xref: /linux/arch/x86/kvm/hyperv.c (revision 07f0148aafe8c95a3a76cd59e9e75b4d78d1d31d)
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 "mmu.h"
27 #include "xen.h"
28 
29 #include <linux/cpu.h>
30 #include <linux/kvm_host.h>
31 #include <linux/highmem.h>
32 #include <linux/sched/cputime.h>
33 #include <linux/spinlock.h>
34 #include <linux/eventfd.h>
35 
36 #include <asm/apicdef.h>
37 #include <asm/mshyperv.h>
38 #include <trace/events/kvm.h>
39 
40 #include "trace.h"
41 #include "irq.h"
42 #include "fpu.h"
43 
44 #define KVM_HV_MAX_SPARSE_VCPU_SET_BITS DIV_ROUND_UP(KVM_MAX_VCPUS, HV_VCPUS_PER_SPARSE_BANK)
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 	bool 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_empty(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_empty(synic->auto_eoi_bitmap, 256);
111 
112 	if (auto_eoi_old == auto_eoi_new)
113 		return;
114 
115 	if (!enable_apicv)
116 		return;
117 
118 	down_write(&vcpu->kvm->arch.apicv_update_lock);
119 
120 	if (auto_eoi_new)
121 		hv->synic_auto_eoi_used++;
122 	else
123 		hv->synic_auto_eoi_used--;
124 
125 	/*
126 	 * Inhibit APICv if any vCPU is using SynIC's AutoEOI, which relies on
127 	 * the hypervisor to manually inject IRQs.
128 	 */
129 	__kvm_set_or_clear_apicv_inhibit(vcpu->kvm,
130 					 APICV_INHIBIT_REASON_HYPERV,
131 					 !!hv->synic_auto_eoi_used);
132 
133 	up_write(&vcpu->kvm->arch.apicv_update_lock);
134 }
135 
136 static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint,
137 			  u64 data, bool host)
138 {
139 	int vector, old_vector;
140 	bool masked;
141 
142 	vector = data & HV_SYNIC_SINT_VECTOR_MASK;
143 	masked = data & HV_SYNIC_SINT_MASKED;
144 
145 	/*
146 	 * Valid vectors are 16-255, however, nested Hyper-V attempts to write
147 	 * default '0x10000' value on boot and this should not #GP. We need to
148 	 * allow zero-initing the register from host as well.
149 	 */
150 	if (vector < HV_SYNIC_FIRST_VALID_VECTOR && !host && !masked)
151 		return 1;
152 	/*
153 	 * Guest may configure multiple SINTs to use the same vector, so
154 	 * we maintain a bitmap of vectors handled by synic, and a
155 	 * bitmap of vectors with auto-eoi behavior.  The bitmaps are
156 	 * updated here, and atomically queried on fast paths.
157 	 */
158 	old_vector = synic_read_sint(synic, sint) & HV_SYNIC_SINT_VECTOR_MASK;
159 
160 	atomic64_set(&synic->sint[sint], data);
161 
162 	synic_update_vector(synic, old_vector);
163 
164 	synic_update_vector(synic, vector);
165 
166 	/* Load SynIC vectors into EOI exit bitmap */
167 	kvm_make_request(KVM_REQ_SCAN_IOAPIC, hv_synic_to_vcpu(synic));
168 	return 0;
169 }
170 
171 static struct kvm_vcpu *get_vcpu_by_vpidx(struct kvm *kvm, u32 vpidx)
172 {
173 	struct kvm_vcpu *vcpu = NULL;
174 	unsigned long i;
175 
176 	if (vpidx >= KVM_MAX_VCPUS)
177 		return NULL;
178 
179 	vcpu = kvm_get_vcpu(kvm, vpidx);
180 	if (vcpu && kvm_hv_get_vpindex(vcpu) == vpidx)
181 		return vcpu;
182 	kvm_for_each_vcpu(i, vcpu, kvm)
183 		if (kvm_hv_get_vpindex(vcpu) == vpidx)
184 			return vcpu;
185 	return NULL;
186 }
187 
188 static struct kvm_vcpu_hv_synic *synic_get(struct kvm *kvm, u32 vpidx)
189 {
190 	struct kvm_vcpu *vcpu;
191 	struct kvm_vcpu_hv_synic *synic;
192 
193 	vcpu = get_vcpu_by_vpidx(kvm, vpidx);
194 	if (!vcpu || !to_hv_vcpu(vcpu))
195 		return NULL;
196 	synic = to_hv_synic(vcpu);
197 	return (synic->active) ? synic : NULL;
198 }
199 
200 static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
201 {
202 	struct kvm *kvm = vcpu->kvm;
203 	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
204 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
205 	struct kvm_vcpu_hv_stimer *stimer;
206 	int gsi, idx;
207 
208 	trace_kvm_hv_notify_acked_sint(vcpu->vcpu_id, sint);
209 
210 	/* Try to deliver pending Hyper-V SynIC timers messages */
211 	for (idx = 0; idx < ARRAY_SIZE(hv_vcpu->stimer); idx++) {
212 		stimer = &hv_vcpu->stimer[idx];
213 		if (stimer->msg_pending && stimer->config.enable &&
214 		    !stimer->config.direct_mode &&
215 		    stimer->config.sintx == sint)
216 			stimer_mark_pending(stimer, false);
217 	}
218 
219 	idx = srcu_read_lock(&kvm->irq_srcu);
220 	gsi = atomic_read(&synic->sint_to_gsi[sint]);
221 	if (gsi != -1)
222 		kvm_notify_acked_gsi(kvm, gsi);
223 	srcu_read_unlock(&kvm->irq_srcu, idx);
224 }
225 
226 static void synic_exit(struct kvm_vcpu_hv_synic *synic, u32 msr)
227 {
228 	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
229 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
230 
231 	hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNIC;
232 	hv_vcpu->exit.u.synic.msr = msr;
233 	hv_vcpu->exit.u.synic.control = synic->control;
234 	hv_vcpu->exit.u.synic.evt_page = synic->evt_page;
235 	hv_vcpu->exit.u.synic.msg_page = synic->msg_page;
236 
237 	kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
238 }
239 
240 static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
241 			 u32 msr, u64 data, bool host)
242 {
243 	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
244 	int ret;
245 
246 	if (!synic->active && (!host || data))
247 		return 1;
248 
249 	trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host);
250 
251 	ret = 0;
252 	switch (msr) {
253 	case HV_X64_MSR_SCONTROL:
254 		synic->control = data;
255 		if (!host)
256 			synic_exit(synic, msr);
257 		break;
258 	case HV_X64_MSR_SVERSION:
259 		if (!host) {
260 			ret = 1;
261 			break;
262 		}
263 		synic->version = data;
264 		break;
265 	case HV_X64_MSR_SIEFP:
266 		if ((data & HV_SYNIC_SIEFP_ENABLE) && !host &&
267 		    !synic->dont_zero_synic_pages)
268 			if (kvm_clear_guest(vcpu->kvm,
269 					    data & PAGE_MASK, PAGE_SIZE)) {
270 				ret = 1;
271 				break;
272 			}
273 		synic->evt_page = data;
274 		if (!host)
275 			synic_exit(synic, msr);
276 		break;
277 	case HV_X64_MSR_SIMP:
278 		if ((data & HV_SYNIC_SIMP_ENABLE) && !host &&
279 		    !synic->dont_zero_synic_pages)
280 			if (kvm_clear_guest(vcpu->kvm,
281 					    data & PAGE_MASK, PAGE_SIZE)) {
282 				ret = 1;
283 				break;
284 			}
285 		synic->msg_page = data;
286 		if (!host)
287 			synic_exit(synic, msr);
288 		break;
289 	case HV_X64_MSR_EOM: {
290 		int i;
291 
292 		if (!synic->active)
293 			break;
294 
295 		for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
296 			kvm_hv_notify_acked_sint(vcpu, i);
297 		break;
298 	}
299 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
300 		ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data, host);
301 		break;
302 	default:
303 		ret = 1;
304 		break;
305 	}
306 	return ret;
307 }
308 
309 static bool kvm_hv_is_syndbg_enabled(struct kvm_vcpu *vcpu)
310 {
311 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
312 
313 	return hv_vcpu->cpuid_cache.syndbg_cap_eax &
314 		HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
315 }
316 
317 static int kvm_hv_syndbg_complete_userspace(struct kvm_vcpu *vcpu)
318 {
319 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
320 
321 	if (vcpu->run->hyperv.u.syndbg.msr == HV_X64_MSR_SYNDBG_CONTROL)
322 		hv->hv_syndbg.control.status =
323 			vcpu->run->hyperv.u.syndbg.status;
324 	return 1;
325 }
326 
327 static void syndbg_exit(struct kvm_vcpu *vcpu, u32 msr)
328 {
329 	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
330 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
331 
332 	hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNDBG;
333 	hv_vcpu->exit.u.syndbg.msr = msr;
334 	hv_vcpu->exit.u.syndbg.control = syndbg->control.control;
335 	hv_vcpu->exit.u.syndbg.send_page = syndbg->control.send_page;
336 	hv_vcpu->exit.u.syndbg.recv_page = syndbg->control.recv_page;
337 	hv_vcpu->exit.u.syndbg.pending_page = syndbg->control.pending_page;
338 	vcpu->arch.complete_userspace_io =
339 			kvm_hv_syndbg_complete_userspace;
340 
341 	kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
342 }
343 
344 static int syndbg_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
345 {
346 	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
347 
348 	if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
349 		return 1;
350 
351 	trace_kvm_hv_syndbg_set_msr(vcpu->vcpu_id,
352 				    to_hv_vcpu(vcpu)->vp_index, msr, data);
353 	switch (msr) {
354 	case HV_X64_MSR_SYNDBG_CONTROL:
355 		syndbg->control.control = data;
356 		if (!host)
357 			syndbg_exit(vcpu, msr);
358 		break;
359 	case HV_X64_MSR_SYNDBG_STATUS:
360 		syndbg->control.status = data;
361 		break;
362 	case HV_X64_MSR_SYNDBG_SEND_BUFFER:
363 		syndbg->control.send_page = data;
364 		break;
365 	case HV_X64_MSR_SYNDBG_RECV_BUFFER:
366 		syndbg->control.recv_page = data;
367 		break;
368 	case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
369 		syndbg->control.pending_page = data;
370 		if (!host)
371 			syndbg_exit(vcpu, msr);
372 		break;
373 	case HV_X64_MSR_SYNDBG_OPTIONS:
374 		syndbg->options = data;
375 		break;
376 	default:
377 		break;
378 	}
379 
380 	return 0;
381 }
382 
383 static int syndbg_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
384 {
385 	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
386 
387 	if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
388 		return 1;
389 
390 	switch (msr) {
391 	case HV_X64_MSR_SYNDBG_CONTROL:
392 		*pdata = syndbg->control.control;
393 		break;
394 	case HV_X64_MSR_SYNDBG_STATUS:
395 		*pdata = syndbg->control.status;
396 		break;
397 	case HV_X64_MSR_SYNDBG_SEND_BUFFER:
398 		*pdata = syndbg->control.send_page;
399 		break;
400 	case HV_X64_MSR_SYNDBG_RECV_BUFFER:
401 		*pdata = syndbg->control.recv_page;
402 		break;
403 	case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
404 		*pdata = syndbg->control.pending_page;
405 		break;
406 	case HV_X64_MSR_SYNDBG_OPTIONS:
407 		*pdata = syndbg->options;
408 		break;
409 	default:
410 		break;
411 	}
412 
413 	trace_kvm_hv_syndbg_get_msr(vcpu->vcpu_id, kvm_hv_get_vpindex(vcpu), msr, *pdata);
414 
415 	return 0;
416 }
417 
418 static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata,
419 			 bool host)
420 {
421 	int ret;
422 
423 	if (!synic->active && !host)
424 		return 1;
425 
426 	ret = 0;
427 	switch (msr) {
428 	case HV_X64_MSR_SCONTROL:
429 		*pdata = synic->control;
430 		break;
431 	case HV_X64_MSR_SVERSION:
432 		*pdata = synic->version;
433 		break;
434 	case HV_X64_MSR_SIEFP:
435 		*pdata = synic->evt_page;
436 		break;
437 	case HV_X64_MSR_SIMP:
438 		*pdata = synic->msg_page;
439 		break;
440 	case HV_X64_MSR_EOM:
441 		*pdata = 0;
442 		break;
443 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
444 		*pdata = atomic64_read(&synic->sint[msr - HV_X64_MSR_SINT0]);
445 		break;
446 	default:
447 		ret = 1;
448 		break;
449 	}
450 	return ret;
451 }
452 
453 static int synic_set_irq(struct kvm_vcpu_hv_synic *synic, u32 sint)
454 {
455 	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
456 	struct kvm_lapic_irq irq;
457 	int ret, vector;
458 
459 	if (KVM_BUG_ON(!lapic_in_kernel(vcpu), vcpu->kvm))
460 		return -EINVAL;
461 
462 	if (sint >= ARRAY_SIZE(synic->sint))
463 		return -EINVAL;
464 
465 	vector = synic_get_sint_vector(synic_read_sint(synic, sint));
466 	if (vector < 0)
467 		return -ENOENT;
468 
469 	memset(&irq, 0, sizeof(irq));
470 	irq.shorthand = APIC_DEST_SELF;
471 	irq.dest_mode = APIC_DEST_PHYSICAL;
472 	irq.delivery_mode = APIC_DM_FIXED;
473 	irq.vector = vector;
474 	irq.level = 1;
475 
476 	ret = kvm_irq_delivery_to_apic(vcpu->kvm, vcpu->arch.apic, &irq, NULL);
477 	trace_kvm_hv_synic_set_irq(vcpu->vcpu_id, sint, irq.vector, ret);
478 	return ret;
479 }
480 
481 int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vpidx, u32 sint)
482 {
483 	struct kvm_vcpu_hv_synic *synic;
484 
485 	synic = synic_get(kvm, vpidx);
486 	if (!synic)
487 		return -EINVAL;
488 
489 	return synic_set_irq(synic, sint);
490 }
491 
492 void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
493 {
494 	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
495 	int i;
496 
497 	trace_kvm_hv_synic_send_eoi(vcpu->vcpu_id, vector);
498 
499 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
500 		if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
501 			kvm_hv_notify_acked_sint(vcpu, i);
502 }
503 
504 static int kvm_hv_set_sint_gsi(struct kvm *kvm, u32 vpidx, u32 sint, int gsi)
505 {
506 	struct kvm_vcpu_hv_synic *synic;
507 
508 	synic = synic_get(kvm, vpidx);
509 	if (!synic)
510 		return -EINVAL;
511 
512 	if (sint >= ARRAY_SIZE(synic->sint_to_gsi))
513 		return -EINVAL;
514 
515 	atomic_set(&synic->sint_to_gsi[sint], gsi);
516 	return 0;
517 }
518 
519 void kvm_hv_irq_routing_update(struct kvm *kvm)
520 {
521 	struct kvm_irq_routing_table *irq_rt;
522 	struct kvm_kernel_irq_routing_entry *e;
523 	u32 gsi;
524 
525 	irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
526 					lockdep_is_held(&kvm->irq_lock));
527 
528 	for (gsi = 0; gsi < irq_rt->nr_rt_entries; gsi++) {
529 		hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
530 			if (e->type == KVM_IRQ_ROUTING_HV_SINT)
531 				kvm_hv_set_sint_gsi(kvm, e->hv_sint.vcpu,
532 						    e->hv_sint.sint, gsi);
533 		}
534 	}
535 }
536 
537 static void synic_init(struct kvm_vcpu_hv_synic *synic)
538 {
539 	int i;
540 
541 	memset(synic, 0, sizeof(*synic));
542 	synic->version = HV_SYNIC_VERSION_1;
543 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
544 		atomic64_set(&synic->sint[i], HV_SYNIC_SINT_MASKED);
545 		atomic_set(&synic->sint_to_gsi[i], -1);
546 	}
547 }
548 
549 static u64 get_time_ref_counter(struct kvm *kvm)
550 {
551 	struct kvm_hv *hv = to_kvm_hv(kvm);
552 	struct kvm_vcpu *vcpu;
553 	u64 tsc;
554 
555 	/*
556 	 * Fall back to get_kvmclock_ns() when TSC page hasn't been set up,
557 	 * is broken, disabled or being updated.
