xref: /openbmc/linux/arch/x86/kvm/hyperv.c (revision 4e95bc26)
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 "hyperv.h"
25 
26 #include <linux/kvm_host.h>
27 #include <linux/highmem.h>
28 #include <linux/sched/cputime.h>
29 #include <linux/eventfd.h>
30 
31 #include <asm/apicdef.h>
32 #include <trace/events/kvm.h>
33 
34 #include "trace.h"
35 
36 #define KVM_HV_MAX_SPARSE_VCPU_SET_BITS DIV_ROUND_UP(KVM_MAX_VCPUS, 64)
37 
38 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
39 				bool vcpu_kick);
40 
41 static inline u64 synic_read_sint(struct kvm_vcpu_hv_synic *synic, int sint)
42 {
43 	return atomic64_read(&synic->sint[sint]);
44 }
45 
46 static inline int synic_get_sint_vector(u64 sint_value)
47 {
48 	if (sint_value & HV_SYNIC_SINT_MASKED)
49 		return -1;
50 	return sint_value & HV_SYNIC_SINT_VECTOR_MASK;
51 }
52 
53 static bool synic_has_vector_connected(struct kvm_vcpu_hv_synic *synic,
54 				      int vector)
55 {
56 	int i;
57 
58 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
59 		if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
60 			return true;
61 	}
62 	return false;
63 }
64 
65 static bool synic_has_vector_auto_eoi(struct kvm_vcpu_hv_synic *synic,
66 				     int vector)
67 {
68 	int i;
69 	u64 sint_value;
70 
71 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
72 		sint_value = synic_read_sint(synic, i);
73 		if (synic_get_sint_vector(sint_value) == vector &&
74 		    sint_value & HV_SYNIC_SINT_AUTO_EOI)
75 			return true;
76 	}
77 	return false;
78 }
79 
80 static void synic_update_vector(struct kvm_vcpu_hv_synic *synic,
81 				int vector)
82 {
83 	if (vector < HV_SYNIC_FIRST_VALID_VECTOR)
84 		return;
85 
86 	if (synic_has_vector_connected(synic, vector))
87 		__set_bit(vector, synic->vec_bitmap);
88 	else
89 		__clear_bit(vector, synic->vec_bitmap);
90 
91 	if (synic_has_vector_auto_eoi(synic, vector))
92 		__set_bit(vector, synic->auto_eoi_bitmap);
93 	else
94 		__clear_bit(vector, synic->auto_eoi_bitmap);
95 }
96 
97 static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint,
98 			  u64 data, bool host)
99 {
100 	int vector, old_vector;
101 	bool masked;
102 
103 	vector = data & HV_SYNIC_SINT_VECTOR_MASK;
104 	masked = data & HV_SYNIC_SINT_MASKED;
105 
106 	/*
107 	 * Valid vectors are 16-255, however, nested Hyper-V attempts to write
108 	 * default '0x10000' value on boot and this should not #GP. We need to
109 	 * allow zero-initing the register from host as well.
110 	 */
111 	if (vector < HV_SYNIC_FIRST_VALID_VECTOR && !host && !masked)
112 		return 1;
113 	/*
114 	 * Guest may configure multiple SINTs to use the same vector, so
115 	 * we maintain a bitmap of vectors handled by synic, and a
116 	 * bitmap of vectors with auto-eoi behavior.  The bitmaps are
117 	 * updated here, and atomically queried on fast paths.
118 	 */
119 	old_vector = synic_read_sint(synic, sint) & HV_SYNIC_SINT_VECTOR_MASK;
120 
121 	atomic64_set(&synic->sint[sint], data);
122 
123 	synic_update_vector(synic, old_vector);
124 
125 	synic_update_vector(synic, vector);
126 
127 	/* Load SynIC vectors into EOI exit bitmap */
128 	kvm_make_request(KVM_REQ_SCAN_IOAPIC, synic_to_vcpu(synic));
129 	return 0;
130 }
131 
132 static struct kvm_vcpu *get_vcpu_by_vpidx(struct kvm *kvm, u32 vpidx)
133 {
134 	struct kvm_vcpu *vcpu = NULL;
135 	int i;
136 
137 	if (vpidx >= KVM_MAX_VCPUS)
138 		return NULL;
139 
140 	vcpu = kvm_get_vcpu(kvm, vpidx);
141 	if (vcpu && vcpu_to_hv_vcpu(vcpu)->vp_index == vpidx)
142 		return vcpu;
143 	kvm_for_each_vcpu(i, vcpu, kvm)
144 		if (vcpu_to_hv_vcpu(vcpu)->vp_index == vpidx)
145 			return vcpu;
146 	return NULL;
147 }
148 
149 static struct kvm_vcpu_hv_synic *synic_get(struct kvm *kvm, u32 vpidx)
150 {
151 	struct kvm_vcpu *vcpu;
152 	struct kvm_vcpu_hv_synic *synic;
153 
154 	vcpu = get_vcpu_by_vpidx(kvm, vpidx);
155 	if (!vcpu)
156 		return NULL;
157 	synic = vcpu_to_synic(vcpu);
158 	return (synic->active) ? synic : NULL;
159 }
160 
161 static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
162 {
163 	struct kvm *kvm = vcpu->kvm;
164 	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
165 	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
166 	struct kvm_vcpu_hv_stimer *stimer;
167 	int gsi, idx;
168 
169 	trace_kvm_hv_notify_acked_sint(vcpu->vcpu_id, sint);
170 
171 	/* Try to deliver pending Hyper-V SynIC timers messages */
172 	for (idx = 0; idx < ARRAY_SIZE(hv_vcpu->stimer); idx++) {
173 		stimer = &hv_vcpu->stimer[idx];
174 		if (stimer->msg_pending && stimer->config.enable &&
175 		    !stimer->config.direct_mode &&
176 		    stimer->config.sintx == sint)
177 			stimer_mark_pending(stimer, false);
178 	}
179 
180 	idx = srcu_read_lock(&kvm->irq_srcu);
181 	gsi = atomic_read(&synic->sint_to_gsi[sint]);
182 	if (gsi != -1)
183 		kvm_notify_acked_gsi(kvm, gsi);
184 	srcu_read_unlock(&kvm->irq_srcu, idx);
185 }
186 
187 static void synic_exit(struct kvm_vcpu_hv_synic *synic, u32 msr)
188 {
189 	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
190 	struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
191 
192 	hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNIC;
193 	hv_vcpu->exit.u.synic.msr = msr;
194 	hv_vcpu->exit.u.synic.control = synic->control;
195 	hv_vcpu->exit.u.synic.evt_page = synic->evt_page;
196 	hv_vcpu->exit.u.synic.msg_page = synic->msg_page;
197 
198 	kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
199 }
200 
201 static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
202 			 u32 msr, u64 data, bool host)
203 {
204 	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
205 	int ret;
206 
207 	if (!synic->active && !host)
208 		return 1;
209 
210 	trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host);
211 
212 	ret = 0;
213 	switch (msr) {
214 	case HV_X64_MSR_SCONTROL:
215 		synic->control = data;
216 		if (!host)
217 			synic_exit(synic, msr);
218 		break;
219 	case HV_X64_MSR_SVERSION:
220 		if (!host) {
221 			ret = 1;
222 			break;
223 		}
224 		synic->version = data;
225 		break;
226 	case HV_X64_MSR_SIEFP:
227 		if ((data & HV_SYNIC_SIEFP_ENABLE) && !host &&
228 		    !synic->dont_zero_synic_pages)
229 			if (kvm_clear_guest(vcpu->kvm,
230 					    data & PAGE_MASK, PAGE_SIZE)) {
231 				ret = 1;
232 				break;
233 			}
234 		synic->evt_page = data;
235 		if (!host)
236 			synic_exit(synic, msr);
237 		break;
238 	case HV_X64_MSR_SIMP:
239 		if ((data & HV_SYNIC_SIMP_ENABLE) && !host &&
240 		    !synic->dont_zero_synic_pages)
241 			if (kvm_clear_guest(vcpu->kvm,
242 					    data & PAGE_MASK, PAGE_SIZE)) {
243 				ret = 1;
244 				break;
245 			}
246 		synic->msg_page = data;
247 		if (!host)
248 			synic_exit(synic, msr);
249 		break;
250 	case HV_X64_MSR_EOM: {
251 		int i;
252 
253 		for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
