xref: /kernel/linux/linux-6.6/arch/x86/kvm/hyperv.c (revision 62306a36)
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
22#include "x86.h"
23#include "lapic.h"
24#include "ioapic.h"
25#include "cpuid.h"
26#include "hyperv.h"
27#include "mmu.h"
28#include "xen.h"
29
30#include <linux/cpu.h>
31#include <linux/kvm_host.h>
32#include <linux/highmem.h>
33#include <linux/sched/cputime.h>
34#include <linux/spinlock.h>
35#include <linux/eventfd.h>
36
37#include <asm/apicdef.h>
38#include <asm/mshyperv.h>
39#include <trace/events/kvm.h>
40
41#include "trace.h"
42#include "irq.h"
43#include "fpu.h"
44
45#define KVM_HV_MAX_SPARSE_VCPU_SET_BITS DIV_ROUND_UP(KVM_MAX_VCPUS, HV_VCPUS_PER_SPARSE_BANK)
46
47/*
48 * As per Hyper-V TLFS, extended hypercalls start from 0x8001
49 * (HvExtCallQueryCapabilities). Response of this hypercalls is a 64 bit value
50 * where each bit tells which extended hypercall is available besides
51 * HvExtCallQueryCapabilities.
52 *
53 * 0x8001 - First extended hypercall, HvExtCallQueryCapabilities, no bit
54 * assigned.
55 *
56 * 0x8002 - Bit 0
57 * 0x8003 - Bit 1
58 * ..
59 * 0x8041 - Bit 63
60 *
61 * Therefore, HV_EXT_CALL_MAX = 0x8001 + 64
62 */
63#define HV_EXT_CALL_MAX (HV_EXT_CALL_QUERY_CAPABILITIES + 64)
64
65static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
66				bool vcpu_kick);
67
68static inline u64 synic_read_sint(struct kvm_vcpu_hv_synic *synic, int sint)
69{
70	return atomic64_read(&synic->sint[sint]);
71}
72
73static inline int synic_get_sint_vector(u64 sint_value)
74{
75	if (sint_value & HV_SYNIC_SINT_MASKED)
76		return -1;
77	return sint_value & HV_SYNIC_SINT_VECTOR_MASK;
78}
79
80static bool synic_has_vector_connected(struct kvm_vcpu_hv_synic *synic,
81				      int vector)
82{
83	int i;
84
85	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
86		if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
87			return true;
88	}
89	return false;
90}
91
92static bool synic_has_vector_auto_eoi(struct kvm_vcpu_hv_synic *synic,
93				     int vector)
94{
95	int i;
96	u64 sint_value;
97
98	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
99		sint_value = synic_read_sint(synic, i);
100		if (synic_get_sint_vector(sint_value) == vector &&
101		    sint_value & HV_SYNIC_SINT_AUTO_EOI)
102			return true;
103	}
104	return false;
105}
106
107static void synic_update_vector(struct kvm_vcpu_hv_synic *synic,
108				int vector)
109{
110	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
111	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
112	bool auto_eoi_old, auto_eoi_new;
113
114	if (vector < HV_SYNIC_FIRST_VALID_VECTOR)
115		return;
116
117	if (synic_has_vector_connected(synic, vector))
118		__set_bit(vector, synic->vec_bitmap);
119	else
120		__clear_bit(vector, synic->vec_bitmap);
121
122	auto_eoi_old = !bitmap_empty(synic->auto_eoi_bitmap, 256);
123
124	if (synic_has_vector_auto_eoi(synic, vector))
125		__set_bit(vector, synic->auto_eoi_bitmap);
126	else
127		__clear_bit(vector, synic->auto_eoi_bitmap);
128
129	auto_eoi_new = !bitmap_empty(synic->auto_eoi_bitmap, 256);
130
131	if (auto_eoi_old == auto_eoi_new)
132		return;
133
134	if (!enable_apicv)
135		return;
136
137	down_write(&vcpu->kvm->arch.apicv_update_lock);
138
139	if (auto_eoi_new)
140		hv->synic_auto_eoi_used++;
141	else
142		hv->synic_auto_eoi_used--;
143
144	/*
145	 * Inhibit APICv if any vCPU is using SynIC's AutoEOI, which relies on
146	 * the hypervisor to manually inject IRQs.
