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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 
27 #include <linux/cpu.h>
28 #include <linux/kvm_host.h>
29 #include <linux/highmem.h>
30 #include <linux/sched/cputime.h>
31 #include <linux/eventfd.h>
32 
33 #include <asm/apicdef.h>
34 #include <trace/events/kvm.h>
35 
36 #include "trace.h"
37 #include "irq.h"
38 
39 #define KVM_HV_MAX_SPARSE_VCPU_SET_BITS DIV_ROUND_UP(KVM_MAX_VCPUS, 64)
40 
41 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
42 				bool vcpu_kick);
43 
synic_read_sint(struct kvm_vcpu_hv_synic * synic,int sint)44 static inline u64 synic_read_sint(struct kvm_vcpu_hv_synic *synic, int sint)
45 {
46 	return atomic64_read(&synic->sint[sint]);
47 }
48 
synic_get_sint_vector(u64 sint_value)49 static inline int synic_get_sint_vector(u64 sint_value)
50 {
51 	if (sint_value & HV_SYNIC_SINT_MASKED)
52 		return -1;
53 	return sint_value & HV_SYNIC_SINT_VECTOR_MASK;
54 }
55 
synic_has_vector_connected(struct kvm_vcpu_hv_synic * synic,int vector)56 static bool synic_has_vector_connected(struct kvm_vcpu_hv_synic *synic,
57 				      int vector)
58 {
59 	int i;
60 
61 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
62 		if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
63 			return true;
64 	}
65 	return false;
66 }
67 
synic_has_vector_auto_eoi(struct kvm_vcpu_hv_synic * synic,int vector)68 static bool synic_has_vector_auto_eoi(struct kvm_vcpu_hv_synic *synic,
69 				     int vector)
70 {
71 	int i;
72 	u64 sint_value;
73 
74 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
75 		sint_value = synic_read_sint(synic, i);
76 		if (synic_get_sint_vector(sint_value) == vector &&
77 		    sint_value & HV_SYNIC_SINT_AUTO_EOI)
78 			return true;
79 	}
80 	return false;
81 }
82 
synic_update_vector(struct kvm_vcpu_hv_synic * synic,int vector)83 static void synic_update_vector(struct kvm_vcpu_hv_synic *synic,
84 				int vector)
85 {
86 	if (vector < HV_SYNIC_FIRST_VALID_VECTOR)
87 		return;
88 
89 	if (synic_has_vector_connected(synic, vector))
90 		__set_bit(vector, synic->vec_bitmap);
91 	else
92 		__clear_bit(vector, synic->vec_bitmap);
93 
94 	if (synic_has_vector_auto_eoi(synic, vector))
95 		__set_bit(vector, synic->auto_eoi_bitmap);
96 	else
97 		__clear_bit(vector, synic->auto_eoi_bitmap);
98 }
99 
synic_set_sint(struct kvm_vcpu_hv_synic * synic,int sint,u64 data,bool host)100 static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint,
101 			  u64 data, bool host)
102 {
103 	int vector, old_vector;
104 	bool masked;
105 
106 	vector = data & HV_SYNIC_SINT_VECTOR_MASK;
107 	masked = data & HV_SYNIC_SINT_MASKED;
108 
109 	/*
110 	 * Valid vectors are 16-255, however, nested Hyper-V attempts to write
111 	 * default '0x10000' value on boot and this should not #GP. We need to
112 	 * allow zero-initing the register from host as well.
113 	 */
114 	if (vector < HV_SYNIC_FIRST_VALID_VECTOR && !host && !masked)
115 		return 1;
116 	/*
117 	 * Guest may configure multiple SINTs to use the same vector, so
118 	 * we maintain a bitmap of vectors handled by synic, and a
119 	 * bitmap of vectors with auto-eoi behavior.  The bitmaps are
120 	 * updated here, and atomically queried on fast paths.
121 	 */
122 	old_vector = synic_read_sint(synic, sint) & HV_SYNIC_SINT_VECTOR_MASK;
123 
124 	atomic64_set(&synic->sint[sint], data);
125 
126 	synic_update_vector(synic, old_vector);
127 
128 	synic_update_vector(synic, vector);
129 
130 	/* Load SynIC vectors into EOI exit bitmap */
131 	kvm_make_request(KVM_REQ_SCAN_IOAPIC, synic_to_vcpu(synic));
132 	return 0;
133 }
134 
get_vcpu_by_vpidx(struct kvm * kvm,u32 vpidx)135 static struct kvm_vcpu *get_vcpu_by_vpidx(struct kvm *kvm, u32 vpidx)
136 {
137 	struct kvm_vcpu *vcpu = NULL;
138 	int i;
139 
140 	if (vpidx >= KVM_MAX_VCPUS)
141 		return NULL;
142 
143 	vcpu = kvm_get_vcpu(kvm, vpidx);
144 	if (vcpu && vcpu_to_hv_vcpu(vcpu)->vp_index == vpidx)
145 		return vcpu;
146 	kvm_for_each_vcpu(i, vcpu, kvm)
147 		if (vcpu_to_hv_vcpu(vcpu)->vp_index == vpidx)
148 			return vcpu;
149 	return NULL;
150 }
151 
synic_get(struct kvm * kvm,u32 vpidx)152 static struct kvm_vcpu_hv_synic *synic_get(struct kvm *kvm, u32 vpidx)
153 {
154 	struct kvm_vcpu *vcpu;
155 	struct kvm_vcpu_hv_synic *synic;
156 
157 	vcpu = get_vcpu_by_vpidx(kvm, vpidx);
158 	if (!vcpu)
159 		return NULL;
160 	synic = vcpu_to_synic(vcpu);
161 	return (synic->active) ? synic : NULL;
162 }
163 
kvm_hv_notify_acked_sint(struct kvm_vcpu * vcpu,u32 sint)164 static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
165 {
166 	struct kvm *kvm = vcpu->kvm;
167 	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
168 	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
169 	struct kvm_vcpu_hv_stimer *stimer;
170 	int gsi, idx;
171 
172 	trace_kvm_hv_notify_acked_sint(vcpu->vcpu_id, sint);
173 
174 	/* Try to deliver pending Hyper-V SynIC timers messages */
175 	for (idx = 0; idx < ARRAY_SIZE(hv_vcpu->stimer); idx++) {
176 		stimer = &hv_vcpu->stimer[idx];
177 		if (stimer->msg_pending && stimer->config.enable &&
178 		    !stimer->config.direct_mode &&
179 		    stimer->config.sintx == sint)
180 			stimer_mark_pending(stimer, false);
181 	}
182 
183 	idx = srcu_read_lock(&kvm->irq_srcu);
184 	gsi = atomic_read(&synic->sint_to_gsi[sint]);
185 	if (gsi != -1)
186 		kvm_notify_acked_gsi(kvm, gsi);
187 	srcu_read_unlock(&kvm->irq_srcu, idx);
188 }
189 
synic_exit(struct kvm_vcpu_hv_synic * synic,u32 msr)190 static void synic_exit(struct kvm_vcpu_hv_synic *synic, u32 msr)
191 {
192 	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
193 	struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
194 
195 	hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNIC;
196 	hv_vcpu->exit.u.synic.msr = msr;
197 	hv_vcpu->exit.u.synic.control = synic->control;
198 	hv_vcpu->exit.u.synic.evt_page = synic->evt_page;
199 	hv_vcpu->exit.u.synic.msg_page = synic->msg_page;
200 
201 	kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
202 }
203 
synic_set_msr(struct kvm_vcpu_hv_synic * synic,u32 msr,u64 data,bool host)204 static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
205 			 u32 msr, u64 data, bool host)
206 {
207 	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
208 	int ret;
209 
210 	if (!synic->active && (!host || data))
211 		return 1;
212 
213 	trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host);
214 
215 	ret = 0;
216 	switch (msr) {
217 	case HV_X64_MSR_SCONTROL:
218 		synic->control = data;
219 		if (!host)
220 			synic_exit(synic, msr);
221 		break;
222 	case HV_X64_MSR_SVERSION:
223 		if (!host) {
224 			ret = 1;
225 			break;
226 		}
227 		synic->version = data;
228 		break;
229 	case HV_X64_MSR_SIEFP:
230 		if ((data & HV_SYNIC_SIEFP_ENABLE) && !host &&
231 		    !synic->dont_zero_synic_pages)
232 			if (kvm_clear_guest(vcpu->kvm,
233 					    data & PAGE_MASK, PAGE_SIZE)) {
234 				ret = 1;
235 				break;
236 			}
237 		synic->evt_page = data;
238 		if (!host)
239 			synic_exit(synic, msr);
240 		break;
241 	case HV_X64_MSR_SIMP:
242 		if ((data & HV_SYNIC_SIMP_ENABLE) && !host &&
243 		    !synic->dont_zero_synic_pages)
244 			if (kvm_clear_guest(vcpu->kvm,
245 					    data & PAGE_MASK, PAGE_SIZE)) {
246 				ret = 1;
247 				break;
248 			}
249 		synic->msg_page = data;
250 		if (!host)
251 			synic_exit(synic, msr);
252 		break;
253 	case HV_X64_MSR_EOM: {
254 		int i;
255 
256 		if (!synic->active)
257 			break;
258 
259 		for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
260 			kvm_hv_notify_acked_sint(vcpu, i);
261 		break;
262 	}
263 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
264 		ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data, host);
265 		break;
266 	default:
267 		ret = 1;
268 		break;
269 	}
270 	return ret;
271 }
272 
kvm_hv_is_syndbg_enabled(struct kvm_vcpu * vcpu)273 static bool kvm_hv_is_syndbg_enabled(struct kvm_vcpu *vcpu)
274 {
275 	struct kvm_cpuid_entry2 *entry;
276 
277 	entry = kvm_find_cpuid_entry(vcpu,
278 				     HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES,
279 				     0);
280 	if (!entry)
281 		return false;
282 
283 	return entry->eax & HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
284 }
285 
kvm_hv_syndbg_complete_userspace(struct kvm_vcpu * vcpu)286 static int kvm_hv_syndbg_complete_userspace(struct kvm_vcpu *vcpu)
287 {
288 	struct kvm *kvm = vcpu->kvm;
289 	struct kvm_hv *hv = &kvm->arch.hyperv;
290 
291 	if (vcpu->run->hyperv.u.syndbg.msr == HV_X64_MSR_SYNDBG_CONTROL)
292 		hv->hv_syndbg.control.status =
293 			vcpu->run->hyperv.u.syndbg.status;
294 	return 1;
295 }
296 
syndbg_exit(struct kvm_vcpu * vcpu,u32 msr)297 static void syndbg_exit(struct kvm_vcpu *vcpu, u32 msr)
298 {
299 	struct kvm_hv_syndbg *syndbg = vcpu_to_hv_syndbg(vcpu);
300 	struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
301 
302 	hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNDBG;
303 	hv_vcpu->exit.u.syndbg.msr = msr;
304 	hv_vcpu->exit.u.syndbg.control = syndbg->control.control;
305 	hv_vcpu->exit.u.syndbg.send_page = syndbg->control.send_page;
306 	hv_vcpu->exit.u.syndbg.recv_page = syndbg->control.recv_page;
307 	hv_vcpu->exit.u.syndbg.pending_page = syndbg->control.pending_page;
308 	vcpu->arch.complete_userspace_io =
309 			kvm_hv_syndbg_complete_userspace;
310 
311 	kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
