xref: /openbmc/linux/arch/x86/kvm/hyperv.c (revision 47010c04)
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 	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 bool kvm_hv_get_assist_page(struct kvm_vcpu *vcpu,
904 			    struct hv_vp_assist_page *assist_page)
905 {
906 	if (!kvm_hv_assist_page_enabled(vcpu))
907 		return false;
908 	return !kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data,
909 				      assist_page, sizeof(*assist_page));
910 }
911 EXPORT_SYMBOL_GPL(kvm_hv_get_assist_page);
912 
913 static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
914 {
915 	struct hv_message *msg = &stimer->msg;
916 	struct hv_timer_message_payload *payload =
917 			(struct hv_timer_message_payload *)&msg->u.payload;
918 
919 	memset(&msg->header, 0, sizeof(msg->header));
920 	msg->header.message_type = HVMSG_TIMER_EXPIRED;
921 	msg->header.payload_size = sizeof(*payload);
922 
923 	payload->timer_index = stimer->index;
924 	payload->expiration_time = 0;
925 	payload->delivery_time = 0;
926 }
927 
928 static void stimer_init(struct kvm_vcpu_hv_stimer *stimer, int timer_index)
929 {
930 	memset(stimer, 0, sizeof(*stimer));
931 	stimer->index = timer_index;
932 	hrtimer_init(&stimer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
933 	stimer->timer.function = stimer_timer_callback;
934 	stimer_prepare_msg(stimer);
935 }
936 
937 static int kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
938 {
939 	struct kvm_vcpu_hv *hv_vcpu;
940 	int i;
941 
942 	hv_vcpu = kzalloc(sizeof(struct kvm_vcpu_hv), GFP_KERNEL_ACCOUNT);
943 	if (!hv_vcpu)
944 		return -ENOMEM;
945 
946 	vcpu->arch.hyperv = hv_vcpu;
947 	hv_vcpu->vcpu = vcpu;
948 
949 	synic_init(&hv_vcpu->synic);
950 
951 	bitmap_zero(hv_vcpu->stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
952 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
953 		stimer_init(&hv_vcpu->stimer[i], i);
954 
955 	hv_vcpu->vp_index = vcpu->vcpu_idx;
956 
957 	return 0;
958 }
959 
960 int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages)
961 {
962 	struct kvm_vcpu_hv_synic *synic;
963 	int r;
964 
965 	if (!to_hv_vcpu(vcpu)) {
966 		r = kvm_hv_vcpu_init(vcpu);
967 		if (r)
968 			return r;
969 	}
970 
971 	synic = to_hv_synic(vcpu);
972 
973 	synic->active = true;
974 	synic->dont_zero_synic_pages = dont_zero_synic_pages;
975 	synic->control = HV_SYNIC_CONTROL_ENABLE;
976 	return 0;
977 }
978 
979 static bool kvm_hv_msr_partition_wide(u32 msr)
980 {
981 	bool r = false;
982 
983 	switch (msr) {
984 	case HV_X64_MSR_GUEST_OS_ID:
985 	case HV_X64_MSR_HYPERCALL:
986 	case HV_X64_MSR_REFERENCE_TSC:
987 	case HV_X64_MSR_TIME_REF_COUNT:
988 	case HV_X64_MSR_CRASH_CTL:
989 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
990 	case HV_X64_MSR_RESET:
991 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
992 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
993 	case HV_X64_MSR_TSC_EMULATION_STATUS:
994 	case HV_X64_MSR_SYNDBG_OPTIONS:
995 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
996 		r = true;
997 		break;
998 	}
999 
1000 	return r;
1001 }
1002 
1003 static int kvm_hv_msr_get_crash_data(struct kvm *kvm, u32 index, u64 *pdata)
1004 {
1005 	struct kvm_hv *hv = to_kvm_hv(kvm);
1006 	size_t size = ARRAY_SIZE(hv->hv_crash_param);
1007 
1008 	if (WARN_ON_ONCE(index >= size))
1009 		return -EINVAL;
1010 
1011 	*pdata = hv->hv_crash_param[array_index_nospec(index, size)];
1012 	return 0;
1013 }
1014 
1015 static int kvm_hv_msr_get_crash_ctl(struct kvm *kvm, u64 *pdata)
1016 {
1017 	struct kvm_hv *hv = to_kvm_hv(kvm);
1018 
1019 	*pdata = hv->hv_crash_ctl;
1020 	return 0;
1021 }
1022 
1023 static int kvm_hv_msr_set_crash_ctl(struct kvm *kvm, u64 data)
1024 {
1025 	struct kvm_hv *hv = to_kvm_hv(kvm);
1026 
1027 	hv->hv_crash_ctl = data & HV_CRASH_CTL_CRASH_NOTIFY;
1028 
1029 	return 0;
1030 }
1031 
1032 static int kvm_hv_msr_set_crash_data(struct kvm *kvm, u32 index, u64 data)
1033 {
1034 	struct kvm_hv *hv = to_kvm_hv(kvm);
1035 	size_t size = ARRAY_SIZE(hv->hv_crash_param);
1036 
1037 	if (WARN_ON_ONCE(index >= size))
1038 		return -EINVAL;
1039 
1040 	hv->hv_crash_param[array_index_nospec(index, size)] = data;
1041 	return 0;
1042 }
1043 
1044 /*
1045  * The kvmclock and Hyper-V TSC page use similar formulas, and converting
1046  * between them is possible:
1047  *
1048  * kvmclock formula:
1049  *    nsec = (ticks - tsc_timestamp) * tsc_to_system_mul * 2^(tsc_shift-32)
1050  *           + system_time
1051  *
1052  * Hyper-V formula:
1053  *    nsec/100 = ticks * scale / 2^64 + offset
1054  *
1055  * When tsc_timestamp = system_time = 0, offset is zero in the Hyper-V formula.
1056  * By dividing the kvmclock formula by 100 and equating what's left we get:
1057  *    ticks * scale / 2^64 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1058  *            scale / 2^64 =         tsc_to_system_mul * 2^(tsc_shift-32) / 100
1059  *            scale        =         tsc_to_system_mul * 2^(32+tsc_shift) / 100
1060  *
1061  * Now expand the kvmclock formula and divide by 100:
1062  *    nsec = ticks * tsc_to_system_mul * 2^(tsc_shift-32)
1063  *           - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32)
1064  *           + system_time
1065  *    nsec/100 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1066  *               - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1067  *               + system_time / 100
1068  *
1069  * Replace tsc_to_system_mul * 2^(tsc_shift-32) / 100 by scale / 2^64:
1070  *    nsec/100 = ticks * scale / 2^64
1071  *               - tsc_timestamp * scale / 2^64
1072  *               + system_time / 100
1073  *
1074  * Equate with the Hyper-V formula so that ticks * scale / 2^64 cancels out:
1075  *    offset = system_time / 100 - tsc_timestamp * scale / 2^64
1076  *
1077  * These two equivalencies are implemented in this function.
1078  */
1079 static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
1080 					struct ms_hyperv_tsc_page *tsc_ref)
1081 {
1082 	u64 max_mul;
1083 
1084 	if (!(hv_clock->flags & PVCLOCK_TSC_STABLE_BIT))
1085 		return false;
1086 
1087 	/*
1088 	 * check if scale would overflow, if so we use the time ref counter
1089 	 *    tsc_to_system_mul * 2^(tsc_shift+32) / 100 >= 2^64
1090 	 *    tsc_to_system_mul / 100 >= 2^(32-tsc_shift)
1091 	 *    tsc_to_system_mul >= 100 * 2^(32-tsc_shift)
1092 	 */
1093 	max_mul = 100ull << (32 - hv_clock->tsc_shift);
1094 	if (hv_clock->tsc_to_system_mul >= max_mul)
1095 		return false;
1096 
1097 	/*
1098 	 * Otherwise compute the scale and offset according to the formulas
1099 	 * derived above.
1100 	 */
1101 	tsc_ref->tsc_scale =
1102 		mul_u64_u32_div(1ULL << (32 + hv_clock->tsc_shift),
1103 				hv_clock->tsc_to_system_mul,
1104 				100);
1105 
1106 	tsc_ref->tsc_offset = hv_clock->system_time;
1107 	do_div(tsc_ref->tsc_offset, 100);
1108 	tsc_ref->tsc_offset -=
1109 		mul_u64_u64_shr(hv_clock->tsc_timestamp, tsc_ref->tsc_scale, 64);
1110 	return true;
1111 }
1112 
1113 /*
1114  * Don't touch TSC page values if the guest has opted for TSC emulation after
1115  * migration. KVM doesn't fully support reenlightenment notifications and TSC
1116  * access emulation and Hyper-V is known to expect the values in TSC page to
1117  * stay constant before TSC access emulation is disabled from guest side
1118  * (HV_X64_MSR_TSC_EMULATION_STATUS). KVM userspace is expected to preserve TSC
1119  * frequency and guest visible TSC value across migration (and prevent it when
1120  * TSC scaling is unsupported).