558 	 */
559 	if (hv->hv_tsc_page_status != HV_TSC_PAGE_SET)
560 		return div_u64(get_kvmclock_ns(kvm), 100);
561 
562 	vcpu = kvm_get_vcpu(kvm, 0);
563 	tsc = kvm_read_l1_tsc(vcpu, rdtsc());
564 	return mul_u64_u64_shr(tsc, hv->tsc_ref.tsc_scale, 64)
565 		+ hv->tsc_ref.tsc_offset;
566 }
567 
568 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
569 				bool vcpu_kick)
570 {
571 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
572 
573 	set_bit(stimer->index,
574 		to_hv_vcpu(vcpu)->stimer_pending_bitmap);
575 	kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
576 	if (vcpu_kick)
577 		kvm_vcpu_kick(vcpu);
578 }
579 
580 static void stimer_cleanup(struct kvm_vcpu_hv_stimer *stimer)
581 {
582 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
583 
584 	trace_kvm_hv_stimer_cleanup(hv_stimer_to_vcpu(stimer)->vcpu_id,
585 				    stimer->index);
586 
587 	hrtimer_cancel(&stimer->timer);
588 	clear_bit(stimer->index,
589 		  to_hv_vcpu(vcpu)->stimer_pending_bitmap);
590 	stimer->msg_pending = false;
591 	stimer->exp_time = 0;
592 }
593 
594 static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer)
595 {
596 	struct kvm_vcpu_hv_stimer *stimer;
597 
598 	stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer);
599 	trace_kvm_hv_stimer_callback(hv_stimer_to_vcpu(stimer)->vcpu_id,
600 				     stimer->index);
601 	stimer_mark_pending(stimer, true);
602 
603 	return HRTIMER_NORESTART;
604 }
605 
606 /*
607  * stimer_start() assumptions:
608  * a) stimer->count is not equal to 0
609  * b) stimer->config has HV_STIMER_ENABLE flag
610  */
611 static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
612 {
613 	u64 time_now;
614 	ktime_t ktime_now;
615 
616 	time_now = get_time_ref_counter(hv_stimer_to_vcpu(stimer)->kvm);
617 	ktime_now = ktime_get();
618 
619 	if (stimer->config.periodic) {
620 		if (stimer->exp_time) {
621 			if (time_now >= stimer->exp_time) {
622 				u64 remainder;
623 
624 				div64_u64_rem(time_now - stimer->exp_time,
625 					      stimer->count, &remainder);
626 				stimer->exp_time =
627 					time_now + (stimer->count - remainder);
628 			}
629 		} else
630 			stimer->exp_time = time_now + stimer->count;
631 
632 		trace_kvm_hv_stimer_start_periodic(
633 					hv_stimer_to_vcpu(stimer)->vcpu_id,
634 					stimer->index,
635 					time_now, stimer->exp_time);
636 
637 		hrtimer_start(&stimer->timer,
638 			      ktime_add_ns(ktime_now,
639 					   100 * (stimer->exp_time - time_now)),
640 			      HRTIMER_MODE_ABS);
641 		return 0;
642 	}
643 	stimer->exp_time = stimer->count;
644 	if (time_now >= stimer->count) {
645 		/*
646 		 * Expire timer according to Hypervisor Top-Level Functional
647 		 * specification v4(15.3.1):
648 		 * "If a one shot is enabled and the specified count is in
649 		 * the past, it will expire immediately."
650 		 */
651 		stimer_mark_pending(stimer, false);
652 		return 0;
653 	}
654 
655 	trace_kvm_hv_stimer_start_one_shot(hv_stimer_to_vcpu(stimer)->vcpu_id,
656 					   stimer->index,
657 					   time_now, stimer->count);
658 
659 	hrtimer_start(&stimer->timer,
660 		      ktime_add_ns(ktime_now, 100 * (stimer->count - time_now)),
661 		      HRTIMER_MODE_ABS);
662 	return 0;
663 }
664 
665 static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
666 			     bool host)
667 {
668 	union hv_stimer_config new_config = {.as_uint64 = config},
669 		old_config = {.as_uint64 = stimer->config.as_uint64};
670 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
671 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
672 	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
673 
674 	if (!synic->active && (!host || config))
675 		return 1;
676 
677 	if (unlikely(!host && hv_vcpu->enforce_cpuid && new_config.direct_mode &&
678 		     !(hv_vcpu->cpuid_cache.features_edx &
679 		       HV_STIMER_DIRECT_MODE_AVAILABLE)))
680 		return 1;
681 
682 	trace_kvm_hv_stimer_set_config(hv_stimer_to_vcpu(stimer)->vcpu_id,
683 				       stimer->index, config, host);
684 
685 	stimer_cleanup(stimer);
686 	if (old_config.enable &&
687 	    !new_config.direct_mode && new_config.sintx == 0)
688 		new_config.enable = 0;
689 	stimer->config.as_uint64 = new_config.as_uint64;
690 
691 	if (stimer->config.enable)
692 		stimer_mark_pending(stimer, false);
693 
694 	return 0;
695 }
696 
697 static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,
698 			    bool host)
699 {
700 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
701 	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
702 
703 	if (!synic->active && (!host || count))
704 		return 1;
705 
706 	trace_kvm_hv_stimer_set_count(hv_stimer_to_vcpu(stimer)->vcpu_id,
707 				      stimer->index, count, host);
708 
709 	stimer_cleanup(stimer);
710 	stimer->count = count;
711 	if (stimer->count == 0)
712 		stimer->config.enable = 0;
713 	else if (stimer->config.auto_enable)
714 		stimer->config.enable = 1;
715 
716 	if (stimer->config.enable)
717 		stimer_mark_pending(stimer, false);
718 
719 	return 0;
720 }
721 
722 static int stimer_get_config(struct kvm_vcpu_hv_stimer *stimer, u64 *pconfig)
723 {
724 	*pconfig = stimer->config.as_uint64;
725 	return 0;
726 }
727 
728 static int stimer_get_count(struct kvm_vcpu_hv_stimer *stimer, u64 *pcount)
729 {
730 	*pcount = stimer->count;
731 	return 0;
732 }
733 
734 static int synic_deliver_msg(struct kvm_vcpu_hv_synic *synic, u32 sint,
735 			     struct hv_message *src_msg, bool no_retry)
736 {
737 	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
738 	int msg_off = offsetof(struct hv_message_page, sint_message[sint]);
739 	gfn_t msg_page_gfn;
740 	struct hv_message_header hv_hdr;
741 	int r;
742 
743 	if (!(synic->msg_page & HV_SYNIC_SIMP_ENABLE))
744 		return -ENOENT;
745 
746 	msg_page_gfn = synic->msg_page >> PAGE_SHIFT;
747 
748 	/*
749 	 * Strictly following the spec-mandated ordering would assume setting
750 	 * .msg_pending before checking .message_type.  However, this function
751 	 * is only called in vcpu context so the entire update is atomic from
752 	 * guest POV and thus the exact order here doesn't matter.
753 	 */
754 	r = kvm_vcpu_read_guest_page(vcpu, msg_page_gfn, &hv_hdr.message_type,
755 				     msg_off + offsetof(struct hv_message,
756 							header.message_type),
757 				     sizeof(hv_hdr.message_type));
758 	if (r < 0)
759 		return r;
760 
761 	if (hv_hdr.message_type != HVMSG_NONE) {
762 		if (no_retry)
763 			return 0;
764 
765 		hv_hdr.message_flags.msg_pending = 1;
766 		r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn,
767 					      &hv_hdr.message_flags,
768 					      msg_off +
769 					      offsetof(struct hv_message,
770 						       header.message_flags),
771 					      sizeof(hv_hdr.message_flags));
772 		if (r < 0)
773 			return r;
774 		return -EAGAIN;
775 	}
776 
777 	r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn, src_msg, msg_off,
778 				      sizeof(src_msg->header) +
779 				      src_msg->header.payload_size);
780 	if (r < 0)
781 		return r;
782 
783 	r = synic_set_irq(synic, sint);
784 	if (r < 0)
785 		return r;
786 	if (r == 0)
787 		return -EFAULT;
788 	return 0;
789 }
790 
791 static int stimer_send_msg(struct kvm_vcpu_hv_stimer *stimer)
792 {
793 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
794 	struct hv_message *msg = &stimer->msg;
795 	struct hv_timer_message_payload *payload =
796 			(struct hv_timer_message_payload *)&msg->u.payload;
797 
798 	/*
799 	 * To avoid piling up periodic ticks, don't retry message
800 	 * delivery for them (within "lazy" lost ticks policy).
