xref: /openbmc/linux/arch/x86/kvm/hyperv.c (revision 240e6d25)
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 	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
92 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
93 	int auto_eoi_old, auto_eoi_new;
94 
95 	if (vector < HV_SYNIC_FIRST_VALID_VECTOR)
96 		return;
97 
98 	if (synic_has_vector_connected(synic, vector))
99 		__set_bit(vector, synic->vec_bitmap);
100 	else
101 		__clear_bit(vector, synic->vec_bitmap);
102 
103 	auto_eoi_old = bitmap_weight(synic->auto_eoi_bitmap, 256);
104 
105 	if (synic_has_vector_auto_eoi(synic, vector))
106 		__set_bit(vector, synic->auto_eoi_bitmap);
107 	else
108 		__clear_bit(vector, synic->auto_eoi_bitmap);
109 
110 	auto_eoi_new = bitmap_weight(synic->auto_eoi_bitmap, 256);
111 
112 	if (!!auto_eoi_old == !!auto_eoi_new)
113 		return;
114 
115 	down_write(&vcpu->kvm->arch.apicv_update_lock);
116 
117 	if (auto_eoi_new)
118 		hv->synic_auto_eoi_used++;
119 	else
120 		hv->synic_auto_eoi_used--;
121 
122 	__kvm_request_apicv_update(vcpu->kvm,
123 				   !hv->synic_auto_eoi_used,
124 				   APICV_INHIBIT_REASON_HYPERV);
125 
126 	up_write(&vcpu->kvm->arch.apicv_update_lock);
127 }
128 
129 static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint,
130 			  u64 data, bool host)
131 {
132 	int vector, old_vector;
133 	bool masked;
134 
135 	vector = data & HV_SYNIC_SINT_VECTOR_MASK;
136 	masked = data & HV_SYNIC_SINT_MASKED;
137 
138 	/*
139 	 * Valid vectors are 16-255, however, nested Hyper-V attempts to write
140 	 * default '0x10000' value on boot and this should not #GP. We need to
141 	 * allow zero-initing the register from host as well.
142 	 */
143 	if (vector < HV_SYNIC_FIRST_VALID_VECTOR && !host && !masked)
144 		return 1;
145 	/*
146 	 * Guest may configure multiple SINTs to use the same vector, so
147 	 * we maintain a bitmap of vectors handled by synic, and a
148 	 * bitmap of vectors with auto-eoi behavior.  The bitmaps are
149 	 * updated here, and atomically queried on fast paths.
150 	 */
151 	old_vector = synic_read_sint(synic, sint) & HV_SYNIC_SINT_VECTOR_MASK;
152 
153 	atomic64_set(&synic->sint[sint], data);
154 
155 	synic_update_vector(synic, old_vector);
156 
157 	synic_update_vector(synic, vector);
158 
159 	/* Load SynIC vectors into EOI exit bitmap */
160 	kvm_make_request(KVM_REQ_SCAN_IOAPIC, hv_synic_to_vcpu(synic));
161 	return 0;
162 }
163 
164 static struct kvm_vcpu *get_vcpu_by_vpidx(struct kvm *kvm, u32 vpidx)
165 {
166 	struct kvm_vcpu *vcpu = NULL;
167 	int i;
168 
169 	if (vpidx >= KVM_MAX_VCPUS)
170 		return NULL;
171 
172 	vcpu = kvm_get_vcpu(kvm, vpidx);
173 	if (vcpu && kvm_hv_get_vpindex(vcpu) == vpidx)
174 		return vcpu;
175 	kvm_for_each_vcpu(i, vcpu, kvm)
176 		if (kvm_hv_get_vpindex(vcpu) == vpidx)
177 			return vcpu;
178 	return NULL;
179 }
180 
181 static struct kvm_vcpu_hv_synic *synic_get(struct kvm *kvm, u32 vpidx)
182 {
183 	struct kvm_vcpu *vcpu;
184 	struct kvm_vcpu_hv_synic *synic;
185 
186 	vcpu = get_vcpu_by_vpidx(kvm, vpidx);
187 	if (!vcpu || !to_hv_vcpu(vcpu))
188 		return NULL;
189 	synic = to_hv_synic(vcpu);
190 	return (synic->active) ? synic : NULL;
191 }
192 
193 static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
194 {
195 	struct kvm *kvm = vcpu->kvm;
196 	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
197 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
198 	struct kvm_vcpu_hv_stimer *stimer;
199 	int gsi, idx;
200 
201 	trace_kvm_hv_notify_acked_sint(vcpu->vcpu_id, sint);
202 
203 	/* Try to deliver pending Hyper-V SynIC timers messages */
204 	for (idx = 0; idx < ARRAY_SIZE(hv_vcpu->stimer); idx++) {
205 		stimer = &hv_vcpu->stimer[idx];
206 		if (stimer->msg_pending && stimer->config.enable &&
207 		    !stimer->config.direct_mode &&
208 		    stimer->config.sintx == sint)
209 			stimer_mark_pending(stimer, false);
210 	}
211 
212 	idx = srcu_read_lock(&kvm->irq_srcu);
213 	gsi = atomic_read(&synic->sint_to_gsi[sint]);
214 	if (gsi != -1)
215 		kvm_notify_acked_gsi(kvm, gsi);
216 	srcu_read_unlock(&kvm->irq_srcu, idx);
217 }
218 
219 static void synic_exit(struct kvm_vcpu_hv_synic *synic, u32 msr)
220 {
221 	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
222 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
223 
224 	hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNIC;
225 	hv_vcpu->exit.u.synic.msr = msr;
226 	hv_vcpu->exit.u.synic.control = synic->control;
227 	hv_vcpu->exit.u.synic.evt_page = synic->evt_page;
228 	hv_vcpu->exit.u.synic.msg_page = synic->msg_page;
229 
230 	kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
231 }
232 
233 static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
234 			 u32 msr, u64 data, bool host)
235 {
236 	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
237 	int ret;
238 
239 	if (!synic->active && !host)
240 		return 1;
241 
242 	trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host);
243 
244 	ret = 0;
245 	switch (msr) {
246 	case HV_X64_MSR_SCONTROL:
247 		synic->control = data;
248 		if (!host)
249 			synic_exit(synic, msr);
250 		break;
251 	case HV_X64_MSR_SVERSION:
252 		if (!host) {
253 			ret = 1;
254 			break;
255 		}
256 		synic->version = data;
257 		break;
258 	case HV_X64_MSR_SIEFP:
259 		if ((data & HV_SYNIC_SIEFP_ENABLE) && !host &&
260 		    !synic->dont_zero_synic_pages)
261 			if (kvm_clear_guest(vcpu->kvm,
262 					    data & PAGE_MASK, PAGE_SIZE)) {
263 				ret = 1;
264 				break;
265 			}
266 		synic->evt_page = data;
267 		if (!host)
268 			synic_exit(synic, msr);
269 		break;
270 	case HV_X64_MSR_SIMP:
271 		if ((data & HV_SYNIC_SIMP_ENABLE) && !host &&
272 		    !synic->dont_zero_synic_pages)
273 			if (kvm_clear_guest(vcpu->kvm,
274 					    data & PAGE_MASK, PAGE_SIZE)) {
275 				ret = 1;
276 				break;
277 			}
278 		synic->msg_page = data;
279 		if (!host)
280 			synic_exit(synic, msr);
281 		break;
282 	case HV_X64_MSR_EOM: {
283 		int i;
284 
285 		for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
286 			kvm_hv_notify_acked_sint(vcpu, i);
287 		break;
288 	}
289 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
290 		ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data, host);
291 		break;
292 	default:
293 		ret = 1;
294 		break;
295 	}
296 	return ret;
297 }
298 
299 static bool kvm_hv_is_syndbg_enabled(struct kvm_vcpu *vcpu)
300 {
301 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
302 
303 	return hv_vcpu->cpuid_cache.syndbg_cap_eax &
304 		HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
305 }
306 
307 static int kvm_hv_syndbg_complete_userspace(struct kvm_vcpu *vcpu)
308 {
309 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
310 
311 	if (vcpu->run->hyperv.u.syndbg.msr == HV_X64_MSR_SYNDBG_CONTROL)
312 		hv->hv_syndbg.control.status =
313 			vcpu->run->hyperv.u.syndbg.status;
314 	return 1;
315 }
316 
317 static void syndbg_exit(struct kvm_vcpu *vcpu, u32 msr)
318 {
319 	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
320 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
321 
322 	hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNDBG;
323 	hv_vcpu->exit.u.syndbg.msr = msr;
324 	hv_vcpu->exit.u.syndbg.control = syndbg->control.control;
325 	hv_vcpu->exit.u.syndbg.send_page = syndbg->control.send_page;
326 	hv_vcpu->exit.u.syndbg.recv_page = syndbg->control.recv_page;
327 	hv_vcpu->exit.u.syndbg.pending_page = syndbg->control.pending_page;
328 	vcpu->arch.complete_userspace_io =
329 			kvm_hv_syndbg_complete_userspace;
330 
331 	kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
332 }
333 
334 static int syndbg_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
335 {
336 	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
337 
338 	if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
339 		return 1;
340 
341 	trace_kvm_hv_syndbg_set_msr(vcpu->vcpu_id,
342 				    to_hv_vcpu(vcpu)->vp_index, msr, data);
343 	switch (msr) {
344 	case HV_X64_MSR_SYNDBG_CONTROL:
345 		syndbg->control.control = data;
346 		if (!host)
347 			syndbg_exit(vcpu, msr);
348 		break;
349 	case HV_X64_MSR_SYNDBG_STATUS:
350 		syndbg->control.status = data;
351 		break;
352 	case HV_X64_MSR_SYNDBG_SEND_BUFFER:
353 		syndbg->control.send_page = data;
354 		break;
355 	case HV_X64_MSR_SYNDBG_RECV_BUFFER:
356 		syndbg->control.recv_page = data;
357 		break;
358 	case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
359 		syndbg->control.pending_page = data;
360 		if (!host)
361 			syndbg_exit(vcpu, msr);
362 		break;
363 	case HV_X64_MSR_SYNDBG_OPTIONS:
364 		syndbg->options = data;
365 		break;
366 	default:
367 		break;
368 	}
369 
370 	return 0;
371 }
372 
373 static int syndbg_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
374 {
375 	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
376 
377 	if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
378 		return 1;
379 
380 	switch (msr) {
381 	case HV_X64_MSR_SYNDBG_CONTROL:
382 		*pdata = syndbg->control.control;
383 		break;
384 	case HV_X64_MSR_SYNDBG_STATUS:
385 		*pdata = syndbg->control.status;
386 		break;
387 	case HV_X64_MSR_SYNDBG_SEND_BUFFER:
388 		*pdata = syndbg->control.send_page;
389 		break;
390 	case HV_X64_MSR_SYNDBG_RECV_BUFFER:
391 		*pdata = syndbg->control.recv_page;
392 		break;
393 	case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
394 		*pdata = syndbg->control.pending_page;
395 		break;
396 	case HV_X64_MSR_SYNDBG_OPTIONS:
397 		*pdata = syndbg->options;
398 		break;
399 	default:
400 		break;
401 	}
402 
403 	trace_kvm_hv_syndbg_get_msr(vcpu->vcpu_id, kvm_hv_get_vpindex(vcpu), msr, *pdata);
404 
405 	return 0;
406 }
407 
408 static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata,