1121  */
1122 static inline bool tsc_page_update_unsafe(struct kvm_hv *hv)
1123 {
1124 	return (hv->hv_tsc_page_status != HV_TSC_PAGE_GUEST_CHANGED) &&
1125 		hv->hv_tsc_emulation_control;
1126 }
1127 
1128 void kvm_hv_setup_tsc_page(struct kvm *kvm,
1129 			   struct pvclock_vcpu_time_info *hv_clock)
1130 {
1131 	struct kvm_hv *hv = to_kvm_hv(kvm);
1132 	u32 tsc_seq;
1133 	u64 gfn;
1134 
1135 	BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
1136 	BUILD_BUG_ON(offsetof(struct ms_hyperv_tsc_page, tsc_sequence) != 0);
1137 
1138 	mutex_lock(&hv->hv_lock);
1139 
1140 	if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN ||
1141 	    hv->hv_tsc_page_status == HV_TSC_PAGE_SET ||
1142 	    hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET)
1143 		goto out_unlock;
1144 
1145 	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
1146 		goto out_unlock;
1147 
1148 	gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
1149 	/*
1150 	 * Because the TSC parameters only vary when there is a
1151 	 * change in the master clock, do not bother with caching.
1152 	 */
1153 	if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
1154 				    &tsc_seq, sizeof(tsc_seq))))
1155 		goto out_err;
1156 
1157 	if (tsc_seq && tsc_page_update_unsafe(hv)) {
1158 		if (kvm_read_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1159 			goto out_err;
1160 
1161 		hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1162 		goto out_unlock;
1163 	}
1164 
1165 	/*
1166 	 * While we're computing and writing the parameters, force the
1167 	 * guest to use the time reference count MSR.
1168 	 */
1169 	hv->tsc_ref.tsc_sequence = 0;
1170 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1171 			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1172 		goto out_err;
1173 
1174 	if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
1175 		goto out_err;
1176 
1177 	/* Ensure sequence is zero before writing the rest of the struct.  */
1178 	smp_wmb();
1179 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1180 		goto out_err;
1181 
1182 	/*
1183 	 * Now switch to the TSC page mechanism by writing the sequence.
1184 	 */
1185 	tsc_seq++;
1186 	if (tsc_seq == 0xFFFFFFFF || tsc_seq == 0)
1187 		tsc_seq = 1;
1188 
1189 	/* Write the struct entirely before the non-zero sequence.  */
1190 	smp_wmb();
1191 
1192 	hv->tsc_ref.tsc_sequence = tsc_seq;
1193 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1194 			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1195 		goto out_err;
1196 
1197 	hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1198 	goto out_unlock;
1199 
1200 out_err:
1201 	hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN;
1202 out_unlock:
1203 	mutex_unlock(&hv->hv_lock);
1204 }
1205 
1206 void kvm_hv_request_tsc_page_update(struct kvm *kvm)
1207 {
1208 	struct kvm_hv *hv = to_kvm_hv(kvm);
1209 
1210 	mutex_lock(&hv->hv_lock);
1211 
1212 	if (hv->hv_tsc_page_status == HV_TSC_PAGE_SET &&
1213 	    !tsc_page_update_unsafe(hv))
1214 		hv->hv_tsc_page_status = HV_TSC_PAGE_HOST_CHANGED;
1215 
1216 	mutex_unlock(&hv->hv_lock);
1217 }
1218 
1219 static bool hv_check_msr_access(struct kvm_vcpu_hv *hv_vcpu, u32 msr)
1220 {
1221 	if (!hv_vcpu->enforce_cpuid)
1222 		return true;
1223 
1224 	switch (msr) {
1225 	case HV_X64_MSR_GUEST_OS_ID:
1226 	case HV_X64_MSR_HYPERCALL:
1227 		return hv_vcpu->cpuid_cache.features_eax &
1228 			HV_MSR_HYPERCALL_AVAILABLE;
1229 	case HV_X64_MSR_VP_RUNTIME:
1230 		return hv_vcpu->cpuid_cache.features_eax &
1231 			HV_MSR_VP_RUNTIME_AVAILABLE;
1232 	case HV_X64_MSR_TIME_REF_COUNT:
1233 		return hv_vcpu->cpuid_cache.features_eax &
1234 			HV_MSR_TIME_REF_COUNT_AVAILABLE;
1235 	case HV_X64_MSR_VP_INDEX:
1236 		return hv_vcpu->cpuid_cache.features_eax &
1237 			HV_MSR_VP_INDEX_AVAILABLE;
1238 	case HV_X64_MSR_RESET:
1239 		return hv_vcpu->cpuid_cache.features_eax &
1240 			HV_MSR_RESET_AVAILABLE;
1241 	case HV_X64_MSR_REFERENCE_TSC:
1242 		return hv_vcpu->cpuid_cache.features_eax &
1243 			HV_MSR_REFERENCE_TSC_AVAILABLE;
1244 	case HV_X64_MSR_SCONTROL:
1245 	case HV_X64_MSR_SVERSION:
1246 	case HV_X64_MSR_SIEFP:
1247 	case HV_X64_MSR_SIMP:
1248 	case HV_X64_MSR_EOM:
1249 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1250 		return hv_vcpu->cpuid_cache.features_eax &
1251 			HV_MSR_SYNIC_AVAILABLE;
1252 	case HV_X64_MSR_STIMER0_CONFIG:
1253 	case HV_X64_MSR_STIMER1_CONFIG:
1254 	case HV_X64_MSR_STIMER2_CONFIG:
1255 	case HV_X64_MSR_STIMER3_CONFIG:
1256 	case HV_X64_MSR_STIMER0_COUNT:
1257 	case HV_X64_MSR_STIMER1_COUNT:
1258 	case HV_X64_MSR_STIMER2_COUNT:
1259 	case HV_X64_MSR_STIMER3_COUNT:
1260 		return hv_vcpu->cpuid_cache.features_eax &
1261 			HV_MSR_SYNTIMER_AVAILABLE;
1262 	case HV_X64_MSR_EOI:
1263 	case HV_X64_MSR_ICR:
1264 	case HV_X64_MSR_TPR:
1265 	case HV_X64_MSR_VP_ASSIST_PAGE:
1266 		return hv_vcpu->cpuid_cache.features_eax &
1267 			HV_MSR_APIC_ACCESS_AVAILABLE;
1268 		break;
1269 	case HV_X64_MSR_TSC_FREQUENCY:
1270 	case HV_X64_MSR_APIC_FREQUENCY:
1271 		return hv_vcpu->cpuid_cache.features_eax &
1272 			HV_ACCESS_FREQUENCY_MSRS;
1273 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1274 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1275 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1276 		return hv_vcpu->cpuid_cache.features_eax &
1277 			HV_ACCESS_REENLIGHTENMENT;
1278 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1279 	case HV_X64_MSR_CRASH_CTL:
1280 		return hv_vcpu->cpuid_cache.features_edx &
1281 			HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
1282 	case HV_X64_MSR_SYNDBG_OPTIONS:
1283 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1284 		return hv_vcpu->cpuid_cache.features_edx &
1285 			HV_FEATURE_DEBUG_MSRS_AVAILABLE;
1286 	default:
1287 		break;
1288 	}
1289 
1290 	return false;
1291 }
1292 
1293 static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
1294 			     bool host)
1295 {
1296 	struct kvm *kvm = vcpu->kvm;
1297 	struct kvm_hv *hv = to_kvm_hv(kvm);
1298 
1299 	if (unlikely(!host && !hv_check_msr_access(to_hv_vcpu(vcpu), msr)))
1300 		return 1;
1301 
1302 	switch (msr) {
1303 	case HV_X64_MSR_GUEST_OS_ID:
1304 		hv->hv_guest_os_id = data;
1305 		/* setting guest os id to zero disables hypercall page */
1306 		if (!hv->hv_guest_os_id)
1307 			hv->hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
1308 		break;
1309 	case HV_X64_MSR_HYPERCALL: {
1310 		u8 instructions[9];
1311 		int i = 0;
1312 		u64 addr;
1313 
1314 		/* if guest os id is not set hypercall should remain disabled */
1315 		if (!hv->hv_guest_os_id)
1316 			break;
1317 		if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
1318 			hv->hv_hypercall = data;
1319 			break;
1320 		}
1321 
1322 		/*
1323 		 * If Xen and Hyper-V hypercalls are both enabled, disambiguate
1324 		 * the same way Xen itself does, by setting the bit 31 of EAX
1325 		 * which is RsvdZ in the 32-bit Hyper-V hypercall ABI and just
1326 		 * going to be clobbered on 64-bit.