147	 */
148	__kvm_set_or_clear_apicv_inhibit(vcpu->kvm,
149					 APICV_INHIBIT_REASON_HYPERV,
150					 !!hv->synic_auto_eoi_used);
151
152	up_write(&vcpu->kvm->arch.apicv_update_lock);
153}
154
155static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint,
156			  u64 data, bool host)
157{
158	int vector, old_vector;
159	bool masked;
160
161	vector = data & HV_SYNIC_SINT_VECTOR_MASK;
162	masked = data & HV_SYNIC_SINT_MASKED;
163
164	/*
165	 * Valid vectors are 16-255, however, nested Hyper-V attempts to write
166	 * default '0x10000' value on boot and this should not #GP. We need to
167	 * allow zero-initing the register from host as well.
168	 */
169	if (vector < HV_SYNIC_FIRST_VALID_VECTOR && !host && !masked)
170		return 1;
171	/*
172	 * Guest may configure multiple SINTs to use the same vector, so
173	 * we maintain a bitmap of vectors handled by synic, and a
174	 * bitmap of vectors with auto-eoi behavior.  The bitmaps are
175	 * updated here, and atomically queried on fast paths.
176	 */
177	old_vector = synic_read_sint(synic, sint) & HV_SYNIC_SINT_VECTOR_MASK;
178
179	atomic64_set(&synic->sint[sint], data);
180
181	synic_update_vector(synic, old_vector);
182
183	synic_update_vector(synic, vector);
184
185	/* Load SynIC vectors into EOI exit bitmap */
186	kvm_make_request(KVM_REQ_SCAN_IOAPIC, hv_synic_to_vcpu(synic));
187	return 0;
188}
189
190static struct kvm_vcpu *get_vcpu_by_vpidx(struct kvm *kvm, u32 vpidx)
191{
192	struct kvm_vcpu *vcpu = NULL;
193	unsigned long i;
194
195	if (vpidx >= KVM_MAX_VCPUS)
196		return NULL;
197
198	vcpu = kvm_get_vcpu(kvm, vpidx);
199	if (vcpu && kvm_hv_get_vpindex(vcpu) == vpidx)
200		return vcpu;
201	kvm_for_each_vcpu(i, vcpu, kvm)
202		if (kvm_hv_get_vpindex(vcpu) == vpidx)
203			return vcpu;
204	return NULL;
205}
206
207static struct kvm_vcpu_hv_synic *synic_get(struct kvm *kvm, u32 vpidx)
208{
209	struct kvm_vcpu *vcpu;
210	struct kvm_vcpu_hv_synic *synic;
211
212	vcpu = get_vcpu_by_vpidx(kvm, vpidx);
213	if (!vcpu || !to_hv_vcpu(vcpu))
214		return NULL;
215	synic = to_hv_synic(vcpu);
216	return (synic->active) ? synic : NULL;
217}
218
219static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
220{
221	struct kvm *kvm = vcpu->kvm;
222	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
223	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
224	struct kvm_vcpu_hv_stimer *stimer;
225	int gsi, idx;
226
227	trace_kvm_hv_notify_acked_sint(vcpu->vcpu_id, sint);
228
229	/* Try to deliver pending Hyper-V SynIC timers messages */
230	for (idx = 0; idx < ARRAY_SIZE(hv_vcpu->stimer); idx++) {
231		stimer = &hv_vcpu->stimer[idx];
232		if (stimer->msg_pending && stimer->config.enable &&
233		    !stimer->config.direct_mode &&
234		    stimer->config.sintx == sint)
235			stimer_mark_pending(stimer, false);
236	}
237
238	idx = srcu_read_lock(&kvm->irq_srcu);
239	gsi = atomic_read(&synic->sint_to_gsi[sint]);
240	if (gsi != -1)
241		kvm_notify_acked_gsi(kvm, gsi);
242	srcu_read_unlock(&kvm->irq_srcu, idx);
243}
244
245static void synic_exit(struct kvm_vcpu_hv_synic *synic, u32 msr)
246{
247	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
248	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
249
250	hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNIC;
251	hv_vcpu->exit.u.synic.msr = msr;
252	hv_vcpu->exit.u.synic.control = synic->control;
253	hv_vcpu->exit.u.synic.evt_page = synic->evt_page;
254	hv_vcpu->exit.u.synic.msg_page = synic->msg_page;
255
256	kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
257}
258
259static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
260			 u32 msr, u64 data, bool host)
261{
262	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