254 			kvm_hv_notify_acked_sint(vcpu, i);
255 		break;
256 	}
257 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
258 		ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data, host);
259 		break;
260 	default:
261 		ret = 1;
262 		break;
263 	}
264 	return ret;
265 }
266 
267 static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata,
268 			 bool host)
269 {
270 	int ret;
271 
272 	if (!synic->active && !host)
273 		return 1;
274 
275 	ret = 0;
276 	switch (msr) {
277 	case HV_X64_MSR_SCONTROL:
278 		*pdata = synic->control;
279 		break;
280 	case HV_X64_MSR_SVERSION:
281 		*pdata = synic->version;
282 		break;
283 	case HV_X64_MSR_SIEFP:
284 		*pdata = synic->evt_page;
285 		break;
286 	case HV_X64_MSR_SIMP:
287 		*pdata = synic->msg_page;
288 		break;
289 	case HV_X64_MSR_EOM:
290 		*pdata = 0;
291 		break;
292 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
293 		*pdata = atomic64_read(&synic->sint[msr - HV_X64_MSR_SINT0]);
294 		break;
295 	default:
296 		ret = 1;
297 		break;
298 	}
299 	return ret;
300 }
301 
302 static int synic_set_irq(struct kvm_vcpu_hv_synic *synic, u32 sint)
303 {
304 	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
305 	struct kvm_lapic_irq irq;
306 	int ret, vector;
307 
308 	if (sint >= ARRAY_SIZE(synic->sint))
309 		return -EINVAL;
310 
311 	vector = synic_get_sint_vector(synic_read_sint(synic, sint));
312 	if (vector < 0)
313 		return -ENOENT;
314 
315 	memset(&irq, 0, sizeof(irq));
316 	irq.shorthand = APIC_DEST_SELF;
317 	irq.dest_mode = APIC_DEST_PHYSICAL;
318 	irq.delivery_mode = APIC_DM_FIXED;
319 	irq.vector = vector;
320 	irq.level = 1;
321 
322 	ret = kvm_irq_delivery_to_apic(vcpu->kvm, vcpu->arch.apic, &irq, NULL);
323 	trace_kvm_hv_synic_set_irq(vcpu->vcpu_id, sint, irq.vector, ret);
324 	return ret;
325 }
326 
327 int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vpidx, u32 sint)
328 {
329 	struct kvm_vcpu_hv_synic *synic;
330 
331 	synic = synic_get(kvm, vpidx);
332 	if (!synic)
333 		return -EINVAL;
334 
335 	return synic_set_irq(synic, sint);
336 }
337 
338 void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
339 {
340 	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
341 	int i;
342 
343 	trace_kvm_hv_synic_send_eoi(vcpu->vcpu_id, vector);
344 
345 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
346 		if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
347 			kvm_hv_notify_acked_sint(vcpu, i);
348 }
349 
350 static int kvm_hv_set_sint_gsi(struct kvm *kvm, u32 vpidx, u32 sint, int gsi)
351 {
352 	struct kvm_vcpu_hv_synic *synic;
353 
354 	synic = synic_get(kvm, vpidx);
355 	if (!synic)
356 		return -EINVAL;
357 
358 	if (sint >= ARRAY_SIZE(synic->sint_to_gsi))
359 		return -EINVAL;
360 
361 	atomic_set(&synic->sint_to_gsi[sint], gsi);
362 	return 0;
363 }
364 
365 void kvm_hv_irq_routing_update(struct kvm *kvm)
366 {
367 	struct kvm_irq_routing_table *irq_rt;
368 	struct kvm_kernel_irq_routing_entry *e;
369 	u32 gsi;
370 
371 	irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
372 					lockdep_is_held(&kvm->irq_lock));
373 
374 	for (gsi = 0; gsi < irq_rt->nr_rt_entries; gsi++) {
375 		hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
376 			if (e->type == KVM_IRQ_ROUTING_HV_SINT)
377 				kvm_hv_set_sint_gsi(kvm, e->hv_sint.vcpu,
378 						    e->hv_sint.sint, gsi);
379 		}
380 	}
381 }
382 
383 static void synic_init(struct kvm_vcpu_hv_synic *synic)
384 {
385 	int i;
386 
387 	memset(synic, 0, sizeof(*synic));
388 	synic->version = HV_SYNIC_VERSION_1;
389 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
390 		atomic64_set(&synic->sint[i], HV_SYNIC_SINT_MASKED);
391 		atomic_set(&synic->sint_to_gsi[i], -1);
392 	}
393 }
394 
395 static u64 get_time_ref_counter(struct kvm *kvm)
396 {
397 	struct kvm_hv *hv = &kvm->arch.hyperv;
398 	struct kvm_vcpu *vcpu;
399 	u64 tsc;
400 
401 	/*
402 	 * The guest has not set up the TSC page or the clock isn't
403 	 * stable, fall back to get_kvmclock_ns.
404 	 */
405 	if (!hv->tsc_ref.tsc_sequence)
406 		return div_u64(get_kvmclock_ns(kvm), 100);
407 
408 	vcpu = kvm_get_vcpu(kvm, 0);
409 	tsc = kvm_read_l1_tsc(vcpu, rdtsc());
410 	return mul_u64_u64_shr(tsc, hv->tsc_ref.tsc_scale, 64)
411 		+ hv->tsc_ref.tsc_offset;
412 }
413 
414 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
415 				bool vcpu_kick)
416 {
417 	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
418 
419 	set_bit(stimer->index,
420 		vcpu_to_hv_vcpu(vcpu)->stimer_pending_bitmap);
421 	kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
422 	if (vcpu_kick)
423 		kvm_vcpu_kick(vcpu);
424 }
425 
426 static void stimer_cleanup(struct kvm_vcpu_hv_stimer *stimer)
427 {
428 	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
429 
430 	trace_kvm_hv_stimer_cleanup(stimer_to_vcpu(stimer)->vcpu_id,
431 				    stimer->index);
432 
433 	hrtimer_cancel(&stimer->timer);
434 	clear_bit(stimer->index,
435 		  vcpu_to_hv_vcpu(vcpu)->stimer_pending_bitmap);
436 	stimer->msg_pending = false;
437 	stimer->exp_time = 0;
438 }
439 
440 static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer)
441 {
442 	struct kvm_vcpu_hv_stimer *stimer;
443 
444 	stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer);
445 	trace_kvm_hv_stimer_callback(stimer_to_vcpu(stimer)->vcpu_id,
446 				     stimer->index);
447 	stimer_mark_pending(stimer, true);
448 
449 	return HRTIMER_NORESTART;
450 }
451 
452 /*
453  * stimer_start() assumptions:
454  * a) stimer->count is not equal to 0
455  * b) stimer->config has HV_STIMER_ENABLE flag
456  */
457 static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
458 {
459 	u64 time_now;
460 	ktime_t ktime_now;
461 
462 	time_now = get_time_ref_counter(stimer_to_vcpu(stimer)->kvm);
463 	ktime_now = ktime_get();
464 
465 	if (stimer->config.periodic) {
466 		if (stimer->exp_time) {
467 			if (time_now >= stimer->exp_time) {
468 				u64 remainder;
469 
470 				div64_u64_rem(time_now - stimer->exp_time,
471 					      stimer->count, &remainder);
472 				stimer->exp_time =
473 					time_now + (stimer->count - remainder);
474 			}
475 		} else
476 			stimer->exp_time = time_now + stimer->count;
477 
478 		trace_kvm_hv_stimer_start_periodic(
479 					stimer_to_vcpu(stimer)->vcpu_id,
480 					stimer->index,
481 					time_now, stimer->exp_time);
482 
483 		hrtimer_start(&stimer->timer,
484 			      ktime_add_ns(ktime_now,
485 					   100 * (stimer->exp_time - time_now)),
486 			      HRTIMER_MODE_ABS);
487 		return 0;
488 	}
489 	stimer->exp_time = stimer->count;
490 	if (time_now >= stimer->count) {
491 		/*
492 		 * Expire timer according to Hypervisor Top-Level Functional
493 		 * specification v4(15.3.1):
494 		 * "If a one shot is enabled and the specified count is in
495 		 * the past, it will expire immediately."