312 }
313 
syndbg_set_msr(struct kvm_vcpu * vcpu,u32 msr,u64 data,bool host)314 static int syndbg_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
315 {
316 	struct kvm_hv_syndbg *syndbg = vcpu_to_hv_syndbg(vcpu);
317 
318 	if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
319 		return 1;
320 
321 	trace_kvm_hv_syndbg_set_msr(vcpu->vcpu_id,
322 				    vcpu_to_hv_vcpu(vcpu)->vp_index, msr, data);
323 	switch (msr) {
324 	case HV_X64_MSR_SYNDBG_CONTROL:
325 		syndbg->control.control = data;
326 		if (!host)
327 			syndbg_exit(vcpu, msr);
328 		break;
329 	case HV_X64_MSR_SYNDBG_STATUS:
330 		syndbg->control.status = data;
331 		break;
332 	case HV_X64_MSR_SYNDBG_SEND_BUFFER:
333 		syndbg->control.send_page = data;
334 		break;
335 	case HV_X64_MSR_SYNDBG_RECV_BUFFER:
336 		syndbg->control.recv_page = data;
337 		break;
338 	case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
339 		syndbg->control.pending_page = data;
340 		if (!host)
341 			syndbg_exit(vcpu, msr);
342 		break;
343 	case HV_X64_MSR_SYNDBG_OPTIONS:
344 		syndbg->options = data;
345 		break;
346 	default:
347 		break;
348 	}
349 
350 	return 0;
351 }
352 
syndbg_get_msr(struct kvm_vcpu * vcpu,u32 msr,u64 * pdata,bool host)353 static int syndbg_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
354 {
355 	struct kvm_hv_syndbg *syndbg = vcpu_to_hv_syndbg(vcpu);
356 
357 	if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
358 		return 1;
359 
360 	switch (msr) {
361 	case HV_X64_MSR_SYNDBG_CONTROL:
362 		*pdata = syndbg->control.control;
363 		break;
364 	case HV_X64_MSR_SYNDBG_STATUS:
365 		*pdata = syndbg->control.status;
366 		break;
367 	case HV_X64_MSR_SYNDBG_SEND_BUFFER:
368 		*pdata = syndbg->control.send_page;
369 		break;
370 	case HV_X64_MSR_SYNDBG_RECV_BUFFER:
371 		*pdata = syndbg->control.recv_page;
372 		break;
373 	case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
374 		*pdata = syndbg->control.pending_page;
375 		break;
376 	case HV_X64_MSR_SYNDBG_OPTIONS:
377 		*pdata = syndbg->options;
378 		break;
379 	default:
380 		break;
381 	}
382 
383 	trace_kvm_hv_syndbg_get_msr(vcpu->vcpu_id,
384 				    vcpu_to_hv_vcpu(vcpu)->vp_index, msr,
385 				    *pdata);
386 
387 	return 0;
388 }
389 
synic_get_msr(struct kvm_vcpu_hv_synic * synic,u32 msr,u64 * pdata,bool host)390 static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata,
391 			 bool host)
392 {
393 	int ret;
394 
395 	if (!synic->active && !host)
396 		return 1;
397 
398 	ret = 0;
399 	switch (msr) {
400 	case HV_X64_MSR_SCONTROL:
401 		*pdata = synic->control;
402 		break;
403 	case HV_X64_MSR_SVERSION:
404 		*pdata = synic->version;
405 		break;
406 	case HV_X64_MSR_SIEFP:
407 		*pdata = synic->evt_page;
408 		break;
409 	case HV_X64_MSR_SIMP:
410 		*pdata = synic->msg_page;
411 		break;
412 	case HV_X64_MSR_EOM:
413 		*pdata = 0;
414 		break;
415 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
416 		*pdata = atomic64_read(&synic->sint[msr - HV_X64_MSR_SINT0]);
417 		break;
418 	default:
419 		ret = 1;
420 		break;
421 	}
422 	return ret;
423 }
424 
synic_set_irq(struct kvm_vcpu_hv_synic * synic,u32 sint)425 static int synic_set_irq(struct kvm_vcpu_hv_synic *synic, u32 sint)
426 {
427 	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
428 	struct kvm_lapic_irq irq;
429 	int ret, vector;
430 
431 	if (sint >= ARRAY_SIZE(synic->sint))
432 		return -EINVAL;
433 
434 	vector = synic_get_sint_vector(synic_read_sint(synic, sint));
435 	if (vector < 0)
436 		return -ENOENT;
437 
438 	memset(&irq, 0, sizeof(irq));
439 	irq.shorthand = APIC_DEST_SELF;
440 	irq.dest_mode = APIC_DEST_PHYSICAL;
441 	irq.delivery_mode = APIC_DM_FIXED;
442 	irq.vector = vector;
443 	irq.level = 1;
444 
445 	ret = kvm_irq_delivery_to_apic(vcpu->kvm, vcpu->arch.apic, &irq, NULL);
446 	trace_kvm_hv_synic_set_irq(vcpu->vcpu_id, sint, irq.vector, ret);
447 	return ret;
448 }
449 
kvm_hv_synic_set_irq(struct kvm * kvm,u32 vpidx,u32 sint)450 int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vpidx, u32 sint)
451 {
452 	struct kvm_vcpu_hv_synic *synic;
453 
454 	synic = synic_get(kvm, vpidx);
455 	if (!synic)
456 		return -EINVAL;
457 
458 	return synic_set_irq(synic, sint);
459 }
460 
kvm_hv_synic_send_eoi(struct kvm_vcpu * vcpu,int vector)461 void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
462 {
463 	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
464 	int i;
465 
466 	trace_kvm_hv_synic_send_eoi(vcpu->vcpu_id, vector);
467 
468 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
469 		if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
470 			kvm_hv_notify_acked_sint(vcpu, i);
471 }
472 
kvm_hv_set_sint_gsi(struct kvm * kvm,u32 vpidx,u32 sint,int gsi)473 static int kvm_hv_set_sint_gsi(struct kvm *kvm, u32 vpidx, u32 sint, int gsi)
474 {
475 	struct kvm_vcpu_hv_synic *synic;
476 
477 	synic = synic_get(kvm, vpidx);
478 	if (!synic)
479 		return -EINVAL;
480 
481 	if (sint >= ARRAY_SIZE(synic->sint_to_gsi))
482 		return -EINVAL;
483 
484 	atomic_set(&synic->sint_to_gsi[sint], gsi);
485 	return 0;
486 }
487 
kvm_hv_irq_routing_update(struct kvm * kvm)488 void kvm_hv_irq_routing_update(struct kvm *kvm)
489 {
490 	struct kvm_irq_routing_table *irq_rt;
491 	struct kvm_kernel_irq_routing_entry *e;
492 	u32 gsi;
493 
494 	irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
495 					lockdep_is_held(&kvm->irq_lock));
496 
497 	for (gsi = 0; gsi < irq_rt->nr_rt_entries; gsi++) {
498 		hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
499 			if (e->type == KVM_IRQ_ROUTING_HV_SINT)
500 				kvm_hv_set_sint_gsi(kvm, e->hv_sint.vcpu,
501 						    e->hv_sint.sint, gsi);
502 		}
503 	}
504 }
505 
synic_init(struct kvm_vcpu_hv_synic * synic)506 static void synic_init(struct kvm_vcpu_hv_synic *synic)
507 {
508 	int i;
509 
510 	memset(synic, 0, sizeof(*synic));
511 	synic->version = HV_SYNIC_VERSION_1;
512 	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
513 		atomic64_set(&synic->sint[i], HV_SYNIC_SINT_MASKED);
514 		atomic_set(&synic->sint_to_gsi[i], -1);
515 	}
516 }
517 
get_time_ref_counter(struct kvm * kvm)518 static u64 get_time_ref_counter(struct kvm *kvm)
519 {
520 	struct kvm_hv *hv = &kvm->arch.hyperv;
521 	struct kvm_vcpu *vcpu;
522 	u64 tsc;
523 
524 	/*
525 	 * The guest has not set up the TSC page or the clock isn't
526 	 * stable, fall back to get_kvmclock_ns.
527 	 */
528 	if (!hv->tsc_ref.tsc_sequence)
529 		return div_u64(get_kvmclock_ns(kvm), 100);
530 
531 	vcpu = kvm_get_vcpu(kvm, 0);
532 	tsc = kvm_read_l1_tsc(vcpu, rdtsc());
533 	return mul_u64_u64_shr(tsc, hv->tsc_ref.tsc_scale, 64)
534 		+ hv->tsc_ref.tsc_offset;
535 }
536 
stimer_mark_pending(struct kvm_vcpu_hv_stimer * stimer,bool vcpu_kick)537 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
538 				bool vcpu_kick)
539 {
540 	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
541 
542 	set_bit(stimer->index,
543 		vcpu_to_hv_vcpu(vcpu)->stimer_pending_bitmap);
544 	kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
545 	if (vcpu_kick)
546 		kvm_vcpu_kick(vcpu);
547 }
548 
stimer_cleanup(struct kvm_vcpu_hv_stimer * stimer)549 static void stimer_cleanup(struct kvm_vcpu_hv_stimer *stimer)
550 {
551 	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
552 
553 	trace_kvm_hv_stimer_cleanup(stimer_to_vcpu(stimer)->vcpu_id,
554 				    stimer->index);
555 
556 	hrtimer_cancel(&stimer->timer);
557 	clear_bit(stimer->index,
558 		  vcpu_to_hv_vcpu(vcpu)->stimer_pending_bitmap);
559 	stimer->msg_pending = false;
560 	stimer->exp_time = 0;
561 }
562 
stimer_timer_callback(struct hrtimer * timer)563 static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer)
564 {
565 	struct kvm_vcpu_hv_stimer *stimer;
566 
567 	stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer);
568 	trace_kvm_hv_stimer_callback(stimer_to_vcpu(stimer)->vcpu_id,
569 				     stimer->index);
570 	stimer_mark_pending(stimer, true);
571 
572 	return HRTIMER_NORESTART;
573 }
574 
575 /*
576  * stimer_start() assumptions:
577  * a) stimer->count is not equal to 0
578  * b) stimer->config has HV_STIMER_ENABLE flag
579  */
stimer_start(struct kvm_vcpu_hv_stimer * stimer)580 static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
581 {
582 	u64 time_now;
583 	ktime_t ktime_now;
584 
585 	time_now = get_time_ref_counter(stimer_to_vcpu(stimer)->kvm);
586 	ktime_now = ktime_get();
587 
588 	if (stimer->config.periodic) {
589 		if (stimer->exp_time) {
590 			if (time_now >= stimer->exp_time) {
591 				u64 remainder;
592 
593 				div64_u64_rem(time_now - stimer->exp_time,
594 					      stimer->count, &remainder);
595 				stimer->exp_time =
596 					time_now + (stimer->count - remainder);
597 			}
598 		} else
599 			stimer->exp_time = time_now + stimer->count;
600 
601 		trace_kvm_hv_stimer_start_periodic(
602 					stimer_to_vcpu(stimer)->vcpu_id,
603 					stimer->index,
604 					time_now, stimer->exp_time);
605 
606 		hrtimer_start(&stimer->timer,
607 			      ktime_add_ns(ktime_now,
608 					   100 * (stimer->exp_time - time_now)),
609 			      HRTIMER_MODE_ABS);
610 		return 0;
611 	}
612 	stimer->exp_time = stimer->count;
613 	if (time_now >= stimer->count) {
614 		/*
615 		 * Expire timer according to Hypervisor Top-Level Functional
616 		 * specification v4(15.3.1):
617 		 * "If a one shot is enabled and the specified count is in
618 		 * the past, it will expire immediately."