263	int ret;
264
265	if (!synic->active && (!host || data))
266		return 1;
267
268	trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host);
269
270	ret = 0;
271	switch (msr) {
272	case HV_X64_MSR_SCONTROL:
273		synic->control = data;
274		if (!host)
275			synic_exit(synic, msr);
276		break;
277	case HV_X64_MSR_SVERSION:
278		if (!host) {
279			ret = 1;
280			break;
281		}
282		synic->version = data;
283		break;
284	case HV_X64_MSR_SIEFP:
285		if ((data & HV_SYNIC_SIEFP_ENABLE) && !host &&
286		    !synic->dont_zero_synic_pages)
287			if (kvm_clear_guest(vcpu->kvm,
288					    data & PAGE_MASK, PAGE_SIZE)) {
289				ret = 1;
290				break;
291			}
292		synic->evt_page = data;
293		if (!host)
294			synic_exit(synic, msr);
295		break;
296	case HV_X64_MSR_SIMP:
297		if ((data & HV_SYNIC_SIMP_ENABLE) && !host &&
298		    !synic->dont_zero_synic_pages)
299			if (kvm_clear_guest(vcpu->kvm,
300					    data & PAGE_MASK, PAGE_SIZE)) {
301				ret = 1;
302				break;
303			}
304		synic->msg_page = data;
305		if (!host)
306			synic_exit(synic, msr);
307		break;
308	case HV_X64_MSR_EOM: {
309		int i;
310
311		if (!synic->active)
312			break;
313
314		for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
315			kvm_hv_notify_acked_sint(vcpu, i);
316		break;
317	}
318	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
319		ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data, host);
320		break;
321	default:
322		ret = 1;
323		break;
324	}
325	return ret;
326}
327
328static bool kvm_hv_is_syndbg_enabled(struct kvm_vcpu *vcpu)
329{
330	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
331
332	return hv_vcpu->cpuid_cache.syndbg_cap_eax &
333		HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
334}
335
336static int kvm_hv_syndbg_complete_userspace(struct kvm_vcpu *vcpu)
337{
338	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
339
340	if (vcpu->run->hyperv.u.syndbg.msr == HV_X64_MSR_SYNDBG_CONTROL)
341		hv->hv_syndbg.control.status =
342			vcpu->run->hyperv.u.syndbg.status;
343	return 1;
344}
345
346static void syndbg_exit(struct kvm_vcpu *vcpu, u32 msr)
347{
348	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
349	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
350
351	hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNDBG;
352	hv_vcpu->exit.u.syndbg.msr = msr;
353	hv_vcpu->exit.u.syndbg.control = syndbg->control.control;
354	hv_vcpu->exit.u.syndbg.send_page = syndbg->control.send_page;
355	hv_vcpu->exit.u.syndbg.recv_page = syndbg->control.recv_page;
356	hv_vcpu->exit.u.syndbg.pending_page = syndbg->control.pending_page;
357	vcpu->arch.complete_userspace_io =
358			kvm_hv_syndbg_complete_userspace;
359
360	kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
361}
362
363static int syndbg_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
364{
365	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
366
367	if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
368		return 1;
369
370	trace_kvm_hv_syndbg_set_msr(vcpu->vcpu_id,
371				    to_hv_vcpu(vcpu)->vp_index, msr, data);
372	switch (msr) {
373	case HV_X64_MSR_SYNDBG_CONTROL:
374		syndbg->control.control = data;
375		if (!host)
376			syndbg_exit(vcpu, msr);
377		break;
378	case HV_X64_MSR_SYNDBG_STATUS:
379		syndbg->control.status = data;
380		break;
381	case HV_X64_MSR_SYNDBG_SEND_BUFFER:
382		syndbg->control.send_page = data;
383		break;
384	case HV_X64_MSR_SYNDBG_RECV_BUFFER:
385		syndbg->control.recv_page = data;
386		break;
387	case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
388		syndbg->control.pending_page = data;
389		if (!host)
390			syndbg_exit(vcpu, msr);
391		break;
392	case HV_X64_MSR_SYNDBG_OPTIONS:
393		syndbg->options = data;