496 		 */
497 		stimer_mark_pending(stimer, false);
498 		return 0;
499 	}
500 
501 	trace_kvm_hv_stimer_start_one_shot(stimer_to_vcpu(stimer)->vcpu_id,
502 					   stimer->index,
503 					   time_now, stimer->count);
504 
505 	hrtimer_start(&stimer->timer,
506 		      ktime_add_ns(ktime_now, 100 * (stimer->count - time_now)),
507 		      HRTIMER_MODE_ABS);
508 	return 0;
509 }
510 
511 static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
512 			     bool host)
513 {
514 	union hv_stimer_config new_config = {.as_uint64 = config},
515 		old_config = {.as_uint64 = stimer->config.as_uint64};
516 
517 	trace_kvm_hv_stimer_set_config(stimer_to_vcpu(stimer)->vcpu_id,
518 				       stimer->index, config, host);
519 
520 	stimer_cleanup(stimer);
521 	if (old_config.enable &&
522 	    !new_config.direct_mode && new_config.sintx == 0)
523 		new_config.enable = 0;
524 	stimer->config.as_uint64 = new_config.as_uint64;
525 
526 	if (stimer->config.enable)
527 		stimer_mark_pending(stimer, false);
528 
529 	return 0;
530 }
531 
532 static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,
533 			    bool host)
534 {
535 	trace_kvm_hv_stimer_set_count(stimer_to_vcpu(stimer)->vcpu_id,
536 				      stimer->index, count, host);
537 
538 	stimer_cleanup(stimer);
539 	stimer->count = count;
540 	if (stimer->count == 0)
541 		stimer->config.enable = 0;
542 	else if (stimer->config.auto_enable)
543 		stimer->config.enable = 1;
544 
545 	if (stimer->config.enable)
546 		stimer_mark_pending(stimer, false);
547 
548 	return 0;
549 }
550 
551 static int stimer_get_config(struct kvm_vcpu_hv_stimer *stimer, u64 *pconfig)
552 {
553 	*pconfig = stimer->config.as_uint64;
554 	return 0;
555 }
556 
557 static int stimer_get_count(struct kvm_vcpu_hv_stimer *stimer, u64 *pcount)
558 {
559 	*pcount = stimer->count;
560 	return 0;
561 }
562 
563 static int synic_deliver_msg(struct kvm_vcpu_hv_synic *synic, u32 sint,
564 			     struct hv_message *src_msg, bool no_retry)
565 {
566 	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
567 	int msg_off = offsetof(struct hv_message_page, sint_message[sint]);
568 	gfn_t msg_page_gfn;
569 	struct hv_message_header hv_hdr;
570 	int r;
571 
572 	if (!(synic->msg_page & HV_SYNIC_SIMP_ENABLE))
573 		return -ENOENT;
574 
575 	msg_page_gfn = synic->msg_page >> PAGE_SHIFT;
576 
577 	/*
578 	 * Strictly following the spec-mandated ordering would assume setting
579 	 * .msg_pending before checking .message_type.  However, this function
580 	 * is only called in vcpu context so the entire update is atomic from
581 	 * guest POV and thus the exact order here doesn't matter.
582 	 */
583 	r = kvm_vcpu_read_guest_page(vcpu, msg_page_gfn, &hv_hdr.message_type,
584 				     msg_off + offsetof(struct hv_message,
585 							header.message_type),
586 				     sizeof(hv_hdr.message_type));
587 	if (r < 0)
588 		return r;
589 
590 	if (hv_hdr.message_type != HVMSG_NONE) {
591 		if (no_retry)
592 			return 0;
593 
594 		hv_hdr.message_flags.msg_pending = 1;
595 		r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn,
596 					      &hv_hdr.message_flags,
597 					      msg_off +
598 					      offsetof(struct hv_message,
599 						       header.message_flags),
600 					      sizeof(hv_hdr.message_flags));
601 		if (r < 0)
602 			return r;
603 		return -EAGAIN;
604 	}
605 
606 	r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn, src_msg, msg_off,
607 				      sizeof(src_msg->header) +
608 				      src_msg->header.payload_size);
609 	if (r < 0)
610 		return r;
611 
612 	r = synic_set_irq(synic, sint);
613 	if (r < 0)
614 		return r;
615 	if (r == 0)
616 		return -EFAULT;
617 	return 0;
618 }
619 
620 static int stimer_send_msg(struct kvm_vcpu_hv_stimer *stimer)
621 {
622 	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
623 	struct hv_message *msg = &stimer->msg;
624 	struct hv_timer_message_payload *payload =
625 			(struct hv_timer_message_payload *)&msg->u.payload;
626 
627 	/*
628 	 * To avoid piling up periodic ticks, don't retry message
629 	 * delivery for them (within "lazy" lost ticks policy).
630 	 */
631 	bool no_retry = stimer->config.periodic;
632 
633 	payload->expiration_time = stimer->exp_time;
634 	payload->delivery_time = get_time_ref_counter(vcpu->kvm);
635 	return synic_deliver_msg(vcpu_to_synic(vcpu),
636 				 stimer->config.sintx, msg,
637 				 no_retry);
638 }
639 
640 static int stimer_notify_direct(struct kvm_vcpu_hv_stimer *stimer)
641 {
642 	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
643 	struct kvm_lapic_irq irq = {
644 		.delivery_mode = APIC_DM_FIXED,
645 		.vector = stimer->config.apic_vector
646 	};
647 
648 	return !kvm_apic_set_irq(vcpu, &irq, NULL);
649 }
650 
651 static void stimer_expiration(struct kvm_vcpu_hv_stimer *stimer)
652 {
653 	int r, direct = stimer->config.direct_mode;
654 
655 	stimer->msg_pending = true;
656 	if (!direct)
657 		r = stimer_send_msg(stimer);
658 	else
659 		r = stimer_notify_direct(stimer);
660 	trace_kvm_hv_stimer_expiration(stimer_to_vcpu(stimer)->vcpu_id,
661 				       stimer->index, direct, r);
662 	if (!r) {
663 		stimer->msg_pending = false;
664 		if (!(stimer->config.periodic))
665 			stimer->config.enable = 0;
666 	}
667 }
668 
669 void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
670 {
671 	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
672 	struct kvm_vcpu_hv_stimer *stimer;
673 	u64 time_now, exp_time;
674 	int i;
675 
676 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
677 		if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) {
678 			stimer = &hv_vcpu->stimer[i];
679 			if (stimer->config.enable) {
680 				exp_time = stimer->exp_time;
681 
682 				if (exp_time) {
683 					time_now =
684 						get_time_ref_counter(vcpu->kvm);
685 					if (time_now >= exp_time)
686 						stimer_expiration(stimer);
687 				}
688 
689 				if ((stimer->config.enable) &&
690 				    stimer->count) {
691 					if (!stimer->msg_pending)
692 						stimer_start(stimer);
693 				} else
694 					stimer_cleanup(stimer);
695 			}
696 		}
697 }
698 
699 void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu)
700 {
701 	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
702 	int i;
703 
704 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
705 		stimer_cleanup(&hv_vcpu->stimer[i]);
706 }
707 
708 bool kvm_hv_assist_page_enabled(struct kvm_vcpu *vcpu)
709 {
710 	if (!(vcpu->arch.hyperv.hv_vapic & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE))
711 		return false;
712 	return vcpu->arch.pv_eoi.msr_val & KVM_MSR_ENABLED;
713 }
714 EXPORT_SYMBOL_GPL(kvm_hv_assist_page_enabled);
715 
716 bool kvm_hv_get_assist_page(struct kvm_vcpu *vcpu,
717 			    struct hv_vp_assist_page *assist_page)
718 {
719 	if (!kvm_hv_assist_page_enabled(vcpu))
720 		return false;
721 	return !kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data,
722 				      assist_page, sizeof(*assist_page));
723 }
724 EXPORT_SYMBOL_GPL(kvm_hv_get_assist_page);
725 
726 static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
727 {
728 	struct hv_message *msg = &stimer->msg;
729 	struct hv_timer_message_payload *payload =
730 			(struct hv_timer_message_payload *)&msg->u.payload;
731 
732 	memset(&msg->header, 0, sizeof(msg->header));
733 	msg->header.message_type = HVMSG_TIMER_EXPIRED;
734 	msg->header.payload_size = sizeof(*payload);
735 
736 	payload->timer_index = stimer->index;
737 	payload->expiration_time = 0;
738 	payload->delivery_time = 0;
739 }
740 
741 static void stimer_init(struct kvm_vcpu_hv_stimer *stimer, int timer_index)
742 {
743 	memset(stimer, 0, sizeof(*stimer));
744 	stimer->index = timer_index;
745 	hrtimer_init(&stimer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
746 	stimer->timer.function = stimer_timer_callback;
747 	stimer_prepare_msg(stimer);
748 }
749 
750 void kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
751 {
752 	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
753 	int i;
754 
755 	synic_init(&hv_vcpu->synic);
756 
757 	bitmap_zero(hv_vcpu->stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
758 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
759 		stimer_init(&hv_vcpu->stimer[i], i);
760 }
761 
762 void kvm_hv_vcpu_postcreate(struct kvm_vcpu *vcpu)
763 {
764 	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
765 
766 	hv_vcpu->vp_index = kvm_vcpu_get_idx(vcpu);
767 }
768 
769 int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages)
770 {
771 	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
772 
773 	/*
774 	 * Hyper-V SynIC auto EOI SINT's are
775 	 * not compatible with APICV, so deactivate APICV
776 	 */
777 	kvm_vcpu_deactivate_apicv(vcpu);
778 	synic->active = true;
779 	synic->dont_zero_synic_pages = dont_zero_synic_pages;
780 	return 0;
781 }
782 
783 static bool kvm_hv_msr_partition_wide(u32 msr)
784 {
785 	bool r = false;
786 
787 	switch (msr) {
788 	case HV_X64_MSR_GUEST_OS_ID:
789 	case HV_X64_MSR_HYPERCALL:
790 	case HV_X64_MSR_REFERENCE_TSC:
791 	case HV_X64_MSR_TIME_REF_COUNT:
792 	case HV_X64_MSR_CRASH_CTL:
793 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
794 	case HV_X64_MSR_RESET:
795 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
796 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
797 	case HV_X64_MSR_TSC_EMULATION_STATUS:
798 		r = true;
799 		break;
800 	}
801 
802 	return r;
803 }
804 
805 static int kvm_hv_msr_get_crash_data(struct kvm_vcpu *vcpu,
806 				     u32 index, u64 *pdata)
807 {
808 	struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
809 
810 	if (WARN_ON_ONCE(index >= ARRAY_SIZE(hv->hv_crash_param)))
811 		return -EINVAL;
812 
813 	*pdata = hv->hv_crash_param[index];
814 	return 0;
815 }
816 
817 static int kvm_hv_msr_get_crash_ctl(struct kvm_vcpu *vcpu, u64 *pdata)
818 {
819 	struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
820 
821 	*pdata = hv->hv_crash_ctl;
822 	return 0;
823 }
824 
825 static int kvm_hv_msr_set_crash_ctl(struct kvm_vcpu *vcpu, u64 data, bool host)
826 {
827 	struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
828 
829 	if (host)
830 		hv->hv_crash_ctl = data & HV_CRASH_CTL_CRASH_NOTIFY;
831 
832 	if (!host && (data & HV_CRASH_CTL_CRASH_NOTIFY)) {
833 
834 		vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx 0x%llx)\n",
835 			  hv->hv_crash_param[0],
836 			  hv->hv_crash_param[1],
837 			  hv->hv_crash_param[2],
838 			  hv->hv_crash_param[3],
839 			  hv->hv_crash_param[4]);
840 
841 		/* Send notification about crash to user space */
842 		kvm_make_request(KVM_REQ_HV_CRASH, vcpu);
843 	}
844 
845 	return 0;
846 }
847 
848 static int kvm_hv_msr_set_crash_data(struct kvm_vcpu *vcpu,
849 				     u32 index, u64 data)
850 {
851 	struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
852 
853 	if (WARN_ON_ONCE(index >= ARRAY_SIZE(hv->hv_crash_param)))
854 		return -EINVAL;
855 
856 	hv->hv_crash_param[index] = data;
857 	return 0;
858 }
859 
860 /*
861  * The kvmclock and Hyper-V TSC page use similar formulas, and converting
862  * between them is possible:
863  *
864  * kvmclock formula:
865  *    nsec = (ticks - tsc_timestamp) * tsc_to_system_mul * 2^(tsc_shift-32)
866  *           + system_time
867  *
868  * Hyper-V formula:
869  *    nsec/100 = ticks * scale / 2^64 + offset
870  *
871  * When tsc_timestamp = system_time = 0, offset is zero in the Hyper-V formula.
