
1483 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1484 		data = hv->hv_tsc_emulation_control;
1485 		break;
1486 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1487 		data = hv->hv_tsc_emulation_status;
1488 		break;
1489 	case HV_X64_MSR_SYNDBG_OPTIONS:
1490 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1491 		return syndbg_get_msr(vcpu, msr, pdata, host);
1492 	default:
1493 		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1494 		return 1;
1495 	}
1496 
1497 	*pdata = data;
1498 	return 0;
1499 }
1500 
1501 static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1502 			  bool host)
1503 {
1504 	u64 data = 0;
1505 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1506 
1507 	switch (msr) {
1508 	case HV_X64_MSR_VP_INDEX:
1509 		data = hv_vcpu->vp_index;
1510 		break;
1511 	case HV_X64_MSR_EOI:
1512 		return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
1513 	case HV_X64_MSR_ICR:
1514 		return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
1515 	case HV_X64_MSR_TPR:
1516 		return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
1517 	case HV_X64_MSR_VP_ASSIST_PAGE:
1518 		data = hv_vcpu->hv_vapic;
1519 		break;
1520 	case HV_X64_MSR_VP_RUNTIME:
1521 		data = current_task_runtime_100ns() + hv_vcpu->runtime_offset;
1522 		break;
1523 	case HV_X64_MSR_SCONTROL:
1524 	case HV_X64_MSR_SVERSION:
1525 	case HV_X64_MSR_SIEFP:
1526 	case HV_X64_MSR_SIMP:
1527 	case HV_X64_MSR_EOM:
1528 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1529 		return synic_get_msr(to_hv_synic(vcpu), msr, pdata, host);
1530 	case HV_X64_MSR_STIMER0_CONFIG:
1531 	case HV_X64_MSR_STIMER1_CONFIG:
1532 	case HV_X64_MSR_STIMER2_CONFIG:
1533 	case HV_X64_MSR_STIMER3_CONFIG: {
1534 		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1535 
1536 		return stimer_get_config(to_hv_stimer(vcpu, timer_index),
1537 					 pdata);
1538 	}
1539 	case HV_X64_MSR_STIMER0_COUNT:
1540 	case HV_X64_MSR_STIMER1_COUNT:
1541 	case HV_X64_MSR_STIMER2_COUNT:
1542 	case HV_X64_MSR_STIMER3_COUNT: {
1543 		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1544 
1545 		return stimer_get_count(to_hv_stimer(vcpu, timer_index),
1546 					pdata);
1547 	}
1548 	case HV_X64_MSR_TSC_FREQUENCY:
1549 		data = (u64)vcpu->arch.virtual_tsc_khz * 1000;
1550 		break;
1551 	case HV_X64_MSR_APIC_FREQUENCY:
1552 		data = APIC_BUS_FREQUENCY;
1553 		break;
1554 	default:
1555 		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1556 		return 1;
1557 	}
1558 	*pdata = data;
1559 	return 0;
1560 }
1561 
1562 int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1563 {
1564 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1565 
1566 	if (!host && !vcpu->arch.hyperv_enabled)
1567 		return 1;
1568 
1569 	if (!to_hv_vcpu(vcpu)) {
1570 		if (kvm_hv_vcpu_init(vcpu))
1571 			return 1;
1572 	}
1573 
1574 	if (kvm_hv_msr_partition_wide(msr)) {
1575 		int r;
1576 
1577 		mutex_lock(&hv->hv_lock);
1578 		r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
1579 		mutex_unlock(&hv->hv_lock);
1580 		return r;
1581 	} else
1582 		return kvm_hv_set_msr(vcpu, msr, data, host);
1583 }
1584 