1327 		 */
1328 		if (kvm_xen_hypercall_enabled(kvm)) {
1329 			/* orl $0x80000000, %eax */
1330 			instructions[i++] = 0x0d;
1331 			instructions[i++] = 0x00;
1332 			instructions[i++] = 0x00;
1333 			instructions[i++] = 0x00;
1334 			instructions[i++] = 0x80;
1335 		}
1336 
1337 		/* vmcall/vmmcall */
1338 		static_call(kvm_x86_patch_hypercall)(vcpu, instructions + i);
1339 		i += 3;
1340 
1341 		/* ret */
1342 		((unsigned char *)instructions)[i++] = 0xc3;
1343 
1344 		addr = data & HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_MASK;
1345 		if (kvm_vcpu_write_guest(vcpu, addr, instructions, i))
1346 			return 1;
1347 		hv->hv_hypercall = data;
1348 		break;
1349 	}
1350 	case HV_X64_MSR_REFERENCE_TSC:
1351 		hv->hv_tsc_page = data;
1352 		if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE) {
1353 			if (!host)
1354 				hv->hv_tsc_page_status = HV_TSC_PAGE_GUEST_CHANGED;
1355 			else
1356 				hv->hv_tsc_page_status = HV_TSC_PAGE_HOST_CHANGED;
1357 			kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
1358 		} else {
1359 			hv->hv_tsc_page_status = HV_TSC_PAGE_UNSET;
1360 		}
1361 		break;
1362 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1363 		return kvm_hv_msr_set_crash_data(kvm,
1364 						 msr - HV_X64_MSR_CRASH_P0,
1365 						 data);
1366 	case HV_X64_MSR_CRASH_CTL:
1367 		if (host)
1368 			return kvm_hv_msr_set_crash_ctl(kvm, data);
1369 
1370 		if (data & HV_CRASH_CTL_CRASH_NOTIFY) {
1371 			vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx 0x%llx)\n",
1372 				   hv->hv_crash_param[0],
1373 				   hv->hv_crash_param[1],
1374 				   hv->hv_crash_param[2],
1375 				   hv->hv_crash_param[3],
1376 				   hv->hv_crash_param[4]);
1377 
1378 			/* Send notification about crash to user space */
1379 			kvm_make_request(KVM_REQ_HV_CRASH, vcpu);
1380 		}
1381 		break;
1382 	case HV_X64_MSR_RESET:
1383 		if (data == 1) {
1384 			vcpu_debug(vcpu, "hyper-v reset requested\n");
1385 			kvm_make_request(KVM_REQ_HV_RESET, vcpu);
1386 		}
1387 		break;
1388 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1389 		hv->hv_reenlightenment_control = data;
1390 		break;
1391 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1392 		hv->hv_tsc_emulation_control = data;
1393 		break;
1394 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1395 		if (data && !host)
1396 			return 1;
1397 
1398 		hv->hv_tsc_emulation_status = data;
1399 		break;
1400 	case HV_X64_MSR_TIME_REF_COUNT:
1401 		/* read-only, but still ignore it if host-initiated */
1402 		if (!host)
1403 			return 1;
1404 		break;
1405 	case HV_X64_MSR_SYNDBG_OPTIONS:
1406 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1407 		return syndbg_set_msr(vcpu, msr, data, host);
1408 	default:
1409 		vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
1410 			    msr, data);
1411 		return 1;
1412 	}
1413 	return 0;
1414 }
1415 
1416 /* Calculate cpu time spent by current task in 100ns units */
1417 static u64 current_task_runtime_100ns(void)
1418 {
1419 	u64 utime, stime;
1420 
1421 	task_cputime_adjusted(current, &utime, &stime);
1422 
1423 	return div_u64(utime + stime, 100);
1424 }
1425 
1426 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1427 {
1428 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1429 
1430 	if (unlikely(!host && !hv_check_msr_access(hv_vcpu, msr)))
1431 		return 1;
1432 
1433 	switch (msr) {
1434 	case HV_X64_MSR_VP_INDEX: {
1435 		struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1436 		u32 new_vp_index = (u32)data;
1437 
1438 		if (!host || new_vp_index >= KVM_MAX_VCPUS)
1439 			return 1;
1440 
1441 		if (new_vp_index == hv_vcpu->vp_index)
1442 			return 0;
1443 
1444 		/*
1445 		 * The VP index is initialized to vcpu_index by
1446 		 * kvm_hv_vcpu_postcreate so they initially match.  Now the
1447 		 * VP index is changing, adjust num_mismatched_vp_indexes if
1448 		 * it now matches or no longer matches vcpu_idx.
1449 		 */
1450 		if (hv_vcpu->vp_index == vcpu->vcpu_idx)
1451 			atomic_inc(&hv->num_mismatched_vp_indexes);
1452 		else if (new_vp_index == vcpu->vcpu_idx)
1453 			atomic_dec(&hv->num_mismatched_vp_indexes);
1454 
1455 		hv_vcpu->vp_index = new_vp_index;
1456 		break;
1457 	}
1458 	case HV_X64_MSR_VP_ASSIST_PAGE: {
1459 		u64 gfn;
1460 		unsigned long addr;
1461 
1462 		if (!(data & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE)) {
1463 			hv_vcpu->hv_vapic = data;
1464 			if (kvm_lapic_set_pv_eoi(vcpu, 0, 0))
1465 				return 1;
1466 			break;
1467 		}
1468 		gfn = data >> HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT;
1469 		addr = kvm_vcpu_gfn_to_hva(vcpu, gfn);
1470 		if (kvm_is_error_hva(addr))
1471 			return 1;
1472 
1473 		/*
1474 		 * Clear apic_assist portion of struct hv_vp_assist_page
1475 		 * only, there can be valuable data in the rest which needs
1476 		 * to be preserved e.g. on migration.