872  * By dividing the kvmclock formula by 100 and equating what's left we get:
873  *    ticks * scale / 2^64 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
874  *            scale / 2^64 =         tsc_to_system_mul * 2^(tsc_shift-32) / 100
875  *            scale        =         tsc_to_system_mul * 2^(32+tsc_shift) / 100
876  *
877  * Now expand the kvmclock formula and divide by 100:
878  *    nsec = ticks * tsc_to_system_mul * 2^(tsc_shift-32)
879  *           - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32)
880  *           + system_time
881  *    nsec/100 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
882  *               - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32) / 100
883  *               + system_time / 100
884  *
885  * Replace tsc_to_system_mul * 2^(tsc_shift-32) / 100 by scale / 2^64:
886  *    nsec/100 = ticks * scale / 2^64
887  *               - tsc_timestamp * scale / 2^64
888  *               + system_time / 100
889  *
890  * Equate with the Hyper-V formula so that ticks * scale / 2^64 cancels out:
891  *    offset = system_time / 100 - tsc_timestamp * scale / 2^64
892  *
893  * These two equivalencies are implemented in this function.
894  */
895 static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
896 					HV_REFERENCE_TSC_PAGE *tsc_ref)
897 {
898 	u64 max_mul;
899 
900 	if (!(hv_clock->flags & PVCLOCK_TSC_STABLE_BIT))
901 		return false;
902 
903 	/*
904 	 * check if scale would overflow, if so we use the time ref counter
905 	 *    tsc_to_system_mul * 2^(tsc_shift+32) / 100 >= 2^64
906 	 *    tsc_to_system_mul / 100 >= 2^(32-tsc_shift)
907 	 *    tsc_to_system_mul >= 100 * 2^(32-tsc_shift)
908 	 */
909 	max_mul = 100ull << (32 - hv_clock->tsc_shift);
910 	if (hv_clock->tsc_to_system_mul >= max_mul)
911 		return false;
912 
913 	/*
914 	 * Otherwise compute the scale and offset according to the formulas
915 	 * derived above.
916 	 */
917 	tsc_ref->tsc_scale =
918 		mul_u64_u32_div(1ULL << (32 + hv_clock->tsc_shift),
919 				hv_clock->tsc_to_system_mul,
920 				100);
921 
922 	tsc_ref->tsc_offset = hv_clock->system_time;
923 	do_div(tsc_ref->tsc_offset, 100);
924 	tsc_ref->tsc_offset -=
925 		mul_u64_u64_shr(hv_clock->tsc_timestamp, tsc_ref->tsc_scale, 64);
926 	return true;
927 }
928 
929 void kvm_hv_setup_tsc_page(struct kvm *kvm,
930 			   struct pvclock_vcpu_time_info *hv_clock)
931 {
932 	struct kvm_hv *hv = &kvm->arch.hyperv;
933 	u32 tsc_seq;
934 	u64 gfn;
935 
936 	BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
937 	BUILD_BUG_ON(offsetof(HV_REFERENCE_TSC_PAGE, tsc_sequence) != 0);
938 
939 	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
940 		return;
941 
942 	mutex_lock(&kvm->arch.hyperv.hv_lock);
943 	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
944 		goto out_unlock;
945 
946 	gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
947 	/*
948 	 * Because the TSC parameters only vary when there is a
949 	 * change in the master clock, do not bother with caching.
950 	 */
951 	if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
952 				    &tsc_seq, sizeof(tsc_seq))))
953 		goto out_unlock;
954 
955 	/*
956 	 * While we're computing and writing the parameters, force the
957 	 * guest to use the time reference count MSR.
958 	 */
959 	hv->tsc_ref.tsc_sequence = 0;
960 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
961 			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
962 		goto out_unlock;
963 
964 	if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
965 		goto out_unlock;
966 
967 	/* Ensure sequence is zero before writing the rest of the struct.  */
968 	smp_wmb();
969 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
970 		goto out_unlock;
971 
972 	/*
973 	 * Now switch to the TSC page mechanism by writing the sequence.
974 	 */
975 	tsc_seq++;
976 	if (tsc_seq == 0xFFFFFFFF || tsc_seq == 0)
977 		tsc_seq = 1;
978 
979 	/* Write the struct entirely before the non-zero sequence.  */
980 	smp_wmb();
981 
982 	hv->tsc_ref.tsc_sequence = tsc_seq;
983 	kvm_write_guest(kvm, gfn_to_gpa(gfn),
984 			&hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence));
985 out_unlock:
986 	mutex_unlock(&kvm->arch.hyperv.hv_lock);
987 }
988 
989 static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
990 			     bool host)
991 {
992 	struct kvm *kvm = vcpu->kvm;
993 	struct kvm_hv *hv = &kvm->arch.hyperv;
994 
995 	switch (msr) {
996 	case HV_X64_MSR_GUEST_OS_ID:
997 		hv->hv_guest_os_id = data;
998 		/* setting guest os id to zero disables hypercall page */
999 		if (!hv->hv_guest_os_id)
1000 			hv->hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
1001 		break;
1002 	case HV_X64_MSR_HYPERCALL: {
1003 		u64 gfn;
1004 		unsigned long addr;
1005 		u8 instructions[4];
1006 
1007 		/* if guest os id is not set hypercall should remain disabled */
1008 		if (!hv->hv_guest_os_id)
1009 			break;
1010 		if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
1011 			hv->hv_hypercall = data;
1012 			break;
1013 		}
1014 		gfn = data >> HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT;
1015 		addr = gfn_to_hva(kvm, gfn);
1016 		if (kvm_is_error_hva(addr))
1017 			return 1;
1018 		kvm_x86_ops->patch_hypercall(vcpu, instructions);
1019 		((unsigned char *)instructions)[3] = 0xc3; /* ret */
1020 		if (__copy_to_user((void __user *)addr, instructions, 4))
1021 			return 1;
1022 		hv->hv_hypercall = data;
1023 		mark_page_dirty(kvm, gfn);
1024 		break;
1025 	}
1026 	case HV_X64_MSR_REFERENCE_TSC:
1027 		hv->hv_tsc_page = data;
1028 		if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE)
1029 			kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
1030 		break;
1031 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1032 		return kvm_hv_msr_set_crash_data(vcpu,
1033 						 msr - HV_X64_MSR_CRASH_P0,
1034 						 data);
1035 	case HV_X64_MSR_CRASH_CTL:
1036 		return kvm_hv_msr_set_crash_ctl(vcpu, data, host);
1037 	case HV_X64_MSR_RESET:
1038 		if (data == 1) {
1039 			vcpu_debug(vcpu, "hyper-v reset requested\n");
1040 			kvm_make_request(KVM_REQ_HV_RESET, vcpu);
1041 		}
1042 		break;
1043 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1044 		hv->hv_reenlightenment_control = data;
1045 		break;
1046 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1047 		hv->hv_tsc_emulation_control = data;
1048 		break;
1049 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1050 		hv->hv_tsc_emulation_status = data;
1051 		break;
1052 	case HV_X64_MSR_TIME_REF_COUNT:
1053 		/* read-only, but still ignore it if host-initiated */
1054 		if (!host)
1055 			return 1;
1056 		break;
1057 	default:
1058 		vcpu_unimpl(vcpu, "Hyper-V uhandled wrmsr: 0x%x data 0x%llx\n",
1059 			    msr, data);
1060 		return 1;
1061 	}
1062 	return 0;
1063 }
1064 
1065 /* Calculate cpu time spent by current task in 100ns units */
1066 static u64 current_task_runtime_100ns(void)
1067 {
1068 	u64 utime, stime;
1069 
1070 	task_cputime_adjusted(current, &utime, &stime);
1071 
1072 	return div_u64(utime + stime, 100);
1073 }
1074 
1075 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1076 {
1077 	struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
1078 
1079 	switch (msr) {
1080 	case HV_X64_MSR_VP_INDEX: {
1081 		struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
1082 		int vcpu_idx = kvm_vcpu_get_idx(vcpu);
1083 		u32 new_vp_index = (u32)data;
1084 
1085 		if (!host || new_vp_index >= KVM_MAX_VCPUS)
1086 			return 1;
1087 
1088 		if (new_vp_index == hv_vcpu->vp_index)
1089 			return 0;
1090 
1091 		/*
1092 		 * The VP index is initialized to vcpu_index by
1093 		 * kvm_hv_vcpu_postcreate so they initially match.  Now the
1094 		 * VP index is changing, adjust num_mismatched_vp_indexes if
1095 		 * it now matches or no longer matches vcpu_idx.