619 		 */
620 		stimer_mark_pending(stimer, false);
621 		return 0;
622 	}
623 
624 	trace_kvm_hv_stimer_start_one_shot(stimer_to_vcpu(stimer)->vcpu_id,
625 					   stimer->index,
626 					   time_now, stimer->count);
627 
628 	hrtimer_start(&stimer->timer,
629 		      ktime_add_ns(ktime_now, 100 * (stimer->count - time_now)),
630 		      HRTIMER_MODE_ABS);
631 	return 0;
632 }
633 
stimer_set_config(struct kvm_vcpu_hv_stimer * stimer,u64 config,bool host)634 static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
635 			     bool host)
636 {
637 	union hv_stimer_config new_config = {.as_uint64 = config},
638 		old_config = {.as_uint64 = stimer->config.as_uint64};
639 	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
640 	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
641 
642 	if (!synic->active && (!host || config))
643 		return 1;
644 
645 	trace_kvm_hv_stimer_set_config(stimer_to_vcpu(stimer)->vcpu_id,
646 				       stimer->index, config, host);
647 
648 	stimer_cleanup(stimer);
649 	if (old_config.enable &&
650 	    !new_config.direct_mode && new_config.sintx == 0)
651 		new_config.enable = 0;
652 	stimer->config.as_uint64 = new_config.as_uint64;
653 
654 	if (stimer->config.enable)
655 		stimer_mark_pending(stimer, false);
656 
657 	return 0;
658 }
659 
stimer_set_count(struct kvm_vcpu_hv_stimer * stimer,u64 count,bool host)660 static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,
661 			    bool host)
662 {
663 	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
664 	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
665 
666 	if (!synic->active && (!host || count))
667 		return 1;
668 
669 	trace_kvm_hv_stimer_set_count(stimer_to_vcpu(stimer)->vcpu_id,
670 				      stimer->index, count, host);
671 
672 	stimer_cleanup(stimer);
673 	stimer->count = count;
674 	if (stimer->count == 0)
675 		stimer->config.enable = 0;
676 	else if (stimer->config.auto_enable)
677 		stimer->config.enable = 1;
678 
679 	if (stimer->config.enable)
680 		stimer_mark_pending(stimer, false);
681 
682 	return 0;
683 }
684 
stimer_get_config(struct kvm_vcpu_hv_stimer * stimer,u64 * pconfig)685 static int stimer_get_config(struct kvm_vcpu_hv_stimer *stimer, u64 *pconfig)
686 {
687 	*pconfig = stimer->config.as_uint64;
688 	return 0;
689 }
690 
stimer_get_count(struct kvm_vcpu_hv_stimer * stimer,u64 * pcount)691 static int stimer_get_count(struct kvm_vcpu_hv_stimer *stimer, u64 *pcount)
692 {
693 	*pcount = stimer->count;
694 	return 0;
695 }
696 
synic_deliver_msg(struct kvm_vcpu_hv_synic * synic,u32 sint,struct hv_message * src_msg,bool no_retry)697 static int synic_deliver_msg(struct kvm_vcpu_hv_synic *synic, u32 sint,
698 			     struct hv_message *src_msg, bool no_retry)
699 {
700 	struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
701 	int msg_off = offsetof(struct hv_message_page, sint_message[sint]);
702 	gfn_t msg_page_gfn;
703 	struct hv_message_header hv_hdr;
704 	int r;
705 
706 	if (!(synic->msg_page & HV_SYNIC_SIMP_ENABLE))
707 		return -ENOENT;
708 
709 	msg_page_gfn = synic->msg_page >> PAGE_SHIFT;
710 
711 	/*
712 	 * Strictly following the spec-mandated ordering would assume setting
713 	 * .msg_pending before checking .message_type.  However, this function
714 	 * is only called in vcpu context so the entire update is atomic from
715 	 * guest POV and thus the exact order here doesn't matter.
716 	 */
717 	r = kvm_vcpu_read_guest_page(vcpu, msg_page_gfn, &hv_hdr.message_type,
718 				     msg_off + offsetof(struct hv_message,
719 							header.message_type),
720 				     sizeof(hv_hdr.message_type));
721 	if (r < 0)
722 		return r;
723 
724 	if (hv_hdr.message_type != HVMSG_NONE) {
725 		if (no_retry)
726 			return 0;
727 
728 		hv_hdr.message_flags.msg_pending = 1;
729 		r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn,
730 					      &hv_hdr.message_flags,
731 					      msg_off +
732 					      offsetof(struct hv_message,
733 						       header.message_flags),
734 					      sizeof(hv_hdr.message_flags));
735 		if (r < 0)
736 			return r;
737 		return -EAGAIN;
738 	}
739 
740 	r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn, src_msg, msg_off,
741 				      sizeof(src_msg->header) +
742 				      src_msg->header.payload_size);
743 	if (r < 0)
744 		return r;
745 
746 	r = synic_set_irq(synic, sint);
747 	if (r < 0)
748 		return r;
749 	if (r == 0)
750 		return -EFAULT;
751 	return 0;
752 }
753 
stimer_send_msg(struct kvm_vcpu_hv_stimer * stimer)754 static int stimer_send_msg(struct kvm_vcpu_hv_stimer *stimer)
755 {
756 	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
757 	struct hv_message *msg = &stimer->msg;
758 	struct hv_timer_message_payload *payload =
759 			(struct hv_timer_message_payload *)&msg->u.payload;
760 
761 	/*
762 	 * To avoid piling up periodic ticks, don't retry message
763 	 * delivery for them (within "lazy" lost ticks policy).
764 	 */
765 	bool no_retry = stimer->config.periodic;
766 
767 	payload->expiration_time = stimer->exp_time;
768 	payload->delivery_time = get_time_ref_counter(vcpu->kvm);
769 	return synic_deliver_msg(vcpu_to_synic(vcpu),
770 				 stimer->config.sintx, msg,
771 				 no_retry);
772 }
773 
stimer_notify_direct(struct kvm_vcpu_hv_stimer * stimer)774 static int stimer_notify_direct(struct kvm_vcpu_hv_stimer *stimer)
775 {
776 	struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
777 	struct kvm_lapic_irq irq = {
778 		.delivery_mode = APIC_DM_FIXED,
779 		.vector = stimer->config.apic_vector
780 	};
781 
782 	if (lapic_in_kernel(vcpu))
783 		return !kvm_apic_set_irq(vcpu, &irq, NULL);
784 	return 0;
785 }
786 
stimer_expiration(struct kvm_vcpu_hv_stimer * stimer)787 static void stimer_expiration(struct kvm_vcpu_hv_stimer *stimer)
788 {
789 	int r, direct = stimer->config.direct_mode;
790 
791 	stimer->msg_pending = true;
792 	if (!direct)
793 		r = stimer_send_msg(stimer);
794 	else
795 		r = stimer_notify_direct(stimer);
796 	trace_kvm_hv_stimer_expiration(stimer_to_vcpu(stimer)->vcpu_id,
797 				       stimer->index, direct, r);
798 	if (!r) {
799 		stimer->msg_pending = false;
800 		if (!(stimer->config.periodic))
801 			stimer->config.enable = 0;
802 	}
803 }
804 
kvm_hv_process_stimers(struct kvm_vcpu * vcpu)805 void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
806 {
807 	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
808 	struct kvm_vcpu_hv_stimer *stimer;
809 	u64 time_now, exp_time;
810 	int i;
811 
812 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
813 		if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) {
814 			stimer = &hv_vcpu->stimer[i];
815 			if (stimer->config.enable) {
816 				exp_time = stimer->exp_time;
817 
818 				if (exp_time) {
819 					time_now =
820 						get_time_ref_counter(vcpu->kvm);
821 					if (time_now >= exp_time)
822 						stimer_expiration(stimer);
823 				}
824 
825 				if ((stimer->config.enable) &&
826 				    stimer->count) {
827 					if (!stimer->msg_pending)
828 						stimer_start(stimer);
829 				} else
830 					stimer_cleanup(stimer);
831 			}
832 		}
833 }
834 
kvm_hv_vcpu_uninit(struct kvm_vcpu * vcpu)835 void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu)
836 {
837 	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
838 	int i;
839 
840 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
841 		stimer_cleanup(&hv_vcpu->stimer[i]);
842 }
843 
kvm_hv_assist_page_enabled(struct kvm_vcpu * vcpu)844 bool kvm_hv_assist_page_enabled(struct kvm_vcpu *vcpu)
845 {
846 	if (!(vcpu->arch.hyperv.hv_vapic & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE))
847 		return false;
848 	return vcpu->arch.pv_eoi.msr_val & KVM_MSR_ENABLED;
849 }
850 EXPORT_SYMBOL_GPL(kvm_hv_assist_page_enabled);
851 
kvm_hv_get_assist_page(struct kvm_vcpu * vcpu,struct hv_vp_assist_page * assist_page)852 bool kvm_hv_get_assist_page(struct kvm_vcpu *vcpu,
853 			    struct hv_vp_assist_page *assist_page)
854 {
855 	if (!kvm_hv_assist_page_enabled(vcpu))
856 		return false;
857 	return !kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data,
858 				      assist_page, sizeof(*assist_page));
859 }
860 EXPORT_SYMBOL_GPL(kvm_hv_get_assist_page);
861 
stimer_prepare_msg(struct kvm_vcpu_hv_stimer * stimer)862 static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
863 {
864 	struct hv_message *msg = &stimer->msg;
865 	struct hv_timer_message_payload *payload =
866 			(struct hv_timer_message_payload *)&msg->u.payload;
867 
868 	memset(&msg->header, 0, sizeof(msg->header));
869 	msg->header.message_type = HVMSG_TIMER_EXPIRED;
870 	msg->header.payload_size = sizeof(*payload);
871 
872 	payload->timer_index = stimer->index;
873 	payload->expiration_time = 0;
874 	payload->delivery_time = 0;
875 }
876 
stimer_init(struct kvm_vcpu_hv_stimer * stimer,int timer_index)877 static void stimer_init(struct kvm_vcpu_hv_stimer *stimer, int timer_index)
878 {
879 	memset(stimer, 0, sizeof(*stimer));
880 	stimer->index = timer_index;
881 	hrtimer_init(&stimer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
882 	stimer->timer.function = stimer_timer_callback;
883 	stimer_prepare_msg(stimer);
884 }
885 
kvm_hv_vcpu_init(struct kvm_vcpu * vcpu)886 void kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
887 {
888 	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
889 	int i;
890 
891 	synic_init(&hv_vcpu->synic);
892 
893 	bitmap_zero(hv_vcpu->stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
894 	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
895 		stimer_init(&hv_vcpu->stimer[i], i);
896 }
897 
kvm_hv_vcpu_postcreate(struct kvm_vcpu * vcpu)898 void kvm_hv_vcpu_postcreate(struct kvm_vcpu *vcpu)
899 {
900 	struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
901 
902 	hv_vcpu->vp_index = kvm_vcpu_get_idx(vcpu);
903 }
904 
kvm_hv_activate_synic(struct kvm_vcpu * vcpu,bool dont_zero_synic_pages)905 int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages)
906 {
907 	struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
908 
909 	/*
910 	 * Hyper-V SynIC auto EOI SINT's are
911 	 * not compatible with APICV, so request
912 	 * to deactivate APICV permanently.