1477 		 */
1478 		if (__put_user(0, (u32 __user *)addr))
1479 			return 1;
1480 		hv_vcpu->hv_vapic = data;
1481 		kvm_vcpu_mark_page_dirty(vcpu, gfn);
1482 		if (kvm_lapic_set_pv_eoi(vcpu,
1483 					    gfn_to_gpa(gfn) | KVM_MSR_ENABLED,
1484 					    sizeof(struct hv_vp_assist_page)))
1485 			return 1;
1486 		break;
1487 	}
1488 	case HV_X64_MSR_EOI:
1489 		return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
1490 	case HV_X64_MSR_ICR:
1491 		return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
1492 	case HV_X64_MSR_TPR:
1493 		return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
1494 	case HV_X64_MSR_VP_RUNTIME:
1495 		if (!host)
1496 			return 1;
1497 		hv_vcpu->runtime_offset = data - current_task_runtime_100ns();
1498 		break;
1499 	case HV_X64_MSR_SCONTROL:
1500 	case HV_X64_MSR_SVERSION:
1501 	case HV_X64_MSR_SIEFP:
1502 	case HV_X64_MSR_SIMP:
1503 	case HV_X64_MSR_EOM:
1504 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1505 		return synic_set_msr(to_hv_synic(vcpu), msr, data, host);
1506 	case HV_X64_MSR_STIMER0_CONFIG:
1507 	case HV_X64_MSR_STIMER1_CONFIG:
1508 	case HV_X64_MSR_STIMER2_CONFIG:
1509 	case HV_X64_MSR_STIMER3_CONFIG: {
1510 		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1511 
1512 		return stimer_set_config(to_hv_stimer(vcpu, timer_index),
1513 					 data, host);
1514 	}
1515 	case HV_X64_MSR_STIMER0_COUNT:
1516 	case HV_X64_MSR_STIMER1_COUNT:
1517 	case HV_X64_MSR_STIMER2_COUNT:
1518 	case HV_X64_MSR_STIMER3_COUNT: {
1519 		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1520 
1521 		return stimer_set_count(to_hv_stimer(vcpu, timer_index),
1522 					data, host);
1523 	}
1524 	case HV_X64_MSR_TSC_FREQUENCY:
1525 	case HV_X64_MSR_APIC_FREQUENCY:
1526 		/* read-only, but still ignore it if host-initiated */
1527 		if (!host)
1528 			return 1;
1529 		break;
1530 	default:
1531 		vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
1532 			    msr, data);
1533 		return 1;
1534 	}
1535 
1536 	return 0;
1537 }
1538 
1539 static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1540 			     bool host)
1541 {
1542 	u64 data = 0;
1543 	struct kvm *kvm = vcpu->kvm;
1544 	struct kvm_hv *hv = to_kvm_hv(kvm);
1545 
1546 	if (unlikely(!host && !hv_check_msr_access(to_hv_vcpu(vcpu), msr)))
1547 		return 1;
1548 
1549 	switch (msr) {
1550 	case HV_X64_MSR_GUEST_OS_ID:
1551 		data = hv->hv_guest_os_id;
1552 		break;
1553 	case HV_X64_MSR_HYPERCALL:
1554 		data = hv->hv_hypercall;
1555 		break;
1556 	case HV_X64_MSR_TIME_REF_COUNT:
1557 		data = get_time_ref_counter(kvm);
1558 		break;
1559 	case HV_X64_MSR_REFERENCE_TSC:
1560 		data = hv->hv_tsc_page;
1561 		break;
1562 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1563 		return kvm_hv_msr_get_crash_data(kvm,
1564 						 msr - HV_X64_MSR_CRASH_P0,
1565 						 pdata);
1566 	case HV_X64_MSR_CRASH_CTL:
1567 		return kvm_hv_msr_get_crash_ctl(kvm, pdata);
1568 	case HV_X64_MSR_RESET:
1569 		data = 0;
1570 		break;
1571 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1572 		data = hv->hv_reenlightenment_control;
1573 		break;
1574 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1575 		data = hv->hv_tsc_emulation_control;
1576 		break;
1577 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1578 		data = hv->hv_tsc_emulation_status;
1579 		break;
1580 	case HV_X64_MSR_SYNDBG_OPTIONS:
1581 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1582 		return syndbg_get_msr(vcpu, msr, pdata, host);
1583 	default:
1584 		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1585 		return 1;
1586 	}
1587 
1588 	*pdata = data;
1589 	return 0;
1590 }
1591 
1592 static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1593 			  bool host)
1594 {
1595 	u64 data = 0;
1596 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1597 
1598 	if (unlikely(!host && !hv_check_msr_access(hv_vcpu, msr)))
1599 		return 1;
1600 
1601 	switch (msr) {
1602 	case HV_X64_MSR_VP_INDEX:
1603 		data = hv_vcpu->vp_index;
1604 		break;
1605 	case HV_X64_MSR_EOI:
1606 		return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
1607 	case HV_X64_MSR_ICR:
1608 		return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
1609 	case HV_X64_MSR_TPR:
1610 		return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
1611 	case HV_X64_MSR_VP_ASSIST_PAGE:
1612 		data = hv_vcpu->hv_vapic;
1613 		break;
1614 	case HV_X64_MSR_VP_RUNTIME:
1615 		data = current_task_runtime_100ns() + hv_vcpu->runtime_offset;
1616 		break;
1617 	case HV_X64_MSR_SCONTROL:
1618 	case HV_X64_MSR_SVERSION:
1619 	case HV_X64_MSR_SIEFP:
1620 	case HV_X64_MSR_SIMP:
1621 	case HV_X64_MSR_EOM:
1622 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1623 		return synic_get_msr(to_hv_synic(vcpu), msr, pdata, host);
1624 	case HV_X64_MSR_STIMER0_CONFIG:
1625 	case HV_X64_MSR_STIMER1_CONFIG:
1626 	case HV_X64_MSR_STIMER2_CONFIG:
1627 	case HV_X64_MSR_STIMER3_CONFIG: {
1628 		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1629 
1630 		return stimer_get_config(to_hv_stimer(vcpu, timer_index),
1631 					 pdata);
1632 	}
1633 	case HV_X64_MSR_STIMER0_COUNT:
1634 	case HV_X64_MSR_STIMER1_COUNT:
1635 	case HV_X64_MSR_STIMER2_COUNT:
1636 	case HV_X64_MSR_STIMER3_COUNT: {
1637 		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1638 
1639 		return stimer_get_count(to_hv_stimer(vcpu, timer_index),
1640 					pdata);
1641 	}
1642 	case HV_X64_MSR_TSC_FREQUENCY:
1643 		data = (u64)vcpu->arch.virtual_tsc_khz * 1000;
1644 		break;
1645 	case HV_X64_MSR_APIC_FREQUENCY:
1646 		data = APIC_BUS_FREQUENCY;
1647 		break;
1648 	default:
1649 		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1650 		return 1;
1651 	}
1652 	*pdata = data;
1653 	return 0;
1654 }
1655 
1656 int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1657 {
1658 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1659 
1660 	if (!host && !vcpu->arch.hyperv_enabled)
1661 		return 1;
1662 
1663 	if (!to_hv_vcpu(vcpu)) {
1664 		if (kvm_hv_vcpu_init(vcpu))
1665 			return 1;
1666 	}
1667 
1668 	if (kvm_hv_msr_partition_wide(msr)) {
1669 		int r;
1670 
1671 		mutex_lock(&hv->hv_lock);
1672 		r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
1673 		mutex_unlock(&hv->hv_lock);
1674 		return r;
1675 	} else
1676 		return kvm_hv_set_msr(vcpu, msr, data, host);
1677 }
1678 
1679 int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
1680 {
1681 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1682 
1683 	if (!host && !vcpu->arch.hyperv_enabled)
1684 		return 1;
1685 
1686 	if (!to_hv_vcpu(vcpu)) {
1687 		if (kvm_hv_vcpu_init(vcpu))
1688 			return 1;
1689 	}
1690 
1691 	if (kvm_hv_msr_partition_wide(msr)) {
1692 		int r;
1693 
1694 		mutex_lock(&hv->hv_lock);
1695 		r = kvm_hv_get_msr_pw(vcpu, msr, pdata, host);
1696 		mutex_unlock(&hv->hv_lock);
1697 		return r;
1698 	} else
1699 		return kvm_hv_get_msr(vcpu, msr, pdata, host);
1700 }
1701 
1702 static void sparse_set_to_vcpu_mask(struct kvm *kvm, u64 *sparse_banks,
1703 				    u64 valid_bank_mask, unsigned long *vcpu_mask)
1704 {
1705 	struct kvm_hv *hv = to_kvm_hv(kvm);
1706 	bool has_mismatch = atomic_read(&hv->num_mismatched_vp_indexes);
1707 	u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1708 	struct kvm_vcpu *vcpu;
1709 	int bank, sbank = 0;
1710 	unsigned long i;
1711 	u64 *bitmap;
1712 
1713 	BUILD_BUG_ON(sizeof(vp_bitmap) >
1714 		     sizeof(*vcpu_mask) * BITS_TO_LONGS(KVM_MAX_VCPUS));
1715 
1716 	/*
1717 	 * If vp_index == vcpu_idx for all vCPUs, fill vcpu_mask directly, else
1718 	 * fill a temporary buffer and manually test each vCPU's VP index.
1719 	 */
1720 	if (likely(!has_mismatch))
1721 		bitmap = (u64 *)vcpu_mask;
1722 	else
1723 		bitmap = vp_bitmap;
1724 
1725 	/*
1726 	 * Each set of 64 VPs is packed into sparse_banks, with valid_bank_mask
1727 	 * having a '1' for each bank that exists in sparse_banks.  Sets must
1728 	 * be in ascending order, i.e. bank0..bankN.
1729 	 */
1730 	memset(bitmap, 0, sizeof(vp_bitmap));
1731 	for_each_set_bit(bank, (unsigned long *)&valid_bank_mask,
1732 			 KVM_HV_MAX_SPARSE_VCPU_SET_BITS)
1733 		bitmap[bank] = sparse_banks[sbank++];
1734 
1735 	if (likely(!has_mismatch))
1736 		return;
1737 
1738 	bitmap_zero(vcpu_mask, KVM_MAX_VCPUS);
1739 	kvm_for_each_vcpu(i, vcpu, kvm) {
1740 		if (test_bit(kvm_hv_get_vpindex(vcpu), (unsigned long *)vp_bitmap))
1741 			__set_bit(i, vcpu_mask);
1742 	}
1743 }
1744 
1745 struct kvm_hv_hcall {
1746 	u64 param;
1747 	u64 ingpa;
1748 	u64 outgpa;
1749 	u16 code;
1750 	u16 var_cnt;
1751 	u16 rep_cnt;
1752 	u16 rep_idx;
1753 	bool fast;
1754 	bool rep;
1755 	sse128_t xmm[HV_HYPERCALL_MAX_XMM_REGISTERS];
1756 };
1757 
1758 static u64 kvm_get_sparse_vp_set(struct kvm *kvm, struct kvm_hv_hcall *hc,
1759 				 int consumed_xmm_halves,
1760 				 u64 *sparse_banks, gpa_t offset)
1761 {
1762 	u16 var_cnt;
1763 	int i;
1764 
1765 	if (hc->var_cnt > 64)
1766 		return -EINVAL;
1767 
1768 	/* Ignore banks that cannot possibly contain a legal VP index. */
1769 	var_cnt = min_t(u16, hc->var_cnt, KVM_HV_MAX_SPARSE_VCPU_SET_BITS);
1770 
1771 	if (hc->fast) {
1772 		/*
1773 		 * Each XMM holds two sparse banks, but do not count halves that
1774 		 * have already been consumed for hypercall parameters.