1096 		 */
1097 		if (hv_vcpu->vp_index == vcpu_idx)
1098 			atomic_inc(&hv->num_mismatched_vp_indexes);
1099 		else if (new_vp_index == vcpu_idx)
1100 			atomic_dec(&hv->num_mismatched_vp_indexes);
1101 
1102 		hv_vcpu->vp_index = new_vp_index;
1103 		break;
1104 	}
1105 	case HV_X64_MSR_VP_ASSIST_PAGE: {
1106 		u64 gfn;
1107 		unsigned long addr;
1108 
1109 		if (!(data & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE)) {
1110 			hv_vcpu->hv_vapic = data;
1111 			if (kvm_lapic_enable_pv_eoi(vcpu, 0, 0))
1112 				return 1;
1113 			break;
1114 		}
1115 		gfn = data >> HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT;
1116 		addr = kvm_vcpu_gfn_to_hva(vcpu, gfn);
1117 		if (kvm_is_error_hva(addr))
1118 			return 1;
1119 
1120 		/*
1121 		 * Clear apic_assist portion of f(struct hv_vp_assist_page
1122 		 * only, there can be valuable data in the rest which needs
1123 		 * to be preserved e.g. on migration.
1124 		 */
1125 		if (__clear_user((void __user *)addr, sizeof(u32)))
1126 			return 1;
1127 		hv_vcpu->hv_vapic = data;
1128 		kvm_vcpu_mark_page_dirty(vcpu, gfn);
1129 		if (kvm_lapic_enable_pv_eoi(vcpu,
1130 					    gfn_to_gpa(gfn) | KVM_MSR_ENABLED,
1131 					    sizeof(struct hv_vp_assist_page)))
1132 			return 1;
1133 		break;
1134 	}
1135 	case HV_X64_MSR_EOI:
1136 		return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
1137 	case HV_X64_MSR_ICR:
1138 		return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
1139 	case HV_X64_MSR_TPR:
1140 		return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
1141 	case HV_X64_MSR_VP_RUNTIME:
1142 		if (!host)
1143 			return 1;
1144 		hv_vcpu->runtime_offset = data - current_task_runtime_100ns();
1145 		break;
1146 	case HV_X64_MSR_SCONTROL:
1147 	case HV_X64_MSR_SVERSION:
1148 	case HV_X64_MSR_SIEFP:
1149 	case HV_X64_MSR_SIMP:
1150 	case HV_X64_MSR_EOM:
1151 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1152 		return synic_set_msr(vcpu_to_synic(vcpu), msr, data, host);
1153 	case HV_X64_MSR_STIMER0_CONFIG:
1154 	case HV_X64_MSR_STIMER1_CONFIG:
1155 	case HV_X64_MSR_STIMER2_CONFIG:
1156 	case HV_X64_MSR_STIMER3_CONFIG: {
1157 		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1158 
1159 		return stimer_set_config(vcpu_to_stimer(vcpu, timer_index),
1160 					 data, host);
1161 	}
1162 	case HV_X64_MSR_STIMER0_COUNT:
1163 	case HV_X64_MSR_STIMER1_COUNT:
1164 	case HV_X64_MSR_STIMER2_COUNT:
1165 	case HV_X64_MSR_STIMER3_COUNT: {
1166 		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1167 
1168 		return stimer_set_count(vcpu_to_stimer(vcpu, timer_index),
1169 					data, host);
1170 	}
1171 	case HV_X64_MSR_TSC_FREQUENCY:
1172 	case HV_X64_MSR_APIC_FREQUENCY:
1173 		/* read-only, but still ignore it if host-initiated */
1174 		if (!host)
1175 			return 1;
1176 		break;
1177 	default:
1178 		vcpu_unimpl(vcpu, "Hyper-V uhandled wrmsr: 0x%x data 0x%llx\n",
1179 			    msr, data);
1180 		return 1;
1181 	}
1182 
1183 	return 0;
1184 }
1185 
1186 static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
1187 {
1188 	u64 data = 0;
1189 	struct kvm *kvm = vcpu->kvm;
1190 	struct kvm_hv *hv = &kvm->arch.hyperv;
1191 
1192 	switch (msr) {
1193 	case HV_X64_MSR_GUEST_OS_ID:
1194 		data = hv->hv_guest_os_id;
1195 		break;
1196 	case HV_X64_MSR_HYPERCALL:
1197 		data = hv->hv_hypercall;
1198 		break;
1199 	case HV_X64_MSR_TIME_REF_COUNT:
1200 		data = get_time_ref_counter(kvm);
1201 		break;
1202 	case HV_X64_MSR_REFERENCE_TSC:
1203 		data = hv->hv_tsc_page;
1204 		break;
1205 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1206 		return kvm_hv_msr_get_crash_data(vcpu,
1207 						 msr - HV_X64_MSR_CRASH_P0,
1208 						 pdata);
1209 	case HV_X64_MSR_CRASH_CTL:
1210 		return kvm_hv_msr_get_crash_ctl(vcpu, pdata);
1211 	case HV_X64_MSR_RESET:
1212 		data = 0;
1213 		break;
1214 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1215 		data = hv->hv_reenlightenment_control;
1216 		break;
1217 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1218 		data = hv->hv_tsc_emulation_control;
1219 		break;
1220 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1221 		data = hv->hv_tsc_emulation_status;
1222 		break;
1223 	default:
1224 		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1225 		return 1;
1226 	}
1227 
1228 	*pdata = data;
1229 	return 0;
1230 }
1231 
1232 static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1233 			  bool host)
1234 {
1235 	u64 data = 0;
1236 	struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
1237 
1238 	switch (msr) {
1239 	case HV_X64_MSR_VP_INDEX:
1240 		data = hv_vcpu->vp_index;
1241 		break;
1242 	case HV_X64_MSR_EOI:
1243 		return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
1244 	case HV_X64_MSR_ICR:
1245 		return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
1246 	case HV_X64_MSR_TPR:
1247 		return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
1248 	case HV_X64_MSR_VP_ASSIST_PAGE:
1249 		data = hv_vcpu->hv_vapic;
1250 		break;
1251 	case HV_X64_MSR_VP_RUNTIME:
1252 		data = current_task_runtime_100ns() + hv_vcpu->runtime_offset;
1253 		break;
1254 	case HV_X64_MSR_SCONTROL:
1255 	case HV_X64_MSR_SVERSION:
1256 	case HV_X64_MSR_SIEFP:
1257 	case HV_X64_MSR_SIMP:
1258 	case HV_X64_MSR_EOM:
1259 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1260 		return synic_get_msr(vcpu_to_synic(vcpu), msr, pdata, host);