801 	 */
802 	bool no_retry = stimer->config.periodic;
803 
804 	payload->expiration_time = stimer->exp_time;
805 	payload->delivery_time = get_time_ref_counter(vcpu->kvm);
806 	return synic_deliver_msg(to_hv_synic(vcpu),
807 				 stimer->config.sintx, msg,
808 				 no_retry);
809 }
810 
811 static int stimer_notify_direct(struct kvm_vcpu_hv_stimer *stimer)
812 {
813 	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
814 	struct kvm_lapic_irq irq = {
815 		.delivery_mode = APIC_DM_FIXED,
816 		.vector = stimer->config.apic_vector
817 	};
818 
819 	if (lapic_in_kernel(vcpu))
820 		return !kvm_apic_set_irq(vcpu, &irq, NULL);
821 	return 0;
822 }
823 
824 static void stimer_expiration(struct kvm_vcpu_hv_stimer *stimer)
825 {
826 	int r, direct = stimer->config.direct_mode;
827 
828 	stimer->msg_pending = true;
829 	if (!direct)
830 		r = stimer_send_msg(stimer);
831 	else
832 		r = stimer_notify_direct(stimer);
833 	trace_kvm_hv_stimer_expiration(hv_stimer_to_vcpu(stimer)->vcpu_id,
834 				       stimer->index, direct, r);
835 	if (!r) {
836 		stimer->msg_pending = false;
837 		if (!(stimer->config.periodic))
838 			stimer->config.enable = 0;
839 	}
840 }
841 
842 void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
843 {
844 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
845 	struct kvm_vcpu_hv_stimer *stimer;
846 	u64 time_now, exp_time;
847 	int i;
848 
849 	if (!hv_vcpu)
850 		return;
851 
852 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
853 		if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) {
854 			stimer = &hv_vcpu->stimer[i];
855 			if (stimer->config.enable) {
856 				exp_time = stimer->exp_time;
857 
858 				if (exp_time) {
859 					time_now =
860 						get_time_ref_counter(vcpu->kvm);
861 					if (time_now >= exp_time)
862 						stimer_expiration(stimer);
863 				}
864 
865 				if ((stimer->config.enable) &&
866 				    stimer->count) {
867 					if (!stimer->msg_pending)
868 						stimer_start(stimer);
869 				} else
870 					stimer_cleanup(stimer);
871 			}
872 		}
873 }
874 
875 void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu)
876 {
877 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
878 	int i;
879 
880 	if (!hv_vcpu)
881 		return;
882 
883 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
884 		stimer_cleanup(&hv_vcpu->stimer[i]);
885 
886 	kfree(hv_vcpu);
887 	vcpu->arch.hyperv = NULL;
888 }
889 
890 bool kvm_hv_assist_page_enabled(struct kvm_vcpu *vcpu)
891 {
892 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
893 
894 	if (!hv_vcpu)
895 		return false;
896 
897 	if (!(hv_vcpu->hv_vapic & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE))
898 		return false;
899 	return vcpu->arch.pv_eoi.msr_val & KVM_MSR_ENABLED;
900 }
901 EXPORT_SYMBOL_GPL(kvm_hv_assist_page_enabled);
902 
903 int kvm_hv_get_assist_page(struct kvm_vcpu *vcpu)
904 {
905 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
906 
907 	if (!hv_vcpu || !kvm_hv_assist_page_enabled(vcpu))
908 		return -EFAULT;
909 
910 	return kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data,
911 				     &hv_vcpu->vp_assist_page, sizeof(struct hv_vp_assist_page));
912 }
913 EXPORT_SYMBOL_GPL(kvm_hv_get_assist_page);
914 
915 static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
916 {
917 	struct hv_message *msg = &stimer->msg;
918 	struct hv_timer_message_payload *payload =
919 			(struct hv_timer_message_payload *)&msg->u.payload;
920 
921 	memset(&msg->header, 0, sizeof(msg->header));
922 	msg->header.message_type = HVMSG_TIMER_EXPIRED;
923 	msg->header.payload_size = sizeof(*payload);
924 
925 	payload->timer_index = stimer->index;
926 	payload->expiration_time = 0;
927 	payload->delivery_time = 0;
928 }
929 
930 static void stimer_init(struct kvm_vcpu_hv_stimer *stimer, int timer_index)
931 {
932 	memset(stimer, 0, sizeof(*stimer));
933 	stimer->index = timer_index;
934 	hrtimer_init(&stimer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
935 	stimer->timer.function = stimer_timer_callback;
936 	stimer_prepare_msg(stimer);
937 }
938 
939 int kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
940 {
941 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
942 	int i;
943 
944 	if (hv_vcpu)
945 		return 0;
946 
947 	hv_vcpu = kzalloc(sizeof(struct kvm_vcpu_hv), GFP_KERNEL_ACCOUNT);
948 	if (!hv_vcpu)
949 		return -ENOMEM;
950 
951 	vcpu->arch.hyperv = hv_vcpu;
952 	hv_vcpu->vcpu = vcpu;
953 
954 	synic_init(&hv_vcpu->synic);
955 
956 	bitmap_zero(hv_vcpu->stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
957 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
958 		stimer_init(&hv_vcpu->stimer[i], i);
959 
960 	hv_vcpu->vp_index = vcpu->vcpu_idx;
961 
962 	for (i = 0; i < HV_NR_TLB_FLUSH_FIFOS; i++) {
963 		INIT_KFIFO(hv_vcpu->tlb_flush_fifo[i].entries);
964 		spin_lock_init(&hv_vcpu->tlb_flush_fifo[i].write_lock);
965 	}
966 
967 	return 0;
968 }
969 
970 int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages)
971 {
972 	struct kvm_vcpu_hv_synic *synic;
973 	int r;
974 
975 	r = kvm_hv_vcpu_init(vcpu);
976 	if (r)
977 		return r;
978 
979 	synic = to_hv_synic(vcpu);
980 
981 	synic->active = true;
982 	synic->dont_zero_synic_pages = dont_zero_synic_pages;
983 	synic->control = HV_SYNIC_CONTROL_ENABLE;
984 	return 0;
985 }
986 
987 static bool kvm_hv_msr_partition_wide(u32 msr)
988 {
989 	bool r = false;
990 
991 	switch (msr) {
992 	case HV_X64_MSR_GUEST_OS_ID:
993 	case HV_X64_MSR_HYPERCALL:
994 	case HV_X64_MSR_REFERENCE_TSC:
995 	case HV_X64_MSR_TIME_REF_COUNT:
996 	case HV_X64_MSR_CRASH_CTL:
997 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
998 	case HV_X64_MSR_RESET:
999 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1000 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1001 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1002 	case HV_X64_MSR_SYNDBG_OPTIONS:
1003 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1004 		r = true;
1005 		break;
1006 	}
1007 
1008 	return r;
1009 }
1010 
1011 static int kvm_hv_msr_get_crash_data(struct kvm *kvm, u32 index, u64 *pdata)
1012 {
1013 	struct kvm_hv *hv = to_kvm_hv(kvm);
1014 	size_t size = ARRAY_SIZE(hv->hv_crash_param);
1015 
1016 	if (WARN_ON_ONCE(index >= size))
1017 		return -EINVAL;
1018 
1019 	*pdata = hv->hv_crash_param[array_index_nospec(index, size)];
1020 	return 0;
1021 }
1022 
1023 static int kvm_hv_msr_get_crash_ctl(struct kvm *kvm, u64 *pdata)
1024 {
1025 	struct kvm_hv *hv = to_kvm_hv(kvm);
1026 
1027 	*pdata = hv->hv_crash_ctl;
1028 	return 0;
1029 }
1030 
1031 static int kvm_hv_msr_set_crash_ctl(struct kvm *kvm, u64 data)
1032 {
1033 	struct kvm_hv *hv = to_kvm_hv(kvm);
1034 
1035 	hv->hv_crash_ctl = data & HV_CRASH_CTL_CRASH_NOTIFY;
1036 
1037 	return 0;
1038 }
1039 
1040 static int kvm_hv_msr_set_crash_data(struct kvm *kvm, u32 index, u64 data)
1041 {
1042 	struct kvm_hv *hv = to_kvm_hv(kvm);
1043 	size_t size = ARRAY_SIZE(hv->hv_crash_param);
1044 
1045 	if (WARN_ON_ONCE(index >= size))
1046 		return -EINVAL;
1047 
1048 	hv->hv_crash_param[array_index_nospec(index, size)] = data;
1049 	return 0;
1050 }
1051 
1052 /*
1053  * The kvmclock and Hyper-V TSC page use similar formulas, and converting
1054  * between them is possible:
1055  *
1056  * kvmclock formula:
1057  *    nsec = (ticks - tsc_timestamp) * tsc_to_system_mul * 2^(tsc_shift-32)
1058  *           + system_time
1059  *
1060  * Hyper-V formula:
1061  *    nsec/100 = ticks * scale / 2^64 + offset
1062  *
1063  * When tsc_timestamp = system_time = 0, offset is zero in the Hyper-V formula.
1064  * By dividing the kvmclock formula by 100 and equating what's left we get:
1065  *    ticks * scale / 2^64 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1066  *            scale / 2^64 =         tsc_to_system_mul * 2^(tsc_shift-32) / 100
1067  *            scale        =         tsc_to_system_mul * 2^(32+tsc_shift) / 100
1068  *
1069  * Now expand the kvmclock formula and divide by 100:
1070  *    nsec = ticks * tsc_to_system_mul * 2^(tsc_shift-32)
1071  *           - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32)
1072  *           + system_time
1073  *    nsec/100 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1074  *               - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1075  *               + system_time / 100
1076  *
1077  * Replace tsc_to_system_mul * 2^(tsc_shift-32) / 100 by scale / 2^64:
1078  *    nsec/100 = ticks * scale / 2^64
1079  *               - tsc_timestamp * scale / 2^64
1080  *               + system_time / 100
1081  *
1082  * Equate with the Hyper-V formula so that ticks * scale / 2^64 cancels out:
1083  *    offset = system_time / 100 - tsc_timestamp * scale / 2^64
1084  *
1085  * These two equivalencies are implemented in this function.
1086  */
1087 static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
1088 					struct ms_hyperv_tsc_page *tsc_ref)
1089 {
1090 	u64 max_mul;
1091 
1092 	if (!(hv_clock->flags & PVCLOCK_TSC_STABLE_BIT))
1093 		return false;
1094 
1095 	/*
1096 	 * check if scale would overflow, if so we use the time ref counter
1097 	 *    tsc_to_system_mul * 2^(tsc_shift+32) / 100 >= 2^64
1098 	 *    tsc_to_system_mul / 100 >= 2^(32-tsc_shift)
1099 	 *    tsc_to_system_mul >= 100 * 2^(32-tsc_shift)
1100 	 */
1101 	max_mul = 100ull << (32 - hv_clock->tsc_shift);
1102 	if (hv_clock->tsc_to_system_mul >= max_mul)
1103 		return false;
1104 
1105 	/*
1106 	 * Otherwise compute the scale and offset according to the formulas
1107 	 * derived above.
1108 	 */
1109 	tsc_ref->tsc_scale =
1110 		mul_u64_u32_div(1ULL << (32 + hv_clock->tsc_shift),
1111 				hv_clock->tsc_to_system_mul,
1112 				100);
1113 
1114 	tsc_ref->tsc_offset = hv_clock->system_time;
1115 	do_div(tsc_ref->tsc_offset, 100);
1116 	tsc_ref->tsc_offset -=
1117 		mul_u64_u64_shr(hv_clock->tsc_timestamp, tsc_ref->tsc_scale, 64);
1118 	return true;
1119 }
1120 
1121 /*
1122  * Don't touch TSC page values if the guest has opted for TSC emulation after
1123  * migration. KVM doesn't fully support reenlightenment notifications and TSC
1124  * access emulation and Hyper-V is known to expect the values in TSC page to
1125  * stay constant before TSC access emulation is disabled from guest side
1126  * (HV_X64_MSR_TSC_EMULATION_STATUS). KVM userspace is expected to preserve TSC
1127  * frequency and guest visible TSC value across migration (and prevent it when
1128  * TSC scaling is unsupported).
1129  */
1130 static inline bool tsc_page_update_unsafe(struct kvm_hv *hv)
1131 {
1132 	return (hv->hv_tsc_page_status != HV_TSC_PAGE_GUEST_CHANGED) &&
1133 		hv->hv_tsc_emulation_control;
1134 }
1135 
1136 void kvm_hv_setup_tsc_page(struct kvm *kvm,
1137 			   struct pvclock_vcpu_time_info *hv_clock)
1138 {
1139 	struct kvm_hv *hv = to_kvm_hv(kvm);
1140 	u32 tsc_seq;
1141 	u64 gfn;
1142 
1143 	BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
1144 	BUILD_BUG_ON(offsetof(struct ms_hyperv_tsc_page, tsc_sequence) != 0);
1145 
1146 	mutex_lock(&hv->hv_lock);
1147 
1148 	if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN ||
1149 	    hv->hv_tsc_page_status == HV_TSC_PAGE_SET ||
1150 	    hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET)
1151 		goto out_unlock;
1152 
1153 	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
1154 		goto out_unlock;
1155 
1156 	gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
1157 	/*
1158 	 * Because the TSC parameters only vary when there is a
1159 	 * change in the master clock, do not bother with caching.
1160 	 */
1161 	if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
1162 				    &tsc_seq, sizeof(tsc_seq))))
1163 		goto out_err;
1164 
1165 	if (tsc_seq && tsc_page_update_unsafe(hv)) {
1166 		if (kvm_read_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1167 			goto out_err;
1168 
1169 		hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1170 		goto out_unlock;
1171 	}
1172 
1173 	/*
1174 	 * While we're computing and writing the parameters, force the
1175 	 * guest to use the time reference count MSR.
1176 	 */
1177 	hv->tsc_ref.tsc_sequence = 0;
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 	if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
1183 		goto out_err;
1184 
1185 	/* Ensure sequence is zero before writing the rest of the struct.  */
1186 	smp_wmb();
1187 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1188 		goto out_err;
1189 
1190 	/*
1191 	 * Now switch to the TSC page mechanism by writing the sequence.