394		break;
395	default:
396		break;
397	}
398
399	return 0;
400}
401
402static int syndbg_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
403{
404	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
405
406	if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
407		return 1;
408
409	switch (msr) {
410	case HV_X64_MSR_SYNDBG_CONTROL:
411		*pdata = syndbg->control.control;
412		break;
413	case HV_X64_MSR_SYNDBG_STATUS:
414		*pdata = syndbg->control.status;
415		break;
416	case HV_X64_MSR_SYNDBG_SEND_BUFFER:
417		*pdata = syndbg->control.send_page;
418		break;
419	case HV_X64_MSR_SYNDBG_RECV_BUFFER:
420		*pdata = syndbg->control.recv_page;
421		break;
422	case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
423		*pdata = syndbg->control.pending_page;
424		break;
425	case HV_X64_MSR_SYNDBG_OPTIONS:
426		*pdata = syndbg->options;
427		break;
428	default:
429		break;
430	}
431
432	trace_kvm_hv_syndbg_get_msr(vcpu->vcpu_id, kvm_hv_get_vpindex(vcpu), msr, *pdata);
433
434	return 0;
435}
436
437static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata,
438			 bool host)
439{
440	int ret;
441
442	if (!synic->active && !host)
443		return 1;
444
445	ret = 0;
446	switch (msr) {
447	case HV_X64_MSR_SCONTROL:
448		*pdata = synic->control;
449		break;
450	case HV_X64_MSR_SVERSION:
451		*pdata = synic->version;
452		break;
453	case HV_X64_MSR_SIEFP:
454		*pdata = synic->evt_page;
455		break;
456	case HV_X64_MSR_SIMP:
457		*pdata = synic->msg_page;
458		break;
459	case HV_X64_MSR_EOM:
460		*pdata = 0;
461		break;
462	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
463		*pdata = atomic64_read(&synic->sint[msr - HV_X64_MSR_SINT0]);
464		break;
465	default:
466		ret = 1;
467		break;
468	}
469	return ret;
470}
471
472static int synic_set_irq(struct kvm_vcpu_hv_synic *synic, u32 sint)
473{
474	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
475	struct kvm_lapic_irq irq;
476	int ret, vector;
477
478	if (KVM_BUG_ON(!lapic_in_kernel(vcpu), vcpu->kvm))
479		return -EINVAL;
480
481	if (sint >= ARRAY_SIZE(synic->sint))
482		return -EINVAL;
483
484	vector = synic_get_sint_vector(synic_read_sint(synic, sint));
485	if (vector < 0)
486		return -ENOENT;
487
488	memset(&irq, 0, sizeof(irq));
489	irq.shorthand = APIC_DEST_SELF;
490	irq.dest_mode = APIC_DEST_PHYSICAL;
491	irq.delivery_mode = APIC_DM_FIXED;
492	irq.vector = vector;
493	irq.level = 1;
494
495	ret = kvm_irq_delivery_to_apic(vcpu->kvm, vcpu->arch.apic, &irq, NULL);
496	trace_kvm_hv_synic_set_irq(vcpu->vcpu_id, sint, irq.vector, ret);
497	return ret;
498}
499
500int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vpidx, u32 sint)
501{
502	struct kvm_vcpu_hv_synic *synic;
503
504	synic = synic_get(kvm, vpidx);
505	if (!synic)
506		return -EINVAL;
507
508	return synic_set_irq(synic, sint);
509}
510
511void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
512{
513	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
514	int i;
515
516	trace_kvm_hv_synic_send_eoi(vcpu->vcpu_id, vector);
517
518	for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
519		if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
520			kvm_hv_notify_acked_sint(vcpu, i);
521}
522
523static int kvm_hv_set_sint_gsi(struct kvm *kvm, u32 vpidx, u32 sint, int gsi)
524{
525	struct kvm_vcpu_hv_synic *synic;
526
527	synic = synic_get(kvm, vpidx);
528	if (!synic)
529		return -EINVAL;
530
531	if (sint >= ARRAY_SIZE(synic->sint_to_gsi))
532		return -EINVAL;
533
534	atomic_set(&synic->sint_to_gsi[sint], gsi);
535	return 0;
536}
537
538void kvm_hv_irq_routing_update(struct kvm *kvm)
539{
540	struct kvm_irq_routing_table *irq_rt;
541	struct kvm_kernel_irq_routing_entry *e;
542	u32 gsi;
543