409 			 bool host)
410 {
411 	int ret;
412 
413 	if (!synic->active && !host)
414 		return 1;
415 
416 	ret = 0;
417 	switch (msr) {
418 	case HV_X64_MSR_SCONTROL:
419 		*pdata = synic->control;
420 		break;
421 	case HV_X64_MSR_SVERSION:
422 		*pdata = synic->version;
423 		break;
424 	case HV_X64_MSR_SIEFP:
425 		*pdata = synic->evt_page;
426 		break;
427 	case HV_X64_MSR_SIMP:
428 		*pdata = synic->msg_page;
429 		break;
430 	case HV_X64_MSR_EOM:
431 		*pdata = 0;
432 		break;
433 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
434 		*pdata = atomic64_read(&synic->sint[msr - HV_X64_MSR_SINT0]);
435 		break;
436 	default:
437 		ret = 1;
438 		break;
439 	}
440 	return ret;
441 }
442 
443 static int synic_set_irq(struct kvm_vcpu_hv_synic *synic, u32 sint)
444 {
445 	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
446 	struct kvm_lapic_irq irq;
447 	int ret, vector;
448 
449 	if (sint >= ARRAY_SIZE(synic->sint))
450 		return -EINVAL;
451 
452 	vector = synic_get_sint_vector(synic_read_sint(synic, sint));
453 	if (vector < 0)
454 		return -ENOENT;
455 
456 	memset(&irq, 0, sizeof(irq));
457 	irq.shorthand = APIC_DEST_SELF;
458 	irq.dest_mode = APIC_DEST_PHYSICAL;
459 	irq.delivery_mode = APIC_DM_FIXED;
460 	irq.vector = vector;
461 	irq.level = 1;
462 
463 	ret = kvm_irq_delivery_to_apic(vcpu->kvm, vcpu->arch.apic, &irq, NULL);
464 	trace_kvm_hv_synic_set_irq(vcpu->vcpu_id, sint, irq.vector, ret);
465 	return ret;
466 }
467 
468 int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vpidx, u32 sint)
469 {
470 	struct kvm_vcpu_hv_synic *synic;
471 
472 	synic = synic_get(kvm, vpidx);
473 	if (!synic)
474 		return -EINVAL;
475 
476 	return synic_set_irq(synic, sint);
477 }
478 
479 void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
480 {
481 	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
482 	int i;
483 
484 	trace_kvm_hv_synic_send_eoi(vcpu->vcpu_id, vector);
485 
486 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
487 		if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
488 			kvm_hv_notify_acked_sint(vcpu, i);
489 }
490 
491 static int kvm_hv_set_sint_gsi(struct kvm *kvm, u32 vpidx, u32 sint, int gsi)
492 {
493 	struct kvm_vcpu_hv_synic *synic;
494 
495 	synic = synic_get(kvm, vpidx);
496 	if (!synic)
497 		return -EINVAL;
498 
499 	if (sint >= ARRAY_SIZE(synic->sint_to_gsi))
500 		return -EINVAL;
501 
502 	atomic_set(&synic->sint_to_gsi[sint], gsi);
503 	return 0;
504 }
505 
506 void kvm_hv_irq_routing_update(struct kvm *kvm)
507 {
508 	struct kvm_irq_routing_table *irq_rt;
509 	struct kvm_kernel_irq_routing_entry *e;
510 	u32 gsi;
511 
512 	irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
513 					lockdep_is_held(&kvm->irq_lock));
514 
515 	for (gsi = 0; gsi < irq_rt->nr_rt_entries; gsi++) {
516 		hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
517 			if (e->type == KVM_IRQ_ROUTING_HV_SINT)
518 				kvm_hv_set_sint_gsi(kvm, e->hv_sint.vcpu,
519 						    e->hv_sint.sint, gsi);
520 		}
521 	}
522 }
523 
524 static void synic_init(struct kvm_vcpu_hv_synic *synic)
525 {
526 	int i;
527 
528 	memset(synic, 0, sizeof(*synic));
529 	synic->version = HV_SYNIC_VERSION_1;
530 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
531 		atomic64_set(&synic->sint[i], HV_SYNIC_SINT_MASKED);
532 		atomic_set(&synic->sint_to_gsi[i], -1);
533 	}
534 }
535 
536 static u64 get_time_ref_counter(struct kvm *kvm)
537 {
538 	struct kvm_hv *hv = to_kvm_hv(kvm);
539 	struct kvm_vcpu *vcpu;
540 	u64 tsc;
541 
542 	/*
543 	 * Fall back to get_kvmclock_ns() when TSC page hasn't been set up,
544 	 * is broken, disabled or being updated.
545 	 */
546 	if (hv->hv_tsc_page_status != HV_TSC_PAGE_SET)
547 		return div_u64(get_kvmclock_ns(kvm), 100);
548 
549 	vcpu = kvm_get_vcpu(kvm, 0);
550 	tsc = kvm_read_l1_tsc(vcpu, rdtsc());
551 	return mul_u64_u64_shr(tsc, hv->tsc_ref.tsc_scale, 64)
552 		+ hv->tsc_ref.tsc_offset;
553 }
554 
555 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
556 				bool vcpu_kick)
557 {
558 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
559 
560 	set_bit(stimer->index,
561 		to_hv_vcpu(vcpu)->stimer_pending_bitmap);
562 	kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
563 	if (vcpu_kick)
564 		kvm_vcpu_kick(vcpu);
565 }
566 
567 static void stimer_cleanup(struct kvm_vcpu_hv_stimer *stimer)
568 {
569 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
570 
571 	trace_kvm_hv_stimer_cleanup(hv_stimer_to_vcpu(stimer)->vcpu_id,
572 				    stimer->index);
573 
574 	hrtimer_cancel(&stimer->timer);
575 	clear_bit(stimer->index,
576 		  to_hv_vcpu(vcpu)->stimer_pending_bitmap);
577 	stimer->msg_pending = false;
578 	stimer->exp_time = 0;
579 }
580 
581 static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer)
582 {
583 	struct kvm_vcpu_hv_stimer *stimer;
584 
585 	stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer);
586 	trace_kvm_hv_stimer_callback(hv_stimer_to_vcpu(stimer)->vcpu_id,
587 				     stimer->index);
588 	stimer_mark_pending(stimer, true);
589 
590 	return HRTIMER_NORESTART;
591 }
592 
593 /*
594  * stimer_start() assumptions:
595  * a) stimer->count is not equal to 0
596  * b) stimer->config has HV_STIMER_ENABLE flag
597  */
598 static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
599 {
600 	u64 time_now;
601 	ktime_t ktime_now;
602 
603 	time_now = get_time_ref_counter(hv_stimer_to_vcpu(stimer)->kvm);
604 	ktime_now = ktime_get();
605 
606 	if (stimer->config.periodic) {
607 		if (stimer->exp_time) {
608 			if (time_now >= stimer->exp_time) {
609 				u64 remainder;
610 
611 				div64_u64_rem(time_now - stimer->exp_time,
612 					      stimer->count, &remainder);
613 				stimer->exp_time =
614 					time_now + (stimer->count - remainder);
615 			}
616 		} else
617 			stimer->exp_time = time_now + stimer->count;
618 
619 		trace_kvm_hv_stimer_start_periodic(
620 					hv_stimer_to_vcpu(stimer)->vcpu_id,
621 					stimer->index,
622 					time_now, stimer->exp_time);
623 
624 		hrtimer_start(&stimer->timer,
625 			      ktime_add_ns(ktime_now,
626 					   100 * (stimer->exp_time - time_now)),
627 			      HRTIMER_MODE_ABS);
628 		return 0;
629 	}
630 	stimer->exp_time = stimer->count;
631 	if (time_now >= stimer->count) {
632 		/*
633 		 * Expire timer according to Hypervisor Top-Level Functional
634 		 * specification v4(15.3.1):
635 		 * "If a one shot is enabled and the specified count is in
636 		 * the past, it will expire immediately."
637 		 */
638 		stimer_mark_pending(stimer, false);
639 		return 0;
640 	}
641 
642 	trace_kvm_hv_stimer_start_one_shot(hv_stimer_to_vcpu(stimer)->vcpu_id,
643 					   stimer->index,
644 					   time_now, stimer->count);
645 
646 	hrtimer_start(&stimer->timer,
647 		      ktime_add_ns(ktime_now, 100 * (stimer->count - time_now)),
648 		      HRTIMER_MODE_ABS);
649 	return 0;
650 }
651 
652 static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
653 			     bool host)
654 {
655 	union hv_stimer_config new_config = {.as_uint64 = config},
656 		old_config = {.as_uint64 = stimer->config.as_uint64};
657 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
658 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
659 	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
660 
661 	if (!synic->active && !host)
662 		return 1;
663 
664 	if (unlikely(!host && hv_vcpu->enforce_cpuid && new_config.direct_mode &&
665 		     !(hv_vcpu->cpuid_cache.features_edx &
666 		       HV_STIMER_DIRECT_MODE_AVAILABLE)))
667 		return 1;
668 
669 	trace_kvm_hv_stimer_set_config(hv_stimer_to_vcpu(stimer)->vcpu_id,
670 				       stimer->index, config, host);
671 
672 	stimer_cleanup(stimer);
673 	if (old_config.enable &&
674 	    !new_config.direct_mode && new_config.sintx == 0)
675 		new_config.enable = 0;
676 	stimer->config.as_uint64 = new_config.as_uint64;
677 
678 	if (stimer->config.enable)
679 		stimer_mark_pending(stimer, false);
680 
681 	return 0;
682 }
683 
684 static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,
685 			    bool host)
686 {
687 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
688 	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
689 
690 	if (!synic->active && !host)
691 		return 1;
692 
693 	trace_kvm_hv_stimer_set_count(hv_stimer_to_vcpu(stimer)->vcpu_id,
694 				      stimer->index, count, host);
695 
696 	stimer_cleanup(stimer);
697 	stimer->count = count;
698 	if (stimer->count == 0)
699 		stimer->config.enable = 0;
700 	else if (stimer->config.auto_enable)
701 		stimer->config.enable = 1;
702 
703 	if (stimer->config.enable)
704 		stimer_mark_pending(stimer, false);
705 
706 	return 0;
707 }
708 
709 static int stimer_get_config(struct kvm_vcpu_hv_stimer *stimer, u64 *pconfig)
710 {
711 	*pconfig = stimer->config.as_uint64;
712 	return 0;
713 }
714 
715 static int stimer_get_count(struct kvm_vcpu_hv_stimer *stimer, u64 *pcount)
716 {
717 	*pcount = stimer->count;
718 	return 0;
719 }
720 
721 static int synic_deliver_msg(struct kvm_vcpu_hv_synic *synic, u32 sint,
722 			     struct hv_message *src_msg, bool no_retry)
723 {
724 	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
725 	int msg_off = offsetof(struct hv_message_page, sint_message[sint]);
726 	gfn_t msg_page_gfn;
727 	struct hv_message_header hv_hdr;
728 	int r;
729 
730 	if (!(synic->msg_page & HV_SYNIC_SIMP_ENABLE))
731 		return -ENOENT;
732 
733 	msg_page_gfn = synic->msg_page >> PAGE_SHIFT;
734 
735 	/*
736 	 * Strictly following the spec-mandated ordering would assume setting
737 	 * .msg_pending before checking .message_type.  However, this function
738 	 * is only called in vcpu context so the entire update is atomic from
739 	 * guest POV and thus the exact order here doesn't matter.