1192 	 */
1193 	tsc_seq++;
1194 	if (tsc_seq == 0xFFFFFFFF || tsc_seq == 0)
1195 		tsc_seq = 1;
1196 
1197 	/* Write the struct entirely before the non-zero sequence.  */
1198 	smp_wmb();
1199 
1200 	hv->tsc_ref.tsc_sequence = tsc_seq;
1201 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1202 			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1203 		goto out_err;
1204 
1205 	hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1206 	goto out_unlock;
1207 
1208 out_err:
1209 	hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN;
1210 out_unlock:
1211 	mutex_unlock(&hv->hv_lock);
1212 }
1213 
1214 void kvm_hv_request_tsc_page_update(struct kvm *kvm)
1215 {
1216 	struct kvm_hv *hv = to_kvm_hv(kvm);
1217 
1218 	mutex_lock(&hv->hv_lock);
1219 
1220 	if (hv->hv_tsc_page_status == HV_TSC_PAGE_SET &&
1221 	    !tsc_page_update_unsafe(hv))
1222 		hv->hv_tsc_page_status = HV_TSC_PAGE_HOST_CHANGED;
1223 
1224 	mutex_unlock(&hv->hv_lock);
1225 }
1226 
1227 static bool hv_check_msr_access(struct kvm_vcpu_hv *hv_vcpu, u32 msr)
1228 {
1229 	if (!hv_vcpu->enforce_cpuid)
1230 		return true;
1231 
1232 	switch (msr) {
1233 	case HV_X64_MSR_GUEST_OS_ID:
1234 	case HV_X64_MSR_HYPERCALL:
1235 		return hv_vcpu->cpuid_cache.features_eax &
1236 			HV_MSR_HYPERCALL_AVAILABLE;
1237 	case HV_X64_MSR_VP_RUNTIME:
1238 		return hv_vcpu->cpuid_cache.features_eax &
1239 			HV_MSR_VP_RUNTIME_AVAILABLE;
1240 	case HV_X64_MSR_TIME_REF_COUNT:
1241 		return hv_vcpu->cpuid_cache.features_eax &
1242 			HV_MSR_TIME_REF_COUNT_AVAILABLE;
1243 	case HV_X64_MSR_VP_INDEX:
1244 		return hv_vcpu->cpuid_cache.features_eax &
1245 			HV_MSR_VP_INDEX_AVAILABLE;
1246 	case HV_X64_MSR_RESET:
1247 		return hv_vcpu->cpuid_cache.features_eax &
1248 			HV_MSR_RESET_AVAILABLE;
1249 	case HV_X64_MSR_REFERENCE_TSC:
1250 		return hv_vcpu->cpuid_cache.features_eax &
1251 			HV_MSR_REFERENCE_TSC_AVAILABLE;
1252 	case HV_X64_MSR_SCONTROL:
1253 	case HV_X64_MSR_SVERSION:
1254 	case HV_X64_MSR_SIEFP:
1255 	case HV_X64_MSR_SIMP:
1256 	case HV_X64_MSR_EOM:
1257 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1258 		return hv_vcpu->cpuid_cache.features_eax &
1259 			HV_MSR_SYNIC_AVAILABLE;
1260 	case HV_X64_MSR_STIMER0_CONFIG:
1261 	case HV_X64_MSR_STIMER1_CONFIG:
1262 	case HV_X64_MSR_STIMER2_CONFIG:
1263 	case HV_X64_MSR_STIMER3_CONFIG:
1264 	case HV_X64_MSR_STIMER0_COUNT:
1265 	case HV_X64_MSR_STIMER1_COUNT:
1266 	case HV_X64_MSR_STIMER2_COUNT:
1267 	case HV_X64_MSR_STIMER3_COUNT:
1268 		return hv_vcpu->cpuid_cache.features_eax &
1269 			HV_MSR_SYNTIMER_AVAILABLE;
1270 	case HV_X64_MSR_EOI:
1271 	case HV_X64_MSR_ICR:
1272 	case HV_X64_MSR_TPR:
1273 	case HV_X64_MSR_VP_ASSIST_PAGE:
1274 		return hv_vcpu->cpuid_cache.features_eax &
1275 			HV_MSR_APIC_ACCESS_AVAILABLE;
1276 		break;
1277 	case HV_X64_MSR_TSC_FREQUENCY:
1278 	case HV_X64_MSR_APIC_FREQUENCY:
1279 		return hv_vcpu->cpuid_cache.features_eax &
1280 			HV_ACCESS_FREQUENCY_MSRS;
1281 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1282 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1283 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1284 		return hv_vcpu->cpuid_cache.features_eax &
1285 			HV_ACCESS_REENLIGHTENMENT;
1286 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1287 	case HV_X64_MSR_CRASH_CTL:
1288 		return hv_vcpu->cpuid_cache.features_edx &
1289 			HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
1290 	case HV_X64_MSR_SYNDBG_OPTIONS:
1291 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1292 		return hv_vcpu->cpuid_cache.features_edx &
1293 			HV_FEATURE_DEBUG_MSRS_AVAILABLE;
1294 	default:
1295 		break;
1296 	}
1297 
1298 	return false;
1299 }
1300 
1301 static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
1302 			     bool host)
1303 {
1304 	struct kvm *kvm = vcpu->kvm;
1305 	struct kvm_hv *hv = to_kvm_hv(kvm);
1306 
1307 	if (unlikely(!host && !hv_check_msr_access(to_hv_vcpu(vcpu), msr)))
1308 		return 1;
1309 
1310 	switch (msr) {
1311 	case HV_X64_MSR_GUEST_OS_ID:
1312 		hv->hv_guest_os_id = data;
1313 		/* setting guest os id to zero disables hypercall page */
1314 		if (!hv->hv_guest_os_id)
1315 			hv->hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
1316 		break;
1317 	case HV_X64_MSR_HYPERCALL: {
1318 		u8 instructions[9];
1319 		int i = 0;
1320 		u64 addr;
1321 
1322 		/* if guest os id is not set hypercall should remain disabled */
1323 		if (!hv->hv_guest_os_id)
1324 			break;
1325 		if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
1326 			hv->hv_hypercall = data;
1327 			break;
1328 		}
1329 
1330 		/*
1331 		 * If Xen and Hyper-V hypercalls are both enabled, disambiguate
1332 		 * the same way Xen itself does, by setting the bit 31 of EAX
1333 		 * which is RsvdZ in the 32-bit Hyper-V hypercall ABI and just
1334 		 * going to be clobbered on 64-bit.
1335 		 */
1336 		if (kvm_xen_hypercall_enabled(kvm)) {
1337 			/* orl $0x80000000, %eax */
1338 			instructions[i++] = 0x0d;
1339 			instructions[i++] = 0x00;
1340 			instructions[i++] = 0x00;
1341 			instructions[i++] = 0x00;
1342 			instructions[i++] = 0x80;
1343 		}
1344 
1345 		/* vmcall/vmmcall */
1346 		static_call(kvm_x86_patch_hypercall)(vcpu, instructions + i);
1347 		i += 3;
1348 
1349 		/* ret */
1350 		((unsigned char *)instructions)[i++] = 0xc3;
1351 
1352 		addr = data & HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_MASK;
1353 		if (kvm_vcpu_write_guest(vcpu, addr, instructions, i))
1354 			return 1;
1355 		hv->hv_hypercall = data;
1356 		break;
1357 	}
1358 	case HV_X64_MSR_REFERENCE_TSC:
1359 		hv->hv_tsc_page = data;
1360 		if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE) {
1361 			if (!host)
1362 				hv->hv_tsc_page_status = HV_TSC_PAGE_GUEST_CHANGED;
1363 			else
1364 				hv->hv_tsc_page_status = HV_TSC_PAGE_HOST_CHANGED;
1365 			kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
1366 		} else {
1367 			hv->hv_tsc_page_status = HV_TSC_PAGE_UNSET;
1368 		}
1369 		break;
1370 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1371 		return kvm_hv_msr_set_crash_data(kvm,
1372 						 msr - HV_X64_MSR_CRASH_P0,
1373 						 data);
1374 	case HV_X64_MSR_CRASH_CTL:
1375 		if (host)
1376 			return kvm_hv_msr_set_crash_ctl(kvm, data);
1377 
1378 		if (data & HV_CRASH_CTL_CRASH_NOTIFY) {
1379 			vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx 0x%llx)\n",
1380 				   hv->hv_crash_param[0],
1381 				   hv->hv_crash_param[1],
1382 				   hv->hv_crash_param[2],
1383 				   hv->hv_crash_param[3],
1384 				   hv->hv_crash_param[4]);
1385 
1386 			/* Send notification about crash to user space */
1387 			kvm_make_request(KVM_REQ_HV_CRASH, vcpu);
1388 		}
1389 		break;
1390 	case HV_X64_MSR_RESET:
1391 		if (data == 1) {
1392 			vcpu_debug(vcpu, "hyper-v reset requested\n");
1393 			kvm_make_request(KVM_REQ_HV_RESET, vcpu);
1394 		}
1395 		break;
1396 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1397 		hv->hv_reenlightenment_control = data;
1398 		break;
1399 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1400 		hv->hv_tsc_emulation_control = data;
1401 		break;
1402 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1403 		if (data && !host)
1404 			return 1;
1405 
1406 		hv->hv_tsc_emulation_status = data;
1407 		break;
1408 	case HV_X64_MSR_TIME_REF_COUNT:
1409 		/* read-only, but still ignore it if host-initiated */
1410 		if (!host)
1411 			return 1;
1412 		break;
1413 	case HV_X64_MSR_SYNDBG_OPTIONS:
1414 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1415 		return syndbg_set_msr(vcpu, msr, data, host);
1416 	default:
1417 		vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
1418 			    msr, data);
1419 		return 1;
1420 	}
1421 	return 0;
1422 }
1423 
1424 /* Calculate cpu time spent by current task in 100ns units */
1425 static u64 current_task_runtime_100ns(void)
1426 {
1427 	u64 utime, stime;
1428 
1429 	task_cputime_adjusted(current, &utime, &stime);
1430 
1431 	return div_u64(utime + stime, 100);
1432 }
1433 
1434 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1435 {
1436 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1437 
1438 	if (unlikely(!host && !hv_check_msr_access(hv_vcpu, msr)))
1439 		return 1;
1440 
1441 	switch (msr) {
1442 	case HV_X64_MSR_VP_INDEX: {
1443 		struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1444 		u32 new_vp_index = (u32)data;
1445 
1446 		if (!host || new_vp_index >= KVM_MAX_VCPUS)
1447 			return 1;
1448 
1449 		if (new_vp_index == hv_vcpu->vp_index)
1450 			return 0;
1451 
1452 		/*
1453 		 * The VP index is initialized to vcpu_index by
1454 		 * kvm_hv_vcpu_postcreate so they initially match.  Now the
1455 		 * VP index is changing, adjust num_mismatched_vp_indexes if
1456 		 * it now matches or no longer matches vcpu_idx.
1457 		 */
1458 		if (hv_vcpu->vp_index == vcpu->vcpu_idx)
1459 			atomic_inc(&hv->num_mismatched_vp_indexes);
1460 		else if (new_vp_index == vcpu->vcpu_idx)
1461 			atomic_dec(&hv->num_mismatched_vp_indexes);
1462 
1463 		hv_vcpu->vp_index = new_vp_index;
1464 		break;
1465 	}
1466 	case HV_X64_MSR_VP_ASSIST_PAGE: {
1467 		u64 gfn;
1468 		unsigned long addr;
1469 
1470 		if (!(data & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE)) {
1471 			hv_vcpu->hv_vapic = data;
1472 			if (kvm_lapic_set_pv_eoi(vcpu, 0, 0))
1473 				return 1;
1474 			break;
1475 		}
1476 		gfn = data >> HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT;
1477 		addr = kvm_vcpu_gfn_to_hva(vcpu, gfn);
1478 		if (kvm_is_error_hva(addr))
1479 			return 1;
1480 
1481 		/*
1482 		 * Clear apic_assist portion of struct hv_vp_assist_page
1483 		 * only, there can be valuable data in the rest which needs
1484 		 * to be preserved e.g. on migration.