1585 int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
1586 {
1587 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1588 
1589 	if (!host && !vcpu->arch.hyperv_enabled)
1590 		return 1;
1591 
1592 	if (!to_hv_vcpu(vcpu)) {
1593 		if (kvm_hv_vcpu_init(vcpu))
1594 			return 1;
1595 	}
1596 
1597 	if (kvm_hv_msr_partition_wide(msr)) {
1598 		int r;
1599 
1600 		mutex_lock(&hv->hv_lock);
1601 		r = kvm_hv_get_msr_pw(vcpu, msr, pdata, host);
1602 		mutex_unlock(&hv->hv_lock);
1603 		return r;
1604 	} else
1605 		return kvm_hv_get_msr(vcpu, msr, pdata, host);
1606 }
1607 
1608 static __always_inline unsigned long *sparse_set_to_vcpu_mask(
1609 	struct kvm *kvm, u64 *sparse_banks, u64 valid_bank_mask,
1610 	u64 *vp_bitmap, unsigned long *vcpu_bitmap)
1611 {
1612 	struct kvm_hv *hv = to_kvm_hv(kvm);
1613 	struct kvm_vcpu *vcpu;
1614 	int i, bank, sbank = 0;
1615 
1616 	memset(vp_bitmap, 0,
1617 	       KVM_HV_MAX_SPARSE_VCPU_SET_BITS * sizeof(*vp_bitmap));
1618 	for_each_set_bit(bank, (unsigned long *)&valid_bank_mask,
1619 			 KVM_HV_MAX_SPARSE_VCPU_SET_BITS)
1620 		vp_bitmap[bank] = sparse_banks[sbank++];
1621 
1622 	if (likely(!atomic_read(&hv->num_mismatched_vp_indexes))) {
1623 		/* for all vcpus vp_index == vcpu_idx */
1624 		return (unsigned long *)vp_bitmap;
1625 	}
1626 
1627 	bitmap_zero(vcpu_bitmap, KVM_MAX_VCPUS);
1628 	kvm_for_each_vcpu(i, vcpu, kvm) {
1629 		if (test_bit(kvm_hv_get_vpindex(vcpu), (unsigned long *)vp_bitmap))
1630 			__set_bit(i, vcpu_bitmap);
1631 	}
1632 	return vcpu_bitmap;
1633 }
1634 
1635 struct kvm_hv_hcall {
1636 	u64 param;
1637 	u64 ingpa;
1638 	u64 outgpa;
1639 	u16 code;
1640 	u16 rep_cnt;
1641 	u16 rep_idx;
1642 	bool fast;
1643 	bool rep;
1644 	sse128_t xmm[HV_HYPERCALL_MAX_XMM_REGISTERS];
1645 };
1646 
1647 static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool ex)
1648 {
1649 	int i;
1650 	gpa_t gpa;
1651 	struct kvm *kvm = vcpu->kvm;
1652 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1653 	struct hv_tlb_flush_ex flush_ex;
1654 	struct hv_tlb_flush flush;
1655 	u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1656 	DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS);
1657 	unsigned long *vcpu_mask;
1658 	u64 valid_bank_mask;
1659 	u64 sparse_banks[64];
1660 	int sparse_banks_len;
1661 	bool all_cpus;
1662 
1663 	if (!ex) {
1664 		if (hc->fast) {
1665 			flush.address_space = hc->ingpa;
1666 			flush.flags = hc->outgpa;
1667 			flush.processor_mask = sse128_lo(hc->xmm[0]);
1668 		} else {
1669 			if (unlikely(kvm_read_guest(kvm, hc->ingpa,
1670 						    &flush, sizeof(flush))))
1671 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1672 		}
1673 
1674 		trace_kvm_hv_flush_tlb(flush.processor_mask,
1675 				       flush.address_space, flush.flags);
1676 
1677 		valid_bank_mask = BIT_ULL(0);
1678 		sparse_banks[0] = flush.processor_mask;
1679 
1680 		/*
1681 		 * Work around possible WS2012 bug: it sends hypercalls
1682 		 * with processor_mask = 0x0 and HV_FLUSH_ALL_PROCESSORS clear,
1683 		 * while also expecting us to flush something and crashing if
1684 		 * we don't. Let's treat processor_mask == 0 same as
1685 		 * HV_FLUSH_ALL_PROCESSORS.