1261 	case HV_X64_MSR_STIMER0_CONFIG:
1262 	case HV_X64_MSR_STIMER1_CONFIG:
1263 	case HV_X64_MSR_STIMER2_CONFIG:
1264 	case HV_X64_MSR_STIMER3_CONFIG: {
1265 		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1266 
1267 		return stimer_get_config(vcpu_to_stimer(vcpu, timer_index),
1268 					 pdata);
1269 	}
1270 	case HV_X64_MSR_STIMER0_COUNT:
1271 	case HV_X64_MSR_STIMER1_COUNT:
1272 	case HV_X64_MSR_STIMER2_COUNT:
1273 	case HV_X64_MSR_STIMER3_COUNT: {
1274 		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1275 
1276 		return stimer_get_count(vcpu_to_stimer(vcpu, timer_index),
1277 					pdata);
1278 	}
1279 	case HV_X64_MSR_TSC_FREQUENCY:
1280 		data = (u64)vcpu->arch.virtual_tsc_khz * 1000;
1281 		break;
1282 	case HV_X64_MSR_APIC_FREQUENCY:
1283 		data = APIC_BUS_FREQUENCY;
1284 		break;
1285 	default:
1286 		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1287 		return 1;
1288 	}
1289 	*pdata = data;
1290 	return 0;
1291 }
1292 
1293 int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1294 {
1295 	if (kvm_hv_msr_partition_wide(msr)) {
1296 		int r;
1297 
1298 		mutex_lock(&vcpu->kvm->arch.hyperv.hv_lock);
1299 		r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
1300 		mutex_unlock(&vcpu->kvm->arch.hyperv.hv_lock);
1301 		return r;
1302 	} else
1303 		return kvm_hv_set_msr(vcpu, msr, data, host);
1304 }
1305 
1306 int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
1307 {
1308 	if (kvm_hv_msr_partition_wide(msr)) {
1309 		int r;
1310 
1311 		mutex_lock(&vcpu->kvm->arch.hyperv.hv_lock);
1312 		r = kvm_hv_get_msr_pw(vcpu, msr, pdata);
1313 		mutex_unlock(&vcpu->kvm->arch.hyperv.hv_lock);
1314 		return r;
1315 	} else
1316 		return kvm_hv_get_msr(vcpu, msr, pdata, host);
1317 }
1318 
1319 static __always_inline unsigned long *sparse_set_to_vcpu_mask(
1320 	struct kvm *kvm, u64 *sparse_banks, u64 valid_bank_mask,
1321 	u64 *vp_bitmap, unsigned long *vcpu_bitmap)
1322 {
1323 	struct kvm_hv *hv = &kvm->arch.hyperv;
1324 	struct kvm_vcpu *vcpu;
1325 	int i, bank, sbank = 0;
1326 
1327 	memset(vp_bitmap, 0,
1328 	       KVM_HV_MAX_SPARSE_VCPU_SET_BITS * sizeof(*vp_bitmap));
1329 	for_each_set_bit(bank, (unsigned long *)&valid_bank_mask,
1330 			 KVM_HV_MAX_SPARSE_VCPU_SET_BITS)
1331 		vp_bitmap[bank] = sparse_banks[sbank++];
1332 
1333 	if (likely(!atomic_read(&hv->num_mismatched_vp_indexes))) {
1334 		/* for all vcpus vp_index == vcpu_idx */
1335 		return (unsigned long *)vp_bitmap;
1336 	}
1337 
1338 	bitmap_zero(vcpu_bitmap, KVM_MAX_VCPUS);
1339 	kvm_for_each_vcpu(i, vcpu, kvm) {
1340 		if (test_bit(vcpu_to_hv_vcpu(vcpu)->vp_index,
1341 			     (unsigned long *)vp_bitmap))
1342 			__set_bit(i, vcpu_bitmap);
1343 	}
1344 	return vcpu_bitmap;
1345 }
1346 
1347 static u64 kvm_hv_flush_tlb(struct kvm_vcpu *current_vcpu, u64 ingpa,
1348 			    u16 rep_cnt, bool ex)
1349 {
1350 	struct kvm *kvm = current_vcpu->kvm;
1351 	struct kvm_vcpu_hv *hv_vcpu = &current_vcpu->arch.hyperv;
1352 	struct hv_tlb_flush_ex flush_ex;
1353 	struct hv_tlb_flush flush;
1354 	u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1355 	DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS);
1356 	unsigned long *vcpu_mask;
1357 	u64 valid_bank_mask;
1358 	u64 sparse_banks[64];
1359 	int sparse_banks_len;
1360 	bool all_cpus;
1361 
1362 	if (!ex) {
1363 		if (unlikely(kvm_read_guest(kvm, ingpa, &flush, sizeof(flush))))
1364 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1365 
1366 		trace_kvm_hv_flush_tlb(flush.processor_mask,
1367 				       flush.address_space, flush.flags);
1368 
1369 		valid_bank_mask = BIT_ULL(0);
1370 		sparse_banks[0] = flush.processor_mask;
1371 
1372 		/*
1373 		 * Work around possible WS2012 bug: it sends hypercalls
1374 		 * with processor_mask = 0x0 and HV_FLUSH_ALL_PROCESSORS clear,
1375 		 * while also expecting us to flush something and crashing if
1376 		 * we don't. Let's treat processor_mask == 0 same as
1377 		 * HV_FLUSH_ALL_PROCESSORS.
1378 		 */
1379 		all_cpus = (flush.flags & HV_FLUSH_ALL_PROCESSORS) ||
1380 			flush.processor_mask == 0;
1381 	} else {
1382 		if (unlikely(kvm_read_guest(kvm, ingpa, &flush_ex,
1383 					    sizeof(flush_ex))))
1384 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1385 
1386 		trace_kvm_hv_flush_tlb_ex(flush_ex.hv_vp_set.valid_bank_mask,
1387 					  flush_ex.hv_vp_set.format,
1388 					  flush_ex.address_space,
1389 					  flush_ex.flags);
1390 
1391 		valid_bank_mask = flush_ex.hv_vp_set.valid_bank_mask;
1392 		all_cpus = flush_ex.hv_vp_set.format !=
1393 			HV_GENERIC_SET_SPARSE_4K;
1394 
1395 		sparse_banks_len =
1396 			bitmap_weight((unsigned long *)&valid_bank_mask, 64) *
1397 			sizeof(sparse_banks[0]);
1398 
1399 		if (!sparse_banks_len && !all_cpus)
1400 			goto ret_success;
1401 
1402 		if (!all_cpus &&
1403 		    kvm_read_guest(kvm,
1404 				   ingpa + offsetof(struct hv_tlb_flush_ex,
1405 						    hv_vp_set.bank_contents),
1406 				   sparse_banks,
1407 				   sparse_banks_len))
1408 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1409 	}
1410 
1411 	cpumask_clear(&hv_vcpu->tlb_flush);
1412 
1413 	vcpu_mask = all_cpus ? NULL :
1414 		sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
1415 					vp_bitmap, vcpu_bitmap);
1416 
1417 	/*
1418 	 * vcpu->arch.cr3 may not be up-to-date for running vCPUs so we can't
1419 	 * analyze it here, flush TLB regardless of the specified address space.