1485 		 */
1486 		if (__put_user(0, (u32 __user *)addr))
1487 			return 1;
1488 		hv_vcpu->hv_vapic = data;
1489 		kvm_vcpu_mark_page_dirty(vcpu, gfn);
1490 		if (kvm_lapic_set_pv_eoi(vcpu,
1491 					    gfn_to_gpa(gfn) | KVM_MSR_ENABLED,
1492 					    sizeof(struct hv_vp_assist_page)))
1493 			return 1;
1494 		break;
1495 	}
1496 	case HV_X64_MSR_EOI:
1497 		return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
1498 	case HV_X64_MSR_ICR:
1499 		return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
1500 	case HV_X64_MSR_TPR:
1501 		return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
1502 	case HV_X64_MSR_VP_RUNTIME:
1503 		if (!host)
1504 			return 1;
1505 		hv_vcpu->runtime_offset = data - current_task_runtime_100ns();
1506 		break;
1507 	case HV_X64_MSR_SCONTROL:
1508 	case HV_X64_MSR_SVERSION:
1509 	case HV_X64_MSR_SIEFP:
1510 	case HV_X64_MSR_SIMP:
1511 	case HV_X64_MSR_EOM:
1512 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1513 		return synic_set_msr(to_hv_synic(vcpu), msr, data, host);
1514 	case HV_X64_MSR_STIMER0_CONFIG:
1515 	case HV_X64_MSR_STIMER1_CONFIG:
1516 	case HV_X64_MSR_STIMER2_CONFIG:
1517 	case HV_X64_MSR_STIMER3_CONFIG: {
1518 		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1519 
1520 		return stimer_set_config(to_hv_stimer(vcpu, timer_index),
1521 					 data, host);
1522 	}
1523 	case HV_X64_MSR_STIMER0_COUNT:
1524 	case HV_X64_MSR_STIMER1_COUNT:
1525 	case HV_X64_MSR_STIMER2_COUNT:
1526 	case HV_X64_MSR_STIMER3_COUNT: {
1527 		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1528 
1529 		return stimer_set_count(to_hv_stimer(vcpu, timer_index),
1530 					data, host);
1531 	}
1532 	case HV_X64_MSR_TSC_FREQUENCY:
1533 	case HV_X64_MSR_APIC_FREQUENCY:
1534 		/* read-only, but still ignore it if host-initiated */
1535 		if (!host)
1536 			return 1;
1537 		break;
1538 	default:
1539 		vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
1540 			    msr, data);
1541 		return 1;
1542 	}
1543 
1544 	return 0;
1545 }
1546 
1547 static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1548 			     bool host)
1549 {
1550 	u64 data = 0;
1551 	struct kvm *kvm = vcpu->kvm;
1552 	struct kvm_hv *hv = to_kvm_hv(kvm);
1553 
1554 	if (unlikely(!host && !hv_check_msr_access(to_hv_vcpu(vcpu), msr)))
1555 		return 1;
1556 
1557 	switch (msr) {
1558 	case HV_X64_MSR_GUEST_OS_ID:
1559 		data = hv->hv_guest_os_id;
1560 		break;
1561 	case HV_X64_MSR_HYPERCALL:
1562 		data = hv->hv_hypercall;
1563 		break;
1564 	case HV_X64_MSR_TIME_REF_COUNT:
1565 		data = get_time_ref_counter(kvm);
1566 		break;
1567 	case HV_X64_MSR_REFERENCE_TSC:
1568 		data = hv->hv_tsc_page;
1569 		break;
1570 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1571 		return kvm_hv_msr_get_crash_data(kvm,
1572 						 msr - HV_X64_MSR_CRASH_P0,
1573 						 pdata);
1574 	case HV_X64_MSR_CRASH_CTL:
1575 		return kvm_hv_msr_get_crash_ctl(kvm, pdata);
1576 	case HV_X64_MSR_RESET:
1577 		data = 0;
1578 		break;
1579 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1580 		data = hv->hv_reenlightenment_control;
1581 		break;
1582 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1583 		data = hv->hv_tsc_emulation_control;
1584 		break;
1585 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1586 		data = hv->hv_tsc_emulation_status;
1587 		break;
1588 	case HV_X64_MSR_SYNDBG_OPTIONS:
1589 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1590 		return syndbg_get_msr(vcpu, msr, pdata, host);
1591 	default:
1592 		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1593 		return 1;
1594 	}
1595 
1596 	*pdata = data;
1597 	return 0;
1598 }
1599 
1600 static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1601 			  bool host)
1602 {
1603 	u64 data = 0;
1604 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1605 
1606 	if (unlikely(!host && !hv_check_msr_access(hv_vcpu, msr)))
1607 		return 1;
1608 
1609 	switch (msr) {
1610 	case HV_X64_MSR_VP_INDEX:
1611 		data = hv_vcpu->vp_index;
1612 		break;
1613 	case HV_X64_MSR_EOI:
1614 		return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
1615 	case HV_X64_MSR_ICR:
1616 		return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
1617 	case HV_X64_MSR_TPR:
1618 		return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
1619 	case HV_X64_MSR_VP_ASSIST_PAGE:
1620 		data = hv_vcpu->hv_vapic;
1621 		break;
1622 	case HV_X64_MSR_VP_RUNTIME:
1623 		data = current_task_runtime_100ns() + hv_vcpu->runtime_offset;
1624 		break;
1625 	case HV_X64_MSR_SCONTROL:
1626 	case HV_X64_MSR_SVERSION:
1627 	case HV_X64_MSR_SIEFP:
1628 	case HV_X64_MSR_SIMP:
1629 	case HV_X64_MSR_EOM:
1630 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1631 		return synic_get_msr(to_hv_synic(vcpu), msr, pdata, host);
1632 	case HV_X64_MSR_STIMER0_CONFIG:
1633 	case HV_X64_MSR_STIMER1_CONFIG:
1634 	case HV_X64_MSR_STIMER2_CONFIG:
1635 	case HV_X64_MSR_STIMER3_CONFIG: {
1636 		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1637 
1638 		return stimer_get_config(to_hv_stimer(vcpu, timer_index),
1639 					 pdata);
1640 	}
1641 	case HV_X64_MSR_STIMER0_COUNT:
1642 	case HV_X64_MSR_STIMER1_COUNT:
1643 	case HV_X64_MSR_STIMER2_COUNT:
1644 	case HV_X64_MSR_STIMER3_COUNT: {
1645 		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1646 
1647 		return stimer_get_count(to_hv_stimer(vcpu, timer_index),
1648 					pdata);
1649 	}
1650 	case HV_X64_MSR_TSC_FREQUENCY:
1651 		data = (u64)vcpu->arch.virtual_tsc_khz * 1000;
1652 		break;
1653 	case HV_X64_MSR_APIC_FREQUENCY:
1654 		data = APIC_BUS_FREQUENCY;
1655 		break;
1656 	default:
1657 		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1658 		return 1;
1659 	}
1660 	*pdata = data;
1661 	return 0;
1662 }
1663 
1664 int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1665 {
1666 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1667 
1668 	if (!host && !vcpu->arch.hyperv_enabled)
1669 		return 1;
1670 
1671 	if (kvm_hv_vcpu_init(vcpu))
1672 		return 1;
1673 
1674 	if (kvm_hv_msr_partition_wide(msr)) {
1675 		int r;
1676 
1677 		mutex_lock(&hv->hv_lock);
1678 		r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
1679 		mutex_unlock(&hv->hv_lock);
1680 		return r;
1681 	} else
1682 		return kvm_hv_set_msr(vcpu, msr, data, host);
1683 }
1684 
1685 int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
1686 {
1687 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1688 
1689 	if (!host && !vcpu->arch.hyperv_enabled)
1690 		return 1;
1691 
1692 	if (kvm_hv_vcpu_init(vcpu))
1693 		return 1;
1694 
1695 	if (kvm_hv_msr_partition_wide(msr)) {
1696 		int r;
1697 
1698 		mutex_lock(&hv->hv_lock);
1699 		r = kvm_hv_get_msr_pw(vcpu, msr, pdata, host);
1700 		mutex_unlock(&hv->hv_lock);
1701 		return r;
1702 	} else
1703 		return kvm_hv_get_msr(vcpu, msr, pdata, host);
1704 }
1705 
1706 static void sparse_set_to_vcpu_mask(struct kvm *kvm, u64 *sparse_banks,
1707 				    u64 valid_bank_mask, unsigned long *vcpu_mask)
1708 {
1709 	struct kvm_hv *hv = to_kvm_hv(kvm);
1710 	bool has_mismatch = atomic_read(&hv->num_mismatched_vp_indexes);
1711 	u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1712 	struct kvm_vcpu *vcpu;
1713 	int bank, sbank = 0;
1714 	unsigned long i;
1715 	u64 *bitmap;
1716 
1717 	BUILD_BUG_ON(sizeof(vp_bitmap) >
1718 		     sizeof(*vcpu_mask) * BITS_TO_LONGS(KVM_MAX_VCPUS));
1719 
1720 	/*
1721 	 * If vp_index == vcpu_idx for all vCPUs, fill vcpu_mask directly, else
1722 	 * fill a temporary buffer and manually test each vCPU's VP index.
1723 	 */
1724 	if (likely(!has_mismatch))
1725 		bitmap = (u64 *)vcpu_mask;
1726 	else
1727 		bitmap = vp_bitmap;
1728 
1729 	/*
1730 	 * Each set of 64 VPs is packed into sparse_banks, with valid_bank_mask
1731 	 * having a '1' for each bank that exists in sparse_banks.  Sets must
1732 	 * be in ascending order, i.e. bank0..bankN.
1733 	 */
1734 	memset(bitmap, 0, sizeof(vp_bitmap));
1735 	for_each_set_bit(bank, (unsigned long *)&valid_bank_mask,
1736 			 KVM_HV_MAX_SPARSE_VCPU_SET_BITS)
1737 		bitmap[bank] = sparse_banks[sbank++];
1738 
1739 	if (likely(!has_mismatch))
1740 		return;
1741 
1742 	bitmap_zero(vcpu_mask, KVM_MAX_VCPUS);
1743 	kvm_for_each_vcpu(i, vcpu, kvm) {
1744 		if (test_bit(kvm_hv_get_vpindex(vcpu), (unsigned long *)vp_bitmap))
1745 			__set_bit(i, vcpu_mask);
1746 	}
1747 }
1748 
1749 static bool hv_is_vp_in_sparse_set(u32 vp_id, u64 valid_bank_mask, u64 sparse_banks[])
1750 {
1751 	int valid_bit_nr = vp_id / HV_VCPUS_PER_SPARSE_BANK;
1752 	unsigned long sbank;
1753 
1754 	if (!test_bit(valid_bit_nr, (unsigned long *)&valid_bank_mask))
1755 		return false;
1756 
1757 	/*
1758 	 * The index into the sparse bank is the number of preceding bits in
1759 	 * the valid mask.  Optimize for VMs with <64 vCPUs by skipping the
1760 	 * fancy math if there can't possibly be preceding bits.
1761 	 */
1762 	if (valid_bit_nr)
1763 		sbank = hweight64(valid_bank_mask & GENMASK_ULL(valid_bit_nr - 1, 0));
1764 	else
1765 		sbank = 0;
1766 
1767 	return test_bit(vp_id % HV_VCPUS_PER_SPARSE_BANK,
1768 			(unsigned long *)&sparse_banks[sbank]);
1769 }
1770 
1771 struct kvm_hv_hcall {
1772 	/* Hypercall input data */
1773 	u64 param;
1774 	u64 ingpa;
1775 	u64 outgpa;
1776 	u16 code;
1777 	u16 var_cnt;
1778 	u16 rep_cnt;
1779 	u16 rep_idx;
1780 	bool fast;
1781 	bool rep;
1782 	sse128_t xmm[HV_HYPERCALL_MAX_XMM_REGISTERS];
1783 
1784 	/*
1785 	 * Current read offset when KVM reads hypercall input data gradually,
1786 	 * either offset in bytes from 'ingpa' for regular hypercalls or the
1787 	 * number of already consumed 'XMM halves' for 'fast' hypercalls.
1788 	 */
1789 	union {
1790 		gpa_t data_offset;
1791 		int consumed_xmm_halves;
1792 	};
1793 };
1794 
1795 
1796 static int kvm_hv_get_hc_data(struct kvm *kvm, struct kvm_hv_hcall *hc,
1797 			      u16 orig_cnt, u16 cnt_cap, u64 *data)
1798 {
1799 	/*
1800 	 * Preserve the original count when ignoring entries via a "cap", KVM
1801 	 * still needs to validate the guest input (though the non-XMM path
1802 	 * punts on the checks).
1803 	 */
1804 	u16 cnt = min(orig_cnt, cnt_cap);
1805 	int i, j;
1806 
1807 	if (hc->fast) {
1808 		/*
1809 		 * Each XMM holds two sparse banks, but do not count halves that
1810 		 * have already been consumed for hypercall parameters.
1811 		 */
1812 		if (orig_cnt > 2 * HV_HYPERCALL_MAX_XMM_REGISTERS - hc->consumed_xmm_halves)
1813 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1814 
1815 		for (i = 0; i < cnt; i++) {
1816 			j = i + hc->consumed_xmm_halves;
1817 			if (j % 2)
1818 				data[i] = sse128_hi(hc->xmm[j / 2]);
1819 			else
1820 				data[i] = sse128_lo(hc->xmm[j / 2]);
1821 		}
1822 		return 0;
1823 	}
1824 
1825 	return kvm_read_guest(kvm, hc->ingpa + hc->data_offset, data,
1826 			      cnt * sizeof(*data));
1827 }
1828 
1829 static u64 kvm_get_sparse_vp_set(struct kvm *kvm, struct kvm_hv_hcall *hc,
1830 				 u64 *sparse_banks)
1831 {
1832 	if (hc->var_cnt > HV_MAX_SPARSE_VCPU_BANKS)
1833 		return -EINVAL;
1834 
1835 	/* Cap var_cnt to ignore banks that cannot contain a legal VP index. */
1836 	return kvm_hv_get_hc_data(kvm, hc, hc->var_cnt, KVM_HV_MAX_SPARSE_VCPU_SET_BITS,
1837 				  sparse_banks);
1838 }
1839 
1840 static int kvm_hv_get_tlb_flush_entries(struct kvm *kvm, struct kvm_hv_hcall *hc, u64 entries[])
1841 {
1842 	return kvm_hv_get_hc_data(kvm, hc, hc->rep_cnt, hc->rep_cnt, entries);
1843 }
1844 
1845 static void hv_tlb_flush_enqueue(struct kvm_vcpu *vcpu,
1846 				 struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo,
1847 				 u64 *entries, int count)
1848 {
1849 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1850 	u64 flush_all_entry = KVM_HV_TLB_FLUSHALL_ENTRY;
1851 
1852 	if (!hv_vcpu)
1853 		return;
1854 
1855 	spin_lock(&tlb_flush_fifo->write_lock);
1856 
1857 	/*
1858 	 * All entries should fit on the fifo leaving one free for 'flush all'
1859 	 * entry in case another request comes in. In case there's not enough
1860 	 * space, just put 'flush all' entry there.
1861 	 */
1862 	if (count && entries && count < kfifo_avail(&tlb_flush_fifo->entries)) {
1863 		WARN_ON(kfifo_in(&tlb_flush_fifo->entries, entries, count) != count);
1864 		goto out_unlock;
1865 	}
1866 
1867 	/*
1868 	 * Note: full fifo always contains 'flush all' entry, no need to check the
1869 	 * return value.