1775 		 */
1776 		if (hc->var_cnt > 2 * HV_HYPERCALL_MAX_XMM_REGISTERS - consumed_xmm_halves)
1777 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1778 		for (i = 0; i < var_cnt; i++) {
1779 			int j = i + consumed_xmm_halves;
1780 			if (j % 2)
1781 				sparse_banks[i] = sse128_hi(hc->xmm[j / 2]);
1782 			else
1783 				sparse_banks[i] = sse128_lo(hc->xmm[j / 2]);
1784 		}
1785 		return 0;
1786 	}
1787 
1788 	return kvm_read_guest(kvm, hc->ingpa + offset, sparse_banks,
1789 			      var_cnt * sizeof(*sparse_banks));
1790 }
1791 
1792 static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
1793 {
1794 	struct kvm *kvm = vcpu->kvm;
1795 	struct hv_tlb_flush_ex flush_ex;
1796 	struct hv_tlb_flush flush;
1797 	DECLARE_BITMAP(vcpu_mask, KVM_MAX_VCPUS);
1798 	u64 valid_bank_mask;
1799 	u64 sparse_banks[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1800 	bool all_cpus;
1801 
1802 	/*
1803 	 * The Hyper-V TLFS doesn't allow more than 64 sparse banks, e.g. the
1804 	 * valid mask is a u64.  Fail the build if KVM's max allowed number of
1805 	 * vCPUs (>4096) would exceed this limit, KVM will additional changes
1806 	 * for Hyper-V support to avoid setting the guest up to fail.
1807 	 */
1808 	BUILD_BUG_ON(KVM_HV_MAX_SPARSE_VCPU_SET_BITS > 64);
1809 
1810 	if (hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST ||
1811 	    hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE) {
1812 		if (hc->fast) {
1813 			flush.address_space = hc->ingpa;
1814 			flush.flags = hc->outgpa;
1815 			flush.processor_mask = sse128_lo(hc->xmm[0]);
1816 		} else {
1817 			if (unlikely(kvm_read_guest(kvm, hc->ingpa,
1818 						    &flush, sizeof(flush))))
1819 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1820 		}
1821 
1822 		trace_kvm_hv_flush_tlb(flush.processor_mask,
1823 				       flush.address_space, flush.flags);
1824 
1825 		valid_bank_mask = BIT_ULL(0);
1826 		sparse_banks[0] = flush.processor_mask;
1827 
1828 		/*
1829 		 * Work around possible WS2012 bug: it sends hypercalls
1830 		 * with processor_mask = 0x0 and HV_FLUSH_ALL_PROCESSORS clear,
1831 		 * while also expecting us to flush something and crashing if
1832 		 * we don't. Let's treat processor_mask == 0 same as
1833 		 * HV_FLUSH_ALL_PROCESSORS.
1834 		 */
1835 		all_cpus = (flush.flags & HV_FLUSH_ALL_PROCESSORS) ||
1836 			flush.processor_mask == 0;
1837 	} else {
1838 		if (hc->fast) {
1839 			flush_ex.address_space = hc->ingpa;
1840 			flush_ex.flags = hc->outgpa;
1841 			memcpy(&flush_ex.hv_vp_set,
1842 			       &hc->xmm[0], sizeof(hc->xmm[0]));
1843 		} else {
1844 			if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush_ex,
1845 						    sizeof(flush_ex))))
1846 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1847 		}
1848 
1849 		trace_kvm_hv_flush_tlb_ex(flush_ex.hv_vp_set.valid_bank_mask,
1850 					  flush_ex.hv_vp_set.format,
1851 					  flush_ex.address_space,
1852 					  flush_ex.flags);
1853 
1854 		valid_bank_mask = flush_ex.hv_vp_set.valid_bank_mask;
1855 		all_cpus = flush_ex.hv_vp_set.format !=
1856 			HV_GENERIC_SET_SPARSE_4K;
1857 
1858 		if (hc->var_cnt != bitmap_weight((unsigned long *)&valid_bank_mask, 64))
1859 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1860 
1861 		if (all_cpus)
1862 			goto do_flush;
1863 
1864 		if (!hc->var_cnt)
1865 			goto ret_success;
1866 
1867 		if (kvm_get_sparse_vp_set(kvm, hc, 2, sparse_banks,
1868 					  offsetof(struct hv_tlb_flush_ex,
1869 						   hv_vp_set.bank_contents)))
1870 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1871 	}
1872 
1873 do_flush:
1874 	/*
1875 	 * vcpu->arch.cr3 may not be up-to-date for running vCPUs so we can't
1876 	 * analyze it here, flush TLB regardless of the specified address space.
1877 	 */
1878 	if (all_cpus) {
1879 		kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH_GUEST);
1880 	} else {
1881 		sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask, vcpu_mask);
1882 
1883 		kvm_make_vcpus_request_mask(kvm, KVM_REQ_TLB_FLUSH_GUEST, vcpu_mask);
1884 	}
1885 
1886 ret_success:
1887 	/* We always do full TLB flush, set 'Reps completed' = 'Rep Count' */
1888 	return (u64)HV_STATUS_SUCCESS |
1889 		((u64)hc->rep_cnt << HV_HYPERCALL_REP_COMP_OFFSET);
1890 }
1891 
1892 static void kvm_send_ipi_to_many(struct kvm *kvm, u32 vector,
1893 				 unsigned long *vcpu_bitmap)
1894 {
1895 	struct kvm_lapic_irq irq = {
1896 		.delivery_mode = APIC_DM_FIXED,
1897 		.vector = vector
1898 	};
1899 	struct kvm_vcpu *vcpu;
1900 	unsigned long i;
1901 
1902 	kvm_for_each_vcpu(i, vcpu, kvm) {
1903 		if (vcpu_bitmap && !test_bit(i, vcpu_bitmap))
1904 			continue;
1905 
1906 		/* We fail only when APIC is disabled */
1907 		kvm_apic_set_irq(vcpu, &irq, NULL);
1908 	}
1909 }
1910 
1911 static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
1912 {
1913 	struct kvm *kvm = vcpu->kvm;
1914 	struct hv_send_ipi_ex send_ipi_ex;
1915 	struct hv_send_ipi send_ipi;
1916 	DECLARE_BITMAP(vcpu_mask, KVM_MAX_VCPUS);
1917 	unsigned long valid_bank_mask;
1918 	u64 sparse_banks[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1919 	u32 vector;
1920 	bool all_cpus;
1921 
1922 	if (hc->code == HVCALL_SEND_IPI) {
1923 		if (!hc->fast) {
1924 			if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi,
1925 						    sizeof(send_ipi))))
1926 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1927 			sparse_banks[0] = send_ipi.cpu_mask;
1928 			vector = send_ipi.vector;
1929 		} else {
1930 			/* 'reserved' part of hv_send_ipi should be 0 */
1931 			if (unlikely(hc->ingpa >> 32 != 0))
1932 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1933 			sparse_banks[0] = hc->outgpa;
1934 			vector = (u32)hc->ingpa;
1935 		}
1936 		all_cpus = false;
1937 		valid_bank_mask = BIT_ULL(0);
1938 
1939 		trace_kvm_hv_send_ipi(vector, sparse_banks[0]);
1940 	} else {
1941 		if (!hc->fast) {
1942 			if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi_ex,
1943 						    sizeof(send_ipi_ex))))
1944 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1945 		} else {
1946 			send_ipi_ex.vector = (u32)hc->ingpa;
1947 			send_ipi_ex.vp_set.format = hc->outgpa;
1948 			send_ipi_ex.vp_set.valid_bank_mask = sse128_lo(hc->xmm[0]);
1949 		}
1950 
1951 		trace_kvm_hv_send_ipi_ex(send_ipi_ex.vector,
1952 					 send_ipi_ex.vp_set.format,
1953 					 send_ipi_ex.vp_set.valid_bank_mask);
1954 
1955 		vector = send_ipi_ex.vector;
1956 		valid_bank_mask = send_ipi_ex.vp_set.valid_bank_mask;
1957 		all_cpus = send_ipi_ex.vp_set.format == HV_GENERIC_SET_ALL;