544	irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
545					lockdep_is_held(&kvm->irq_lock));
546
547	for (gsi = 0; gsi < irq_rt->nr_rt_entries; gsi++) {
548		hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
549			if (e->type == KVM_IRQ_ROUTING_HV_SINT)
550				kvm_hv_set_sint_gsi(kvm, e->hv_sint.vcpu,
551						    e->hv_sint.sint, gsi);
552		}
553	}
554}
555
556static void synic_init(struct kvm_vcpu_hv_synic *synic)
557{
558	int i;
559
560	memset(synic, 0, sizeof(*synic));
561	synic->version = HV_SYNIC_VERSION_1;
562	for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
563		atomic64_set(&synic->sint[i], HV_SYNIC_SINT_MASKED);
564		atomic_set(&synic->sint_to_gsi[i], -1);
565	}
566}
567
568static u64 get_time_ref_counter(struct kvm *kvm)
569{
570	struct kvm_hv *hv = to_kvm_hv(kvm);
571	struct kvm_vcpu *vcpu;
572	u64 tsc;
573
574	/*
575	 * Fall back to get_kvmclock_ns() when TSC page hasn't been set up,
576	 * is broken, disabled or being updated.
577	 */
578	if (hv->hv_tsc_page_status != HV_TSC_PAGE_SET)
579		return div_u64(get_kvmclock_ns(kvm), 100);
580
581	vcpu = kvm_get_vcpu(kvm, 0);
582	tsc = kvm_read_l1_tsc(vcpu, rdtsc());
583	return mul_u64_u64_shr(tsc, hv->tsc_ref.tsc_scale, 64)
584		+ hv->tsc_ref.tsc_offset;
585}
586
587static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
588				bool vcpu_kick)
589{
590	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
591
592	set_bit(stimer->index,
593		to_hv_vcpu(vcpu)->stimer_pending_bitmap);
594	kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
595	if (vcpu_kick)
596		kvm_vcpu_kick(vcpu);
597}
598
599static void stimer_cleanup(struct kvm_vcpu_hv_stimer *stimer)
600{
601	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
602
603	trace_kvm_hv_stimer_cleanup(hv_stimer_to_vcpu(stimer)->vcpu_id,
604				    stimer->index);
605
606	hrtimer_cancel(&stimer->timer);
607	clear_bit(stimer->index,
608		  to_hv_vcpu(vcpu)->stimer_pending_bitmap);
609	stimer->msg_pending = false;
610	stimer->exp_time = 0;
611}
612
613static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer)
614{
615	struct kvm_vcpu_hv_stimer *stimer;
616
617	stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer);
618	trace_kvm_hv_stimer_callback(hv_stimer_to_vcpu(stimer)->vcpu_id,
619				     stimer->index);
620	stimer_mark_pending(stimer, true);
621
622	return HRTIMER_NORESTART;
623}
624
625/*
626 * stimer_start() assumptions:
627 * a) stimer->count is not equal to 0
628 * b) stimer->config has HV_STIMER_ENABLE flag
629 */
630static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
631{
632	u64 time_now;
633	ktime_t ktime_now;
634
635	time_now = get_time_ref_counter(hv_stimer_to_vcpu(stimer)->kvm);
636	ktime_now = ktime_get();
637
638	if (stimer->config.periodic) {
639		if (stimer->exp_time) {
640			if (time_now >= stimer->exp_time) {
641				u64 remainder;
642
643				div64_u64_rem(time_now - stimer->exp_time,
644					      stimer->count, &remainder);
645				stimer->exp_time =
646					time_now + (stimer->count - remainder);
647			}
648		} else
649			stimer->exp_time = time_now + stimer->count;
650
651		trace_kvm_hv_stimer_start_periodic(
652					hv_stimer_to_vcpu(stimer)->vcpu_id,
653					stimer->index,
654					time_now, stimer->exp_time);
655
656		hrtimer_start(&stimer->timer,
657			      ktime_add_ns(ktime_now,
658					   100 * (stimer->exp_time - time_now)),
659			      HRTIMER_MODE_ABS);
660		return 0;
661	}
662	stimer->exp_time = stimer->count;
663	if (time_now >= stimer->count) {
664		/*
665		 * Expire timer according to Hypervisor Top-Level Functional
666		 * specification v4(15.3.1):
667		 * "If a one shot is enabled and the specified count is in
668		 * the past, it will expire immediately."