1870 	 */
1871 	kfifo_in(&tlb_flush_fifo->entries, &flush_all_entry, 1);
1872 
1873 out_unlock:
1874 	spin_unlock(&tlb_flush_fifo->write_lock);
1875 }
1876 
1877 int kvm_hv_vcpu_flush_tlb(struct kvm_vcpu *vcpu)
1878 {
1879 	struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo;
1880 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1881 	u64 entries[KVM_HV_TLB_FLUSH_FIFO_SIZE];
1882 	int i, j, count;
1883 	gva_t gva;
1884 
1885 	if (!tdp_enabled || !hv_vcpu)
1886 		return -EINVAL;
1887 
1888 	tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(vcpu, is_guest_mode(vcpu));
1889 
1890 	count = kfifo_out(&tlb_flush_fifo->entries, entries, KVM_HV_TLB_FLUSH_FIFO_SIZE);
1891 
1892 	for (i = 0; i < count; i++) {
1893 		if (entries[i] == KVM_HV_TLB_FLUSHALL_ENTRY)
1894 			goto out_flush_all;
1895 
1896 		/*
1897 		 * Lower 12 bits of 'address' encode the number of additional
1898 		 * pages to flush.
1899 		 */
1900 		gva = entries[i] & PAGE_MASK;
1901 		for (j = 0; j < (entries[i] & ~PAGE_MASK) + 1; j++)
1902 			static_call(kvm_x86_flush_tlb_gva)(vcpu, gva + j * PAGE_SIZE);
1903 
1904 		++vcpu->stat.tlb_flush;
1905 	}
1906 	return 0;
1907 
1908 out_flush_all:
1909 	kfifo_reset_out(&tlb_flush_fifo->entries);
1910 
1911 	/* Fall back to full flush. */
1912 	return -ENOSPC;
1913 }
1914 
1915 static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
1916 {
1917 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1918 	u64 *sparse_banks = hv_vcpu->sparse_banks;
1919 	struct kvm *kvm = vcpu->kvm;
1920 	struct hv_tlb_flush_ex flush_ex;
1921 	struct hv_tlb_flush flush;
1922 	DECLARE_BITMAP(vcpu_mask, KVM_MAX_VCPUS);
1923 	struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo;
1924 	/*
1925 	 * Normally, there can be no more than 'KVM_HV_TLB_FLUSH_FIFO_SIZE'
1926 	 * entries on the TLB flush fifo. The last entry, however, needs to be
1927 	 * always left free for 'flush all' entry which gets placed when
1928 	 * there is not enough space to put all the requested entries.
1929 	 */
1930 	u64 __tlb_flush_entries[KVM_HV_TLB_FLUSH_FIFO_SIZE - 1];
1931 	u64 *tlb_flush_entries;
1932 	u64 valid_bank_mask;
1933 	struct kvm_vcpu *v;
1934 	unsigned long i;
1935 	bool all_cpus;
1936 
1937 	/*
1938 	 * The Hyper-V TLFS doesn't allow more than HV_MAX_SPARSE_VCPU_BANKS
1939 	 * sparse banks. Fail the build if KVM's max allowed number of
1940 	 * vCPUs (>4096) exceeds this limit.
1941 	 */
1942 	BUILD_BUG_ON(KVM_HV_MAX_SPARSE_VCPU_SET_BITS > HV_MAX_SPARSE_VCPU_BANKS);
1943 
1944 	/*
1945 	 * 'Slow' hypercall's first parameter is the address in guest's memory
1946 	 * where hypercall parameters are placed. This is either a GPA or a
1947 	 * nested GPA when KVM is handling the call from L2 ('direct' TLB
1948 	 * flush).  Translate the address here so the memory can be uniformly
1949 	 * read with kvm_read_guest().
1950 	 */
1951 	if (!hc->fast && is_guest_mode(vcpu)) {
1952 		hc->ingpa = translate_nested_gpa(vcpu, hc->ingpa, 0, NULL);
1953 		if (unlikely(hc->ingpa == INVALID_GPA))
1954 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1955 	}
1956 
1957 	if (hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST ||
1958 	    hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE) {
1959 		if (hc->fast) {
1960 			flush.address_space = hc->ingpa;
1961 			flush.flags = hc->outgpa;
1962 			flush.processor_mask = sse128_lo(hc->xmm[0]);
1963 			hc->consumed_xmm_halves = 1;
1964 		} else {
1965 			if (unlikely(kvm_read_guest(kvm, hc->ingpa,
1966 						    &flush, sizeof(flush))))
1967 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1968 			hc->data_offset = sizeof(flush);
1969 		}
1970 
1971 		trace_kvm_hv_flush_tlb(flush.processor_mask,
1972 				       flush.address_space, flush.flags,
1973 				       is_guest_mode(vcpu));
1974 
1975 		valid_bank_mask = BIT_ULL(0);
1976 		sparse_banks[0] = flush.processor_mask;
1977 
1978 		/*
1979 		 * Work around possible WS2012 bug: it sends hypercalls
1980 		 * with processor_mask = 0x0 and HV_FLUSH_ALL_PROCESSORS clear,
1981 		 * while also expecting us to flush something and crashing if
1982 		 * we don't. Let's treat processor_mask == 0 same as
1983 		 * HV_FLUSH_ALL_PROCESSORS.
1984 		 */
1985 		all_cpus = (flush.flags & HV_FLUSH_ALL_PROCESSORS) ||
1986 			flush.processor_mask == 0;
1987 	} else {
1988 		if (hc->fast) {
1989 			flush_ex.address_space = hc->ingpa;
1990 			flush_ex.flags = hc->outgpa;
1991 			memcpy(&flush_ex.hv_vp_set,
1992 			       &hc->xmm[0], sizeof(hc->xmm[0]));
1993 			hc->consumed_xmm_halves = 2;
1994 		} else {
1995 			if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush_ex,
1996 						    sizeof(flush_ex))))
1997 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1998 			hc->data_offset = sizeof(flush_ex);
1999 		}
2000 
2001 		trace_kvm_hv_flush_tlb_ex(flush_ex.hv_vp_set.valid_bank_mask,
2002 					  flush_ex.hv_vp_set.format,
2003 					  flush_ex.address_space,
2004 					  flush_ex.flags, is_guest_mode(vcpu));
2005 
2006 		valid_bank_mask = flush_ex.hv_vp_set.valid_bank_mask;
2007 		all_cpus = flush_ex.hv_vp_set.format !=
2008 			HV_GENERIC_SET_SPARSE_4K;
2009 
2010 		if (hc->var_cnt != hweight64(valid_bank_mask))
2011 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
2012 
2013 		if (!all_cpus) {
2014 			if (!hc->var_cnt)
2015 				goto ret_success;
2016 
2017 			if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks))
2018 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
2019 		}
2020 
2021 		/*
2022 		 * Hyper-V TLFS doesn't explicitly forbid non-empty sparse vCPU
2023 		 * banks (and, thus, non-zero 'var_cnt') for the 'all vCPUs'
2024 		 * case (HV_GENERIC_SET_ALL).  Always adjust data_offset and
2025 		 * consumed_xmm_halves to make sure TLB flush entries are read
2026 		 * from the correct offset.
2027 		 */
2028 		if (hc->fast)
2029 			hc->consumed_xmm_halves += hc->var_cnt;
2030 		else
2031 			hc->data_offset += hc->var_cnt * sizeof(sparse_banks[0]);
2032 	}
2033 
2034 	if (hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE ||
2035 	    hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX ||
2036 	    hc->rep_cnt > ARRAY_SIZE(__tlb_flush_entries)) {
2037 		tlb_flush_entries = NULL;
2038 	} else {
2039 		if (kvm_hv_get_tlb_flush_entries(kvm, hc, __tlb_flush_entries))
2040 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
2041 		tlb_flush_entries = __tlb_flush_entries;
2042 	}
2043 
2044 	/*
2045 	 * vcpu->arch.cr3 may not be up-to-date for running vCPUs so we can't
2046 	 * analyze it here, flush TLB regardless of the specified address space.
2047 	 */
2048 	if (all_cpus && !is_guest_mode(vcpu)) {
2049 		kvm_for_each_vcpu(i, v, kvm) {
2050 			tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(v, false);
2051 			hv_tlb_flush_enqueue(v, tlb_flush_fifo,
2052 					     tlb_flush_entries, hc->rep_cnt);
2053 		}
2054 
2055 		kvm_make_all_cpus_request(kvm, KVM_REQ_HV_TLB_FLUSH);
2056 	} else if (!is_guest_mode(vcpu)) {
2057 		sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask, vcpu_mask);
2058 
2059 		for_each_set_bit(i, vcpu_mask, KVM_MAX_VCPUS) {
2060 			v = kvm_get_vcpu(kvm, i);
2061 			if (!v)
2062 				continue;
2063 			tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(v, false);
2064 			hv_tlb_flush_enqueue(v, tlb_flush_fifo,
2065 					     tlb_flush_entries, hc->rep_cnt);
2066 		}
2067 
2068 		kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask);
2069 	} else {
2070 		struct kvm_vcpu_hv *hv_v;
2071 
2072 		bitmap_zero(vcpu_mask, KVM_MAX_VCPUS);
2073 
2074 		kvm_for_each_vcpu(i, v, kvm) {
2075 			hv_v = to_hv_vcpu(v);
2076 
2077 			/*
2078 			 * The following check races with nested vCPUs entering/exiting
2079 			 * and/or migrating between L1's vCPUs, however the only case when
2080 			 * KVM *must* flush the TLB is when the target L2 vCPU keeps
2081 			 * running on the same L1 vCPU from the moment of the request until
2082 			 * kvm_hv_flush_tlb() returns. TLB is fully flushed in all other
2083 			 * cases, e.g. when the target L2 vCPU migrates to a different L1
2084 			 * vCPU or when the corresponding L1 vCPU temporary switches to a
2085 			 * different L2 vCPU while the request is being processed.
2086 			 */
2087 			if (!hv_v || hv_v->nested.vm_id != hv_vcpu->nested.vm_id)
2088 				continue;
2089 
2090 			if (!all_cpus &&
2091 			    !hv_is_vp_in_sparse_set(hv_v->nested.vp_id, valid_bank_mask,
2092 						    sparse_banks))
2093 				continue;
2094 
2095 			__set_bit(i, vcpu_mask);
2096 			tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(v, true);
2097 			hv_tlb_flush_enqueue(v, tlb_flush_fifo,
2098 					     tlb_flush_entries, hc->rep_cnt);
2099 		}
2100 
2101 		kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask);
2102 	}
2103 
2104 ret_success:
2105 	/* We always do full TLB flush, set 'Reps completed' = 'Rep Count' */
2106 	return (u64)HV_STATUS_SUCCESS |
2107 		((u64)hc->rep_cnt << HV_HYPERCALL_REP_COMP_OFFSET);
2108 }
2109 
2110 static void kvm_hv_send_ipi_to_many(struct kvm *kvm, u32 vector,
2111 				    u64 *sparse_banks, u64 valid_bank_mask)
2112 {
2113 	struct kvm_lapic_irq irq = {
2114 		.delivery_mode = APIC_DM_FIXED,
2115 		.vector = vector
2116 	};
2117 	struct kvm_vcpu *vcpu;
2118 	unsigned long i;
2119 
2120 	kvm_for_each_vcpu(i, vcpu, kvm) {
2121 		if (sparse_banks &&
2122 		    !hv_is_vp_in_sparse_set(kvm_hv_get_vpindex(vcpu),
2123 					    valid_bank_mask, sparse_banks))
2124 			continue;
2125 
2126 		/* We fail only when APIC is disabled */
2127 		kvm_apic_set_irq(vcpu, &irq, NULL);
2128 	}
2129 }
2130 
2131 static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
2132 {
2133 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
2134 	u64 *sparse_banks = hv_vcpu->sparse_banks;
2135 	struct kvm *kvm = vcpu->kvm;
2136 	struct hv_send_ipi_ex send_ipi_ex;
2137 	struct hv_send_ipi send_ipi;
2138 	u64 valid_bank_mask;
2139 	u32 vector;
2140 	bool all_cpus;
2141 
2142 	if (hc->code == HVCALL_SEND_IPI) {
2143 		if (!hc->fast) {
2144 			if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi,
2145 						    sizeof(send_ipi))))
2146 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
2147 			sparse_banks[0] = send_ipi.cpu_mask;
2148 			vector = send_ipi.vector;
2149 		} else {
2150 			/* 'reserved' part of hv_send_ipi should be 0 */
2151 			if (unlikely(hc->ingpa >> 32 != 0))
2152 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
2153 			sparse_banks[0] = hc->outgpa;
2154 			vector = (u32)hc->ingpa;
2155 		}
2156 		all_cpus = false;
2157 		valid_bank_mask = BIT_ULL(0);
2158 
2159 		trace_kvm_hv_send_ipi(vector, sparse_banks[0]);
2160 	} else {
2161 		if (!hc->fast) {
2162 			if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi_ex,
2163 						    sizeof(send_ipi_ex))))
2164 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
2165 		} else {
2166 			send_ipi_ex.vector = (u32)hc->ingpa;
2167 			send_ipi_ex.vp_set.format = hc->outgpa;
2168 			send_ipi_ex.vp_set.valid_bank_mask = sse128_lo(hc->xmm[0]);
2169 		}
2170 
2171 		trace_kvm_hv_send_ipi_ex(send_ipi_ex.vector,
2172 					 send_ipi_ex.vp_set.format,
2173 					 send_ipi_ex.vp_set.valid_bank_mask);
2174 
2175 		vector = send_ipi_ex.vector;
2176 		valid_bank_mask = send_ipi_ex.vp_set.valid_bank_mask;
2177 		all_cpus = send_ipi_ex.vp_set.format == HV_GENERIC_SET_ALL;
2178 
2179 		if (hc->var_cnt != hweight64(valid_bank_mask))
2180 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
2181 
2182 		if (all_cpus)
2183 			goto check_and_send_ipi;
2184 
2185 		if (!hc->var_cnt)
2186 			goto ret_success;
2187 
2188 		if (!hc->fast)
2189 			hc->data_offset = offsetof(struct hv_send_ipi_ex,
2190 						   vp_set.bank_contents);
2191 		else
2192 			hc->consumed_xmm_halves = 1;
2193 
2194 		if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks))
2195 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
2196 	}
2197 
2198 check_and_send_ipi:
2199 	if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR))
2200 		return HV_STATUS_INVALID_HYPERCALL_INPUT;
2201 
2202 	if (all_cpus)
2203 		kvm_hv_send_ipi_to_many(kvm, vector, NULL, 0);
2204 	else
2205 		kvm_hv_send_ipi_to_many(kvm, vector, sparse_banks, valid_bank_mask);
2206 
2207 ret_success:
2208 	return HV_STATUS_SUCCESS;
2209 }
2210 
2211 void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu, bool hyperv_enabled)
2212 {
2213 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
2214 	struct kvm_cpuid_entry2 *entry;
2215 
2216 	vcpu->arch.hyperv_enabled = hyperv_enabled;
2217 
2218 	if (!hv_vcpu) {
2219 		/*
2220 		 * KVM should have already allocated kvm_vcpu_hv if Hyper-V is
2221 		 * enabled in CPUID.