740 	 */
741 	r = kvm_vcpu_read_guest_page(vcpu, msg_page_gfn, &hv_hdr.message_type,
742 				     msg_off + offsetof(struct hv_message,
743 							header.message_type),
744 				     sizeof(hv_hdr.message_type));
745 	if (r < 0)
746 		return r;
747 
748 	if (hv_hdr.message_type != HVMSG_NONE) {
749 		if (no_retry)
750 			return 0;
751 
752 		hv_hdr.message_flags.msg_pending = 1;
753 		r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn,
754 					      &hv_hdr.message_flags,
755 					      msg_off +
756 					      offsetof(struct hv_message,
757 						       header.message_flags),
758 					      sizeof(hv_hdr.message_flags));
759 		if (r < 0)
760 			return r;
761 		return -EAGAIN;
762 	}
763 
764 	r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn, src_msg, msg_off,
765 				      sizeof(src_msg->header) +
766 				      src_msg->header.payload_size);
767 	if (r < 0)
768 		return r;
769 
770 	r = synic_set_irq(synic, sint);
771 	if (r < 0)
772 		return r;
773 	if (r == 0)
774 		return -EFAULT;
775 	return 0;
776 }
777 
778 static int stimer_send_msg(struct kvm_vcpu_hv_stimer *stimer)
779 {
780 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
781 	struct hv_message *msg = &stimer->msg;
782 	struct hv_timer_message_payload *payload =
783 			(struct hv_timer_message_payload *)&msg->u.payload;
784 
785 	/*
786 	 * To avoid piling up periodic ticks, don't retry message
787 	 * delivery for them (within "lazy" lost ticks policy).
788 	 */
789 	bool no_retry = stimer->config.periodic;
790 
791 	payload->expiration_time = stimer->exp_time;
792 	payload->delivery_time = get_time_ref_counter(vcpu->kvm);
793 	return synic_deliver_msg(to_hv_synic(vcpu),
794 				 stimer->config.sintx, msg,
795 				 no_retry);
796 }
797 
798 static int stimer_notify_direct(struct kvm_vcpu_hv_stimer *stimer)
799 {
800 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
801 	struct kvm_lapic_irq irq = {
802 		.delivery_mode = APIC_DM_FIXED,
803 		.vector = stimer->config.apic_vector
804 	};
805 
806 	if (lapic_in_kernel(vcpu))
807 		return !kvm_apic_set_irq(vcpu, &irq, NULL);
808 	return 0;
809 }
810 
811 static void stimer_expiration(struct kvm_vcpu_hv_stimer *stimer)
812 {
813 	int r, direct = stimer->config.direct_mode;
814 
815 	stimer->msg_pending = true;
816 	if (!direct)
817 		r = stimer_send_msg(stimer);
818 	else
819 		r = stimer_notify_direct(stimer);
820 	trace_kvm_hv_stimer_expiration(hv_stimer_to_vcpu(stimer)->vcpu_id,
821 				       stimer->index, direct, r);
822 	if (!r) {
823 		stimer->msg_pending = false;
824 		if (!(stimer->config.periodic))
825 			stimer->config.enable = 0;
826 	}
827 }
828 
829 void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
830 {
831 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
832 	struct kvm_vcpu_hv_stimer *stimer;
833 	u64 time_now, exp_time;
834 	int i;
835 
836 	if (!hv_vcpu)
837 		return;
838 
839 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
840 		if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) {
841 			stimer = &hv_vcpu->stimer[i];
842 			if (stimer->config.enable) {
843 				exp_time = stimer->exp_time;
844 
845 				if (exp_time) {
846 					time_now =
847 						get_time_ref_counter(vcpu->kvm);
848 					if (time_now >= exp_time)
849 						stimer_expiration(stimer);
850 				}
851 
852 				if ((stimer->config.enable) &&
853 				    stimer->count) {
854 					if (!stimer->msg_pending)
855 						stimer_start(stimer);
856 				} else
857 					stimer_cleanup(stimer);
858 			}
859 		}
860 }
861 
862 void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu)
863 {
864 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
865 	int i;
866 
867 	if (!hv_vcpu)
868 		return;
869 
870 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
871 		stimer_cleanup(&hv_vcpu->stimer[i]);
872 
873 	kfree(hv_vcpu);
874 	vcpu->arch.hyperv = NULL;
875 }
876 
877 bool kvm_hv_assist_page_enabled(struct kvm_vcpu *vcpu)
878 {
879 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
880 
881 	if (!hv_vcpu)
882 		return false;
883 
884 	if (!(hv_vcpu->hv_vapic & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE))
885 		return false;
886 	return vcpu->arch.pv_eoi.msr_val & KVM_MSR_ENABLED;
887 }
888 EXPORT_SYMBOL_GPL(kvm_hv_assist_page_enabled);
889 
890 bool kvm_hv_get_assist_page(struct kvm_vcpu *vcpu,
891 			    struct hv_vp_assist_page *assist_page)
892 {
893 	if (!kvm_hv_assist_page_enabled(vcpu))
894 		return false;
895 	return !kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data,
896 				      assist_page, sizeof(*assist_page));
897 }
898 EXPORT_SYMBOL_GPL(kvm_hv_get_assist_page);
899 
900 static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
901 {
902 	struct hv_message *msg = &stimer->msg;
903 	struct hv_timer_message_payload *payload =
904 			(struct hv_timer_message_payload *)&msg->u.payload;
905 
906 	memset(&msg->header, 0, sizeof(msg->header));
907 	msg->header.message_type = HVMSG_TIMER_EXPIRED;
908 	msg->header.payload_size = sizeof(*payload);
909 
910 	payload->timer_index = stimer->index;
911 	payload->expiration_time = 0;
912 	payload->delivery_time = 0;
913 }
914 
915 static void stimer_init(struct kvm_vcpu_hv_stimer *stimer, int timer_index)
916 {
917 	memset(stimer, 0, sizeof(*stimer));
918 	stimer->index = timer_index;
919 	hrtimer_init(&stimer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
920 	stimer->timer.function = stimer_timer_callback;
921 	stimer_prepare_msg(stimer);
922 }
923 
924 static int kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
925 {
926 	struct kvm_vcpu_hv *hv_vcpu;
927 	int i;
928 
929 	hv_vcpu = kzalloc(sizeof(struct kvm_vcpu_hv), GFP_KERNEL_ACCOUNT);
930 	if (!hv_vcpu)
931 		return -ENOMEM;
932 
933 	vcpu->arch.hyperv = hv_vcpu;
934 	hv_vcpu->vcpu = vcpu;
935 
936 	synic_init(&hv_vcpu->synic);
937 
938 	bitmap_zero(hv_vcpu->stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
939 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
940 		stimer_init(&hv_vcpu->stimer[i], i);
941 
942 	hv_vcpu->vp_index = vcpu->vcpu_idx;
943 
944 	return 0;
945 }
946 
947 int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages)
948 {
949 	struct kvm_vcpu_hv_synic *synic;
950 	int r;
951 
952 	if (!to_hv_vcpu(vcpu)) {
953 		r = kvm_hv_vcpu_init(vcpu);
954 		if (r)
955 			return r;
956 	}
957 
958 	synic = to_hv_synic(vcpu);
959 
960 	synic->active = true;
961 	synic->dont_zero_synic_pages = dont_zero_synic_pages;
962 	synic->control = HV_SYNIC_CONTROL_ENABLE;
963 	return 0;
964 }
965 
966 static bool kvm_hv_msr_partition_wide(u32 msr)
967 {
968 	bool r = false;
969 
970 	switch (msr) {
971 	case HV_X64_MSR_GUEST_OS_ID:
972 	case HV_X64_MSR_HYPERCALL:
973 	case HV_X64_MSR_REFERENCE_TSC:
974 	case HV_X64_MSR_TIME_REF_COUNT:
975 	case HV_X64_MSR_CRASH_CTL:
976 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
977 	case HV_X64_MSR_RESET:
978 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
979 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
980 	case HV_X64_MSR_TSC_EMULATION_STATUS:
981 	case HV_X64_MSR_SYNDBG_OPTIONS:
982 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
983 		r = true;
984 		break;
985 	}
986 
987 	return r;
988 }
989 
990 static int kvm_hv_msr_get_crash_data(struct kvm *kvm, u32 index, u64 *pdata)
991 {
992 	struct kvm_hv *hv = to_kvm_hv(kvm);
993 	size_t size = ARRAY_SIZE(hv->hv_crash_param);
994 
995 	if (WARN_ON_ONCE(index >= size))
996 		return -EINVAL;
997 
998 	*pdata = hv->hv_crash_param[array_index_nospec(index, size)];
999 	return 0;
1000 }
1001 
1002 static int kvm_hv_msr_get_crash_ctl(struct kvm *kvm, u64 *pdata)
1003 {
1004 	struct kvm_hv *hv = to_kvm_hv(kvm);
1005 
1006 	*pdata = hv->hv_crash_ctl;
1007 	return 0;
1008 }
1009 
1010 static int kvm_hv_msr_set_crash_ctl(struct kvm *kvm, u64 data)
1011 {
1012 	struct kvm_hv *hv = to_kvm_hv(kvm);
1013 
1014 	hv->hv_crash_ctl = data & HV_CRASH_CTL_CRASH_NOTIFY;
1015 
1016 	return 0;
1017 }
1018 
1019 static int kvm_hv_msr_set_crash_data(struct kvm *kvm, u32 index, u64 data)
1020 {
1021 	struct kvm_hv *hv = to_kvm_hv(kvm);
1022 	size_t size = ARRAY_SIZE(hv->hv_crash_param);
1023 
1024 	if (WARN_ON_ONCE(index >= size))
1025 		return -EINVAL;
1026 
1027 	hv->hv_crash_param[array_index_nospec(index, size)] = data;
1028 	return 0;
1029 }
1030 
1031 /*
1032  * The kvmclock and Hyper-V TSC page use similar formulas, and converting
1033  * between them is possible:
1034  *
1035  * kvmclock formula:
1036  *    nsec = (ticks - tsc_timestamp) * tsc_to_system_mul * 2^(tsc_shift-32)
1037  *           + system_time
1038  *
1039  * Hyper-V formula:
1040  *    nsec/100 = ticks * scale / 2^64 + offset
1041  *
1042  * When tsc_timestamp = system_time = 0, offset is zero in the Hyper-V formula.
1043  * By dividing the kvmclock formula by 100 and equating what's left we get:
1044  *    ticks * scale / 2^64 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1045  *            scale / 2^64 =         tsc_to_system_mul * 2^(tsc_shift-32) / 100
1046  *            scale        =         tsc_to_system_mul * 2^(32+tsc_shift) / 100
1047  *
1048  * Now expand the kvmclock formula and divide by 100:
1049  *    nsec = ticks * tsc_to_system_mul * 2^(tsc_shift-32)
1050  *           - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32)
1051  *           + system_time
1052  *    nsec/100 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1053  *               - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1054  *               + system_time / 100
1055  *
1056  * Replace tsc_to_system_mul * 2^(tsc_shift-32) / 100 by scale / 2^64:
1057  *    nsec/100 = ticks * scale / 2^64
1058  *               - tsc_timestamp * scale / 2^64
1059  *               + system_time / 100
1060  *
1061  * Equate with the Hyper-V formula so that ticks * scale / 2^64 cancels out:
1062  *    offset = system_time / 100 - tsc_timestamp * scale / 2^64
1063  *
1064  * These two equivalencies are implemented in this function.
1065  */
1066 static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
1067 					struct ms_hyperv_tsc_page *tsc_ref)
1068 {
1069 	u64 max_mul;
1070 
1071 	if (!(hv_clock->flags & PVCLOCK_TSC_STABLE_BIT))
1072 		return false;
1073 
1074 	/*
1075 	 * check if scale would overflow, if so we use the time ref counter
1076 	 *    tsc_to_system_mul * 2^(tsc_shift+32) / 100 >= 2^64
1077 	 *    tsc_to_system_mul / 100 >= 2^(32-tsc_shift)
1078 	 *    tsc_to_system_mul >= 100 * 2^(32-tsc_shift)
1079 	 */
1080 	max_mul = 100ull << (32 - hv_clock->tsc_shift);
1081 	if (hv_clock->tsc_to_system_mul >= max_mul)
1082 		return false;
1083 
1084 	/*
1085 	 * Otherwise compute the scale and offset according to the formulas
1086 	 * derived above.