1686 		 */
1687 		all_cpus = (flush.flags & HV_FLUSH_ALL_PROCESSORS) ||
1688 			flush.processor_mask == 0;
1689 	} else {
1690 		if (hc->fast) {
1691 			flush_ex.address_space = hc->ingpa;
1692 			flush_ex.flags = hc->outgpa;
1693 			memcpy(&flush_ex.hv_vp_set,
1694 			       &hc->xmm[0], sizeof(hc->xmm[0]));
1695 		} else {
1696 			if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush_ex,
1697 						    sizeof(flush_ex))))
1698 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1699 		}
1700 
1701 		trace_kvm_hv_flush_tlb_ex(flush_ex.hv_vp_set.valid_bank_mask,
1702 					  flush_ex.hv_vp_set.format,
1703 					  flush_ex.address_space,
1704 					  flush_ex.flags);
1705 
1706 		valid_bank_mask = flush_ex.hv_vp_set.valid_bank_mask;
1707 		all_cpus = flush_ex.hv_vp_set.format !=
1708 			HV_GENERIC_SET_SPARSE_4K;
1709 
1710 		sparse_banks_len = bitmap_weight((unsigned long *)&valid_bank_mask, 64);
1711 
1712 		if (!sparse_banks_len && !all_cpus)
1713 			goto ret_success;
1714 
1715 		if (!all_cpus) {
1716 			if (hc->fast) {
1717 				if (sparse_banks_len > HV_HYPERCALL_MAX_XMM_REGISTERS - 1)
1718 					return HV_STATUS_INVALID_HYPERCALL_INPUT;
1719 				for (i = 0; i < sparse_banks_len; i += 2) {
1720 					sparse_banks[i] = sse128_lo(hc->xmm[i / 2 + 1]);
1721 					sparse_banks[i + 1] = sse128_hi(hc->xmm[i / 2 + 1]);
1722 				}
1723 			} else {
1724 				gpa = hc->ingpa + offsetof(struct hv_tlb_flush_ex,
1725 							   hv_vp_set.bank_contents);
1726 				if (unlikely(kvm_read_guest(kvm, gpa, sparse_banks,
1727 							    sparse_banks_len *
1728 							    sizeof(sparse_banks[0]))))
1729 					return HV_STATUS_INVALID_HYPERCALL_INPUT;
1730 			}
1731 		}
1732 	}
1733 
1734 	cpumask_clear(&hv_vcpu->tlb_flush);
1735 
1736 	vcpu_mask = all_cpus ? NULL :
1737 		sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
1738 					vp_bitmap, vcpu_bitmap);
1739 
1740 	/*
1741 	 * vcpu->arch.cr3 may not be up-to-date for running vCPUs so we can't
1742 	 * analyze it here, flush TLB regardless of the specified address space.
1743 	 */
1744 	kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH,
1745 				    NULL, vcpu_mask, &hv_vcpu->tlb_flush);
1746 
1747 ret_success:
1748 	/* We always do full TLB flush, set 'Reps completed' = 'Rep Count' */
1749 	return (u64)HV_STATUS_SUCCESS |
1750 		((u64)hc->rep_cnt << HV_HYPERCALL_REP_COMP_OFFSET);
1751 }
1752 
1753 static void kvm_send_ipi_to_many(struct kvm *kvm, u32 vector,
1754 				 unsigned long *vcpu_bitmap)
1755 {
1756 	struct kvm_lapic_irq irq = {
1757 		.delivery_mode = APIC_DM_FIXED,
1758 		.vector = vector
1759 	};
1760 	struct kvm_vcpu *vcpu;
1761 	int i;
1762 
1763 	kvm_for_each_vcpu(i, vcpu, kvm) {
1764 		if (vcpu_bitmap && !test_bit(i, vcpu_bitmap))
1765 			continue;
1766 
1767 		/* We fail only when APIC is disabled */
1768 		kvm_apic_set_irq(vcpu, &irq, NULL);
1769 	}
1770 }
1771 
1772 static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool ex)
1773 {
1774 	struct kvm *kvm = vcpu->kvm;
1775 	struct hv_send_ipi_ex send_ipi_ex;
1776 	struct hv_send_ipi send_ipi;
1777 	u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1778 	DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS);
1779 	unsigned long *vcpu_mask;
1780 	unsigned long valid_bank_mask;
1781 	u64 sparse_banks[64];
1782 	int sparse_banks_len;
1783 	u32 vector;
1784 	bool all_cpus;
1785 
1786 	if (!ex) {
1787 		if (!hc->fast) {
1788 			if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi,
1789 						    sizeof(send_ipi))))
1790 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1791 			sparse_banks[0] = send_ipi.cpu_mask;
1792 			vector = send_ipi.vector;
1793 		} else {