1958 
1959 		if (hc->var_cnt != bitmap_weight(&valid_bank_mask, 64))
1960 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1961 
1962 		if (all_cpus)
1963 			goto check_and_send_ipi;
1964 
1965 		if (!hc->var_cnt)
1966 			goto ret_success;
1967 
1968 		if (kvm_get_sparse_vp_set(kvm, hc, 1, sparse_banks,
1969 					  offsetof(struct hv_send_ipi_ex,
1970 						   vp_set.bank_contents)))
1971 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1972 	}
1973 
1974 check_and_send_ipi:
1975 	if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR))
1976 		return HV_STATUS_INVALID_HYPERCALL_INPUT;
1977 
1978 	if (all_cpus) {
1979 		kvm_send_ipi_to_many(kvm, vector, NULL);
1980 	} else {
1981 		sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask, vcpu_mask);
1982 
1983 		kvm_send_ipi_to_many(kvm, vector, vcpu_mask);
1984 	}
1985 
1986 ret_success:
1987 	return HV_STATUS_SUCCESS;
1988 }
1989 
1990 void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu)
1991 {
1992 	struct kvm_cpuid_entry2 *entry;
1993 	struct kvm_vcpu_hv *hv_vcpu;
1994 
1995 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_INTERFACE, 0);
1996 	if (entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX) {
1997 		vcpu->arch.hyperv_enabled = true;
1998 	} else {
1999 		vcpu->arch.hyperv_enabled = false;
2000 		return;
2001 	}
2002 
2003 	if (!to_hv_vcpu(vcpu) && kvm_hv_vcpu_init(vcpu))
2004 		return;
2005 
2006 	hv_vcpu = to_hv_vcpu(vcpu);
2007 
2008 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_FEATURES, 0);
2009 	if (entry) {
2010 		hv_vcpu->cpuid_cache.features_eax = entry->eax;
2011 		hv_vcpu->cpuid_cache.features_ebx = entry->ebx;
2012 		hv_vcpu->cpuid_cache.features_edx = entry->edx;
2013 	} else {
2014 		hv_vcpu->cpuid_cache.features_eax = 0;
2015 		hv_vcpu->cpuid_cache.features_ebx = 0;
2016 		hv_vcpu->cpuid_cache.features_edx = 0;
2017 	}
2018 
2019 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_ENLIGHTMENT_INFO, 0);
2020 	if (entry) {
2021 		hv_vcpu->cpuid_cache.enlightenments_eax = entry->eax;
2022 		hv_vcpu->cpuid_cache.enlightenments_ebx = entry->ebx;
2023 	} else {
2024 		hv_vcpu->cpuid_cache.enlightenments_eax = 0;
2025 		hv_vcpu->cpuid_cache.enlightenments_ebx = 0;
2026 	}
2027 
2028 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES, 0);
2029 	if (entry)
2030 		hv_vcpu->cpuid_cache.syndbg_cap_eax = entry->eax;
2031 	else
2032 		hv_vcpu->cpuid_cache.syndbg_cap_eax = 0;
2033 }
2034 
2035 int kvm_hv_set_enforce_cpuid(struct kvm_vcpu *vcpu, bool enforce)
2036 {
2037 	struct kvm_vcpu_hv *hv_vcpu;
2038 	int ret = 0;
2039 
2040 	if (!to_hv_vcpu(vcpu)) {
2041 		if (enforce) {
2042 			ret = kvm_hv_vcpu_init(vcpu);
2043 			if (ret)
2044 				return ret;
2045 		} else {
2046 			return 0;
2047 		}
2048 	}
2049 
2050 	hv_vcpu = to_hv_vcpu(vcpu);
2051 	hv_vcpu->enforce_cpuid = enforce;
2052 
2053 	return ret;
2054 }
2055 
2056 static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
2057 {
2058 	bool longmode;
2059 
2060 	longmode = is_64_bit_hypercall(vcpu);
2061 	if (longmode)
2062 		kvm_rax_write(vcpu, result);
2063 	else {
2064 		kvm_rdx_write(vcpu, result >> 32);
2065 		kvm_rax_write(vcpu, result & 0xffffffff);
2066 	}
2067 }
2068 
2069 static int kvm_hv_hypercall_complete(struct kvm_vcpu *vcpu, u64 result)
2070 {
2071 	trace_kvm_hv_hypercall_done(result);
2072 	kvm_hv_hypercall_set_result(vcpu, result);
2073 	++vcpu->stat.hypercalls;
2074 	return kvm_skip_emulated_instruction(vcpu);
2075 }
2076 
2077 static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
2078 {
2079 	return kvm_hv_hypercall_complete(vcpu, vcpu->run->hyperv.u.hcall.result);
2080 }
2081 
2082 static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
2083 {
2084 	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
2085 	struct eventfd_ctx *eventfd;
2086 
2087 	if (unlikely(!hc->fast)) {
2088 		int ret;
2089 		gpa_t gpa = hc->ingpa;
2090 
2091 		if ((gpa & (__alignof__(hc->ingpa) - 1)) ||
2092 		    offset_in_page(gpa) + sizeof(hc->ingpa) > PAGE_SIZE)
2093 			return HV_STATUS_INVALID_ALIGNMENT;
2094 
2095 		ret = kvm_vcpu_read_guest(vcpu, gpa,
2096 					  &hc->ingpa, sizeof(hc->ingpa));
2097 		if (ret < 0)
2098 			return HV_STATUS_INVALID_ALIGNMENT;
2099 	}
2100 
2101 	/*
2102 	 * Per spec, bits 32-47 contain the extra "flag number".  However, we
2103 	 * have no use for it, and in all known usecases it is zero, so just
2104 	 * report lookup failure if it isn't.
2105 	 */
2106 	if (hc->ingpa & 0xffff00000000ULL)
2107 		return HV_STATUS_INVALID_PORT_ID;
2108 	/* remaining bits are reserved-zero */
2109 	if (hc->ingpa & ~KVM_HYPERV_CONN_ID_MASK)
2110 		return HV_STATUS_INVALID_HYPERCALL_INPUT;
2111 
2112 	/* the eventfd is protected by vcpu->kvm->srcu, but conn_to_evt isn't */
2113 	rcu_read_lock();
2114 	eventfd = idr_find(&hv->conn_to_evt, hc->ingpa);
2115 	rcu_read_unlock();
2116 	if (!eventfd)
2117 		return HV_STATUS_INVALID_PORT_ID;
2118 
2119 	eventfd_signal(eventfd, 1);
2120 	return HV_STATUS_SUCCESS;
2121 }
2122 
2123 static bool is_xmm_fast_hypercall(struct kvm_hv_hcall *hc)
2124 {
2125 	switch (hc->code) {
2126 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2127 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2128 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2129 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2130 	case HVCALL_SEND_IPI_EX:
2131 		return true;
2132 	}
2133 
2134 	return false;
2135 }
2136 
2137 static void kvm_hv_hypercall_read_xmm(struct kvm_hv_hcall *hc)
2138 {
2139 	int reg;
2140 
2141 	kvm_fpu_get();
2142 	for (reg = 0; reg < HV_HYPERCALL_MAX_XMM_REGISTERS; reg++)
2143 		_kvm_read_sse_reg(reg, &hc->xmm[reg]);
2144 	kvm_fpu_put();
2145 }
2146 
2147 static bool hv_check_hypercall_access(struct kvm_vcpu_hv *hv_vcpu, u16 code)
2148 {
2149 	if (!hv_vcpu->enforce_cpuid)
2150 		return true;
2151 
2152 	switch (code) {
2153 	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
2154 		return hv_vcpu->cpuid_cache.enlightenments_ebx &&
2155 			hv_vcpu->cpuid_cache.enlightenments_ebx != U32_MAX;
2156 	case HVCALL_POST_MESSAGE:
2157 		return hv_vcpu->cpuid_cache.features_ebx & HV_POST_MESSAGES;
2158 	case HVCALL_SIGNAL_EVENT:
2159 		return hv_vcpu->cpuid_cache.features_ebx & HV_SIGNAL_EVENTS;
2160 	case HVCALL_POST_DEBUG_DATA:
2161 	case HVCALL_RETRIEVE_DEBUG_DATA:
2162 	case HVCALL_RESET_DEBUG_SESSION:
2163 		/*
2164 		 * Return 'true' when SynDBG is disabled so the resulting code
2165 		 * will be HV_STATUS_INVALID_HYPERCALL_CODE.