1087 	 */
1088 	tsc_ref->tsc_scale =
1089 		mul_u64_u32_div(1ULL << (32 + hv_clock->tsc_shift),
1090 				hv_clock->tsc_to_system_mul,
1091 				100);
1092 
1093 	tsc_ref->tsc_offset = hv_clock->system_time;
1094 	do_div(tsc_ref->tsc_offset, 100);
1095 	tsc_ref->tsc_offset -=
1096 		mul_u64_u64_shr(hv_clock->tsc_timestamp, tsc_ref->tsc_scale, 64);
1097 	return true;
1098 }
1099 
1100 /*
1101  * Don't touch TSC page values if the guest has opted for TSC emulation after
1102  * migration. KVM doesn't fully support reenlightenment notifications and TSC
1103  * access emulation and Hyper-V is known to expect the values in TSC page to
1104  * stay constant before TSC access emulation is disabled from guest side
1105  * (HV_X64_MSR_TSC_EMULATION_STATUS). KVM userspace is expected to preserve TSC
1106  * frequency and guest visible TSC value across migration (and prevent it when
1107  * TSC scaling is unsupported).
1108  */
1109 static inline bool tsc_page_update_unsafe(struct kvm_hv *hv)
1110 {
1111 	return (hv->hv_tsc_page_status != HV_TSC_PAGE_GUEST_CHANGED) &&
1112 		hv->hv_tsc_emulation_control;
1113 }
1114 
1115 void kvm_hv_setup_tsc_page(struct kvm *kvm,
1116 			   struct pvclock_vcpu_time_info *hv_clock)
1117 {
1118 	struct kvm_hv *hv = to_kvm_hv(kvm);
1119 	u32 tsc_seq;
1120 	u64 gfn;
1121 
1122 	BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
1123 	BUILD_BUG_ON(offsetof(struct ms_hyperv_tsc_page, tsc_sequence) != 0);
1124 
1125 	if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN ||
1126 	    hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET)
1127 		return;
1128 
1129 	mutex_lock(&hv->hv_lock);
1130 	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
1131 		goto out_unlock;
1132 
1133 	gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
1134 	/*
1135 	 * Because the TSC parameters only vary when there is a
1136 	 * change in the master clock, do not bother with caching.
1137 	 */
1138 	if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
1139 				    &tsc_seq, sizeof(tsc_seq))))
1140 		goto out_err;
1141 
1142 	if (tsc_seq && tsc_page_update_unsafe(hv)) {
1143 		if (kvm_read_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1144 			goto out_err;
1145 
1146 		hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1147 		goto out_unlock;
1148 	}
1149 
1150 	/*
1151 	 * While we're computing and writing the parameters, force the
1152 	 * guest to use the time reference count MSR.
1153 	 */
1154 	hv->tsc_ref.tsc_sequence = 0;
1155 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1156 			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1157 		goto out_err;
1158 
1159 	if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
1160 		goto out_err;
1161 
1162 	/* Ensure sequence is zero before writing the rest of the struct.  */
1163 	smp_wmb();
1164 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1165 		goto out_err;
1166 
1167 	/*
1168 	 * Now switch to the TSC page mechanism by writing the sequence.
1169 	 */
1170 	tsc_seq++;
1171 	if (tsc_seq == 0xFFFFFFFF || tsc_seq == 0)
1172 		tsc_seq = 1;
1173 
1174 	/* Write the struct entirely before the non-zero sequence.  */
1175 	smp_wmb();
1176 
1177 	hv->tsc_ref.tsc_sequence = tsc_seq;
1178 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1179 			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1180 		goto out_err;
1181 
1182 	hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1183 	goto out_unlock;
1184 
1185 out_err:
1186 	hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN;
1187 out_unlock:
1188 	mutex_unlock(&hv->hv_lock);
1189 }
1190 
1191 void kvm_hv_invalidate_tsc_page(struct kvm *kvm)
1192 {
1193 	struct kvm_hv *hv = to_kvm_hv(kvm);
1194 	u64 gfn;
1195 	int idx;
1196 
1197 	if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN ||
1198 	    hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET ||
1199 	    tsc_page_update_unsafe(hv))
1200 		return;
1201 
1202 	mutex_lock(&hv->hv_lock);
1203 
1204 	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
1205 		goto out_unlock;
1206 
1207 	/* Preserve HV_TSC_PAGE_GUEST_CHANGED/HV_TSC_PAGE_HOST_CHANGED states */
1208 	if (hv->hv_tsc_page_status == HV_TSC_PAGE_SET)
1209 		hv->hv_tsc_page_status = HV_TSC_PAGE_UPDATING;
1210 
1211 	gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
1212 
1213 	hv->tsc_ref.tsc_sequence = 0;
1214 
1215 	/*
1216 	 * Take the srcu lock as memslots will be accessed to check the gfn
1217 	 * cache generation against the memslots generation.
1218 	 */
1219 	idx = srcu_read_lock(&kvm->srcu);
1220 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1221 			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1222 		hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN;
1223 	srcu_read_unlock(&kvm->srcu, idx);
1224 
1225 out_unlock:
1226 	mutex_unlock(&hv->hv_lock);
1227 }
1228 
1229 
1230 static bool hv_check_msr_access(struct kvm_vcpu_hv *hv_vcpu, u32 msr)
1231 {
1232 	if (!hv_vcpu->enforce_cpuid)
1233 		return true;
1234 
1235 	switch (msr) {
1236 	case HV_X64_MSR_GUEST_OS_ID:
1237 	case HV_X64_MSR_HYPERCALL:
1238 		return hv_vcpu->cpuid_cache.features_eax &
1239 			HV_MSR_HYPERCALL_AVAILABLE;
1240 	case HV_X64_MSR_VP_RUNTIME:
1241 		return hv_vcpu->cpuid_cache.features_eax &
1242 			HV_MSR_VP_RUNTIME_AVAILABLE;
1243 	case HV_X64_MSR_TIME_REF_COUNT:
1244 		return hv_vcpu->cpuid_cache.features_eax &
1245 			HV_MSR_TIME_REF_COUNT_AVAILABLE;
1246 	case HV_X64_MSR_VP_INDEX:
1247 		return hv_vcpu->cpuid_cache.features_eax &
1248 			HV_MSR_VP_INDEX_AVAILABLE;
1249 	case HV_X64_MSR_RESET:
1250 		return hv_vcpu->cpuid_cache.features_eax &
1251 			HV_MSR_RESET_AVAILABLE;
1252 	case HV_X64_MSR_REFERENCE_TSC:
1253 		return hv_vcpu->cpuid_cache.features_eax &
1254 			HV_MSR_REFERENCE_TSC_AVAILABLE;
1255 	case HV_X64_MSR_SCONTROL:
1256 	case HV_X64_MSR_SVERSION:
1257 	case HV_X64_MSR_SIEFP:
1258 	case HV_X64_MSR_SIMP:
1259 	case HV_X64_MSR_EOM:
1260 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1261 		return hv_vcpu->cpuid_cache.features_eax &
1262 			HV_MSR_SYNIC_AVAILABLE;
1263 	case HV_X64_MSR_STIMER0_CONFIG:
1264 	case HV_X64_MSR_STIMER1_CONFIG:
1265 	case HV_X64_MSR_STIMER2_CONFIG:
1266 	case HV_X64_MSR_STIMER3_CONFIG:
1267 	case HV_X64_MSR_STIMER0_COUNT:
1268 	case HV_X64_MSR_STIMER1_COUNT:
1269 	case HV_X64_MSR_STIMER2_COUNT:
1270 	case HV_X64_MSR_STIMER3_COUNT:
1271 		return hv_vcpu->cpuid_cache.features_eax &
1272 			HV_MSR_SYNTIMER_AVAILABLE;
1273 	case HV_X64_MSR_EOI:
1274 	case HV_X64_MSR_ICR:
1275 	case HV_X64_MSR_TPR:
1276 	case HV_X64_MSR_VP_ASSIST_PAGE:
1277 		return hv_vcpu->cpuid_cache.features_eax &
1278 			HV_MSR_APIC_ACCESS_AVAILABLE;
1279 		break;
1280 	case HV_X64_MSR_TSC_FREQUENCY:
1281 	case HV_X64_MSR_APIC_FREQUENCY:
1282 		return hv_vcpu->cpuid_cache.features_eax &
1283 			HV_ACCESS_FREQUENCY_MSRS;
1284 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1285 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1286 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1287 		return hv_vcpu->cpuid_cache.features_eax &
1288 			HV_ACCESS_REENLIGHTENMENT;
1289 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1290 	case HV_X64_MSR_CRASH_CTL:
1291 		return hv_vcpu->cpuid_cache.features_edx &
1292 			HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
1293 	case HV_X64_MSR_SYNDBG_OPTIONS:
1294 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1295 		return hv_vcpu->cpuid_cache.features_edx &
1296 			HV_FEATURE_DEBUG_MSRS_AVAILABLE;
1297 	default:
1298 		break;
1299 	}
1300 
1301 	return false;
1302 }
1303 
1304 static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
1305 			     bool host)
1306 {
1307 	struct kvm *kvm = vcpu->kvm;
1308 	struct kvm_hv *hv = to_kvm_hv(kvm);
1309 
1310 	if (unlikely(!host && !hv_check_msr_access(to_hv_vcpu(vcpu), msr)))
1311 		return 1;
1312 
1313 	switch (msr) {
1314 	case HV_X64_MSR_GUEST_OS_ID:
1315 		hv->hv_guest_os_id = data;
1316 		/* setting guest os id to zero disables hypercall page */
1317 		if (!hv->hv_guest_os_id)
1318 			hv->hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
1319 		break;
1320 	case HV_X64_MSR_HYPERCALL: {
1321 		u8 instructions[9];
1322 		int i = 0;
1323 		u64 addr;
1324 
1325 		/* if guest os id is not set hypercall should remain disabled */
1326 		if (!hv->hv_guest_os_id)
1327 			break;
1328 		if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
1329 			hv->hv_hypercall = data;
1330 			break;
1331 		}
1332 
1333 		/*
1334 		 * If Xen and Hyper-V hypercalls are both enabled, disambiguate
1335 		 * the same way Xen itself does, by setting the bit 31 of EAX
1336 		 * which is RsvdZ in the 32-bit Hyper-V hypercall ABI and just
1337 		 * going to be clobbered on 64-bit.