1794 			/* 'reserved' part of hv_send_ipi should be 0 */
1795 			if (unlikely(hc->ingpa >> 32 != 0))
1796 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1797 			sparse_banks[0] = hc->outgpa;
1798 			vector = (u32)hc->ingpa;
1799 		}
1800 		all_cpus = false;
1801 		valid_bank_mask = BIT_ULL(0);
1802 
1803 		trace_kvm_hv_send_ipi(vector, sparse_banks[0]);
1804 	} else {
1805 		if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi_ex,
1806 					    sizeof(send_ipi_ex))))
1807 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1808 
1809 		trace_kvm_hv_send_ipi_ex(send_ipi_ex.vector,
1810 					 send_ipi_ex.vp_set.format,
1811 					 send_ipi_ex.vp_set.valid_bank_mask);
1812 
1813 		vector = send_ipi_ex.vector;
1814 		valid_bank_mask = send_ipi_ex.vp_set.valid_bank_mask;
1815 		sparse_banks_len = bitmap_weight(&valid_bank_mask, 64) *
1816 			sizeof(sparse_banks[0]);
1817 
1818 		all_cpus = send_ipi_ex.vp_set.format == HV_GENERIC_SET_ALL;
1819 
1820 		if (!sparse_banks_len)
1821 			goto ret_success;
1822 
1823 		if (!all_cpus &&
1824 		    kvm_read_guest(kvm,
1825 				   hc->ingpa + offsetof(struct hv_send_ipi_ex,
1826 							vp_set.bank_contents),
1827 				   sparse_banks,
1828 				   sparse_banks_len))
1829 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1830 	}
1831 
1832 	if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR))
1833 		return HV_STATUS_INVALID_HYPERCALL_INPUT;
1834 
1835 	vcpu_mask = all_cpus ? NULL :
1836 		sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
1837 					vp_bitmap, vcpu_bitmap);
1838 
1839 	kvm_send_ipi_to_many(kvm, vector, vcpu_mask);
1840 
1841 ret_success:
1842 	return HV_STATUS_SUCCESS;
1843 }
1844 
1845 void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu)
1846 {
1847 	struct kvm_cpuid_entry2 *entry;
1848 
1849 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_INTERFACE, 0);
1850 	if (entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX)
1851 		vcpu->arch.hyperv_enabled = true;
1852 	else
1853 		vcpu->arch.hyperv_enabled = false;
1854 }
1855 
1856 bool kvm_hv_hypercall_enabled(struct kvm_vcpu *vcpu)
1857 {
1858 	return vcpu->arch.hyperv_enabled && to_kvm_hv(vcpu->kvm)->hv_guest_os_id;
1859 }
1860 
1861 static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
1862 {
1863 	bool longmode;
1864 
1865 	longmode = is_64_bit_mode(vcpu);
1866 	if (longmode)
1867 		kvm_rax_write(vcpu, result);
1868 	else {
1869 		kvm_rdx_write(vcpu, result >> 32);
1870 		kvm_rax_write(vcpu, result & 0xffffffff);
1871 	}
1872 }
1873 
1874 static int kvm_hv_hypercall_complete(struct kvm_vcpu *vcpu, u64 result)
1875 {
1876 	kvm_hv_hypercall_set_result(vcpu, result);
1877 	++vcpu->stat.hypercalls;
1878 	return kvm_skip_emulated_instruction(vcpu);
1879 }
1880 
1881 static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
1882 {
1883 	return kvm_hv_hypercall_complete(vcpu, vcpu->run->hyperv.u.hcall.result);
1884 }
1885 
1886 static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
1887 {
1888 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1889 	struct eventfd_ctx *eventfd;
1890 
1891 	if (unlikely(!hc->fast)) {
1892 		int ret;
1893 		gpa_t gpa = hc->ingpa;
1894 
1895 		if ((gpa & (__alignof__(hc->ingpa) - 1)) ||
1896 		    offset_in_page(gpa) + sizeof(hc->ingpa) > PAGE_SIZE)
1897 			return HV_STATUS_INVALID_ALIGNMENT;
1898 
1899 		ret = kvm_vcpu_read_guest(vcpu, gpa,
1900 					  &hc->ingpa, sizeof(hc->ingpa));
1901 		if (ret < 0)
1902 			return HV_STATUS_INVALID_ALIGNMENT;
1903 	}
1904 
1905 	/*
1906 	 * Per spec, bits 32-47 contain the extra "flag number".  However, we
1907 	 * have no use for it, and in all known usecases it is zero, so just
1908 	 * report lookup failure if it isn't.