913 	 */
914 	kvm_request_apicv_update(vcpu->kvm, false, APICV_INHIBIT_REASON_HYPERV);
915 	synic->active = true;
916 	synic->dont_zero_synic_pages = dont_zero_synic_pages;
917 	synic->control = HV_SYNIC_CONTROL_ENABLE;
918 	return 0;
919 }
920 
kvm_hv_msr_partition_wide(u32 msr)921 static bool kvm_hv_msr_partition_wide(u32 msr)
922 {
923 	bool r = false;
924 
925 	switch (msr) {
926 	case HV_X64_MSR_GUEST_OS_ID:
927 	case HV_X64_MSR_HYPERCALL:
928 	case HV_X64_MSR_REFERENCE_TSC:
929 	case HV_X64_MSR_TIME_REF_COUNT:
930 	case HV_X64_MSR_CRASH_CTL:
931 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
932 	case HV_X64_MSR_RESET:
933 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
934 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
935 	case HV_X64_MSR_TSC_EMULATION_STATUS:
936 	case HV_X64_MSR_SYNDBG_OPTIONS:
937 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
938 		r = true;
939 		break;
940 	}
941 
942 	return r;
943 }
944 
kvm_hv_msr_get_crash_data(struct kvm_vcpu * vcpu,u32 index,u64 * pdata)945 static int kvm_hv_msr_get_crash_data(struct kvm_vcpu *vcpu,
946 				     u32 index, u64 *pdata)
947 {
948 	struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
949 	size_t size = ARRAY_SIZE(hv->hv_crash_param);
950 
951 	if (WARN_ON_ONCE(index >= size))
952 		return -EINVAL;
953 
954 	*pdata = hv->hv_crash_param[array_index_nospec(index, size)];
955 	return 0;
956 }
957 
kvm_hv_msr_get_crash_ctl(struct kvm_vcpu * vcpu,u64 * pdata)958 static int kvm_hv_msr_get_crash_ctl(struct kvm_vcpu *vcpu, u64 *pdata)
959 {
960 	struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
961 
962 	*pdata = hv->hv_crash_ctl;
963 	return 0;
964 }
965 
kvm_hv_msr_set_crash_ctl(struct kvm_vcpu * vcpu,u64 data,bool host)966 static int kvm_hv_msr_set_crash_ctl(struct kvm_vcpu *vcpu, u64 data, bool host)
967 {
968 	struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
969 
970 	if (host)
971 		hv->hv_crash_ctl = data & HV_CRASH_CTL_CRASH_NOTIFY;
972 
973 	if (!host && (data & HV_CRASH_CTL_CRASH_NOTIFY)) {
974 
975 		vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx 0x%llx)\n",
976 			  hv->hv_crash_param[0],
977 			  hv->hv_crash_param[1],
978 			  hv->hv_crash_param[2],
979 			  hv->hv_crash_param[3],
980 			  hv->hv_crash_param[4]);
981 
982 		/* Send notification about crash to user space */
983 		kvm_make_request(KVM_REQ_HV_CRASH, vcpu);
984 	}
985 
986 	return 0;
987 }
988 
kvm_hv_msr_set_crash_data(struct kvm_vcpu * vcpu,u32 index,u64 data)989 static int kvm_hv_msr_set_crash_data(struct kvm_vcpu *vcpu,
990 				     u32 index, u64 data)
991 {
992 	struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
993 	size_t size = ARRAY_SIZE(hv->hv_crash_param);
994 
995 	if (WARN_ON_ONCE(index >= size))
996 		return -EINVAL;
997 
998 	hv->hv_crash_param[array_index_nospec(index, size)] = data;
999 	return 0;
1000 }
1001 
1002 /*
1003  * The kvmclock and Hyper-V TSC page use similar formulas, and converting
1004  * between them is possible:
1005  *
1006  * kvmclock formula:
1007  *    nsec = (ticks - tsc_timestamp) * tsc_to_system_mul * 2^(tsc_shift-32)
1008  *           + system_time
1009  *
1010  * Hyper-V formula:
1011  *    nsec/100 = ticks * scale / 2^64 + offset
1012  *
1013  * When tsc_timestamp = system_time = 0, offset is zero in the Hyper-V formula.
1014  * By dividing the kvmclock formula by 100 and equating what's left we get:
1015  *    ticks * scale / 2^64 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1016  *            scale / 2^64 =         tsc_to_system_mul * 2^(tsc_shift-32) / 100
1017  *            scale        =         tsc_to_system_mul * 2^(32+tsc_shift) / 100
1018  *
1019  * Now expand the kvmclock formula and divide by 100:
1020  *    nsec = ticks * tsc_to_system_mul * 2^(tsc_shift-32)
1021  *           - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32)
1022  *           + system_time
1023  *    nsec/100 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1024  *               - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1025  *               + system_time / 100
1026  *
1027  * Replace tsc_to_system_mul * 2^(tsc_shift-32) / 100 by scale / 2^64:
1028  *    nsec/100 = ticks * scale / 2^64
1029  *               - tsc_timestamp * scale / 2^64
1030  *               + system_time / 100
1031  *
1032  * Equate with the Hyper-V formula so that ticks * scale / 2^64 cancels out:
1033  *    offset = system_time / 100 - tsc_timestamp * scale / 2^64
1034  *
1035  * These two equivalencies are implemented in this function.
1036  */
compute_tsc_page_parameters(struct pvclock_vcpu_time_info * hv_clock,struct ms_hyperv_tsc_page * tsc_ref)1037 static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
1038 					struct ms_hyperv_tsc_page *tsc_ref)
1039 {
1040 	u64 max_mul;
1041 
1042 	if (!(hv_clock->flags & PVCLOCK_TSC_STABLE_BIT))
1043 		return false;
1044 
1045 	/*
1046 	 * check if scale would overflow, if so we use the time ref counter
1047 	 *    tsc_to_system_mul * 2^(tsc_shift+32) / 100 >= 2^64
1048 	 *    tsc_to_system_mul / 100 >= 2^(32-tsc_shift)
1049 	 *    tsc_to_system_mul >= 100 * 2^(32-tsc_shift)
1050 	 */
1051 	max_mul = 100ull << (32 - hv_clock->tsc_shift);
1052 	if (hv_clock->tsc_to_system_mul >= max_mul)
1053 		return false;
1054 
1055 	/*
1056 	 * Otherwise compute the scale and offset according to the formulas
1057 	 * derived above.
1058 	 */
1059 	tsc_ref->tsc_scale =
1060 		mul_u64_u32_div(1ULL << (32 + hv_clock->tsc_shift),
1061 				hv_clock->tsc_to_system_mul,
1062 				100);
1063 
1064 	tsc_ref->tsc_offset = hv_clock->system_time;
1065 	do_div(tsc_ref->tsc_offset, 100);
1066 	tsc_ref->tsc_offset -=
1067 		mul_u64_u64_shr(hv_clock->tsc_timestamp, tsc_ref->tsc_scale, 64);
1068 	return true;
1069 }
1070 
kvm_hv_setup_tsc_page(struct kvm * kvm,struct pvclock_vcpu_time_info * hv_clock)1071 void kvm_hv_setup_tsc_page(struct kvm *kvm,
1072 			   struct pvclock_vcpu_time_info *hv_clock)
1073 {
1074 	struct kvm_hv *hv = &kvm->arch.hyperv;
1075 	u32 tsc_seq;
1076 	u64 gfn;
1077 
1078 	BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
1079 	BUILD_BUG_ON(offsetof(struct ms_hyperv_tsc_page, tsc_sequence) != 0);
1080 
1081 	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
1082 		return;
1083 
1084 	mutex_lock(&kvm->arch.hyperv.hv_lock);
1085 	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
1086 		goto out_unlock;
1087 
1088 	gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
1089 	/*
1090 	 * Because the TSC parameters only vary when there is a
1091 	 * change in the master clock, do not bother with caching.
1092 	 */
1093 	if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
1094 				    &tsc_seq, sizeof(tsc_seq))))
1095 		goto out_unlock;
1096 
1097 	/*
1098 	 * While we're computing and writing the parameters, force the
1099 	 * guest to use the time reference count MSR.
1100 	 */
1101 	hv->tsc_ref.tsc_sequence = 0;
1102 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1103 			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1104 		goto out_unlock;
1105 
1106 	if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
1107 		goto out_unlock;
1108 
1109 	/* Ensure sequence is zero before writing the rest of the struct.  */
1110 	smp_wmb();
1111 	if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1112 		goto out_unlock;
1113 
1114 	/*
1115 	 * Now switch to the TSC page mechanism by writing the sequence.