1338 		 */
1339 		if (kvm_xen_hypercall_enabled(kvm)) {
1340 			/* orl $0x80000000, %eax */
1341 			instructions[i++] = 0x0d;
1342 			instructions[i++] = 0x00;
1343 			instructions[i++] = 0x00;
1344 			instructions[i++] = 0x00;
1345 			instructions[i++] = 0x80;
1346 		}
1347 
1348 		/* vmcall/vmmcall */
1349 		static_call(kvm_x86_patch_hypercall)(vcpu, instructions + i);
1350 		i += 3;
1351 
1352 		/* ret */
1353 		((unsigned char *)instructions)[i++] = 0xc3;
1354 
1355 		addr = data & HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_MASK;
1356 		if (kvm_vcpu_write_guest(vcpu, addr, instructions, i))
1357 			return 1;
1358 		hv->hv_hypercall = data;
1359 		break;
1360 	}
1361 	case HV_X64_MSR_REFERENCE_TSC:
1362 		hv->hv_tsc_page = data;
1363 		if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE) {
1364 			if (!host)
1365 				hv->hv_tsc_page_status = HV_TSC_PAGE_GUEST_CHANGED;
1366 			else
1367 				hv->hv_tsc_page_status = HV_TSC_PAGE_HOST_CHANGED;
1368 			kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
1369 		} else {
1370 			hv->hv_tsc_page_status = HV_TSC_PAGE_UNSET;
1371 		}
1372 		break;
1373 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1374 		return kvm_hv_msr_set_crash_data(kvm,
1375 						 msr - HV_X64_MSR_CRASH_P0,
1376 						 data);
1377 	case HV_X64_MSR_CRASH_CTL:
1378 		if (host)
1379 			return kvm_hv_msr_set_crash_ctl(kvm, data);
1380 
1381 		if (data & HV_CRASH_CTL_CRASH_NOTIFY) {
1382 			vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx 0x%llx)\n",
1383 				   hv->hv_crash_param[0],
1384 				   hv->hv_crash_param[1],
1385 				   hv->hv_crash_param[2],
1386 				   hv->hv_crash_param[3],
1387 				   hv->hv_crash_param[4]);
1388 
1389 			/* Send notification about crash to user space */
1390 			kvm_make_request(KVM_REQ_HV_CRASH, vcpu);
1391 		}
1392 		break;
1393 	case HV_X64_MSR_RESET:
1394 		if (data == 1) {
1395 			vcpu_debug(vcpu, "hyper-v reset requested\n");
1396 			kvm_make_request(KVM_REQ_HV_RESET, vcpu);
1397 		}
1398 		break;
1399 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1400 		hv->hv_reenlightenment_control = data;
1401 		break;
1402 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1403 		hv->hv_tsc_emulation_control = data;
1404 		break;
1405 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1406 		if (data && !host)
1407 			return 1;
1408 
1409 		hv->hv_tsc_emulation_status = data;
1410 		break;
1411 	case HV_X64_MSR_TIME_REF_COUNT:
1412 		/* read-only, but still ignore it if host-initiated */
1413 		if (!host)
1414 			return 1;
1415 		break;
1416 	case HV_X64_MSR_SYNDBG_OPTIONS:
1417 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1418 		return syndbg_set_msr(vcpu, msr, data, host);
1419 	default:
1420 		vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
1421 			    msr, data);
1422 		return 1;
1423 	}
1424 	return 0;
1425 }
1426 
1427 /* Calculate cpu time spent by current task in 100ns units */
1428 static u64 current_task_runtime_100ns(void)
1429 {
1430 	u64 utime, stime;
1431 
1432 	task_cputime_adjusted(current, &utime, &stime);
1433 
1434 	return div_u64(utime + stime, 100);
1435 }
1436 
1437 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1438 {
1439 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1440 
1441 	if (unlikely(!host && !hv_check_msr_access(hv_vcpu, msr)))
1442 		return 1;
1443 
1444 	switch (msr) {
1445 	case HV_X64_MSR_VP_INDEX: {
1446 		struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1447 		u32 new_vp_index = (u32)data;
1448 
1449 		if (!host || new_vp_index >= KVM_MAX_VCPUS)
1450 			return 1;
1451 
1452 		if (new_vp_index == hv_vcpu->vp_index)
1453 			return 0;
1454 
1455 		/*
1456 		 * The VP index is initialized to vcpu_index by
1457 		 * kvm_hv_vcpu_postcreate so they initially match.  Now the
1458 		 * VP index is changing, adjust num_mismatched_vp_indexes if
1459 		 * it now matches or no longer matches vcpu_idx.
1460 		 */
1461 		if (hv_vcpu->vp_index == vcpu->vcpu_idx)
1462 			atomic_inc(&hv->num_mismatched_vp_indexes);
1463 		else if (new_vp_index == vcpu->vcpu_idx)
1464 			atomic_dec(&hv->num_mismatched_vp_indexes);
1465 
1466 		hv_vcpu->vp_index = new_vp_index;
1467 		break;
1468 	}
1469 	case HV_X64_MSR_VP_ASSIST_PAGE: {
1470 		u64 gfn;
1471 		unsigned long addr;
1472 
1473 		if (!(data & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE)) {
1474 			hv_vcpu->hv_vapic = data;
1475 			if (kvm_lapic_set_pv_eoi(vcpu, 0, 0))
1476 				return 1;
1477 			break;
1478 		}
1479 		gfn = data >> HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT;
1480 		addr = kvm_vcpu_gfn_to_hva(vcpu, gfn);
1481 		if (kvm_is_error_hva(addr))
1482 			return 1;
1483 
1484 		/*
1485 		 * Clear apic_assist portion of struct hv_vp_assist_page
1486 		 * only, there can be valuable data in the rest which needs
1487 		 * to be preserved e.g. on migration.
1488 		 */
1489 		if (__put_user(0, (u32 __user *)addr))
1490 			return 1;
1491 		hv_vcpu->hv_vapic = data;
1492 		kvm_vcpu_mark_page_dirty(vcpu, gfn);
1493 		if (kvm_lapic_set_pv_eoi(vcpu,
1494 					    gfn_to_gpa(gfn) | KVM_MSR_ENABLED,
1495 					    sizeof(struct hv_vp_assist_page)))
1496 			return 1;
1497 		break;
1498 	}
1499 	case HV_X64_MSR_EOI:
1500 		return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
1501 	case HV_X64_MSR_ICR:
1502 		return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
1503 	case HV_X64_MSR_TPR:
1504 		return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
1505 	case HV_X64_MSR_VP_RUNTIME:
1506 		if (!host)
1507 			return 1;
1508 		hv_vcpu->runtime_offset = data - current_task_runtime_100ns();
1509 		break;
1510 	case HV_X64_MSR_SCONTROL:
1511 	case HV_X64_MSR_SVERSION:
1512 	case HV_X64_MSR_SIEFP:
1513 	case HV_X64_MSR_SIMP:
1514 	case HV_X64_MSR_EOM:
1515 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1516 		return synic_set_msr(to_hv_synic(vcpu), msr, data, host);
1517 	case HV_X64_MSR_STIMER0_CONFIG:
1518 	case HV_X64_MSR_STIMER1_CONFIG:
1519 	case HV_X64_MSR_STIMER2_CONFIG:
1520 	case HV_X64_MSR_STIMER3_CONFIG: {
1521 		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1522 
1523 		return stimer_set_config(to_hv_stimer(vcpu, timer_index),
1524 					 data, host);
1525 	}
1526 	case HV_X64_MSR_STIMER0_COUNT:
1527 	case HV_X64_MSR_STIMER1_COUNT:
1528 	case HV_X64_MSR_STIMER2_COUNT:
1529 	case HV_X64_MSR_STIMER3_COUNT: {
1530 		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1531 
1532 		return stimer_set_count(to_hv_stimer(vcpu, timer_index),
1533 					data, host);
1534 	}
1535 	case HV_X64_MSR_TSC_FREQUENCY:
1536 	case HV_X64_MSR_APIC_FREQUENCY:
1537 		/* read-only, but still ignore it if host-initiated */
1538 		if (!host)
1539 			return 1;
1540 		break;
1541 	default:
1542 		vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
1543 			    msr, data);
1544 		return 1;
1545 	}
1546 
1547 	return 0;
1548 }
1549 
1550 static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1551 			     bool host)
1552 {
1553 	u64 data = 0;
1554 	struct kvm *kvm = vcpu->kvm;
1555 	struct kvm_hv *hv = to_kvm_hv(kvm);
1556 
1557 	if (unlikely(!host && !hv_check_msr_access(to_hv_vcpu(vcpu), msr)))
1558 		return 1;
1559 
1560 	switch (msr) {
1561 	case HV_X64_MSR_GUEST_OS_ID:
1562 		data = hv->hv_guest_os_id;
1563 		break;
1564 	case HV_X64_MSR_HYPERCALL:
1565 		data = hv->hv_hypercall;
1566 		break;
1567 	case HV_X64_MSR_TIME_REF_COUNT:
1568 		data = get_time_ref_counter(kvm);
1569 		break;
1570 	case HV_X64_MSR_REFERENCE_TSC:
1571 		data = hv->hv_tsc_page;
1572 		break;
1573 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1574 		return kvm_hv_msr_get_crash_data(kvm,
1575 						 msr - HV_X64_MSR_CRASH_P0,
1576 						 pdata);
1577 	case HV_X64_MSR_CRASH_CTL:
1578 		return kvm_hv_msr_get_crash_ctl(kvm, pdata);
1579 	case HV_X64_MSR_RESET:
1580 		data = 0;
1581 		break;
1582 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1583 		data = hv->hv_reenlightenment_control;
1584 		break;
1585 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1586 		data = hv->hv_tsc_emulation_control;
1587 		break;
1588 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1589 		data = hv->hv_tsc_emulation_status;
1590 		break;
1591 	case HV_X64_MSR_SYNDBG_OPTIONS:
1592 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1593 		return syndbg_get_msr(vcpu, msr, pdata, host);
1594 	default:
1595 		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1596 		return 1;
1597 	}
1598 
1599 	*pdata = data;
1600 	return 0;
1601 }
1602 
1603 static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1604 			  bool host)
1605 {
1606 	u64 data = 0;
1607 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1608 
1609 	if (unlikely(!host && !hv_check_msr_access(hv_vcpu, msr)))
1610 		return 1;
1611 
1612 	switch (msr) {
1613 	case HV_X64_MSR_VP_INDEX:
1614 		data = hv_vcpu->vp_index;
1615 		break;
1616 	case HV_X64_MSR_EOI:
1617 		return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
1618 	case HV_X64_MSR_ICR:
1619 		return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
1620 	case HV_X64_MSR_TPR:
1621 		return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
1622 	case HV_X64_MSR_VP_ASSIST_PAGE:
1623 		data = hv_vcpu->hv_vapic;
1624 		break;
1625 	case HV_X64_MSR_VP_RUNTIME:
1626 		data = current_task_runtime_100ns() + hv_vcpu->runtime_offset;
1627 		break;
1628 	case HV_X64_MSR_SCONTROL:
1629 	case HV_X64_MSR_SVERSION:
1630 	case HV_X64_MSR_SIEFP:
1631 	case HV_X64_MSR_SIMP:
1632 	case HV_X64_MSR_EOM:
1633 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1634 		return synic_get_msr(to_hv_synic(vcpu), msr, pdata, host);
1635 	case HV_X64_MSR_STIMER0_CONFIG:
1636 	case HV_X64_MSR_STIMER1_CONFIG:
1637 	case HV_X64_MSR_STIMER2_CONFIG:
1638 	case HV_X64_MSR_STIMER3_CONFIG: {