1909 	 */
1910 	if (hc->ingpa & 0xffff00000000ULL)
1911 		return HV_STATUS_INVALID_PORT_ID;
1912 	/* remaining bits are reserved-zero */
1913 	if (hc->ingpa & ~KVM_HYPERV_CONN_ID_MASK)
1914 		return HV_STATUS_INVALID_HYPERCALL_INPUT;
1915 
1916 	/* the eventfd is protected by vcpu->kvm->srcu, but conn_to_evt isn't */
1917 	rcu_read_lock();
1918 	eventfd = idr_find(&hv->conn_to_evt, hc->ingpa);
1919 	rcu_read_unlock();
1920 	if (!eventfd)
1921 		return HV_STATUS_INVALID_PORT_ID;
1922 
1923 	eventfd_signal(eventfd, 1);
1924 	return HV_STATUS_SUCCESS;
1925 }
1926 
1927 static bool is_xmm_fast_hypercall(struct kvm_hv_hcall *hc)
1928 {
1929 	switch (hc->code) {
1930 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
1931 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
1932 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
1933 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
1934 		return true;
1935 	}
1936 
1937 	return false;
1938 }
1939 
1940 static void kvm_hv_hypercall_read_xmm(struct kvm_hv_hcall *hc)
1941 {
1942 	int reg;
1943 
1944 	kvm_fpu_get();
1945 	for (reg = 0; reg < HV_HYPERCALL_MAX_XMM_REGISTERS; reg++)
1946 		_kvm_read_sse_reg(reg, &hc->xmm[reg]);
1947 	kvm_fpu_put();
1948 }
1949 
1950 int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
1951 {
1952 	struct kvm_hv_hcall hc;
1953 	u64 ret = HV_STATUS_SUCCESS;
1954 
1955 	/*
1956 	 * hypercall generates UD from non zero cpl and real mode
1957 	 * per HYPER-V spec
1958 	 */
1959 	if (static_call(kvm_x86_get_cpl)(vcpu) != 0 || !is_protmode(vcpu)) {
1960 		kvm_queue_exception(vcpu, UD_VECTOR);
1961 		return 1;
1962 	}
1963 
1964 #ifdef CONFIG_X86_64
1965 	if (is_64_bit_mode(vcpu)) {
1966 		hc.param = kvm_rcx_read(vcpu);
1967 		hc.ingpa = kvm_rdx_read(vcpu);
1968 		hc.outgpa = kvm_r8_read(vcpu);
1969 	} else
1970 #endif
1971 	{
1972 		hc.param = ((u64)kvm_rdx_read(vcpu) << 32) |
1973 			    (kvm_rax_read(vcpu) & 0xffffffff);
1974 		hc.ingpa = ((u64)kvm_rbx_read(vcpu) << 32) |
1975 			    (kvm_rcx_read(vcpu) & 0xffffffff);
1976 		hc.outgpa = ((u64)kvm_rdi_read(vcpu) << 32) |
1977 			     (kvm_rsi_read(vcpu) & 0xffffffff);
1978 	}
1979 
1980 	hc.code = hc.param & 0xffff;
1981 	hc.fast = !!(hc.param & HV_HYPERCALL_FAST_BIT);
1982 	hc.rep_cnt = (hc.param >> HV_HYPERCALL_REP_COMP_OFFSET) & 0xfff;
1983 	hc.rep_idx = (hc.param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff;
1984 	hc.rep = !!(hc.rep_cnt || hc.rep_idx);
1985 
1986 	if (hc.fast && is_xmm_fast_hypercall(&hc))
1987 		kvm_hv_hypercall_read_xmm(&hc);
1988 
1989 	trace_kvm_hv_hypercall(hc.code, hc.fast, hc.rep_cnt, hc.rep_idx,
1990 			       hc.ingpa, hc.outgpa);
1991 
1992 	switch (hc.code) {
1993 	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
1994 		if (unlikely(hc.rep)) {
1995 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1996 			break;
1997 		}
1998 		kvm_vcpu_on_spin(vcpu, true);
1999 		break;
2000 	case HVCALL_SIGNAL_EVENT:
2001 		if (unlikely(hc.rep)) {
2002 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2003 			break;
2004 		}
2005 		ret = kvm_hvcall_signal_event(vcpu, &hc);
2006 		if (ret != HV_STATUS_INVALID_PORT_ID)
2007 			break;
2008 		fallthrough;	/* maybe userspace knows this conn_id */
2009 	case HVCALL_POST_MESSAGE:
2010 		/* don't bother userspace if it has no way to handle it */
2011 		if (unlikely(hc.rep || !to_hv_synic(vcpu)->active)) {