1420 	 */
1421 	kvm_make_vcpus_request_mask(kvm,
1422 				    KVM_REQ_TLB_FLUSH | KVM_REQUEST_NO_WAKEUP,
1423 				    vcpu_mask, &hv_vcpu->tlb_flush);
1424 
1425 ret_success:
1426 	/* We always do full TLB flush, set rep_done = rep_cnt. */
1427 	return (u64)HV_STATUS_SUCCESS |
1428 		((u64)rep_cnt << HV_HYPERCALL_REP_COMP_OFFSET);
1429 }
1430 
1431 static void kvm_send_ipi_to_many(struct kvm *kvm, u32 vector,
1432 				 unsigned long *vcpu_bitmap)
1433 {
1434 	struct kvm_lapic_irq irq = {
1435 		.delivery_mode = APIC_DM_FIXED,
1436 		.vector = vector
1437 	};
1438 	struct kvm_vcpu *vcpu;
1439 	int i;
1440 
1441 	kvm_for_each_vcpu(i, vcpu, kvm) {
1442 		if (vcpu_bitmap && !test_bit(i, vcpu_bitmap))
1443 			continue;
1444 
1445 		/* We fail only when APIC is disabled */
1446 		kvm_apic_set_irq(vcpu, &irq, NULL);
1447 	}
1448 }
1449 
1450 static u64 kvm_hv_send_ipi(struct kvm_vcpu *current_vcpu, u64 ingpa, u64 outgpa,
1451 			   bool ex, bool fast)
1452 {
1453 	struct kvm *kvm = current_vcpu->kvm;
1454 	struct hv_send_ipi_ex send_ipi_ex;
1455 	struct hv_send_ipi send_ipi;
1456 	u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1457 	DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS);
1458 	unsigned long *vcpu_mask;
1459 	unsigned long valid_bank_mask;
1460 	u64 sparse_banks[64];
1461 	int sparse_banks_len;
1462 	u32 vector;
1463 	bool all_cpus;
1464 
1465 	if (!ex) {
1466 		if (!fast) {
1467 			if (unlikely(kvm_read_guest(kvm, ingpa, &send_ipi,
1468 						    sizeof(send_ipi))))
1469 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1470 			sparse_banks[0] = send_ipi.cpu_mask;
1471 			vector = send_ipi.vector;
1472 		} else {
1473 			/* 'reserved' part of hv_send_ipi should be 0 */
1474 			if (unlikely(ingpa >> 32 != 0))
1475 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1476 			sparse_banks[0] = outgpa;
1477 			vector = (u32)ingpa;
1478 		}
1479 		all_cpus = false;
1480 		valid_bank_mask = BIT_ULL(0);
1481 
1482 		trace_kvm_hv_send_ipi(vector, sparse_banks[0]);
1483 	} else {
1484 		if (unlikely(kvm_read_guest(kvm, ingpa, &send_ipi_ex,
1485 					    sizeof(send_ipi_ex))))
1486 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1487 
1488 		trace_kvm_hv_send_ipi_ex(send_ipi_ex.vector,
1489 					 send_ipi_ex.vp_set.format,
1490 					 send_ipi_ex.vp_set.valid_bank_mask);
1491 
1492 		vector = send_ipi_ex.vector;
1493 		valid_bank_mask = send_ipi_ex.vp_set.valid_bank_mask;
1494 		sparse_banks_len = bitmap_weight(&valid_bank_mask, 64) *
1495 			sizeof(sparse_banks[0]);
1496 
1497 		all_cpus = send_ipi_ex.vp_set.format == HV_GENERIC_SET_ALL;
1498 
1499 		if (!sparse_banks_len)
1500 			goto ret_success;
1501 
1502 		if (!all_cpus &&
1503 		    kvm_read_guest(kvm,
1504 				   ingpa + offsetof(struct hv_send_ipi_ex,
1505 						    vp_set.bank_contents),
1506 				   sparse_banks,
1507 				   sparse_banks_len))
1508 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1509 	}
1510 
1511 	if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR))
1512 		return HV_STATUS_INVALID_HYPERCALL_INPUT;
1513 
1514 	vcpu_mask = all_cpus ? NULL :
1515 		sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
1516 					vp_bitmap, vcpu_bitmap);
1517 
1518 	kvm_send_ipi_to_many(kvm, vector, vcpu_mask);
1519 
1520 ret_success:
1521 	return HV_STATUS_SUCCESS;
1522 }
1523 
1524 bool kvm_hv_hypercall_enabled(struct kvm *kvm)
1525 {
1526 	return READ_ONCE(kvm->arch.hyperv.hv_hypercall) & HV_X64_MSR_HYPERCALL_ENABLE;
1527 }
1528 
1529 static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
1530 {
1531 	bool longmode;
1532 
1533 	longmode = is_64_bit_mode(vcpu);
1534 	if (longmode)
1535 		kvm_rax_write(vcpu, result);
1536 	else {
1537 		kvm_rdx_write(vcpu, result >> 32);
1538 		kvm_rax_write(vcpu, result & 0xffffffff);
1539 	}
1540 }
1541 
1542 static int kvm_hv_hypercall_complete(struct kvm_vcpu *vcpu, u64 result)
1543 {
1544 	kvm_hv_hypercall_set_result(vcpu, result);
1545 	++vcpu->stat.hypercalls;
1546 	return kvm_skip_emulated_instruction(vcpu);
1547 }
1548 
1549 static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
1550 {
1551 	return kvm_hv_hypercall_complete(vcpu, vcpu->run->hyperv.u.hcall.result);
1552 }
1553 
1554 static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, bool fast, u64 param)
1555 {
1556 	struct eventfd_ctx *eventfd;
1557 
1558 	if (unlikely(!fast)) {
1559 		int ret;
1560 		gpa_t gpa = param;
1561 
1562 		if ((gpa & (__alignof__(param) - 1)) ||
1563 		    offset_in_page(gpa) + sizeof(param) > PAGE_SIZE)
1564 			return HV_STATUS_INVALID_ALIGNMENT;
1565 
1566 		ret = kvm_vcpu_read_guest(vcpu, gpa, &param, sizeof(param));
1567 		if (ret < 0)
1568 			return HV_STATUS_INVALID_ALIGNMENT;
1569 	}
1570 
1571 	/*
1572 	 * Per spec, bits 32-47 contain the extra "flag number".  However, we
1573 	 * have no use for it, and in all known usecases it is zero, so just
1574 	 * report lookup failure if it isn't.
1575 	 */
1576 	if (param & 0xffff00000000ULL)
1577 		return HV_STATUS_INVALID_PORT_ID;
1578 	/* remaining bits are reserved-zero */
1579 	if (param & ~KVM_HYPERV_CONN_ID_MASK)
1580 		return HV_STATUS_INVALID_HYPERCALL_INPUT;
1581 
1582 	/* the eventfd is protected by vcpu->kvm->srcu, but conn_to_evt isn't */
1583 	rcu_read_lock();
1584 	eventfd = idr_find(&vcpu->kvm->arch.hyperv.conn_to_evt, param);
1585 	rcu_read_unlock();
1586 	if (!eventfd)
1587 		return HV_STATUS_INVALID_PORT_ID;
1588 
1589 	eventfd_signal(eventfd, 1);
1590 	return HV_STATUS_SUCCESS;
1591 }
1592 
1593 int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
1594 {
1595 	u64 param, ingpa, outgpa, ret = HV_STATUS_SUCCESS;
1596 	uint16_t code, rep_idx, rep_cnt;
1597 	bool fast, longmode, rep;
1598 
1599 	/*
1600 	 * hypercall generates UD from non zero cpl and real mode
1601 	 * per HYPER-V spec
1602 	 */
1603 	if (kvm_x86_ops->get_cpl(vcpu) != 0 || !is_protmode(vcpu)) {
1604 		kvm_queue_exception(vcpu, UD_VECTOR);
1605 		return 1;
1606 	}
1607 
1608 	longmode = is_64_bit_mode(vcpu);
1609 
1610 	if (!longmode) {
1611 		param = ((u64)kvm_rdx_read(vcpu) << 32) |
1612 			(kvm_rax_read(vcpu) & 0xffffffff);
1613 		ingpa = ((u64)kvm_rbx_read(vcpu) << 32) |
1614 			(kvm_rcx_read(vcpu) & 0xffffffff);
1615 		outgpa = ((u64)kvm_rdi_read(vcpu) << 32) |
1616 			(kvm_rsi_read(vcpu) & 0xffffffff);
1617 	}
1618 #ifdef CONFIG_X86_64
1619 	else {
1620 		param = kvm_rcx_read(vcpu);
1621 		ingpa = kvm_rdx_read(vcpu);
1622 		outgpa = kvm_r8_read(vcpu);
1623 	}
1624 #endif
1625 
1626 	code = param & 0xffff;
1627 	fast = !!(param & HV_HYPERCALL_FAST_BIT);
1628 	rep_cnt = (param >> HV_HYPERCALL_REP_COMP_OFFSET) & 0xfff;
1629 	rep_idx = (param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff;
1630 	rep = !!(rep_cnt || rep_idx);
1631 
1632 	trace_kvm_hv_hypercall(code, fast, rep_cnt, rep_idx, ingpa, outgpa);
1633 
1634 	switch (code) {
1635 	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
1636 		if (unlikely(rep)) {
1637 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1638 			break;
1639 		}
1640 		kvm_vcpu_on_spin(vcpu, true);
1641 		break;
1642 	case HVCALL_SIGNAL_EVENT:
1643 		if (unlikely(rep)) {
1644 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1645 			break;
1646 		}
1647 		ret = kvm_hvcall_signal_event(vcpu, fast, ingpa);
1648 		if (ret != HV_STATUS_INVALID_PORT_ID)
1649 			break;
1650 		/* fall through - maybe userspace knows this conn_id. */
1651 	case HVCALL_POST_MESSAGE:
1652 		/* don't bother userspace if it has no way to handle it */
1653 		if (unlikely(rep || !vcpu_to_synic(vcpu)->active)) {
1654 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1655 			break;
1656 		}
1657 		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