2222 		 */
2223 		WARN_ON_ONCE(vcpu->arch.hyperv_enabled);
2224 		return;
2225 	}
2226 
2227 	memset(&hv_vcpu->cpuid_cache, 0, sizeof(hv_vcpu->cpuid_cache));
2228 
2229 	if (!vcpu->arch.hyperv_enabled)
2230 		return;
2231 
2232 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_FEATURES);
2233 	if (entry) {
2234 		hv_vcpu->cpuid_cache.features_eax = entry->eax;
2235 		hv_vcpu->cpuid_cache.features_ebx = entry->ebx;
2236 		hv_vcpu->cpuid_cache.features_edx = entry->edx;
2237 	}
2238 
2239 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_ENLIGHTMENT_INFO);
2240 	if (entry) {
2241 		hv_vcpu->cpuid_cache.enlightenments_eax = entry->eax;
2242 		hv_vcpu->cpuid_cache.enlightenments_ebx = entry->ebx;
2243 	}
2244 
2245 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES);
2246 	if (entry)
2247 		hv_vcpu->cpuid_cache.syndbg_cap_eax = entry->eax;
2248 
2249 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_NESTED_FEATURES);
2250 	if (entry) {
2251 		hv_vcpu->cpuid_cache.nested_eax = entry->eax;
2252 		hv_vcpu->cpuid_cache.nested_ebx = entry->ebx;
2253 	}
2254 }
2255 
2256 int kvm_hv_set_enforce_cpuid(struct kvm_vcpu *vcpu, bool enforce)
2257 {
2258 	struct kvm_vcpu_hv *hv_vcpu;
2259 	int ret = 0;
2260 
2261 	if (!to_hv_vcpu(vcpu)) {
2262 		if (enforce) {
2263 			ret = kvm_hv_vcpu_init(vcpu);
2264 			if (ret)
2265 				return ret;
2266 		} else {
2267 			return 0;
2268 		}
2269 	}
2270 
2271 	hv_vcpu = to_hv_vcpu(vcpu);
2272 	hv_vcpu->enforce_cpuid = enforce;
2273 
2274 	return ret;
2275 }
2276 
2277 static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
2278 {
2279 	bool longmode;
2280 
2281 	longmode = is_64_bit_hypercall(vcpu);
2282 	if (longmode)
2283 		kvm_rax_write(vcpu, result);
2284 	else {
2285 		kvm_rdx_write(vcpu, result >> 32);
2286 		kvm_rax_write(vcpu, result & 0xffffffff);
2287 	}
2288 }
2289 
2290 static int kvm_hv_hypercall_complete(struct kvm_vcpu *vcpu, u64 result)
2291 {
2292 	u32 tlb_lock_count = 0;
2293 	int ret;
2294 
2295 	if (hv_result_success(result) && is_guest_mode(vcpu) &&
2296 	    kvm_hv_is_tlb_flush_hcall(vcpu) &&
2297 	    kvm_read_guest(vcpu->kvm, to_hv_vcpu(vcpu)->nested.pa_page_gpa,
2298 			   &tlb_lock_count, sizeof(tlb_lock_count)))
2299 		result = HV_STATUS_INVALID_HYPERCALL_INPUT;
2300 
2301 	trace_kvm_hv_hypercall_done(result);
2302 	kvm_hv_hypercall_set_result(vcpu, result);
2303 	++vcpu->stat.hypercalls;
2304 
2305 	ret = kvm_skip_emulated_instruction(vcpu);
2306 
2307 	if (tlb_lock_count)
2308 		kvm_x86_ops.nested_ops->hv_inject_synthetic_vmexit_post_tlb_flush(vcpu);
2309 
2310 	return ret;
2311 }
2312 
2313 static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
2314 {
2315 	return kvm_hv_hypercall_complete(vcpu, vcpu->run->hyperv.u.hcall.result);
2316 }
2317 
2318 static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
2319 {
2320 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
2321 	struct eventfd_ctx *eventfd;
2322 
2323 	if (unlikely(!hc->fast)) {
2324 		int ret;
2325 		gpa_t gpa = hc->ingpa;
2326 
2327 		if ((gpa & (__alignof__(hc->ingpa) - 1)) ||
2328 		    offset_in_page(gpa) + sizeof(hc->ingpa) > PAGE_SIZE)
2329 			return HV_STATUS_INVALID_ALIGNMENT;
2330 
2331 		ret = kvm_vcpu_read_guest(vcpu, gpa,
2332 					  &hc->ingpa, sizeof(hc->ingpa));
2333 		if (ret < 0)
2334 			return HV_STATUS_INVALID_ALIGNMENT;
2335 	}
2336 
2337 	/*
2338 	 * Per spec, bits 32-47 contain the extra "flag number".  However, we
2339 	 * have no use for it, and in all known usecases it is zero, so just
2340 	 * report lookup failure if it isn't.
2341 	 */
2342 	if (hc->ingpa & 0xffff00000000ULL)
2343 		return HV_STATUS_INVALID_PORT_ID;
2344 	/* remaining bits are reserved-zero */
2345 	if (hc->ingpa & ~KVM_HYPERV_CONN_ID_MASK)
2346 		return HV_STATUS_INVALID_HYPERCALL_INPUT;
2347 
2348 	/* the eventfd is protected by vcpu->kvm->srcu, but conn_to_evt isn't */
2349 	rcu_read_lock();
2350 	eventfd = idr_find(&hv->conn_to_evt, hc->ingpa);
2351 	rcu_read_unlock();
2352 	if (!eventfd)
2353 		return HV_STATUS_INVALID_PORT_ID;
2354 
2355 	eventfd_signal(eventfd, 1);
2356 	return HV_STATUS_SUCCESS;
2357 }
2358 
2359 static bool is_xmm_fast_hypercall(struct kvm_hv_hcall *hc)
2360 {
2361 	switch (hc->code) {
2362 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2363 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2364 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2365 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2366 	case HVCALL_SEND_IPI_EX:
2367 		return true;
2368 	}
2369 
2370 	return false;
2371 }
2372 
2373 static void kvm_hv_hypercall_read_xmm(struct kvm_hv_hcall *hc)
2374 {
2375 	int reg;
2376 
2377 	kvm_fpu_get();
2378 	for (reg = 0; reg < HV_HYPERCALL_MAX_XMM_REGISTERS; reg++)
2379 		_kvm_read_sse_reg(reg, &hc->xmm[reg]);
2380 	kvm_fpu_put();
2381 }
2382 
2383 static bool hv_check_hypercall_access(struct kvm_vcpu_hv *hv_vcpu, u16 code)
2384 {
2385 	if (!hv_vcpu->enforce_cpuid)
2386 		return true;
2387 
2388 	switch (code) {
2389 	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
2390 		return hv_vcpu->cpuid_cache.enlightenments_ebx &&
2391 			hv_vcpu->cpuid_cache.enlightenments_ebx != U32_MAX;
2392 	case HVCALL_POST_MESSAGE:
2393 		return hv_vcpu->cpuid_cache.features_ebx & HV_POST_MESSAGES;
2394 	case HVCALL_SIGNAL_EVENT:
2395 		return hv_vcpu->cpuid_cache.features_ebx & HV_SIGNAL_EVENTS;
2396 	case HVCALL_POST_DEBUG_DATA:
2397 	case HVCALL_RETRIEVE_DEBUG_DATA:
2398 	case HVCALL_RESET_DEBUG_SESSION:
2399 		/*
2400 		 * Return 'true' when SynDBG is disabled so the resulting code
2401 		 * will be HV_STATUS_INVALID_HYPERCALL_CODE.