2012 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2013 			break;
2014 		}
2015 		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
2016 		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
2017 		vcpu->run->hyperv.u.hcall.input = hc.param;
2018 		vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
2019 		vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
2020 		vcpu->arch.complete_userspace_io =
2021 				kvm_hv_hypercall_complete_userspace;
2022 		return 0;
2023 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2024 		if (unlikely(!hc.rep_cnt || hc.rep_idx)) {
2025 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2026 			break;
2027 		}
2028 		ret = kvm_hv_flush_tlb(vcpu, &hc, false);
2029 		break;
2030 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2031 		if (unlikely(hc.rep)) {
2032 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2033 			break;
2034 		}
2035 		ret = kvm_hv_flush_tlb(vcpu, &hc, false);
2036 		break;
2037 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2038 		if (unlikely(!hc.rep_cnt || hc.rep_idx)) {
2039 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2040 			break;
2041 		}
2042 		ret = kvm_hv_flush_tlb(vcpu, &hc, true);
2043 		break;
2044 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2045 		if (unlikely(hc.rep)) {
2046 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2047 			break;
2048 		}
2049 		ret = kvm_hv_flush_tlb(vcpu, &hc, true);
2050 		break;
2051 	case HVCALL_SEND_IPI:
2052 		if (unlikely(hc.rep)) {
2053 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2054 			break;
2055 		}
2056 		ret = kvm_hv_send_ipi(vcpu, &hc, false);
2057 		break;
2058 	case HVCALL_SEND_IPI_EX:
2059 		if (unlikely(hc.fast || hc.rep)) {
2060 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2061 			break;
2062 		}
2063 		ret = kvm_hv_send_ipi(vcpu, &hc, true);
2064 		break;
2065 	case HVCALL_POST_DEBUG_DATA:
2066 	case HVCALL_RETRIEVE_DEBUG_DATA:
2067 		if (unlikely(hc.fast)) {
2068 			ret = HV_STATUS_INVALID_PARAMETER;
2069 			break;
2070 		}
2071 		fallthrough;
2072 	case HVCALL_RESET_DEBUG_SESSION: {
2073 		struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
2074 
2075 		if (!kvm_hv_is_syndbg_enabled(vcpu)) {
2076 			ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2077 			break;
2078 		}
2079 
2080 		if (!(syndbg->options & HV_X64_SYNDBG_OPTION_USE_HCALLS)) {
2081 			ret = HV_STATUS_OPERATION_DENIED;
2082 			break;
2083 		}
2084 		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
2085 		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
2086 		vcpu->run->hyperv.u.hcall.input = hc.param;
2087 		vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
2088 		vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
2089 		vcpu->arch.complete_userspace_io =
2090 				kvm_hv_hypercall_complete_userspace;
2091 		return 0;
2092 	}
2093 	default:
2094 		ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2095 		break;
2096 	}
2097 
2098 	return kvm_hv_hypercall_complete(vcpu, ret);
2099 }
2100 
2101 void kvm_hv_init_vm(struct kvm *kvm)
2102 {
2103 	struct kvm_hv *hv = to_kvm_hv(kvm);
2104 
2105 	mutex_init(&hv->hv_lock);
2106 	idr_init(&hv->conn_to_evt);
2107 }
2108 
2109 void kvm_hv_destroy_vm(struct kvm *kvm)
2110 {
2111 	struct kvm_hv *hv = to_kvm_hv(kvm);
2112 	struct eventfd_ctx *eventfd;
2113 	int i;
2114 
2115 	idr_for_each_entry(&hv->conn_to_evt, eventfd, i)
2116 		eventfd_ctx_put(eventfd);