1116 	 */
1117 	tsc_seq++;
1118 	if (tsc_seq == 0xFFFFFFFF || tsc_seq == 0)
1119 		tsc_seq = 1;
1120 
1121 	/* Write the struct entirely before the non-zero sequence.  */
1122 	smp_wmb();
1123 
1124 	hv->tsc_ref.tsc_sequence = tsc_seq;
1125 	kvm_write_guest(kvm, gfn_to_gpa(gfn),
1126 			&hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence));
1127 out_unlock:
1128 	mutex_unlock(&kvm->arch.hyperv.hv_lock);
1129 }
1130 
kvm_hv_set_msr_pw(struct kvm_vcpu * vcpu,u32 msr,u64 data,bool host)1131 static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
1132 			     bool host)
1133 {
1134 	struct kvm *kvm = vcpu->kvm;
1135 	struct kvm_hv *hv = &kvm->arch.hyperv;
1136 
1137 	switch (msr) {
1138 	case HV_X64_MSR_GUEST_OS_ID:
1139 		hv->hv_guest_os_id = data;
1140 		/* setting guest os id to zero disables hypercall page */
1141 		if (!hv->hv_guest_os_id)
1142 			hv->hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
1143 		break;
1144 	case HV_X64_MSR_HYPERCALL: {
1145 		u64 gfn;
1146 		unsigned long addr;
1147 		u8 instructions[4];
1148 
1149 		/* if guest os id is not set hypercall should remain disabled */
1150 		if (!hv->hv_guest_os_id)
1151 			break;
1152 		if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
1153 			hv->hv_hypercall = data;
1154 			break;
1155 		}
1156 		gfn = data >> HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT;
1157 		addr = gfn_to_hva(kvm, gfn);
1158 		if (kvm_is_error_hva(addr))
1159 			return 1;
1160 		kvm_x86_ops.patch_hypercall(vcpu, instructions);
1161 		((unsigned char *)instructions)[3] = 0xc3; /* ret */
1162 		if (__copy_to_user((void __user *)addr, instructions, 4))
1163 			return 1;
1164 		hv->hv_hypercall = data;
1165 		mark_page_dirty(kvm, gfn);
1166 		break;
1167 	}
1168 	case HV_X64_MSR_REFERENCE_TSC:
1169 		hv->hv_tsc_page = data;
1170 		if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE)
1171 			kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
1172 		break;
1173 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1174 		return kvm_hv_msr_set_crash_data(vcpu,
1175 						 msr - HV_X64_MSR_CRASH_P0,
1176 						 data);
1177 	case HV_X64_MSR_CRASH_CTL:
1178 		return kvm_hv_msr_set_crash_ctl(vcpu, data, host);
1179 	case HV_X64_MSR_RESET:
1180 		if (data == 1) {
1181 			vcpu_debug(vcpu, "hyper-v reset requested\n");
1182 			kvm_make_request(KVM_REQ_HV_RESET, vcpu);
1183 		}
1184 		break;
1185 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1186 		hv->hv_reenlightenment_control = data;
1187 		break;
1188 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1189 		hv->hv_tsc_emulation_control = data;
1190 		break;
1191 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1192 		hv->hv_tsc_emulation_status = data;
1193 		break;
1194 	case HV_X64_MSR_TIME_REF_COUNT:
1195 		/* read-only, but still ignore it if host-initiated */
1196 		if (!host)
1197 			return 1;
1198 		break;
1199 	case HV_X64_MSR_SYNDBG_OPTIONS:
1200 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1201 		return syndbg_set_msr(vcpu, msr, data, host);
1202 	default:
1203 		vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
1204 			    msr, data);
1205 		return 1;
1206 	}
1207 	return 0;
1208 }
1209 
1210 /* Calculate cpu time spent by current task in 100ns units */
current_task_runtime_100ns(void)1211 static u64 current_task_runtime_100ns(void)
1212 {
1213 	u64 utime, stime;
1214 
1215 	task_cputime_adjusted(current, &utime, &stime);
1216 
1217 	return div_u64(utime + stime, 100);
1218 }
1219 
kvm_hv_set_msr(struct kvm_vcpu * vcpu,u32 msr,u64 data,bool host)1220 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1221 {
1222 	struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
1223 
1224 	switch (msr) {
1225 	case HV_X64_MSR_VP_INDEX: {
1226 		struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
1227 		int vcpu_idx = kvm_vcpu_get_idx(vcpu);
1228 		u32 new_vp_index = (u32)data;
1229 
1230 		if (!host || new_vp_index >= KVM_MAX_VCPUS)
1231 			return 1;
1232 
1233 		if (new_vp_index == hv_vcpu->vp_index)
1234 			return 0;
1235 
1236 		/*
1237 		 * The VP index is initialized to vcpu_index by
1238 		 * kvm_hv_vcpu_postcreate so they initially match.  Now the
1239 		 * VP index is changing, adjust num_mismatched_vp_indexes if
1240 		 * it now matches or no longer matches vcpu_idx.
1241 		 */
1242 		if (hv_vcpu->vp_index == vcpu_idx)
1243 			atomic_inc(&hv->num_mismatched_vp_indexes);
1244 		else if (new_vp_index == vcpu_idx)
1245 			atomic_dec(&hv->num_mismatched_vp_indexes);
1246 
1247 		hv_vcpu->vp_index = new_vp_index;
1248 		break;
1249 	}
1250 	case HV_X64_MSR_VP_ASSIST_PAGE: {
1251 		u64 gfn;
1252 		unsigned long addr;
1253 
1254 		if (!(data & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE)) {
1255 			hv_vcpu->hv_vapic = data;
1256 			if (kvm_lapic_enable_pv_eoi(vcpu, 0, 0))
1257 				return 1;
1258 			break;
1259 		}
1260 		gfn = data >> HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT;
1261 		addr = kvm_vcpu_gfn_to_hva(vcpu, gfn);
1262 		if (kvm_is_error_hva(addr))
1263 			return 1;
1264 
1265 		/*
1266 		 * Clear apic_assist portion of struct hv_vp_assist_page
1267 		 * only, there can be valuable data in the rest which needs
1268 		 * to be preserved e.g. on migration.
1269 		 */
1270 		if (__put_user(0, (u32 __user *)addr))
1271 			return 1;
1272 		hv_vcpu->hv_vapic = data;
1273 		kvm_vcpu_mark_page_dirty(vcpu, gfn);
1274 		if (kvm_lapic_enable_pv_eoi(vcpu,
1275 					    gfn_to_gpa(gfn) | KVM_MSR_ENABLED,
1276 					    sizeof(struct hv_vp_assist_page)))
1277 			return 1;
1278 		break;
1279 	}
1280 	case HV_X64_MSR_EOI:
1281 		return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
1282 	case HV_X64_MSR_ICR:
1283 		return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
1284 	case HV_X64_MSR_TPR:
1285 		return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
1286 	case HV_X64_MSR_VP_RUNTIME:
1287 		if (!host)
1288 			return 1;
1289 		hv_vcpu->runtime_offset = data - current_task_runtime_100ns();
1290 		break;
1291 	case HV_X64_MSR_SCONTROL:
1292 	case HV_X64_MSR_SVERSION:
1293 	case HV_X64_MSR_SIEFP:
1294 	case HV_X64_MSR_SIMP:
1295 	case HV_X64_MSR_EOM:
1296 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1297 		return synic_set_msr(vcpu_to_synic(vcpu), msr, data, host);
1298 	case HV_X64_MSR_STIMER0_CONFIG:
1299 	case HV_X64_MSR_STIMER1_CONFIG:
1300 	case HV_X64_MSR_STIMER2_CONFIG:
1301 	case HV_X64_MSR_STIMER3_CONFIG: {
1302 		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1303 
1304 		return stimer_set_config(vcpu_to_stimer(vcpu, timer_index),
1305 					 data, host);
1306 	}
1307 	case HV_X64_MSR_STIMER0_COUNT:
1308 	case HV_X64_MSR_STIMER1_COUNT:
1309 	case HV_X64_MSR_STIMER2_COUNT:
1310 	case HV_X64_MSR_STIMER3_COUNT: {
1311 		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1312 
1313 		return stimer_set_count(vcpu_to_stimer(vcpu, timer_index),
1314 					data, host);
1315 	}
1316 	case HV_X64_MSR_TSC_FREQUENCY:
1317 	case HV_X64_MSR_APIC_FREQUENCY:
1318 		/* read-only, but still ignore it if host-initiated */
1319 		if (!host)
1320 			return 1;
1321 		break;
1322 	default:
1323 		vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
1324 			    msr, data);
1325 		return 1;
1326 	}
1327 
1328 	return 0;
1329 }
1330 
kvm_hv_get_msr_pw(struct kvm_vcpu * vcpu,u32 msr,u64 * pdata,bool host)1331 static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1332 			     bool host)
1333 {
1334 	u64 data = 0;
1335 	struct kvm *kvm = vcpu->kvm;
1336 	struct kvm_hv *hv = &kvm->arch.hyperv;
1337 
1338 	switch (msr) {
1339 	case HV_X64_MSR_GUEST_OS_ID:
1340 		data = hv->hv_guest_os_id;
1341 		break;
1342 	case HV_X64_MSR_HYPERCALL:
1343 		data = hv->hv_hypercall;
1344 		break;
1345 	case HV_X64_MSR_TIME_REF_COUNT:
1346 		data = get_time_ref_counter(kvm);
1347 		break;
1348 	case HV_X64_MSR_REFERENCE_TSC:
1349 		data = hv->hv_tsc_page;
1350 		break;
1351 	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1352 		return kvm_hv_msr_get_crash_data(vcpu,
1353 						 msr - HV_X64_MSR_CRASH_P0,
1354 						 pdata);
1355 	case HV_X64_MSR_CRASH_CTL:
1356 		return kvm_hv_msr_get_crash_ctl(vcpu, pdata);
1357 	case HV_X64_MSR_RESET:
1358 		data = 0;
1359 		break;
1360 	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1361 		data = hv->hv_reenlightenment_control;
1362 		break;
1363 	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1364 		data = hv->hv_tsc_emulation_control;
1365 		break;
1366 	case HV_X64_MSR_TSC_EMULATION_STATUS:
1367 		data = hv->hv_tsc_emulation_status;
1368 		break;
1369 	case HV_X64_MSR_SYNDBG_OPTIONS:
1370 	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1371 		return syndbg_get_msr(vcpu, msr, pdata, host);
1372 	default:
1373 		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1374 		return 1;
1375 	}
1376 
1377 	*pdata = data;
1378 	return 0;
1379 }
1380 
kvm_hv_get_msr(struct kvm_vcpu * vcpu,u32 msr,u64 * pdata,bool host)1381 static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1382 			  bool host)
1383 {
1384 	u64 data = 0;
1385 	struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
1386 
1387 	switch (msr) {
1388 	case HV_X64_MSR_VP_INDEX:
1389 		data = hv_vcpu->vp_index;
1390 		break;
1391 	case HV_X64_MSR_EOI:
1392 		return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
1393 	case HV_X64_MSR_ICR:
1394 		return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
1395 	case HV_X64_MSR_TPR:
1396 		return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
1397 	case HV_X64_MSR_VP_ASSIST_PAGE:
1398 		data = hv_vcpu->hv_vapic;
1399 		break;
1400 	case HV_X64_MSR_VP_RUNTIME:
1401 		data = current_task_runtime_100ns() + hv_vcpu->runtime_offset;
1402 		break;
1403 	case HV_X64_MSR_SCONTROL:
1404 	case HV_X64_MSR_SVERSION:
1405 	case HV_X64_MSR_SIEFP:
1406 	case HV_X64_MSR_SIMP:
1407 	case HV_X64_MSR_EOM:
1408 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1409 		return synic_get_msr(vcpu_to_synic(vcpu), msr, pdata, host);
1410 	case HV_X64_MSR_STIMER0_CONFIG:
1411 	case HV_X64_MSR_STIMER1_CONFIG:
1412 	case HV_X64_MSR_STIMER2_CONFIG:
1413 	case HV_X64_MSR_STIMER3_CONFIG: {
1414 		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1415 
1416 		return stimer_get_config(vcpu_to_stimer(vcpu, timer_index),
1417 					 pdata);
1418 	}
1419 	case HV_X64_MSR_STIMER0_COUNT:
1420 	case HV_X64_MSR_STIMER1_COUNT:
1421 	case HV_X64_MSR_STIMER2_COUNT:
1422 	case HV_X64_MSR_STIMER3_COUNT: {
1423 		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1424 
1425 		return stimer_get_count(vcpu_to_stimer(vcpu, timer_index),
1426 					pdata);
1427 	}
1428 	case HV_X64_MSR_TSC_FREQUENCY:
1429 		data = (u64)vcpu->arch.virtual_tsc_khz * 1000;
1430 		break;
1431 	case HV_X64_MSR_APIC_FREQUENCY:
1432 		data = APIC_BUS_FREQUENCY;
1433 		break;
1434 	default:
1435 		vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1436 		return 1;
1437 	}
1438 	*pdata = data;
1439 	return 0;
1440 }
1441 
kvm_hv_set_msr_common(struct kvm_vcpu * vcpu,u32 msr,u64 data,bool host)1442 int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1443 {
1444 	if (kvm_hv_msr_partition_wide(msr)) {
1445 		int r;
1446 
1447 		mutex_lock(&vcpu->kvm->arch.hyperv.hv_lock);
1448 		r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
1449 		mutex_unlock(&vcpu->kvm->arch.hyperv.hv_lock);
1450 		return r;
1451 	} else
1452 		return kvm_hv_set_msr(vcpu, msr, data, host);
1453 }
1454 
kvm_hv_get_msr_common(struct kvm_vcpu * vcpu,u32 msr,u64 * pdata,bool host)1455 int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
1456 {
1457 	if (kvm_hv_msr_partition_wide(msr)) {
1458 		int r;
1459 
1460 		mutex_lock(&vcpu->kvm->arch.hyperv.hv_lock);
1461 		r = kvm_hv_get_msr_pw(vcpu, msr, pdata, host);
1462 		mutex_unlock(&vcpu->kvm->arch.hyperv.hv_lock);
1463 		return r;
1464 	} else
1465 		return kvm_hv_get_msr(vcpu, msr, pdata, host);
1466 }
1467 
sparse_set_to_vcpu_mask(struct kvm * kvm,u64 * sparse_banks,u64 valid_bank_mask,u64 * vp_bitmap,unsigned long * vcpu_bitmap)1468 static __always_inline unsigned long *sparse_set_to_vcpu_mask(
1469 	struct kvm *kvm, u64 *sparse_banks, u64 valid_bank_mask,
1470 	u64 *vp_bitmap, unsigned long *vcpu_bitmap)
1471 {
1472 	struct kvm_hv *hv = &kvm->arch.hyperv;
1473 	struct kvm_vcpu *vcpu;
1474 	int i, bank, sbank = 0;
1475 
1476 	memset(vp_bitmap, 0,
1477 	       KVM_HV_MAX_SPARSE_VCPU_SET_BITS * sizeof(*vp_bitmap));
1478 	for_each_set_bit(bank, (unsigned long *)&valid_bank_mask,
1479 			 KVM_HV_MAX_SPARSE_VCPU_SET_BITS)
1480 		vp_bitmap[bank] = sparse_banks[sbank++];
1481 
1482 	if (likely(!atomic_read(&hv->num_mismatched_vp_indexes))) {
1483 		/* for all vcpus vp_index == vcpu_idx */
1484 		return (unsigned long *)vp_bitmap;
1485 	}
1486 
1487 	bitmap_zero(vcpu_bitmap, KVM_MAX_VCPUS);
1488 	kvm_for_each_vcpu(i, vcpu, kvm) {
1489 		if (test_bit(vcpu_to_hv_vcpu(vcpu)->vp_index,
1490 			     (unsigned long *)vp_bitmap))
1491 			__set_bit(i, vcpu_bitmap);
1492 	}
1493 	return vcpu_bitmap;
1494 }
1495 
kvm_hv_flush_tlb(struct kvm_vcpu * current_vcpu,u64 ingpa,u16 rep_cnt,bool ex)1496 static u64 kvm_hv_flush_tlb(struct kvm_vcpu *current_vcpu, u64 ingpa,
1497 			    u16 rep_cnt, bool ex)
1498 {
1499 	struct kvm *kvm = current_vcpu->kvm;
1500 	struct kvm_vcpu_hv *hv_vcpu = &current_vcpu->arch.hyperv;
1501 	struct hv_tlb_flush_ex flush_ex;
1502 	struct hv_tlb_flush flush;
1503 	u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1504 	DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS);
1505 	unsigned long *vcpu_mask;
1506 	u64 valid_bank_mask;
1507 	u64 sparse_banks[64];
1508 	int sparse_banks_len;
1509 	bool all_cpus;
1510 
1511 	if (!ex) {
1512 		if (unlikely(kvm_read_guest(kvm, ingpa, &flush, sizeof(flush))))
1513 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1514 
1515 		trace_kvm_hv_flush_tlb(flush.processor_mask,
1516 				       flush.address_space, flush.flags);
1517 
1518 		valid_bank_mask = BIT_ULL(0);
1519 		sparse_banks[0] = flush.processor_mask;
1520 
1521 		/*
1522 		 * Work around possible WS2012 bug: it sends hypercalls
1523 		 * with processor_mask = 0x0 and HV_FLUSH_ALL_PROCESSORS clear,
1524 		 * while also expecting us to flush something and crashing if
1525 		 * we don't. Let's treat processor_mask == 0 same as
1526 		 * HV_FLUSH_ALL_PROCESSORS.
1527 		 */
1528 		all_cpus = (flush.flags & HV_FLUSH_ALL_PROCESSORS) ||
1529 			flush.processor_mask == 0;
1530 	} else {
1531 		if (unlikely(kvm_read_guest(kvm, ingpa, &flush_ex,
1532 					    sizeof(flush_ex))))
1533 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1534 
1535 		trace_kvm_hv_flush_tlb_ex(flush_ex.hv_vp_set.valid_bank_mask,
1536 					  flush_ex.hv_vp_set.format,
1537 					  flush_ex.address_space,
1538 					  flush_ex.flags);
1539 
1540 		valid_bank_mask = flush_ex.hv_vp_set.valid_bank_mask;
1541 		all_cpus = flush_ex.hv_vp_set.format !=
1542 			HV_GENERIC_SET_SPARSE_4K;
1543 
1544 		sparse_banks_len =
1545 			bitmap_weight((unsigned long *)&valid_bank_mask, 64) *
1546 			sizeof(sparse_banks[0]);
1547 
1548 		if (!sparse_banks_len && !all_cpus)
1549 			goto ret_success;
1550 
1551 		if (!all_cpus &&
1552 		    kvm_read_guest(kvm,
1553 				   ingpa + offsetof(struct hv_tlb_flush_ex,
1554 						    hv_vp_set.bank_contents),
1555 				   sparse_banks,
1556 				   sparse_banks_len))
1557 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1558 	}
1559 
1560 	cpumask_clear(&hv_vcpu->tlb_flush);
1561 
1562 	vcpu_mask = all_cpus ? NULL :
1563 		sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
1564 					vp_bitmap, vcpu_bitmap);
1565 
1566 	/*
1567 	 * vcpu->arch.cr3 may not be up-to-date for running vCPUs so we can't
1568 	 * analyze it here, flush TLB regardless of the specified address space.