2402 		 */
2403 		return !kvm_hv_is_syndbg_enabled(hv_vcpu->vcpu) ||
2404 			hv_vcpu->cpuid_cache.features_ebx & HV_DEBUGGING;
2405 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2406 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2407 		if (!(hv_vcpu->cpuid_cache.enlightenments_eax &
2408 		      HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
2409 			return false;
2410 		fallthrough;
2411 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2412 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2413 		return hv_vcpu->cpuid_cache.enlightenments_eax &
2414 			HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
2415 	case HVCALL_SEND_IPI_EX:
2416 		if (!(hv_vcpu->cpuid_cache.enlightenments_eax &
2417 		      HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
2418 			return false;
2419 		fallthrough;
2420 	case HVCALL_SEND_IPI:
2421 		return hv_vcpu->cpuid_cache.enlightenments_eax &
2422 			HV_X64_CLUSTER_IPI_RECOMMENDED;
2423 	default:
2424 		break;
2425 	}
2426 
2427 	return true;
2428 }
2429 
2430 int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
2431 {
2432 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
2433 	struct kvm_hv_hcall hc;
2434 	u64 ret = HV_STATUS_SUCCESS;
2435 
2436 	/*
2437 	 * hypercall generates UD from non zero cpl and real mode
2438 	 * per HYPER-V spec
2439 	 */
2440 	if (static_call(kvm_x86_get_cpl)(vcpu) != 0 || !is_protmode(vcpu)) {
2441 		kvm_queue_exception(vcpu, UD_VECTOR);
2442 		return 1;
2443 	}
2444 
2445 #ifdef CONFIG_X86_64
2446 	if (is_64_bit_hypercall(vcpu)) {
2447 		hc.param = kvm_rcx_read(vcpu);
2448 		hc.ingpa = kvm_rdx_read(vcpu);
2449 		hc.outgpa = kvm_r8_read(vcpu);
2450 	} else
2451 #endif
2452 	{
2453 		hc.param = ((u64)kvm_rdx_read(vcpu) << 32) |
2454 			    (kvm_rax_read(vcpu) & 0xffffffff);
2455 		hc.ingpa = ((u64)kvm_rbx_read(vcpu) << 32) |
2456 			    (kvm_rcx_read(vcpu) & 0xffffffff);
2457 		hc.outgpa = ((u64)kvm_rdi_read(vcpu) << 32) |
2458 			     (kvm_rsi_read(vcpu) & 0xffffffff);
2459 	}
2460 
2461 	hc.code = hc.param & 0xffff;
2462 	hc.var_cnt = (hc.param & HV_HYPERCALL_VARHEAD_MASK) >> HV_HYPERCALL_VARHEAD_OFFSET;
2463 	hc.fast = !!(hc.param & HV_HYPERCALL_FAST_BIT);
2464 	hc.rep_cnt = (hc.param >> HV_HYPERCALL_REP_COMP_OFFSET) & 0xfff;
2465 	hc.rep_idx = (hc.param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff;
2466 	hc.rep = !!(hc.rep_cnt || hc.rep_idx);
2467 
2468 	trace_kvm_hv_hypercall(hc.code, hc.fast, hc.var_cnt, hc.rep_cnt,
2469 			       hc.rep_idx, hc.ingpa, hc.outgpa);
2470 
2471 	if (unlikely(!hv_check_hypercall_access(hv_vcpu, hc.code))) {
2472 		ret = HV_STATUS_ACCESS_DENIED;
2473 		goto hypercall_complete;
2474 	}
2475 
2476 	if (unlikely(hc.param & HV_HYPERCALL_RSVD_MASK)) {
2477 		ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2478 		goto hypercall_complete;
2479 	}
2480 
2481 	if (hc.fast && is_xmm_fast_hypercall(&hc)) {
2482 		if (unlikely(hv_vcpu->enforce_cpuid &&
2483 			     !(hv_vcpu->cpuid_cache.features_edx &
2484 			       HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE))) {
2485 			kvm_queue_exception(vcpu, UD_VECTOR);
2486 			return 1;
2487 		}
2488 
2489 		kvm_hv_hypercall_read_xmm(&hc);
2490 	}
2491 
2492 	switch (hc.code) {
2493 	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
2494 		if (unlikely(hc.rep || hc.var_cnt)) {
2495 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2496 			break;
2497 		}
2498 		kvm_vcpu_on_spin(vcpu, true);
2499 		break;
2500 	case HVCALL_SIGNAL_EVENT:
2501 		if (unlikely(hc.rep || hc.var_cnt)) {
2502 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2503 			break;
2504 		}
2505 		ret = kvm_hvcall_signal_event(vcpu, &hc);
2506 		if (ret != HV_STATUS_INVALID_PORT_ID)
2507 			break;
2508 		fallthrough;	/* maybe userspace knows this conn_id */
2509 	case HVCALL_POST_MESSAGE:
2510 		/* don't bother userspace if it has no way to handle it */
2511 		if (unlikely(hc.rep || hc.var_cnt || !to_hv_synic(vcpu)->active)) {
2512 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2513 			break;
2514 		}
2515 		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
2516 		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
2517 		vcpu->run->hyperv.u.hcall.input = hc.param;
2518 		vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
2519 		vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
2520 		vcpu->arch.complete_userspace_io =
2521 				kvm_hv_hypercall_complete_userspace;
2522 		return 0;
2523 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2524 		if (unlikely(hc.var_cnt)) {
2525 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2526 			break;
2527 		}
2528 		fallthrough;
2529 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2530 		if (unlikely(!hc.rep_cnt || hc.rep_idx)) {
2531 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2532 			break;
2533 		}
2534 		ret = kvm_hv_flush_tlb(vcpu, &hc);
2535 		break;
2536 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2537 		if (unlikely(hc.var_cnt)) {
2538 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2539 			break;
2540 		}
2541 		fallthrough;
2542 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2543 		if (unlikely(hc.rep)) {
2544 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2545 			break;
2546 		}
2547 		ret = kvm_hv_flush_tlb(vcpu, &hc);
2548 		break;
2549 	case HVCALL_SEND_IPI:
2550 		if (unlikely(hc.var_cnt)) {
2551 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2552 			break;
2553 		}
2554 		fallthrough;
2555 	case HVCALL_SEND_IPI_EX:
2556 		if (unlikely(hc.rep)) {
2557 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2558 			break;
2559 		}
2560 		ret = kvm_hv_send_ipi(vcpu, &hc);
2561 		break;
2562 	case HVCALL_POST_DEBUG_DATA:
2563 	case HVCALL_RETRIEVE_DEBUG_DATA:
2564 		if (unlikely(hc.fast)) {
2565 			ret = HV_STATUS_INVALID_PARAMETER;
2566 			break;
2567 		}
2568 		fallthrough;
2569 	case HVCALL_RESET_DEBUG_SESSION: {
2570 		struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
2571 
2572 		if (!kvm_hv_is_syndbg_enabled(vcpu)) {
2573 			ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2574 			break;
2575 		}
2576 
2577 		if (!(syndbg->options & HV_X64_SYNDBG_OPTION_USE_HCALLS)) {
2578 			ret = HV_STATUS_OPERATION_DENIED;
2579 			break;
2580 		}
2581 		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
2582 		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
2583 		vcpu->run->hyperv.u.hcall.input = hc.param;
2584 		vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
2585 		vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
2586 		vcpu->arch.complete_userspace_io =
2587 				kvm_hv_hypercall_complete_userspace;
2588 		return 0;
2589 	}
2590 	default:
2591 		ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2592 		break;
2593 	}
2594 
2595 hypercall_complete:
2596 	return kvm_hv_hypercall_complete(vcpu, ret);
2597 }
2598 
2599 void kvm_hv_init_vm(struct kvm *kvm)
2600 {
2601 	struct kvm_hv *hv = to_kvm_hv(kvm);
2602 
2603 	mutex_init(&hv->hv_lock);
2604 	idr_init(&hv->conn_to_evt);
2605 }
2606 
2607 void kvm_hv_destroy_vm(struct kvm *kvm)
2608 {
2609 	struct kvm_hv *hv = to_kvm_hv(kvm);
2610 	struct eventfd_ctx *eventfd;
2611 	int i;
2612 
2613 	idr_for_each_entry(&hv->conn_to_evt, eventfd, i)
2614 		eventfd_ctx_put(eventfd);
2615 	idr_destroy(&hv->conn_to_evt);
2616 }
2617 
2618 static int kvm_hv_eventfd_assign(struct kvm *kvm, u32 conn_id, int fd)
2619 {
2620 	struct kvm_hv *hv = to_kvm_hv(kvm);
2621 	struct eventfd_ctx *eventfd;
2622 	int ret;
2623 
2624 	eventfd = eventfd_ctx_fdget(fd);
2625 	if (IS_ERR(eventfd))
2626 		return PTR_ERR(eventfd);
2627 
2628 	mutex_lock(&hv->hv_lock);
2629 	ret = idr_alloc(&hv->conn_to_evt, eventfd, conn_id, conn_id + 1,
2630 			GFP_KERNEL_ACCOUNT);
2631 	mutex_unlock(&hv->hv_lock);
2632 
2633 	if (ret >= 0)
2634 		return 0;
2635 
2636 	if (ret == -ENOSPC)
2637 		ret = -EEXIST;
2638 	eventfd_ctx_put(eventfd);
2639 	return ret;
2640 }
2641 
2642 static int kvm_hv_eventfd_deassign(struct kvm *kvm, u32 conn_id)
2643 {
2644 	struct kvm_hv *hv = to_kvm_hv(kvm);
2645 	struct eventfd_ctx *eventfd;
2646 
2647 	mutex_lock(&hv->hv_lock);
2648 	eventfd = idr_remove(&hv->conn_to_evt, conn_id);
2649 	mutex_unlock(&hv->hv_lock);
2650 
2651 	if (!eventfd)
2652 		return -ENOENT;
2653 
2654 	synchronize_srcu(&kvm->srcu);
2655 	eventfd_ctx_put(eventfd);
2656 	return 0;
2657 }
2658 
2659 int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args)
2660 {
2661 	if ((args->flags & ~KVM_HYPERV_EVENTFD_DEASSIGN) ||
2662 	    (args->conn_id & ~KVM_HYPERV_CONN_ID_MASK))
2663 		return -EINVAL;
2664 
2665 	if (args->flags == KVM_HYPERV_EVENTFD_DEASSIGN)
2666 		return kvm_hv_eventfd_deassign(kvm, args->conn_id);
2667 	return kvm_hv_eventfd_assign(kvm, args->conn_id, args->fd);
2668 }
2669 
2670 int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
2671 		     struct kvm_cpuid_entry2 __user *entries)
2672 {
2673 	uint16_t evmcs_ver = 0;
2674 	struct kvm_cpuid_entry2 cpuid_entries[] = {
2675 		{ .function = HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS },
2676 		{ .function = HYPERV_CPUID_INTERFACE },
2677 		{ .function = HYPERV_CPUID_VERSION },
2678 		{ .function = HYPERV_CPUID_FEATURES },
2679 		{ .function = HYPERV_CPUID_ENLIGHTMENT_INFO },
2680 		{ .function = HYPERV_CPUID_IMPLEMENT_LIMITS },
2681 		{ .function = HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS },
2682 		{ .function = HYPERV_CPUID_SYNDBG_INTERFACE },
2683 		{ .function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES	},
2684 		{ .function = HYPERV_CPUID_NESTED_FEATURES },
2685 	};
2686 	int i, nent = ARRAY_SIZE(cpuid_entries);
2687 
2688 	if (kvm_x86_ops.nested_ops->get_evmcs_version)
2689 		evmcs_ver = kvm_x86_ops.nested_ops->get_evmcs_version(vcpu);
2690 
2691 	if (cpuid->nent < nent)
2692 		return -E2BIG;
2693 
2694 	if (cpuid->nent > nent)
2695 		cpuid->nent = nent;
2696 
2697 	for (i = 0; i < nent; i++) {
2698 		struct kvm_cpuid_entry2 *ent = &cpuid_entries[i];
2699 		u32 signature[3];
2700 
2701 		switch (ent->function) {
2702 		case HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS:
2703 			memcpy(signature, "Linux KVM Hv", 12);
2704 
2705 			ent->eax = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES;
2706 			ent->ebx = signature[0];
2707 			ent->ecx = signature[1];
2708 			ent->edx = signature[2];
2709 			break;
2710 
2711 		case HYPERV_CPUID_INTERFACE:
2712 			ent->eax = HYPERV_CPUID_SIGNATURE_EAX;
2713 			break;
2714 
2715 		case HYPERV_CPUID_VERSION:
2716 			/*
2717 			 * We implement some Hyper-V 2016 functions so let's use
2718 			 * this version.
2719 			 */
2720 			ent->eax = 0x00003839;
2721 			ent->ebx = 0x000A0000;
2722 			break;
2723 
2724 		case HYPERV_CPUID_FEATURES:
2725 			ent->eax |= HV_MSR_VP_RUNTIME_AVAILABLE;
2726 			ent->eax |= HV_MSR_TIME_REF_COUNT_AVAILABLE;
2727 			ent->eax |= HV_MSR_SYNIC_AVAILABLE;
2728 			ent->eax |= HV_MSR_SYNTIMER_AVAILABLE;
2729 			ent->eax |= HV_MSR_APIC_ACCESS_AVAILABLE;
2730 			ent->eax |= HV_MSR_HYPERCALL_AVAILABLE;
2731 			ent->eax |= HV_MSR_VP_INDEX_AVAILABLE;
2732 			ent->eax |= HV_MSR_RESET_AVAILABLE;
2733 			ent->eax |= HV_MSR_REFERENCE_TSC_AVAILABLE;
2734 			ent->eax |= HV_ACCESS_FREQUENCY_MSRS;
2735 			ent->eax |= HV_ACCESS_REENLIGHTENMENT;
2736 
2737 			ent->ebx |= HV_POST_MESSAGES;
2738 			ent->ebx |= HV_SIGNAL_EVENTS;
2739 
2740 			ent->edx |= HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE;
2741 			ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
2742 			ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
2743 
2744 			ent->ebx |= HV_DEBUGGING;
2745 			ent->edx |= HV_X64_GUEST_DEBUGGING_AVAILABLE;
2746 			ent->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
2747 			ent->edx |= HV_FEATURE_EXT_GVA_RANGES_FLUSH;
2748 
2749 			/*
2750 			 * Direct Synthetic timers only make sense with in-kernel
2751 			 * LAPIC
2752 			 */
2753 			if (!vcpu || lapic_in_kernel(vcpu))
2754 				ent->edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
2755 
2756 			break;
2757 
2758 		case HYPERV_CPUID_ENLIGHTMENT_INFO:
2759 			ent->eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
2760 			ent->eax |= HV_X64_APIC_ACCESS_RECOMMENDED;
2761 			ent->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED;
2762 			ent->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
2763 			ent->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
2764 			if (evmcs_ver)
2765 				ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;
2766 			if (!cpu_smt_possible())
2767 				ent->eax |= HV_X64_NO_NONARCH_CORESHARING;
2768 
2769 			ent->eax |= HV_DEPRECATING_AEOI_RECOMMENDED;
2770 			/*
2771 			 * Default number of spinlock retry attempts, matches
2772 			 * HyperV 2016.
2773 			 */
2774 			ent->ebx = 0x00000FFF;
2775 
2776 			break;
2777 
2778 		case HYPERV_CPUID_IMPLEMENT_LIMITS:
2779 			/* Maximum number of virtual processors */
2780 			ent->eax = KVM_MAX_VCPUS;
2781 			/*
2782 			 * Maximum number of logical processors, matches
2783 			 * HyperV 2016.
2784 			 */
2785 			ent->ebx = 64;
2786 
2787 			break;
2788 
2789 		case HYPERV_CPUID_NESTED_FEATURES:
2790 			ent->eax = evmcs_ver;
2791 			ent->eax |= HV_X64_NESTED_DIRECT_FLUSH;
2792 			ent->eax |= HV_X64_NESTED_MSR_BITMAP;
2793 			ent->ebx |= HV_X64_NESTED_EVMCS1_PERF_GLOBAL_CTRL;
2794 			break;
2795 
2796 		case HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS:
2797 			memcpy(signature, "Linux KVM Hv", 12);
2798 
2799 			ent->eax = 0;
2800 			ent->ebx = signature[0];
2801 			ent->ecx = signature[1];
2802 			ent->edx = signature[2];
2803 			break;
2804 
2805 		case HYPERV_CPUID_SYNDBG_INTERFACE:
2806 			memcpy(signature, "VS#1\0\0\0\0\0\0\0\0", 12);
2807 			ent->eax = signature[0];
2808 			break;
2809 
2810 		case HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES:
2811 			ent->eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
2812 			break;
2813 
2814 		default:
2815 			break;
2816 		}
2817 	}
2818 
2819 	if (copy_to_user(entries, cpuid_entries,
2820 			 nent * sizeof(struct kvm_cpuid_entry2)))
2821 		return -EFAULT;
2822 
2823 	return 0;
2824 }
2825