1639 		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1640 
1641 		return stimer_get_config(to_hv_stimer(vcpu, timer_index),
1642 					 pdata);
1643 	}
1644 	case HV_X64_MSR_STIMER0_COUNT:
1645 	case HV_X64_MSR_STIMER1_COUNT:
1646 	case HV_X64_MSR_STIMER2_COUNT:
1647 	case HV_X64_MSR_STIMER3_COUNT: {
1648 		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1649 
1650 		return stimer_get_count(to_hv_stimer(vcpu, timer_index),
1651 					pdata);
1652 	}
1653 	case HV_X64_MSR_TSC_FREQUENCY:
1654 		data = (u64)vcpu->arch.virtual_tsc_khz * 1000;
1655 		break;
1656 	case HV_X64_MSR_APIC_FREQUENCY:
1657 		data = APIC_BUS_FREQUENCY;
1658 		break;
1659 	default:
1660 		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1661 		return 1;
1662 	}
1663 	*pdata = data;
1664 	return 0;
1665 }
1666 
1667 int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1668 {
1669 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1670 
1671 	if (!host && !vcpu->arch.hyperv_enabled)
1672 		return 1;
1673 
1674 	if (!to_hv_vcpu(vcpu)) {
1675 		if (kvm_hv_vcpu_init(vcpu))
1676 			return 1;
1677 	}
1678 
1679 	if (kvm_hv_msr_partition_wide(msr)) {
1680 		int r;
1681 
1682 		mutex_lock(&hv->hv_lock);
1683 		r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
1684 		mutex_unlock(&hv->hv_lock);
1685 		return r;
1686 	} else
1687 		return kvm_hv_set_msr(vcpu, msr, data, host);
1688 }
1689 
1690 int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
1691 {
1692 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1693 
1694 	if (!host && !vcpu->arch.hyperv_enabled)
1695 		return 1;
1696 
1697 	if (!to_hv_vcpu(vcpu)) {
1698 		if (kvm_hv_vcpu_init(vcpu))
1699 			return 1;
1700 	}
1701 
1702 	if (kvm_hv_msr_partition_wide(msr)) {
1703 		int r;
1704 
1705 		mutex_lock(&hv->hv_lock);
1706 		r = kvm_hv_get_msr_pw(vcpu, msr, pdata, host);
1707 		mutex_unlock(&hv->hv_lock);
1708 		return r;
1709 	} else
1710 		return kvm_hv_get_msr(vcpu, msr, pdata, host);
1711 }
1712 
1713 static __always_inline unsigned long *sparse_set_to_vcpu_mask(
1714 	struct kvm *kvm, u64 *sparse_banks, u64 valid_bank_mask,
1715 	u64 *vp_bitmap, unsigned long *vcpu_bitmap)
1716 {
1717 	struct kvm_hv *hv = to_kvm_hv(kvm);
1718 	struct kvm_vcpu *vcpu;
1719 	int i, bank, sbank = 0;
1720 
1721 	memset(vp_bitmap, 0,
1722 	       KVM_HV_MAX_SPARSE_VCPU_SET_BITS * sizeof(*vp_bitmap));
1723 	for_each_set_bit(bank, (unsigned long *)&valid_bank_mask,
1724 			 KVM_HV_MAX_SPARSE_VCPU_SET_BITS)
1725 		vp_bitmap[bank] = sparse_banks[sbank++];
1726 
1727 	if (likely(!atomic_read(&hv->num_mismatched_vp_indexes))) {
1728 		/* for all vcpus vp_index == vcpu_idx */
1729 		return (unsigned long *)vp_bitmap;
1730 	}
1731 
1732 	bitmap_zero(vcpu_bitmap, KVM_MAX_VCPUS);
1733 	kvm_for_each_vcpu(i, vcpu, kvm) {
1734 		if (test_bit(kvm_hv_get_vpindex(vcpu), (unsigned long *)vp_bitmap))
1735 			__set_bit(i, vcpu_bitmap);
1736 	}
1737 	return vcpu_bitmap;
1738 }
1739 
1740 struct kvm_hv_hcall {
1741 	u64 param;
1742 	u64 ingpa;
1743 	u64 outgpa;
1744 	u16 code;
1745 	u16 rep_cnt;
1746 	u16 rep_idx;
1747 	bool fast;
1748 	bool rep;
1749 	sse128_t xmm[HV_HYPERCALL_MAX_XMM_REGISTERS];
1750 };
1751 
1752 static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool ex)
1753 {
1754 	int i;
1755 	gpa_t gpa;
1756 	struct kvm *kvm = vcpu->kvm;
1757 	struct hv_tlb_flush_ex flush_ex;
1758 	struct hv_tlb_flush flush;
1759 	u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1760 	DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS);
1761 	unsigned long *vcpu_mask;
1762 	u64 valid_bank_mask;
1763 	u64 sparse_banks[64];
1764 	int sparse_banks_len;
1765 	bool all_cpus;
1766 
1767 	if (!ex) {
1768 		if (hc->fast) {
1769 			flush.address_space = hc->ingpa;
1770 			flush.flags = hc->outgpa;
1771 			flush.processor_mask = sse128_lo(hc->xmm[0]);
1772 		} else {
1773 			if (unlikely(kvm_read_guest(kvm, hc->ingpa,
1774 						    &flush, sizeof(flush))))
1775 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1776 		}
1777 
1778 		trace_kvm_hv_flush_tlb(flush.processor_mask,
1779 				       flush.address_space, flush.flags);
1780 
1781 		valid_bank_mask = BIT_ULL(0);
1782 		sparse_banks[0] = flush.processor_mask;
1783 
1784 		/*
1785 		 * Work around possible WS2012 bug: it sends hypercalls
1786 		 * with processor_mask = 0x0 and HV_FLUSH_ALL_PROCESSORS clear,
1787 		 * while also expecting us to flush something and crashing if
1788 		 * we don't. Let's treat processor_mask == 0 same as
1789 		 * HV_FLUSH_ALL_PROCESSORS.
1790 		 */
1791 		all_cpus = (flush.flags & HV_FLUSH_ALL_PROCESSORS) ||
1792 			flush.processor_mask == 0;
1793 	} else {
1794 		if (hc->fast) {
1795 			flush_ex.address_space = hc->ingpa;
1796 			flush_ex.flags = hc->outgpa;
1797 			memcpy(&flush_ex.hv_vp_set,
1798 			       &hc->xmm[0], sizeof(hc->xmm[0]));
1799 		} else {
1800 			if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush_ex,
1801 						    sizeof(flush_ex))))
1802 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1803 		}
1804 
1805 		trace_kvm_hv_flush_tlb_ex(flush_ex.hv_vp_set.valid_bank_mask,
1806 					  flush_ex.hv_vp_set.format,
1807 					  flush_ex.address_space,
1808 					  flush_ex.flags);
1809 
1810 		valid_bank_mask = flush_ex.hv_vp_set.valid_bank_mask;
1811 		all_cpus = flush_ex.hv_vp_set.format !=
1812 			HV_GENERIC_SET_SPARSE_4K;
1813 
1814 		sparse_banks_len = bitmap_weight((unsigned long *)&valid_bank_mask, 64);
1815 
1816 		if (!sparse_banks_len && !all_cpus)
1817 			goto ret_success;
1818 
1819 		if (!all_cpus) {
1820 			if (hc->fast) {
1821 				if (sparse_banks_len > HV_HYPERCALL_MAX_XMM_REGISTERS - 1)
1822 					return HV_STATUS_INVALID_HYPERCALL_INPUT;
1823 				for (i = 0; i < sparse_banks_len; i += 2) {
1824 					sparse_banks[i] = sse128_lo(hc->xmm[i / 2 + 1]);
1825 					sparse_banks[i + 1] = sse128_hi(hc->xmm[i / 2 + 1]);
1826 				}
1827 			} else {
1828 				gpa = hc->ingpa + offsetof(struct hv_tlb_flush_ex,
1829 							   hv_vp_set.bank_contents);
1830 				if (unlikely(kvm_read_guest(kvm, gpa, sparse_banks,
1831 							    sparse_banks_len *
1832 							    sizeof(sparse_banks[0]))))
1833 					return HV_STATUS_INVALID_HYPERCALL_INPUT;
1834 			}
1835 		}
1836 	}
1837 
1838 	/*
1839 	 * vcpu->arch.cr3 may not be up-to-date for running vCPUs so we can't
1840 	 * analyze it here, flush TLB regardless of the specified address space.
1841 	 */
1842 	if (all_cpus) {
1843 		kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH_GUEST);
1844 	} else {
1845 		vcpu_mask = sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
1846 						    vp_bitmap, vcpu_bitmap);
1847 
1848 		kvm_make_vcpus_request_mask(kvm, KVM_REQ_TLB_FLUSH_GUEST,
1849 					    vcpu_mask);
1850 	}
1851 
1852 ret_success:
1853 	/* We always do full TLB flush, set 'Reps completed' = 'Rep Count' */
1854 	return (u64)HV_STATUS_SUCCESS |
1855 		((u64)hc->rep_cnt << HV_HYPERCALL_REP_COMP_OFFSET);
1856 }
1857 
1858 static void kvm_send_ipi_to_many(struct kvm *kvm, u32 vector,
1859 				 unsigned long *vcpu_bitmap)
1860 {
1861 	struct kvm_lapic_irq irq = {
1862 		.delivery_mode = APIC_DM_FIXED,
1863 		.vector = vector
1864 	};
1865 	struct kvm_vcpu *vcpu;
1866 	int i;
1867 
1868 	kvm_for_each_vcpu(i, vcpu, kvm) {
1869 		if (vcpu_bitmap && !test_bit(i, vcpu_bitmap))
1870 			continue;
1871 
1872 		/* We fail only when APIC is disabled */
1873 		kvm_apic_set_irq(vcpu, &irq, NULL);
1874 	}
1875 }
1876 
1877 static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool ex)
1878 {
1879 	struct kvm *kvm = vcpu->kvm;
1880 	struct hv_send_ipi_ex send_ipi_ex;
1881 	struct hv_send_ipi send_ipi;
1882 	u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1883 	DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS);
1884 	unsigned long *vcpu_mask;
1885 	unsigned long valid_bank_mask;
1886 	u64 sparse_banks[64];
1887 	int sparse_banks_len;
1888 	u32 vector;
1889 	bool all_cpus;
1890 
1891 	if (!ex) {
1892 		if (!hc->fast) {
1893 			if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi,
1894 						    sizeof(send_ipi))))
1895 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1896 			sparse_banks[0] = send_ipi.cpu_mask;
1897 			vector = send_ipi.vector;
1898 		} else {
1899 			/* 'reserved' part of hv_send_ipi should be 0 */
1900 			if (unlikely(hc->ingpa >> 32 != 0))
1901 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1902 			sparse_banks[0] = hc->outgpa;
1903 			vector = (u32)hc->ingpa;
1904 		}
1905 		all_cpus = false;
1906 		valid_bank_mask = BIT_ULL(0);
1907 
1908 		trace_kvm_hv_send_ipi(vector, sparse_banks[0]);
1909 	} else {
1910 		if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi_ex,
1911 					    sizeof(send_ipi_ex))))
1912 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1913 
1914 		trace_kvm_hv_send_ipi_ex(send_ipi_ex.vector,
1915 					 send_ipi_ex.vp_set.format,
1916 					 send_ipi_ex.vp_set.valid_bank_mask);
1917 
1918 		vector = send_ipi_ex.vector;
1919 		valid_bank_mask = send_ipi_ex.vp_set.valid_bank_mask;
1920 		sparse_banks_len = bitmap_weight(&valid_bank_mask, 64) *
1921 			sizeof(sparse_banks[0]);
1922 
1923 		all_cpus = send_ipi_ex.vp_set.format == HV_GENERIC_SET_ALL;
1924 
1925 		if (!sparse_banks_len)
1926 			goto ret_success;
1927 
1928 		if (!all_cpus &&
1929 		    kvm_read_guest(kvm,
1930 				   hc->ingpa + offsetof(struct hv_send_ipi_ex,
1931 							vp_set.bank_contents),
1932 				   sparse_banks,
1933 				   sparse_banks_len))
1934 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1935 	}
1936 
1937 	if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR))
1938 		return HV_STATUS_INVALID_HYPERCALL_INPUT;
1939 
1940 	vcpu_mask = all_cpus ? NULL :
1941 		sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
1942 					vp_bitmap, vcpu_bitmap);
1943 
1944 	kvm_send_ipi_to_many(kvm, vector, vcpu_mask);
1945 