1569 	 */
1570 	kvm_make_vcpus_request_mask(kvm, KVM_REQ_TLB_FLUSH_GUEST,
1571 				    NULL, vcpu_mask, &hv_vcpu->tlb_flush);
1572 
1573 ret_success:
1574 	/* We always do full TLB flush, set rep_done = rep_cnt. */
1575 	return (u64)HV_STATUS_SUCCESS |
1576 		((u64)rep_cnt << HV_HYPERCALL_REP_COMP_OFFSET);
1577 }
1578 
kvm_send_ipi_to_many(struct kvm * kvm,u32 vector,unsigned long * vcpu_bitmap)1579 static void kvm_send_ipi_to_many(struct kvm *kvm, u32 vector,
1580 				 unsigned long *vcpu_bitmap)
1581 {
1582 	struct kvm_lapic_irq irq = {
1583 		.delivery_mode = APIC_DM_FIXED,
1584 		.vector = vector
1585 	};
1586 	struct kvm_vcpu *vcpu;
1587 	int i;
1588 
1589 	kvm_for_each_vcpu(i, vcpu, kvm) {
1590 		if (vcpu_bitmap && !test_bit(i, vcpu_bitmap))
1591 			continue;
1592 
1593 		/* We fail only when APIC is disabled */
1594 		kvm_apic_set_irq(vcpu, &irq, NULL);
1595 	}
1596 }
1597 
kvm_hv_send_ipi(struct kvm_vcpu * current_vcpu,u64 ingpa,u64 outgpa,bool ex,bool fast)1598 static u64 kvm_hv_send_ipi(struct kvm_vcpu *current_vcpu, u64 ingpa, u64 outgpa,
1599 			   bool ex, bool fast)
1600 {
1601 	struct kvm *kvm = current_vcpu->kvm;
1602 	struct hv_send_ipi_ex send_ipi_ex;
1603 	struct hv_send_ipi send_ipi;
1604 	u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1605 	DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS);
1606 	unsigned long *vcpu_mask;
1607 	unsigned long valid_bank_mask;
1608 	u64 sparse_banks[64];
1609 	int sparse_banks_len;
1610 	u32 vector;
1611 	bool all_cpus;
1612 
1613 	if (!ex) {
1614 		if (!fast) {
1615 			if (unlikely(kvm_read_guest(kvm, ingpa, &send_ipi,
1616 						    sizeof(send_ipi))))
1617 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1618 			sparse_banks[0] = send_ipi.cpu_mask;
1619 			vector = send_ipi.vector;
1620 		} else {
1621 			/* 'reserved' part of hv_send_ipi should be 0 */
1622 			if (unlikely(ingpa >> 32 != 0))
1623 				return HV_STATUS_INVALID_HYPERCALL_INPUT;
1624 			sparse_banks[0] = outgpa;
1625 			vector = (u32)ingpa;
1626 		}
1627 		all_cpus = false;
1628 		valid_bank_mask = BIT_ULL(0);
1629 
1630 		trace_kvm_hv_send_ipi(vector, sparse_banks[0]);
1631 	} else {
1632 		if (unlikely(kvm_read_guest(kvm, ingpa, &send_ipi_ex,
1633 					    sizeof(send_ipi_ex))))
1634 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1635 
1636 		trace_kvm_hv_send_ipi_ex(send_ipi_ex.vector,
1637 					 send_ipi_ex.vp_set.format,
1638 					 send_ipi_ex.vp_set.valid_bank_mask);
1639 
1640 		vector = send_ipi_ex.vector;
1641 		valid_bank_mask = send_ipi_ex.vp_set.valid_bank_mask;
1642 		sparse_banks_len = bitmap_weight(&valid_bank_mask, 64) *
1643 			sizeof(sparse_banks[0]);
1644 
1645 		all_cpus = send_ipi_ex.vp_set.format == HV_GENERIC_SET_ALL;
1646 
1647 		if (all_cpus)
1648 			goto check_and_send_ipi;
1649 
1650 		if (!sparse_banks_len)
1651 			goto ret_success;
1652 
1653 		if (kvm_read_guest(kvm,
1654 				   ingpa + offsetof(struct hv_send_ipi_ex,
1655 						    vp_set.bank_contents),
1656 				   sparse_banks,
1657 				   sparse_banks_len))
1658 			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1659 	}
1660 
1661 check_and_send_ipi:
1662 	if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR))
1663 		return HV_STATUS_INVALID_HYPERCALL_INPUT;
1664 
1665 	vcpu_mask = all_cpus ? NULL :
1666 		sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
1667 					vp_bitmap, vcpu_bitmap);
1668 
1669 	kvm_send_ipi_to_many(kvm, vector, vcpu_mask);
1670 
1671 ret_success:
1672 	return HV_STATUS_SUCCESS;
1673 }
1674 
kvm_hv_hypercall_enabled(struct kvm * kvm)1675 bool kvm_hv_hypercall_enabled(struct kvm *kvm)
1676 {
1677 	return READ_ONCE(kvm->arch.hyperv.hv_guest_os_id) != 0;
1678 }
1679 
kvm_hv_hypercall_set_result(struct kvm_vcpu * vcpu,u64 result)1680 static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
1681 {
1682 	bool longmode;
1683 
1684 	longmode = is_64_bit_mode(vcpu);
1685 	if (longmode)
1686 		kvm_rax_write(vcpu, result);
1687 	else {
1688 		kvm_rdx_write(vcpu, result >> 32);
1689 		kvm_rax_write(vcpu, result & 0xffffffff);
1690 	}
1691 }
1692 
kvm_hv_hypercall_complete(struct kvm_vcpu * vcpu,u64 result)1693 static int kvm_hv_hypercall_complete(struct kvm_vcpu *vcpu, u64 result)
1694 {
1695 	kvm_hv_hypercall_set_result(vcpu, result);
1696 	++vcpu->stat.hypercalls;
1697 	return kvm_skip_emulated_instruction(vcpu);
1698 }
1699 
kvm_hv_hypercall_complete_userspace(struct kvm_vcpu * vcpu)1700 static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
1701 {
1702 	return kvm_hv_hypercall_complete(vcpu, vcpu->run->hyperv.u.hcall.result);
1703 }
1704 
kvm_hvcall_signal_event(struct kvm_vcpu * vcpu,bool fast,u64 param)1705 static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, bool fast, u64 param)
1706 {
1707 	struct eventfd_ctx *eventfd;
1708 
1709 	if (unlikely(!fast)) {
1710 		int ret;
1711 		gpa_t gpa = param;
1712 
1713 		if ((gpa & (__alignof__(param) - 1)) ||
1714 		    offset_in_page(gpa) + sizeof(param) > PAGE_SIZE)
1715 			return HV_STATUS_INVALID_ALIGNMENT;
1716 
1717 		ret = kvm_vcpu_read_guest(vcpu, gpa, &param, sizeof(param));
1718 		if (ret < 0)
1719 			return HV_STATUS_INVALID_ALIGNMENT;
1720 	}
1721 
1722 	/*
1723 	 * Per spec, bits 32-47 contain the extra "flag number".  However, we
1724 	 * have no use for it, and in all known usecases it is zero, so just
1725 	 * report lookup failure if it isn't.
1726 	 */
1727 	if (param & 0xffff00000000ULL)
1728 		return HV_STATUS_INVALID_PORT_ID;
1729 	/* remaining bits are reserved-zero */
1730 	if (param & ~KVM_HYPERV_CONN_ID_MASK)
1731 		return HV_STATUS_INVALID_HYPERCALL_INPUT;
1732 
1733 	/* the eventfd is protected by vcpu->kvm->srcu, but conn_to_evt isn't */
1734 	rcu_read_lock();
1735 	eventfd = idr_find(&vcpu->kvm->arch.hyperv.conn_to_evt, param);
1736 	rcu_read_unlock();
1737 	if (!eventfd)
1738 		return HV_STATUS_INVALID_PORT_ID;
1739 
1740 	eventfd_signal(eventfd, 1);
1741 	return HV_STATUS_SUCCESS;
1742 }
1743 
kvm_hv_hypercall(struct kvm_vcpu * vcpu)1744 int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
1745 {
1746 	u64 param, ingpa, outgpa, ret = HV_STATUS_SUCCESS;
1747 	uint16_t code, rep_idx, rep_cnt;
1748 	bool fast, rep;
1749 
1750 	/*
1751 	 * hypercall generates UD from non zero cpl and real mode
1752 	 * per HYPER-V spec
1753 	 */
1754 	if (kvm_x86_ops.get_cpl(vcpu) != 0 || !is_protmode(vcpu)) {
1755 		kvm_queue_exception(vcpu, UD_VECTOR);
1756 		return 1;
1757 	}
1758 
1759 #ifdef CONFIG_X86_64
1760 	if (is_64_bit_mode(vcpu)) {
1761 		param = kvm_rcx_read(vcpu);
1762 		ingpa = kvm_rdx_read(vcpu);
1763 		outgpa = kvm_r8_read(vcpu);
1764 	} else
1765 #endif
1766 	{
1767 		param = ((u64)kvm_rdx_read(vcpu) << 32) |
1768 			(kvm_rax_read(vcpu) & 0xffffffff);
1769 		ingpa = ((u64)kvm_rbx_read(vcpu) << 32) |
1770 			(kvm_rcx_read(vcpu) & 0xffffffff);
1771 		outgpa = ((u64)kvm_rdi_read(vcpu) << 32) |
1772 			(kvm_rsi_read(vcpu) & 0xffffffff);
1773 	}
1774 
1775 	code = param & 0xffff;
1776 	fast = !!(param & HV_HYPERCALL_FAST_BIT);
1777 	rep_cnt = (param >> HV_HYPERCALL_REP_COMP_OFFSET) & 0xfff;
1778 	rep_idx = (param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff;
1779 	rep = !!(rep_cnt || rep_idx);
1780 
1781 	trace_kvm_hv_hypercall(code, fast, rep_cnt, rep_idx, ingpa, outgpa);
1782 
1783 	switch (code) {
1784 	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
1785 		if (unlikely(rep)) {
1786 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1787 			break;
1788 		}
1789 		kvm_vcpu_on_spin(vcpu, true);
1790 		break;
1791 	case HVCALL_SIGNAL_EVENT:
1792 		if (unlikely(rep)) {
1793 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1794 			break;
1795 		}
1796 		ret = kvm_hvcall_signal_event(vcpu, fast, ingpa);
1797 		if (ret != HV_STATUS_INVALID_PORT_ID)
1798 			break;
1799 		fallthrough;	/* maybe userspace knows this conn_id */
1800 	case HVCALL_POST_MESSAGE:
1801 		/* don't bother userspace if it has no way to handle it */
1802 		if (unlikely(rep || !vcpu_to_synic(vcpu)->active)) {
1803 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1804 			break;
1805 		}
1806 		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
1807 		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
1808 		vcpu->run->hyperv.u.hcall.input = param;
1809 		vcpu->run->hyperv.u.hcall.params[0] = ingpa;
1810 		vcpu->run->hyperv.u.hcall.params[1] = outgpa;
1811 		vcpu->arch.complete_userspace_io =
1812 				kvm_hv_hypercall_complete_userspace;
1813 		return 0;
1814 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
1815 		if (unlikely(fast || !rep_cnt || rep_idx)) {
1816 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1817 			break;
1818 		}
1819 		ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, false);
1820 		break;
1821 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
1822 		if (unlikely(fast || rep)) {
1823 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1824 			break;
1825 		}
1826 		ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, false);
1827 		break;
1828 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
1829 		if (unlikely(fast || !rep_cnt || rep_idx)) {
1830 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1831 			break;
1832 		}