2117 	idr_destroy(&hv->conn_to_evt);
2118 }
2119 
2120 static int kvm_hv_eventfd_assign(struct kvm *kvm, u32 conn_id, int fd)
2121 {
2122 	struct kvm_hv *hv = to_kvm_hv(kvm);
2123 	struct eventfd_ctx *eventfd;
2124 	int ret;
2125 
2126 	eventfd = eventfd_ctx_fdget(fd);
2127 	if (IS_ERR(eventfd))
2128 		return PTR_ERR(eventfd);
2129 
2130 	mutex_lock(&hv->hv_lock);
2131 	ret = idr_alloc(&hv->conn_to_evt, eventfd, conn_id, conn_id + 1,
2132 			GFP_KERNEL_ACCOUNT);
2133 	mutex_unlock(&hv->hv_lock);
2134 
2135 	if (ret >= 0)
2136 		return 0;
2137 
2138 	if (ret == -ENOSPC)
2139 		ret = -EEXIST;
2140 	eventfd_ctx_put(eventfd);
2141 	return ret;
2142 }
2143 
2144 static int kvm_hv_eventfd_deassign(struct kvm *kvm, u32 conn_id)
2145 {
2146 	struct kvm_hv *hv = to_kvm_hv(kvm);
2147 	struct eventfd_ctx *eventfd;
2148 
2149 	mutex_lock(&hv->hv_lock);
2150 	eventfd = idr_remove(&hv->conn_to_evt, conn_id);
2151 	mutex_unlock(&hv->hv_lock);
2152 
2153 	if (!eventfd)
2154 		return -ENOENT;
2155 
2156 	synchronize_srcu(&kvm->srcu);
2157 	eventfd_ctx_put(eventfd);
2158 	return 0;
2159 }
2160 
2161 int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args)
2162 {
2163 	if ((args->flags & ~KVM_HYPERV_EVENTFD_DEASSIGN) ||
2164 	    (args->conn_id & ~KVM_HYPERV_CONN_ID_MASK))
2165 		return -EINVAL;
2166 
2167 	if (args->flags == KVM_HYPERV_EVENTFD_DEASSIGN)
2168 		return kvm_hv_eventfd_deassign(kvm, args->conn_id);
2169 	return kvm_hv_eventfd_assign(kvm, args->conn_id, args->fd);
2170 }
2171 
2172 int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
2173 		     struct kvm_cpuid_entry2 __user *entries)
2174 {
2175 	uint16_t evmcs_ver = 0;
2176 	struct kvm_cpuid_entry2 cpuid_entries[] = {
2177 		{ .function = HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS },
2178 		{ .function = HYPERV_CPUID_INTERFACE },
2179 		{ .function = HYPERV_CPUID_VERSION },
2180 		{ .function = HYPERV_CPUID_FEATURES },
2181 		{ .function = HYPERV_CPUID_ENLIGHTMENT_INFO },
2182 		{ .function = HYPERV_CPUID_IMPLEMENT_LIMITS },
2183 		{ .function = HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS },
2184 		{ .function = HYPERV_CPUID_SYNDBG_INTERFACE },
2185 		{ .function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES	},
2186 		{ .function = HYPERV_CPUID_NESTED_FEATURES },
2187 	};
2188 	int i, nent = ARRAY_SIZE(cpuid_entries);
2189 
2190 	if (kvm_x86_ops.nested_ops->get_evmcs_version)
2191 		evmcs_ver = kvm_x86_ops.nested_ops->get_evmcs_version(vcpu);
2192 
2193 	/* Skip NESTED_FEATURES if eVMCS is not supported */
2194 	if (!evmcs_ver)
2195 		--nent;
2196 
2197 	if (cpuid->nent < nent)
2198 		return -E2BIG;
2199 
2200 	if (cpuid->nent > nent)
2201 		cpuid->nent = nent;
2202 
2203 	for (i = 0; i < nent; i++) {
2204 		struct kvm_cpuid_entry2 *ent = &cpuid_entries[i];
2205 		u32 signature[3];
2206 
2207 		switch (ent->function) {
2208 		case HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS:
2209 			memcpy(signature, "Linux KVM Hv", 12);
2210 
2211 			ent->eax = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES;
2212 			ent->ebx = signature[0];
2213 			ent->ecx = signature[1];
2214 			ent->edx = signature[2];
2215 			break;
2216 
2217 		case HYPERV_CPUID_INTERFACE:
2218 			ent->eax = HYPERV_CPUID_SIGNATURE_EAX;
2219 			break;
2220 
2221 		case HYPERV_CPUID_VERSION:
2222 			/*
2223 			 * We implement some Hyper-V 2016 functions so let's use
2224 			 * this version.