1946 ret_success:
1947 	return HV_STATUS_SUCCESS;
1948 }
1949 
1950 void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu)
1951 {
1952 	struct kvm_cpuid_entry2 *entry;
1953 	struct kvm_vcpu_hv *hv_vcpu;
1954 
1955 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_INTERFACE, 0);
1956 	if (entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX) {
1957 		vcpu->arch.hyperv_enabled = true;
1958 	} else {
1959 		vcpu->arch.hyperv_enabled = false;
1960 		return;
1961 	}
1962 
1963 	if (!to_hv_vcpu(vcpu) && kvm_hv_vcpu_init(vcpu))
1964 		return;
1965 
1966 	hv_vcpu = to_hv_vcpu(vcpu);
1967 
1968 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_FEATURES, 0);
1969 	if (entry) {
1970 		hv_vcpu->cpuid_cache.features_eax = entry->eax;
1971 		hv_vcpu->cpuid_cache.features_ebx = entry->ebx;
1972 		hv_vcpu->cpuid_cache.features_edx = entry->edx;
1973 	} else {
1974 		hv_vcpu->cpuid_cache.features_eax = 0;
1975 		hv_vcpu->cpuid_cache.features_ebx = 0;
1976 		hv_vcpu->cpuid_cache.features_edx = 0;
1977 	}
1978 
1979 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_ENLIGHTMENT_INFO, 0);
1980 	if (entry) {
1981 		hv_vcpu->cpuid_cache.enlightenments_eax = entry->eax;
1982 		hv_vcpu->cpuid_cache.enlightenments_ebx = entry->ebx;
1983 	} else {
1984 		hv_vcpu->cpuid_cache.enlightenments_eax = 0;
1985 		hv_vcpu->cpuid_cache.enlightenments_ebx = 0;
1986 	}
1987 
1988 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES, 0);
1989 	if (entry)
1990 		hv_vcpu->cpuid_cache.syndbg_cap_eax = entry->eax;
1991 	else
1992 		hv_vcpu->cpuid_cache.syndbg_cap_eax = 0;
1993 }
1994 
1995 int kvm_hv_set_enforce_cpuid(struct kvm_vcpu *vcpu, bool enforce)
1996 {
1997 	struct kvm_vcpu_hv *hv_vcpu;
1998 	int ret = 0;
1999 
2000 	if (!to_hv_vcpu(vcpu)) {
2001 		if (enforce) {
2002 			ret = kvm_hv_vcpu_init(vcpu);
2003 			if (ret)
2004 				return ret;
2005 		} else {
2006 			return 0;
2007 		}
2008 	}
2009 
2010 	hv_vcpu = to_hv_vcpu(vcpu);
2011 	hv_vcpu->enforce_cpuid = enforce;
2012 
2013 	return ret;
2014 }
2015 
2016 bool kvm_hv_hypercall_enabled(struct kvm_vcpu *vcpu)
2017 {
2018 	return vcpu->arch.hyperv_enabled && to_kvm_hv(vcpu->kvm)->hv_guest_os_id;
2019 }
2020 
2021 static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
2022 {
2023 	bool longmode;
2024 
2025 	longmode = is_64_bit_mode(vcpu);
2026 	if (longmode)
2027 		kvm_rax_write(vcpu, result);
2028 	else {
2029 		kvm_rdx_write(vcpu, result >> 32);
2030 		kvm_rax_write(vcpu, result & 0xffffffff);
2031 	}
2032 }
2033 
2034 static int kvm_hv_hypercall_complete(struct kvm_vcpu *vcpu, u64 result)
2035 {
2036 	trace_kvm_hv_hypercall_done(result);
2037 	kvm_hv_hypercall_set_result(vcpu, result);
2038 	++vcpu->stat.hypercalls;
2039 	return kvm_skip_emulated_instruction(vcpu);
2040 }
2041 
2042 static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
2043 {
2044 	return kvm_hv_hypercall_complete(vcpu, vcpu->run->hyperv.u.hcall.result);
2045 }
2046 
2047 static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
2048 {
2049 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
2050 	struct eventfd_ctx *eventfd;
2051 
2052 	if (unlikely(!hc->fast)) {
2053 		int ret;
2054 		gpa_t gpa = hc->ingpa;
2055 
2056 		if ((gpa & (__alignof__(hc->ingpa) - 1)) ||
2057 		    offset_in_page(gpa) + sizeof(hc->ingpa) > PAGE_SIZE)
2058 			return HV_STATUS_INVALID_ALIGNMENT;
2059 
2060 		ret = kvm_vcpu_read_guest(vcpu, gpa,
2061 					  &hc->ingpa, sizeof(hc->ingpa));
2062 		if (ret < 0)
2063 			return HV_STATUS_INVALID_ALIGNMENT;
2064 	}
2065 
2066 	/*
2067 	 * Per spec, bits 32-47 contain the extra "flag number".  However, we
2068 	 * have no use for it, and in all known usecases it is zero, so just
2069 	 * report lookup failure if it isn't.
2070 	 */
2071 	if (hc->ingpa & 0xffff00000000ULL)
2072 		return HV_STATUS_INVALID_PORT_ID;
2073 	/* remaining bits are reserved-zero */
2074 	if (hc->ingpa & ~KVM_HYPERV_CONN_ID_MASK)
2075 		return HV_STATUS_INVALID_HYPERCALL_INPUT;
2076 
2077 	/* the eventfd is protected by vcpu->kvm->srcu, but conn_to_evt isn't */
2078 	rcu_read_lock();
2079 	eventfd = idr_find(&hv->conn_to_evt, hc->ingpa);
2080 	rcu_read_unlock();
2081 	if (!eventfd)
2082 		return HV_STATUS_INVALID_PORT_ID;
2083 
2084 	eventfd_signal(eventfd, 1);
2085 	return HV_STATUS_SUCCESS;
2086 }
2087 
2088 static bool is_xmm_fast_hypercall(struct kvm_hv_hcall *hc)
2089 {
2090 	switch (hc->code) {
2091 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2092 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2093 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2094 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2095 		return true;
2096 	}
2097 
2098 	return false;
2099 }
2100 
2101 static void kvm_hv_hypercall_read_xmm(struct kvm_hv_hcall *hc)
2102 {
2103 	int reg;
2104 
2105 	kvm_fpu_get();
2106 	for (reg = 0; reg < HV_HYPERCALL_MAX_XMM_REGISTERS; reg++)
2107 		_kvm_read_sse_reg(reg, &hc->xmm[reg]);
2108 	kvm_fpu_put();
2109 }
2110 
2111 static bool hv_check_hypercall_access(struct kvm_vcpu_hv *hv_vcpu, u16 code)
2112 {
2113 	if (!hv_vcpu->enforce_cpuid)
2114 		return true;
2115 
2116 	switch (code) {
2117 	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
2118 		return hv_vcpu->cpuid_cache.enlightenments_ebx &&
2119 			hv_vcpu->cpuid_cache.enlightenments_ebx != U32_MAX;
2120 	case HVCALL_POST_MESSAGE:
2121 		return hv_vcpu->cpuid_cache.features_ebx & HV_POST_MESSAGES;
2122 	case HVCALL_SIGNAL_EVENT:
2123 		return hv_vcpu->cpuid_cache.features_ebx & HV_SIGNAL_EVENTS;
2124 	case HVCALL_POST_DEBUG_DATA:
2125 	case HVCALL_RETRIEVE_DEBUG_DATA:
2126 	case HVCALL_RESET_DEBUG_SESSION:
2127 		/*
2128 		 * Return 'true' when SynDBG is disabled so the resulting code
2129 		 * will be HV_STATUS_INVALID_HYPERCALL_CODE.
2130 		 */
2131 		return !kvm_hv_is_syndbg_enabled(hv_vcpu->vcpu) ||
2132 			hv_vcpu->cpuid_cache.features_ebx & HV_DEBUGGING;
2133 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2134 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2135 		if (!(hv_vcpu->cpuid_cache.enlightenments_eax &
2136 		      HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
2137 			return false;
2138 		fallthrough;
2139 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2140 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2141 		return hv_vcpu->cpuid_cache.enlightenments_eax &
2142 			HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
2143 	case HVCALL_SEND_IPI_EX:
2144 		if (!(hv_vcpu->cpuid_cache.enlightenments_eax &
2145 		      HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
2146 			return false;
2147 		fallthrough;
2148 	case HVCALL_SEND_IPI:
2149 		return hv_vcpu->cpuid_cache.enlightenments_eax &
2150 			HV_X64_CLUSTER_IPI_RECOMMENDED;
2151 	default:
2152 		break;
2153 	}
2154 
2155 	return true;
2156 }
2157 
2158 int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
2159 {
2160 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
2161 	struct kvm_hv_hcall hc;
2162 	u64 ret = HV_STATUS_SUCCESS;
2163 
2164 	/*
2165 	 * hypercall generates UD from non zero cpl and real mode
2166 	 * per HYPER-V spec
2167 	 */
2168 	if (static_call(kvm_x86_get_cpl)(vcpu) != 0 || !is_protmode(vcpu)) {
2169 		kvm_queue_exception(vcpu, UD_VECTOR);
2170 		return 1;
2171 	}
2172 
2173 #ifdef CONFIG_X86_64
2174 	if (is_64_bit_mode(vcpu)) {
2175 		hc.param = kvm_rcx_read(vcpu);
2176 		hc.ingpa = kvm_rdx_read(vcpu);
2177 		hc.outgpa = kvm_r8_read(vcpu);
2178 	} else
2179 #endif
2180 	{
2181 		hc.param = ((u64)kvm_rdx_read(vcpu) << 32) |
2182 			    (kvm_rax_read(vcpu) & 0xffffffff);
2183 		hc.ingpa = ((u64)kvm_rbx_read(vcpu) << 32) |
2184 			    (kvm_rcx_read(vcpu) & 0xffffffff);
2185 		hc.outgpa = ((u64)kvm_rdi_read(vcpu) << 32) |
2186 			     (kvm_rsi_read(vcpu) & 0xffffffff);
2187 	}
2188 
2189 	hc.code = hc.param & 0xffff;
2190 	hc.fast = !!(hc.param & HV_HYPERCALL_FAST_BIT);
2191 	hc.rep_cnt = (hc.param >> HV_HYPERCALL_REP_COMP_OFFSET) & 0xfff;
2192 	hc.rep_idx = (hc.param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff;
2193 	hc.rep = !!(hc.rep_cnt || hc.rep_idx);
2194 
2195 	trace_kvm_hv_hypercall(hc.code, hc.fast, hc.rep_cnt, hc.rep_idx,
2196 			       hc.ingpa, hc.outgpa);
2197 
2198 	if (unlikely(!hv_check_hypercall_access(hv_vcpu, hc.code))) {
2199 		ret = HV_STATUS_ACCESS_DENIED;
2200 		goto hypercall_complete;
2201 	}
2202 
2203 	if (hc.fast && is_xmm_fast_hypercall(&hc)) {
2204 		if (unlikely(hv_vcpu->enforce_cpuid &&
2205 			     !(hv_vcpu->cpuid_cache.features_edx &
2206 			       HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE))) {
2207 			kvm_queue_exception(vcpu, UD_VECTOR);
2208 			return 1;
2209 		}
2210 
2211 		kvm_hv_hypercall_read_xmm(&hc);
2212 	}
2213 
2214 	switch (hc.code) {
2215 	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
2216 		if (unlikely(hc.rep)) {
2217 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2218 			break;
2219 		}
2220 		kvm_vcpu_on_spin(vcpu, true);
2221 		break;
2222 	case HVCALL_SIGNAL_EVENT:
2223 		if (unlikely(hc.rep)) {
2224 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2225 			break;
2226 		}
2227 		ret = kvm_hvcall_signal_event(vcpu, &hc);
2228 		if (ret != HV_STATUS_INVALID_PORT_ID)
2229 			break;
2230 		fallthrough;	/* maybe userspace knows this conn_id */
2231 	case HVCALL_POST_MESSAGE:
2232 		/* don't bother userspace if it has no way to handle it */
2233 		if (unlikely(hc.rep || !to_hv_synic(vcpu)->active)) {
2234 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2235 			break;
2236 		}
2237 		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
2238 		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
2239 		vcpu->run->hyperv.u.hcall.input = hc.param;
2240 		vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
2241 		vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