1658 		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
1659 		vcpu->run->hyperv.u.hcall.input = param;
1660 		vcpu->run->hyperv.u.hcall.params[0] = ingpa;
1661 		vcpu->run->hyperv.u.hcall.params[1] = outgpa;
1662 		vcpu->arch.complete_userspace_io =
1663 				kvm_hv_hypercall_complete_userspace;
1664 		return 0;
1665 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
1666 		if (unlikely(fast || !rep_cnt || rep_idx)) {
1667 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1668 			break;
1669 		}
1670 		ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, false);
1671 		break;
1672 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
1673 		if (unlikely(fast || rep)) {
1674 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1675 			break;
1676 		}
1677 		ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, false);
1678 		break;
1679 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
1680 		if (unlikely(fast || !rep_cnt || rep_idx)) {
1681 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1682 			break;
1683 		}
1684 		ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, true);
1685 		break;
1686 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
1687 		if (unlikely(fast || rep)) {
1688 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1689 			break;
1690 		}
1691 		ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, true);
1692 		break;
1693 	case HVCALL_SEND_IPI:
1694 		if (unlikely(rep)) {
1695 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1696 			break;
1697 		}
1698 		ret = kvm_hv_send_ipi(vcpu, ingpa, outgpa, false, fast);
1699 		break;
1700 	case HVCALL_SEND_IPI_EX:
1701 		if (unlikely(fast || rep)) {
1702 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1703 			break;
1704 		}
1705 		ret = kvm_hv_send_ipi(vcpu, ingpa, outgpa, true, false);
1706 		break;
1707 	default:
1708 		ret = HV_STATUS_INVALID_HYPERCALL_CODE;
1709 		break;
1710 	}
1711 
1712 	return kvm_hv_hypercall_complete(vcpu, ret);
1713 }
1714 
1715 void kvm_hv_init_vm(struct kvm *kvm)
1716 {
1717 	mutex_init(&kvm->arch.hyperv.hv_lock);
1718 	idr_init(&kvm->arch.hyperv.conn_to_evt);
1719 }
1720 
1721 void kvm_hv_destroy_vm(struct kvm *kvm)
1722 {
1723 	struct eventfd_ctx *eventfd;
1724 	int i;
1725 
1726 	idr_for_each_entry(&kvm->arch.hyperv.conn_to_evt, eventfd, i)
1727 		eventfd_ctx_put(eventfd);
1728 	idr_destroy(&kvm->arch.hyperv.conn_to_evt);
1729 }
1730 
1731 static int kvm_hv_eventfd_assign(struct kvm *kvm, u32 conn_id, int fd)
1732 {
1733 	struct kvm_hv *hv = &kvm->arch.hyperv;
1734 	struct eventfd_ctx *eventfd;
1735 	int ret;
1736 
1737 	eventfd = eventfd_ctx_fdget(fd);
1738 	if (IS_ERR(eventfd))
1739 		return PTR_ERR(eventfd);
1740 
1741 	mutex_lock(&hv->hv_lock);
1742 	ret = idr_alloc(&hv->conn_to_evt, eventfd, conn_id, conn_id + 1,
1743 			GFP_KERNEL_ACCOUNT);
1744 	mutex_unlock(&hv->hv_lock);
1745 
1746 	if (ret >= 0)
1747 		return 0;
1748 
1749 	if (ret == -ENOSPC)
1750 		ret = -EEXIST;
1751 	eventfd_ctx_put(eventfd);
1752 	return ret;
1753 }
1754 
1755 static int kvm_hv_eventfd_deassign(struct kvm *kvm, u32 conn_id)
1756 {
1757 	struct kvm_hv *hv = &kvm->arch.hyperv;
1758 	struct eventfd_ctx *eventfd;
1759 
1760 	mutex_lock(&hv->hv_lock);
1761 	eventfd = idr_remove(&hv->conn_to_evt, conn_id);
1762 	mutex_unlock(&hv->hv_lock);
1763 
1764 	if (!eventfd)
1765 		return -ENOENT;
1766 
1767 	synchronize_srcu(&kvm->srcu);
1768 	eventfd_ctx_put(eventfd);
1769 	return 0;
1770 }
1771 
1772 int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args)
1773 {
1774 	if ((args->flags & ~KVM_HYPERV_EVENTFD_DEASSIGN) ||
1775 	    (args->conn_id & ~KVM_HYPERV_CONN_ID_MASK))
1776 		return -EINVAL;
1777 
1778 	if (args->flags == KVM_HYPERV_EVENTFD_DEASSIGN)
1779 		return kvm_hv_eventfd_deassign(kvm, args->conn_id);
1780 	return kvm_hv_eventfd_assign(kvm, args->conn_id, args->fd);
1781 }
1782 
1783 int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
1784 				struct kvm_cpuid_entry2 __user *entries)
1785 {
1786 	uint16_t evmcs_ver = kvm_x86_ops->nested_get_evmcs_version(vcpu);
1787 	struct kvm_cpuid_entry2 cpuid_entries[] = {
1788 		{ .function = HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS },
1789 		{ .function = HYPERV_CPUID_INTERFACE },
1790 		{ .function = HYPERV_CPUID_VERSION },
1791 		{ .function = HYPERV_CPUID_FEATURES },
1792 		{ .function = HYPERV_CPUID_ENLIGHTMENT_INFO },
1793 		{ .function = HYPERV_CPUID_IMPLEMENT_LIMITS },
1794 		{ .function = HYPERV_CPUID_NESTED_FEATURES },
1795 	};
1796 	int i, nent = ARRAY_SIZE(cpuid_entries);
1797 
1798 	/* Skip NESTED_FEATURES if eVMCS is not supported */
1799 	if (!evmcs_ver)
1800 		--nent;
1801 
1802 	if (cpuid->nent < nent)
1803 		return -E2BIG;
1804 
1805 	if (cpuid->nent > nent)
1806 		cpuid->nent = nent;
1807 
1808 	for (i = 0; i < nent; i++) {
1809 		struct kvm_cpuid_entry2 *ent = &cpuid_entries[i];
1810 		u32 signature[3];
1811 
1812 		switch (ent->function) {
1813 		case HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS:
1814 			memcpy(signature, "Linux KVM Hv", 12);
1815 
1816 			ent->eax = HYPERV_CPUID_NESTED_FEATURES;
1817 			ent->ebx = signature[0];
1818 			ent->ecx = signature[1];
1819 			ent->edx = signature[2];
1820 			break;
1821 
1822 		case HYPERV_CPUID_INTERFACE:
1823 			memcpy(signature, "Hv#1\0\0\0\0\0\0\0\0", 12);
1824 			ent->eax = signature[0];
1825 			break;
1826 
1827 		case HYPERV_CPUID_VERSION:
1828 			/*
1829 			 * We implement some Hyper-V 2016 functions so let's use
1830 			 * this version.
1831 			 */
1832 			ent->eax = 0x00003839;
1833 			ent->ebx = 0x000A0000;
1834 			break;
1835 
1836 		case HYPERV_CPUID_FEATURES:
1837 			ent->eax |= HV_X64_MSR_VP_RUNTIME_AVAILABLE;
1838 			ent->eax |= HV_MSR_TIME_REF_COUNT_AVAILABLE;
1839 			ent->eax |= HV_X64_MSR_SYNIC_AVAILABLE;
1840 			ent->eax |= HV_MSR_SYNTIMER_AVAILABLE;
1841 			ent->eax |= HV_X64_MSR_APIC_ACCESS_AVAILABLE;
1842 			ent->eax |= HV_X64_MSR_HYPERCALL_AVAILABLE;
1843 			ent->eax |= HV_X64_MSR_VP_INDEX_AVAILABLE;
1844 			ent->eax |= HV_X64_MSR_RESET_AVAILABLE;
1845 			ent->eax |= HV_MSR_REFERENCE_TSC_AVAILABLE;
1846 			ent->eax |= HV_X64_ACCESS_FREQUENCY_MSRS;
1847 			ent->eax |= HV_X64_ACCESS_REENLIGHTENMENT;
1848 
1849 			ent->ebx |= HV_X64_POST_MESSAGES;
1850 			ent->ebx |= HV_X64_SIGNAL_EVENTS;
1851 
1852 			ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
1853 			ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
1854 			ent->edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
1855 
1856 			break;
1857 
1858 		case HYPERV_CPUID_ENLIGHTMENT_INFO:
1859 			ent->eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
1860 			ent->eax |= HV_X64_APIC_ACCESS_RECOMMENDED;
1861 			ent->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED;
1862 			ent->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
1863 			ent->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
1864 			if (evmcs_ver)
1865 				ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;
1866 
1867 			/*
1868 			 * Default number of spinlock retry attempts, matches
1869 			 * HyperV 2016.
1870 			 */
1871 			ent->ebx = 0x00000FFF;
1872 
1873 			break;
1874 
1875 		case HYPERV_CPUID_IMPLEMENT_LIMITS:
1876 			/* Maximum number of virtual processors */
1877 			ent->eax = KVM_MAX_VCPUS;
1878 			/*
1879 			 * Maximum number of logical processors, matches
1880 			 * HyperV 2016.
1881 			 */
1882 			ent->ebx = 64;
1883 
1884 			break;
1885 
1886 		case HYPERV_CPUID_NESTED_FEATURES:
1887 			ent->eax = evmcs_ver;
1888 
1889 			break;
1890 
1891 		default:
1892 			break;
1893 		}
1894 	}
1895 
1896 	if (copy_to_user(entries, cpuid_entries,
1897 			 nent * sizeof(struct kvm_cpuid_entry2)))
1898 		return -EFAULT;
1899 
1900 	return 0;
1901 }
1902