2166 		 */
2167 		return !kvm_hv_is_syndbg_enabled(hv_vcpu->vcpu) ||
2168 			hv_vcpu->cpuid_cache.features_ebx & HV_DEBUGGING;
2169 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2170 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2171 		if (!(hv_vcpu->cpuid_cache.enlightenments_eax &
2172 		      HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
2173 			return false;
2174 		fallthrough;
2175 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2176 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2177 		return hv_vcpu->cpuid_cache.enlightenments_eax &
2178 			HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
2179 	case HVCALL_SEND_IPI_EX:
2180 		if (!(hv_vcpu->cpuid_cache.enlightenments_eax &
2181 		      HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
2182 			return false;
2183 		fallthrough;
2184 	case HVCALL_SEND_IPI:
2185 		return hv_vcpu->cpuid_cache.enlightenments_eax &
2186 			HV_X64_CLUSTER_IPI_RECOMMENDED;
2187 	default:
2188 		break;
2189 	}
2190 
2191 	return true;
2192 }
2193 
2194 int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
2195 {
2196 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
2197 	struct kvm_hv_hcall hc;
2198 	u64 ret = HV_STATUS_SUCCESS;
2199 
2200 	/*
2201 	 * hypercall generates UD from non zero cpl and real mode
2202 	 * per HYPER-V spec
2203 	 */
2204 	if (static_call(kvm_x86_get_cpl)(vcpu) != 0 || !is_protmode(vcpu)) {
2205 		kvm_queue_exception(vcpu, UD_VECTOR);
2206 		return 1;
2207 	}
2208 
2209 #ifdef CONFIG_X86_64
2210 	if (is_64_bit_hypercall(vcpu)) {
2211 		hc.param = kvm_rcx_read(vcpu);
2212 		hc.ingpa = kvm_rdx_read(vcpu);
2213 		hc.outgpa = kvm_r8_read(vcpu);
2214 	} else
2215 #endif
2216 	{
2217 		hc.param = ((u64)kvm_rdx_read(vcpu) << 32) |
2218 			    (kvm_rax_read(vcpu) & 0xffffffff);
2219 		hc.ingpa = ((u64)kvm_rbx_read(vcpu) << 32) |
2220 			    (kvm_rcx_read(vcpu) & 0xffffffff);
2221 		hc.outgpa = ((u64)kvm_rdi_read(vcpu) << 32) |
2222 			     (kvm_rsi_read(vcpu) & 0xffffffff);
2223 	}
2224 
2225 	hc.code = hc.param & 0xffff;
2226 	hc.var_cnt = (hc.param & HV_HYPERCALL_VARHEAD_MASK) >> HV_HYPERCALL_VARHEAD_OFFSET;
2227 	hc.fast = !!(hc.param & HV_HYPERCALL_FAST_BIT);
2228 	hc.rep_cnt = (hc.param >> HV_HYPERCALL_REP_COMP_OFFSET) & 0xfff;
2229 	hc.rep_idx = (hc.param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff;
2230 	hc.rep = !!(hc.rep_cnt || hc.rep_idx);
2231 
2232 	trace_kvm_hv_hypercall(hc.code, hc.fast, hc.var_cnt, hc.rep_cnt,
2233 			       hc.rep_idx, hc.ingpa, hc.outgpa);
2234 
2235 	if (unlikely(!hv_check_hypercall_access(hv_vcpu, hc.code))) {
2236 		ret = HV_STATUS_ACCESS_DENIED;
2237 		goto hypercall_complete;
2238 	}
2239 
2240 	if (unlikely(hc.param & HV_HYPERCALL_RSVD_MASK)) {
2241 		ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2242 		goto hypercall_complete;
2243 	}
2244 
2245 	if (hc.fast && is_xmm_fast_hypercall(&hc)) {
2246 		if (unlikely(hv_vcpu->enforce_cpuid &&
2247 			     !(hv_vcpu->cpuid_cache.features_edx &
2248 			       HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE))) {
2249 			kvm_queue_exception(vcpu, UD_VECTOR);
2250 			return 1;
2251 		}
2252 
2253 		kvm_hv_hypercall_read_xmm(&hc);
2254 	}
2255 
2256 	switch (hc.code) {
2257 	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
2258 		if (unlikely(hc.rep || hc.var_cnt)) {
2259 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2260 			break;
2261 		}
2262 		kvm_vcpu_on_spin(vcpu, true);
2263 		break;
2264 	case HVCALL_SIGNAL_EVENT:
2265 		if (unlikely(hc.rep || hc.var_cnt)) {
2266 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2267 			break;
2268 		}
2269 		ret = kvm_hvcall_signal_event(vcpu, &hc);
2270 		if (ret != HV_STATUS_INVALID_PORT_ID)
2271 			break;
2272 		fallthrough;	/* maybe userspace knows this conn_id */
2273 	case HVCALL_POST_MESSAGE:
2274 		/* don't bother userspace if it has no way to handle it */
2275 		if (unlikely(hc.rep || hc.var_cnt || !to_hv_synic(vcpu)->active)) {
2276 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2277 			break;
2278 		}
2279 		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
2280 		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
2281 		vcpu->run->hyperv.u.hcall.input = hc.param;
2282 		vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
2283 		vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
2284 		vcpu->arch.complete_userspace_io =
2285 				kvm_hv_hypercall_complete_userspace;
2286 		return 0;
2287 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2288 		if (unlikely(hc.var_cnt)) {
2289 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2290 			break;
2291 		}
2292 		fallthrough;
2293 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2294 		if (unlikely(!hc.rep_cnt || hc.rep_idx)) {
2295 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2296 			break;
2297 		}
2298 		ret = kvm_hv_flush_tlb(vcpu, &hc);
2299 		break;
2300 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2301 		if (unlikely(hc.var_cnt)) {
2302 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2303 			break;
2304 		}
2305 		fallthrough;
2306 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2307 		if (unlikely(hc.rep)) {
2308 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2309 			break;
2310 		}
2311 		ret = kvm_hv_flush_tlb(vcpu, &hc);
2312 		break;
2313 	case HVCALL_SEND_IPI:
2314 		if (unlikely(hc.var_cnt)) {
2315 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2316 			break;
2317 		}
2318 		fallthrough;
2319 	case HVCALL_SEND_IPI_EX:
2320 		if (unlikely(hc.rep)) {
2321 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2322 			break;
2323 		}
2324 		ret = kvm_hv_send_ipi(vcpu, &hc);
2325 		break;
2326 	case HVCALL_POST_DEBUG_DATA:
2327 	case HVCALL_RETRIEVE_DEBUG_DATA:
2328 		if (unlikely(hc.fast)) {
2329 			ret = HV_STATUS_INVALID_PARAMETER;
2330 			break;
2331 		}
2332 		fallthrough;
2333 	case HVCALL_RESET_DEBUG_SESSION: {
2334 		struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
2335 
2336 		if (!kvm_hv_is_syndbg_enabled(vcpu)) {
2337 			ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2338 			break;
2339 		}
2340 
2341 		if (!(syndbg->options & HV_X64_SYNDBG_OPTION_USE_HCALLS)) {
2342 			ret = HV_STATUS_OPERATION_DENIED;
2343 			break;
2344 		}
2345 		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
2346 		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
2347 		vcpu->run->hyperv.u.hcall.input = hc.param;
2348 		vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
2349 		vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
2350 		vcpu->arch.complete_userspace_io =
2351 				kvm_hv_hypercall_complete_userspace;
2352 		return 0;
2353 	}
2354 	default:
2355 		ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2356 		break;
2357 	}
2358 
2359 hypercall_complete:
2360 	return kvm_hv_hypercall_complete(vcpu, ret);
2361 }
2362 
2363 void kvm_hv_init_vm(struct kvm *kvm)
2364 {
2365 	struct kvm_hv *hv = to_kvm_hv(kvm);
2366 