2242 		vcpu->arch.complete_userspace_io =
2243 				kvm_hv_hypercall_complete_userspace;
2244 		return 0;
2245 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2246 		if (unlikely(!hc.rep_cnt || hc.rep_idx)) {
2247 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2248 			break;
2249 		}
2250 		ret = kvm_hv_flush_tlb(vcpu, &hc, false);
2251 		break;
2252 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2253 		if (unlikely(hc.rep)) {
2254 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2255 			break;
2256 		}
2257 		ret = kvm_hv_flush_tlb(vcpu, &hc, false);
2258 		break;
2259 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2260 		if (unlikely(!hc.rep_cnt || hc.rep_idx)) {
2261 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2262 			break;
2263 		}
2264 		ret = kvm_hv_flush_tlb(vcpu, &hc, true);
2265 		break;
2266 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2267 		if (unlikely(hc.rep)) {
2268 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2269 			break;
2270 		}
2271 		ret = kvm_hv_flush_tlb(vcpu, &hc, true);
2272 		break;
2273 	case HVCALL_SEND_IPI:
2274 		if (unlikely(hc.rep)) {
2275 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2276 			break;
2277 		}
2278 		ret = kvm_hv_send_ipi(vcpu, &hc, false);
2279 		break;
2280 	case HVCALL_SEND_IPI_EX:
2281 		if (unlikely(hc.fast || hc.rep)) {
2282 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2283 			break;
2284 		}
2285 		ret = kvm_hv_send_ipi(vcpu, &hc, true);
2286 		break;
2287 	case HVCALL_POST_DEBUG_DATA:
2288 	case HVCALL_RETRIEVE_DEBUG_DATA:
2289 		if (unlikely(hc.fast)) {
2290 			ret = HV_STATUS_INVALID_PARAMETER;
2291 			break;
2292 		}
2293 		fallthrough;
2294 	case HVCALL_RESET_DEBUG_SESSION: {
2295 		struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
2296 
2297 		if (!kvm_hv_is_syndbg_enabled(vcpu)) {
2298 			ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2299 			break;
2300 		}
2301 
2302 		if (!(syndbg->options & HV_X64_SYNDBG_OPTION_USE_HCALLS)) {
2303 			ret = HV_STATUS_OPERATION_DENIED;
2304 			break;
2305 		}
2306 		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
2307 		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
2308 		vcpu->run->hyperv.u.hcall.input = hc.param;
2309 		vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
2310 		vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
2311 		vcpu->arch.complete_userspace_io =
2312 				kvm_hv_hypercall_complete_userspace;
2313 		return 0;
2314 	}
2315 	default:
2316 		ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2317 		break;
2318 	}
2319 
2320 hypercall_complete:
2321 	return kvm_hv_hypercall_complete(vcpu, ret);
2322 }
2323 
2324 void kvm_hv_init_vm(struct kvm *kvm)
2325 {
2326 	struct kvm_hv *hv = to_kvm_hv(kvm);
2327 
2328 	mutex_init(&hv->hv_lock);
2329 	idr_init(&hv->conn_to_evt);
2330 }
2331 
2332 void kvm_hv_destroy_vm(struct kvm *kvm)
2333 {
2334 	struct kvm_hv *hv = to_kvm_hv(kvm);
2335 	struct eventfd_ctx *eventfd;
2336 	int i;
2337 
2338 	idr_for_each_entry(&hv->conn_to_evt, eventfd, i)
2339 		eventfd_ctx_put(eventfd);
2340 	idr_destroy(&hv->conn_to_evt);
2341 }
2342 
2343 static int kvm_hv_eventfd_assign(struct kvm *kvm, u32 conn_id, int fd)
2344 {
2345 	struct kvm_hv *hv = to_kvm_hv(kvm);
2346 	struct eventfd_ctx *eventfd;
2347 	int ret;
2348 
2349 	eventfd = eventfd_ctx_fdget(fd);
2350 	if (IS_ERR(eventfd))
2351 		return PTR_ERR(eventfd);
2352 
2353 	mutex_lock(&hv->hv_lock);
2354 	ret = idr_alloc(&hv->conn_to_evt, eventfd, conn_id, conn_id + 1,
2355 			GFP_KERNEL_ACCOUNT);
2356 	mutex_unlock(&hv->hv_lock);
2357 
2358 	if (ret >= 0)
2359 		return 0;
2360 
2361 	if (ret == -ENOSPC)
2362 		ret = -EEXIST;
2363 	eventfd_ctx_put(eventfd);
2364 	return ret;
2365 }
2366 
2367 static int kvm_hv_eventfd_deassign(struct kvm *kvm, u32 conn_id)
2368 {
2369 	struct kvm_hv *hv = to_kvm_hv(kvm);
2370 	struct eventfd_ctx *eventfd;
2371 
2372 	mutex_lock(&hv->hv_lock);
2373 	eventfd = idr_remove(&hv->conn_to_evt, conn_id);
2374 	mutex_unlock(&hv->hv_lock);
2375 
2376 	if (!eventfd)
2377 		return -ENOENT;
2378 
2379 	synchronize_srcu(&kvm->srcu);
2380 	eventfd_ctx_put(eventfd);
2381 	return 0;
2382 }
2383 
2384 int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args)
2385 {
2386 	if ((args->flags & ~KVM_HYPERV_EVENTFD_DEASSIGN) ||
2387 	    (args->conn_id & ~KVM_HYPERV_CONN_ID_MASK))
2388 		return -EINVAL;
2389 
2390 	if (args->flags == KVM_HYPERV_EVENTFD_DEASSIGN)
2391 		return kvm_hv_eventfd_deassign(kvm, args->conn_id);
2392 	return kvm_hv_eventfd_assign(kvm, args->conn_id, args->fd);
2393 }
2394 
2395 int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
2396 		     struct kvm_cpuid_entry2 __user *entries)
2397 {
2398 	uint16_t evmcs_ver = 0;
2399 	struct kvm_cpuid_entry2 cpuid_entries[] = {
2400 		{ .function = HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS },
2401 		{ .function = HYPERV_CPUID_INTERFACE },
2402 		{ .function = HYPERV_CPUID_VERSION },
2403 		{ .function = HYPERV_CPUID_FEATURES },
2404 		{ .function = HYPERV_CPUID_ENLIGHTMENT_INFO },
2405 		{ .function = HYPERV_CPUID_IMPLEMENT_LIMITS },
2406 		{ .function = HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS },
2407 		{ .function = HYPERV_CPUID_SYNDBG_INTERFACE },
2408 		{ .function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES	},
2409 		{ .function = HYPERV_CPUID_NESTED_FEATURES },
2410 	};
2411 	int i, nent = ARRAY_SIZE(cpuid_entries);
2412 
2413 	if (kvm_x86_ops.nested_ops->get_evmcs_version)
2414 		evmcs_ver = kvm_x86_ops.nested_ops->get_evmcs_version(vcpu);
2415 
2416 	/* Skip NESTED_FEATURES if eVMCS is not supported */
2417 	if (!evmcs_ver)
2418 		--nent;
2419 
2420 	if (cpuid->nent < nent)
2421 		return -E2BIG;
2422 
2423 	if (cpuid->nent > nent)
2424 		cpuid->nent = nent;
2425 
2426 	for (i = 0; i < nent; i++) {
2427 		struct kvm_cpuid_entry2 *ent = &cpuid_entries[i];
2428 		u32 signature[3];
2429 
2430 		switch (ent->function) {
2431 		case HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS:
2432 			memcpy(signature, "Linux KVM Hv", 12);
2433 
2434 			ent->eax = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES;
2435 			ent->ebx = signature[0];
2436 			ent->ecx = signature[1];
2437 			ent->edx = signature[2];
2438 			break;
2439 
2440 		case HYPERV_CPUID_INTERFACE:
2441 			ent->eax = HYPERV_CPUID_SIGNATURE_EAX;
2442 			break;
2443 
2444 		case HYPERV_CPUID_VERSION:
2445 			/*
2446 			 * We implement some Hyper-V 2016 functions so let's use
2447 			 * this version.
2448 			 */
2449 			ent->eax = 0x00003839;
2450 			ent->ebx = 0x000A0000;
2451 			break;
2452 
2453 		case HYPERV_CPUID_FEATURES:
2454 			ent->eax |= HV_MSR_VP_RUNTIME_AVAILABLE;
2455 			ent->eax |= HV_MSR_TIME_REF_COUNT_AVAILABLE;
2456 			ent->eax |= HV_MSR_SYNIC_AVAILABLE;
2457 			ent->eax |= HV_MSR_SYNTIMER_AVAILABLE;
2458 			ent->eax |= HV_MSR_APIC_ACCESS_AVAILABLE;
2459 			ent->eax |= HV_MSR_HYPERCALL_AVAILABLE;
2460 			ent->eax |= HV_MSR_VP_INDEX_AVAILABLE;
2461 			ent->eax |= HV_MSR_RESET_AVAILABLE;
2462 			ent->eax |= HV_MSR_REFERENCE_TSC_AVAILABLE;
2463 			ent->eax |= HV_ACCESS_FREQUENCY_MSRS;
2464 			ent->eax |= HV_ACCESS_REENLIGHTENMENT;
2465 
2466 			ent->ebx |= HV_POST_MESSAGES;
2467 			ent->ebx |= HV_SIGNAL_EVENTS;
2468 
2469 			ent->edx |= HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE;
2470 			ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
2471 			ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
2472 
2473 			ent->ebx |= HV_DEBUGGING;
2474 			ent->edx |= HV_X64_GUEST_DEBUGGING_AVAILABLE;
2475 			ent->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
2476 
2477 			/*
2478 			 * Direct Synthetic timers only make sense with in-kernel
2479 			 * LAPIC
2480 			 */
2481 			if (!vcpu || lapic_in_kernel(vcpu))
2482 				ent->edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
2483 
2484 			break;
2485 
2486 		case HYPERV_CPUID_ENLIGHTMENT_INFO:
2487 			ent->eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
2488 			ent->eax |= HV_X64_APIC_ACCESS_RECOMMENDED;
2489 			ent->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED;
2490 			ent->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
2491 			ent->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
2492 			if (evmcs_ver)
2493 				ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;
2494 			if (!cpu_smt_possible())
2495 				ent->eax |= HV_X64_NO_NONARCH_CORESHARING;
2496 
2497 			ent->eax |= HV_DEPRECATING_AEOI_RECOMMENDED;
2498 			/*
2499 			 * Default number of spinlock retry attempts, matches
2500 			 * HyperV 2016.
2501 			 */
2502 			ent->ebx = 0x00000FFF;
2503 
2504 			break;
2505 
2506 		case HYPERV_CPUID_IMPLEMENT_LIMITS:
2507 			/* Maximum number of virtual processors */
2508 			ent->eax = KVM_MAX_VCPUS;
2509 			/*
2510 			 * Maximum number of logical processors, matches
2511 			 * HyperV 2016.
2512 			 */
2513 			ent->ebx = 64;
2514 
2515 			break;
2516 
2517 		case HYPERV_CPUID_NESTED_FEATURES:
2518 			ent->eax = evmcs_ver;
2519 
2520 			break;
2521 
2522 		case HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS:
2523 			memcpy(signature, "Linux KVM Hv", 12);
2524 
2525 			ent->eax = 0;
2526 			ent->ebx = signature[0];
2527 			ent->ecx = signature[1];
2528 			ent->edx = signature[2];
2529 			break;
2530 
2531 		case HYPERV_CPUID_SYNDBG_INTERFACE:
2532 			memcpy(signature, "VS#1\0\0\0\0\0\0\0\0", 12);
2533 			ent->eax = signature[0];
2534 			break;
2535 
2536 		case HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES:
2537 			ent->eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
2538 			break;
2539 
2540 		default:
2541 			break;
2542 		}
2543 	}
2544 
2545 	if (copy_to_user(entries, cpuid_entries,
2546 			 nent * sizeof(struct kvm_cpuid_entry2)))
2547 		return -EFAULT;
2548 
2549 	return 0;
2550 }
2551