2225 			 */
2226 			ent->eax = 0x00003839;
2227 			ent->ebx = 0x000A0000;
2228 			break;
2229 
2230 		case HYPERV_CPUID_FEATURES:
2231 			ent->eax |= HV_MSR_VP_RUNTIME_AVAILABLE;
2232 			ent->eax |= HV_MSR_TIME_REF_COUNT_AVAILABLE;
2233 			ent->eax |= HV_MSR_SYNIC_AVAILABLE;
2234 			ent->eax |= HV_MSR_SYNTIMER_AVAILABLE;
2235 			ent->eax |= HV_MSR_APIC_ACCESS_AVAILABLE;
2236 			ent->eax |= HV_MSR_HYPERCALL_AVAILABLE;
2237 			ent->eax |= HV_MSR_VP_INDEX_AVAILABLE;
2238 			ent->eax |= HV_MSR_RESET_AVAILABLE;
2239 			ent->eax |= HV_MSR_REFERENCE_TSC_AVAILABLE;
2240 			ent->eax |= HV_ACCESS_FREQUENCY_MSRS;
2241 			ent->eax |= HV_ACCESS_REENLIGHTENMENT;
2242 
2243 			ent->ebx |= HV_POST_MESSAGES;
2244 			ent->ebx |= HV_SIGNAL_EVENTS;
2245 
2246 			ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
2247 			ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
2248 
2249 			ent->ebx |= HV_DEBUGGING;
2250 			ent->edx |= HV_X64_GUEST_DEBUGGING_AVAILABLE;
2251 			ent->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
2252 
2253 			/*
2254 			 * Direct Synthetic timers only make sense with in-kernel
2255 			 * LAPIC
2256 			 */
2257 			if (!vcpu || lapic_in_kernel(vcpu))
2258 				ent->edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
2259 
2260 			break;
2261 
2262 		case HYPERV_CPUID_ENLIGHTMENT_INFO:
2263 			ent->eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
2264 			ent->eax |= HV_X64_APIC_ACCESS_RECOMMENDED;
2265 			ent->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED;
2266 			ent->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
2267 			ent->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
2268 			if (evmcs_ver)
2269 				ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;
2270 			if (!cpu_smt_possible())
2271 				ent->eax |= HV_X64_NO_NONARCH_CORESHARING;
2272 			/*
2273 			 * Default number of spinlock retry attempts, matches
2274 			 * HyperV 2016.
2275 			 */
2276 			ent->ebx = 0x00000FFF;
2277 
2278 			break;
2279 
2280 		case HYPERV_CPUID_IMPLEMENT_LIMITS:
2281 			/* Maximum number of virtual processors */
2282 			ent->eax = KVM_MAX_VCPUS;
2283 			/*
2284 			 * Maximum number of logical processors, matches
2285 			 * HyperV 2016.
2286 			 */
2287 			ent->ebx = 64;
2288 
2289 			break;
2290 
2291 		case HYPERV_CPUID_NESTED_FEATURES:
2292 			ent->eax = evmcs_ver;
2293 
2294 			break;
2295 
2296 		case HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS:
2297 			memcpy(signature, "Linux KVM Hv", 12);
2298 
2299 			ent->eax = 0;
2300 			ent->ebx = signature[0];
2301 			ent->ecx = signature[1];
2302 			ent->edx = signature[2];
2303 			break;
2304 
2305 		case HYPERV_CPUID_SYNDBG_INTERFACE:
2306 			memcpy(signature, "VS#1\0\0\0\0\0\0\0\0", 12);
2307 			ent->eax = signature[0];
2308 			break;
2309 
2310 		case HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES:
2311 			ent->eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
2312 			break;
2313 
2314 		default:
2315 			break;
2316 		}
2317 	}
2318 
2319 	if (copy_to_user(entries, cpuid_entries,
2320 			 nent * sizeof(struct kvm_cpuid_entry2)))
2321 		return -EFAULT;
2322 
2323 	return 0;
2324 }
2325