2367 	mutex_init(&hv->hv_lock);
2368 	idr_init(&hv->conn_to_evt);
2369 }
2370 
2371 void kvm_hv_destroy_vm(struct kvm *kvm)
2372 {
2373 	struct kvm_hv *hv = to_kvm_hv(kvm);
2374 	struct eventfd_ctx *eventfd;
2375 	int i;
2376 
2377 	idr_for_each_entry(&hv->conn_to_evt, eventfd, i)
2378 		eventfd_ctx_put(eventfd);
2379 	idr_destroy(&hv->conn_to_evt);
2380 }
2381 
2382 static int kvm_hv_eventfd_assign(struct kvm *kvm, u32 conn_id, int fd)
2383 {
2384 	struct kvm_hv *hv = to_kvm_hv(kvm);
2385 	struct eventfd_ctx *eventfd;
2386 	int ret;
2387 
2388 	eventfd = eventfd_ctx_fdget(fd);
2389 	if (IS_ERR(eventfd))
2390 		return PTR_ERR(eventfd);
2391 
2392 	mutex_lock(&hv->hv_lock);
2393 	ret = idr_alloc(&hv->conn_to_evt, eventfd, conn_id, conn_id + 1,
2394 			GFP_KERNEL_ACCOUNT);
2395 	mutex_unlock(&hv->hv_lock);
2396 
2397 	if (ret >= 0)
2398 		return 0;
2399 
2400 	if (ret == -ENOSPC)
2401 		ret = -EEXIST;
2402 	eventfd_ctx_put(eventfd);
2403 	return ret;
2404 }
2405 
2406 static int kvm_hv_eventfd_deassign(struct kvm *kvm, u32 conn_id)
2407 {
2408 	struct kvm_hv *hv = to_kvm_hv(kvm);
2409 	struct eventfd_ctx *eventfd;
2410 
2411 	mutex_lock(&hv->hv_lock);
2412 	eventfd = idr_remove(&hv->conn_to_evt, conn_id);
2413 	mutex_unlock(&hv->hv_lock);
2414 
2415 	if (!eventfd)
2416 		return -ENOENT;
2417 
2418 	synchronize_srcu(&kvm->srcu);
2419 	eventfd_ctx_put(eventfd);
2420 	return 0;
2421 }
2422 
2423 int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args)
2424 {
2425 	if ((args->flags & ~KVM_HYPERV_EVENTFD_DEASSIGN) ||
2426 	    (args->conn_id & ~KVM_HYPERV_CONN_ID_MASK))
2427 		return -EINVAL;
2428 
2429 	if (args->flags == KVM_HYPERV_EVENTFD_DEASSIGN)
2430 		return kvm_hv_eventfd_deassign(kvm, args->conn_id);
2431 	return kvm_hv_eventfd_assign(kvm, args->conn_id, args->fd);
2432 }
2433 
2434 int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
2435 		     struct kvm_cpuid_entry2 __user *entries)
2436 {
2437 	uint16_t evmcs_ver = 0;
2438 	struct kvm_cpuid_entry2 cpuid_entries[] = {
2439 		{ .function = HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS },
2440 		{ .function = HYPERV_CPUID_INTERFACE },
2441 		{ .function = HYPERV_CPUID_VERSION },
2442 		{ .function = HYPERV_CPUID_FEATURES },
2443 		{ .function = HYPERV_CPUID_ENLIGHTMENT_INFO },
2444 		{ .function = HYPERV_CPUID_IMPLEMENT_LIMITS },
2445 		{ .function = HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS },
2446 		{ .function = HYPERV_CPUID_SYNDBG_INTERFACE },
2447 		{ .function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES	},
2448 		{ .function = HYPERV_CPUID_NESTED_FEATURES },
2449 	};
2450 	int i, nent = ARRAY_SIZE(cpuid_entries);
2451 
2452 	if (kvm_x86_ops.nested_ops->get_evmcs_version)
2453 		evmcs_ver = kvm_x86_ops.nested_ops->get_evmcs_version(vcpu);
2454 
2455 	if (cpuid->nent < nent)
2456 		return -E2BIG;
2457 
2458 	if (cpuid->nent > nent)
2459 		cpuid->nent = nent;
2460 
2461 	for (i = 0; i < nent; i++) {
2462 		struct kvm_cpuid_entry2 *ent = &cpuid_entries[i];
2463 		u32 signature[3];
2464 
2465 		switch (ent->function) {
2466 		case HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS:
2467 			memcpy(signature, "Linux KVM Hv", 12);
2468 
2469 			ent->eax = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES;
2470 			ent->ebx = signature[0];
2471 			ent->ecx = signature[1];
2472 			ent->edx = signature[2];
2473 			break;
2474 
2475 		case HYPERV_CPUID_INTERFACE:
2476 			ent->eax = HYPERV_CPUID_SIGNATURE_EAX;
2477 			break;
2478 
2479 		case HYPERV_CPUID_VERSION:
2480 			/*
2481 			 * We implement some Hyper-V 2016 functions so let's use
2482 			 * this version.
2483 			 */
2484 			ent->eax = 0x00003839;
2485 			ent->ebx = 0x000A0000;
2486 			break;
2487 
2488 		case HYPERV_CPUID_FEATURES:
2489 			ent->eax |= HV_MSR_VP_RUNTIME_AVAILABLE;
2490 			ent->eax |= HV_MSR_TIME_REF_COUNT_AVAILABLE;
2491 			ent->eax |= HV_MSR_SYNIC_AVAILABLE;
2492 			ent->eax |= HV_MSR_SYNTIMER_AVAILABLE;
2493 			ent->eax |= HV_MSR_APIC_ACCESS_AVAILABLE;
2494 			ent->eax |= HV_MSR_HYPERCALL_AVAILABLE;
2495 			ent->eax |= HV_MSR_VP_INDEX_AVAILABLE;
2496 			ent->eax |= HV_MSR_RESET_AVAILABLE;
2497 			ent->eax |= HV_MSR_REFERENCE_TSC_AVAILABLE;
2498 			ent->eax |= HV_ACCESS_FREQUENCY_MSRS;
2499 			ent->eax |= HV_ACCESS_REENLIGHTENMENT;
2500 
2501 			ent->ebx |= HV_POST_MESSAGES;
2502 			ent->ebx |= HV_SIGNAL_EVENTS;
2503 
2504 			ent->edx |= HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE;
2505 			ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
2506 			ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
2507 
2508 			ent->ebx |= HV_DEBUGGING;
2509 			ent->edx |= HV_X64_GUEST_DEBUGGING_AVAILABLE;
2510 			ent->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
2511 
2512 			/*
2513 			 * Direct Synthetic timers only make sense with in-kernel
2514 			 * LAPIC
2515 			 */
2516 			if (!vcpu || lapic_in_kernel(vcpu))
2517 				ent->edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
2518 
2519 			break;
2520 
2521 		case HYPERV_CPUID_ENLIGHTMENT_INFO:
2522 			ent->eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
2523 			ent->eax |= HV_X64_APIC_ACCESS_RECOMMENDED;
2524 			ent->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED;
2525 			ent->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
2526 			ent->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
2527 			if (evmcs_ver)
2528 				ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;
2529 			if (!cpu_smt_possible())
2530 				ent->eax |= HV_X64_NO_NONARCH_CORESHARING;
2531 
2532 			ent->eax |= HV_DEPRECATING_AEOI_RECOMMENDED;
2533 			/*
2534 			 * Default number of spinlock retry attempts, matches
2535 			 * HyperV 2016.
2536 			 */
2537 			ent->ebx = 0x00000FFF;
2538 
2539 			break;
2540 
2541 		case HYPERV_CPUID_IMPLEMENT_LIMITS:
2542 			/* Maximum number of virtual processors */
2543 			ent->eax = KVM_MAX_VCPUS;
2544 			/*
2545 			 * Maximum number of logical processors, matches
2546 			 * HyperV 2016.
2547 			 */
2548 			ent->ebx = 64;
2549 
2550 			break;
2551 
2552 		case HYPERV_CPUID_NESTED_FEATURES:
2553 			ent->eax = evmcs_ver;
2554 			ent->eax |= HV_X64_NESTED_MSR_BITMAP;
2555 
2556 			break;
2557 
2558 		case HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS:
2559 			memcpy(signature, "Linux KVM Hv", 12);
2560 
2561 			ent->eax = 0;
2562 			ent->ebx = signature[0];
2563 			ent->ecx = signature[1];
2564 			ent->edx = signature[2];
2565 			break;
2566 
2567 		case HYPERV_CPUID_SYNDBG_INTERFACE:
2568 			memcpy(signature, "VS#1\0\0\0\0\0\0\0\0", 12);
2569 			ent->eax = signature[0];
2570 			break;
2571 
2572 		case HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES:
2573 			ent->eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
2574 			break;
2575 
2576 		default:
2577 			break;
2578 		}
2579 	}
2580 
2581 	if (copy_to_user(entries, cpuid_entries,
2582 			 nent * sizeof(struct kvm_cpuid_entry2)))
2583 		return -EFAULT;
2584 
2585 	return 0;
2586 }
2587