1833 		ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, true);
1834 		break;
1835 	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
1836 		if (unlikely(fast || rep)) {
1837 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1838 			break;
1839 		}
1840 		ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, true);
1841 		break;
1842 	case HVCALL_SEND_IPI:
1843 		if (unlikely(rep)) {
1844 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1845 			break;
1846 		}
1847 		ret = kvm_hv_send_ipi(vcpu, ingpa, outgpa, false, fast);
1848 		break;
1849 	case HVCALL_SEND_IPI_EX:
1850 		if (unlikely(fast || rep)) {
1851 			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1852 			break;
1853 		}
1854 		ret = kvm_hv_send_ipi(vcpu, ingpa, outgpa, true, false);
1855 		break;
1856 	case HVCALL_POST_DEBUG_DATA:
1857 	case HVCALL_RETRIEVE_DEBUG_DATA:
1858 		if (unlikely(fast)) {
1859 			ret = HV_STATUS_INVALID_PARAMETER;
1860 			break;
1861 		}
1862 		fallthrough;
1863 	case HVCALL_RESET_DEBUG_SESSION: {
1864 		struct kvm_hv_syndbg *syndbg = vcpu_to_hv_syndbg(vcpu);
1865 
1866 		if (!kvm_hv_is_syndbg_enabled(vcpu)) {
1867 			ret = HV_STATUS_INVALID_HYPERCALL_CODE;
1868 			break;
1869 		}
1870 
1871 		if (!(syndbg->options & HV_X64_SYNDBG_OPTION_USE_HCALLS)) {
1872 			ret = HV_STATUS_OPERATION_DENIED;
1873 			break;
1874 		}
1875 		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
1876 		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
1877 		vcpu->run->hyperv.u.hcall.input = param;
1878 		vcpu->run->hyperv.u.hcall.params[0] = ingpa;
1879 		vcpu->run->hyperv.u.hcall.params[1] = outgpa;
1880 		vcpu->arch.complete_userspace_io =
1881 				kvm_hv_hypercall_complete_userspace;
1882 		return 0;
1883 	}
1884 	default:
1885 		ret = HV_STATUS_INVALID_HYPERCALL_CODE;
1886 		break;
1887 	}
1888 
1889 	return kvm_hv_hypercall_complete(vcpu, ret);
1890 }
1891 
kvm_hv_init_vm(struct kvm * kvm)1892 void kvm_hv_init_vm(struct kvm *kvm)
1893 {
1894 	mutex_init(&kvm->arch.hyperv.hv_lock);
1895 	idr_init(&kvm->arch.hyperv.conn_to_evt);
1896 }
1897 
kvm_hv_destroy_vm(struct kvm * kvm)1898 void kvm_hv_destroy_vm(struct kvm *kvm)
1899 {
1900 	struct eventfd_ctx *eventfd;
1901 	int i;
1902 
1903 	idr_for_each_entry(&kvm->arch.hyperv.conn_to_evt, eventfd, i)
1904 		eventfd_ctx_put(eventfd);
1905 	idr_destroy(&kvm->arch.hyperv.conn_to_evt);
1906 }
1907 
kvm_hv_eventfd_assign(struct kvm * kvm,u32 conn_id,int fd)1908 static int kvm_hv_eventfd_assign(struct kvm *kvm, u32 conn_id, int fd)
1909 {
1910 	struct kvm_hv *hv = &kvm->arch.hyperv;
1911 	struct eventfd_ctx *eventfd;
1912 	int ret;
1913 
1914 	eventfd = eventfd_ctx_fdget(fd);
1915 	if (IS_ERR(eventfd))
1916 		return PTR_ERR(eventfd);
1917 
1918 	mutex_lock(&hv->hv_lock);
1919 	ret = idr_alloc(&hv->conn_to_evt, eventfd, conn_id, conn_id + 1,
1920 			GFP_KERNEL_ACCOUNT);
1921 	mutex_unlock(&hv->hv_lock);
1922 
1923 	if (ret >= 0)
1924 		return 0;
1925 
1926 	if (ret == -ENOSPC)
1927 		ret = -EEXIST;
1928 	eventfd_ctx_put(eventfd);
1929 	return ret;
1930 }
1931 
kvm_hv_eventfd_deassign(struct kvm * kvm,u32 conn_id)1932 static int kvm_hv_eventfd_deassign(struct kvm *kvm, u32 conn_id)
1933 {
1934 	struct kvm_hv *hv = &kvm->arch.hyperv;
1935 	struct eventfd_ctx *eventfd;
1936 
1937 	mutex_lock(&hv->hv_lock);
1938 	eventfd = idr_remove(&hv->conn_to_evt, conn_id);
1939 	mutex_unlock(&hv->hv_lock);
1940 
1941 	if (!eventfd)
1942 		return -ENOENT;
1943 
1944 	synchronize_srcu(&kvm->srcu);
1945 	eventfd_ctx_put(eventfd);
1946 	return 0;
1947 }
1948 
kvm_vm_ioctl_hv_eventfd(struct kvm * kvm,struct kvm_hyperv_eventfd * args)1949 int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args)
1950 {
1951 	if ((args->flags & ~KVM_HYPERV_EVENTFD_DEASSIGN) ||
1952 	    (args->conn_id & ~KVM_HYPERV_CONN_ID_MASK))
1953 		return -EINVAL;
1954 
1955 	if (args->flags == KVM_HYPERV_EVENTFD_DEASSIGN)
1956 		return kvm_hv_eventfd_deassign(kvm, args->conn_id);
1957 	return kvm_hv_eventfd_assign(kvm, args->conn_id, args->fd);
1958 }
1959 
kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu * vcpu,struct kvm_cpuid2 * cpuid,struct kvm_cpuid_entry2 __user * entries)1960 int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
1961 				struct kvm_cpuid_entry2 __user *entries)
1962 {
1963 	uint16_t evmcs_ver = 0;
1964 	struct kvm_cpuid_entry2 cpuid_entries[] = {
1965 		{ .function = HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS },
1966 		{ .function = HYPERV_CPUID_INTERFACE },
1967 		{ .function = HYPERV_CPUID_VERSION },
1968 		{ .function = HYPERV_CPUID_FEATURES },
1969 		{ .function = HYPERV_CPUID_ENLIGHTMENT_INFO },
1970 		{ .function = HYPERV_CPUID_IMPLEMENT_LIMITS },
1971 		{ .function = HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS },
1972 		{ .function = HYPERV_CPUID_SYNDBG_INTERFACE },
1973 		{ .function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES	},
1974 		{ .function = HYPERV_CPUID_NESTED_FEATURES },
1975 	};
1976 	int i, nent = ARRAY_SIZE(cpuid_entries);
1977 
1978 	if (kvm_x86_ops.nested_ops->get_evmcs_version)
1979 		evmcs_ver = kvm_x86_ops.nested_ops->get_evmcs_version(vcpu);
1980 
1981 	/* Skip NESTED_FEATURES if eVMCS is not supported */
1982 	if (!evmcs_ver)
1983 		--nent;
1984 
1985 	if (cpuid->nent < nent)
1986 		return -E2BIG;
1987 
1988 	if (cpuid->nent > nent)
1989 		cpuid->nent = nent;
1990 
1991 	for (i = 0; i < nent; i++) {
1992 		struct kvm_cpuid_entry2 *ent = &cpuid_entries[i];
1993 		u32 signature[3];
1994 
1995 		switch (ent->function) {
1996 		case HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS:
1997 			memcpy(signature, "Linux KVM Hv", 12);
1998 
1999 			ent->eax = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES;
2000 			ent->ebx = signature[0];
2001 			ent->ecx = signature[1];
2002 			ent->edx = signature[2];
2003 			break;
2004 
2005 		case HYPERV_CPUID_INTERFACE:
2006 			memcpy(signature, "Hv#1\0\0\0\0\0\0\0\0", 12);
2007 			ent->eax = signature[0];
2008 			break;
2009 
2010 		case HYPERV_CPUID_VERSION:
2011 			/*
2012 			 * We implement some Hyper-V 2016 functions so let's use
2013 			 * this version.
2014 			 */
2015 			ent->eax = 0x00003839;
2016 			ent->ebx = 0x000A0000;
2017 			break;
2018 
2019 		case HYPERV_CPUID_FEATURES:
2020 			ent->eax |= HV_MSR_VP_RUNTIME_AVAILABLE;
2021 			ent->eax |= HV_MSR_TIME_REF_COUNT_AVAILABLE;
2022 			ent->eax |= HV_MSR_SYNIC_AVAILABLE;
2023 			ent->eax |= HV_MSR_SYNTIMER_AVAILABLE;
2024 			ent->eax |= HV_MSR_APIC_ACCESS_AVAILABLE;
2025 			ent->eax |= HV_MSR_HYPERCALL_AVAILABLE;
2026 			ent->eax |= HV_MSR_VP_INDEX_AVAILABLE;
2027 			ent->eax |= HV_MSR_RESET_AVAILABLE;
2028 			ent->eax |= HV_MSR_REFERENCE_TSC_AVAILABLE;
2029 			ent->eax |= HV_ACCESS_FREQUENCY_MSRS;
2030 			ent->eax |= HV_ACCESS_REENLIGHTENMENT;
2031 
2032 			ent->ebx |= HV_POST_MESSAGES;
2033 			ent->ebx |= HV_SIGNAL_EVENTS;
2034 
2035 			ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
2036 			ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
2037 
2038 			ent->ebx |= HV_DEBUGGING;
2039 			ent->edx |= HV_X64_GUEST_DEBUGGING_AVAILABLE;
2040 			ent->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
2041 
2042 			/*
2043 			 * Direct Synthetic timers only make sense with in-kernel
2044 			 * LAPIC
2045 			 */
2046 			if (lapic_in_kernel(vcpu))
2047 				ent->edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
2048 
2049 			break;
2050 
2051 		case HYPERV_CPUID_ENLIGHTMENT_INFO:
2052 			ent->eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
2053 			ent->eax |= HV_X64_APIC_ACCESS_RECOMMENDED;
2054 			ent->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED;
2055 			ent->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
2056 			ent->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
2057 			if (evmcs_ver)
2058 				ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;
2059 			if (!cpu_smt_possible())
2060 				ent->eax |= HV_X64_NO_NONARCH_CORESHARING;
2061 			/*
2062 			 * Default number of spinlock retry attempts, matches
2063 			 * HyperV 2016.
2064 			 */
2065 			ent->ebx = 0x00000FFF;
2066 
2067 			break;
2068 
2069 		case HYPERV_CPUID_IMPLEMENT_LIMITS:
2070 			/* Maximum number of virtual processors */
2071 			ent->eax = KVM_MAX_VCPUS;
2072 			/*
2073 			 * Maximum number of logical processors, matches
2074 			 * HyperV 2016.
2075 			 */
2076 			ent->ebx = 64;
2077 
2078 			break;
2079 
2080 		case HYPERV_CPUID_NESTED_FEATURES:
2081 			ent->eax = evmcs_ver;
2082 
2083 			break;
2084 
2085 		case HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS:
2086 			memcpy(signature, "Linux KVM Hv", 12);
2087 
2088 			ent->eax = 0;
2089 			ent->ebx = signature[0];
2090 			ent->ecx = signature[1];
2091 			ent->edx = signature[2];
2092 			break;
2093 
2094 		case HYPERV_CPUID_SYNDBG_INTERFACE:
2095 			memcpy(signature, "VS#1\0\0\0\0\0\0\0\0", 12);
2096 			ent->eax = signature[0];
2097 			break;
2098 
2099 		case HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES:
2100 			ent->eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
2101 			break;
2102 
2103 		default:
2104 			break;
2105 		}
2106 	}
2107 
2108 	if (copy_to_user(entries, cpuid_entries,
2109 			 nent * sizeof(struct kvm_cpuid_entry2)))
2110 		return -EFAULT;
2111 
2112 	return 0;
2113 }
2114