669		 */
670		stimer_mark_pending(stimer, false);
671		return 0;
672	}
673
674	trace_kvm_hv_stimer_start_one_shot(hv_stimer_to_vcpu(stimer)->vcpu_id,
675					   stimer->index,
676					   time_now, stimer->count);
677
678	hrtimer_start(&stimer->timer,
679		      ktime_add_ns(ktime_now, 100 * (stimer->count - time_now)),
680		      HRTIMER_MODE_ABS);
681	return 0;
682}
683
684static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
685			     bool host)
686{
687	union hv_stimer_config new_config = {.as_uint64 = config},
688		old_config = {.as_uint64 = stimer->config.as_uint64};
689	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
690	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
691	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
692
693	if (!synic->active && (!host || config))
694		return 1;
695
696	if (unlikely(!host && hv_vcpu->enforce_cpuid && new_config.direct_mode &&
697		     !(hv_vcpu->cpuid_cache.features_edx &
698		       HV_STIMER_DIRECT_MODE_AVAILABLE)))
699		return 1;
700
701	trace_kvm_hv_stimer_set_config(hv_stimer_to_vcpu(stimer)->vcpu_id,
702				       stimer->index, config, host);
703
704	stimer_cleanup(stimer);
705	if (old_config.enable &&
706	    !new_config.direct_mode && new_config.sintx == 0)
707		new_config.enable = 0;
708	stimer->config.as_uint64 = new_config.as_uint64;
709
710	if (stimer->config.enable)
711		stimer_mark_pending(stimer, false);
712
713	return 0;
714}
715
716static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,
717			    bool host)
718{
719	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
720	struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
721
722	if (!synic->active && (!host || count))
723		return 1;
724
725	trace_kvm_hv_stimer_set_count(hv_stimer_to_vcpu(stimer)->vcpu_id,
726				      stimer->index, count, host);
727
728	stimer_cleanup(stimer);
729	stimer->count = count;
730	if (!host) {
731		if (stimer->count == 0)
732			stimer->config.enable = 0;
733		else if (stimer->config.auto_enable)
734			stimer->config.enable = 1;
735	}
736
737	if (stimer->config.enable)
738		stimer_mark_pending(stimer, false);
739
740	return 0;
741}
742
743static int stimer_get_config(struct kvm_vcpu_hv_stimer *stimer, u64 *pconfig)
744{
745	*pconfig = stimer->config.as_uint64;
746	return 0;
747}
748
749static int stimer_get_count(struct kvm_vcpu_hv_stimer *stimer, u64 *pcount)
750{
751	*pcount = stimer->count;
752	return 0;
753}
754
755static int synic_deliver_msg(struct kvm_vcpu_hv_synic *synic, u32 sint,
756			     struct hv_message *src_msg, bool no_retry)
757{
758	struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
759	int msg_off = offsetof(struct hv_message_page, sint_message[sint]);
760	gfn_t msg_page_gfn;
761	struct hv_message_header hv_hdr;
762	int r;
763
764	if (!(synic->msg_page & HV_SYNIC_SIMP_ENABLE))
765		return -ENOENT;
766
767	msg_page_gfn = synic->msg_page >> PAGE_SHIFT;
768
769	/*
770	 * Strictly following the spec-mandated ordering would assume setting
771	 * .msg_pending before checking .message_type.  However, this function
772	 * is only called in vcpu context so the entire update is atomic from
773	 * guest POV and thus the exact order here doesn't matter.
774	 */
775	r = kvm_vcpu_read_guest_page(vcpu, msg_page_gfn, &hv_hdr.message_type,
776				     msg_off + offsetof(struct hv_message,
777							header.message_type),
778				     sizeof(hv_hdr.message_type));
779	if (r < 0)
780		return r;
781
782	if (hv_hdr.message_type != HVMSG_NONE) {
783		if (no_retry)
784			return 0;
785
786		hv_hdr.message_flags.msg_pending = 1;
787		r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn,
788					      &hv_hdr.message_flags,
789					      msg_off +
790					      offsetof(struct hv_message,
791						       header.message_flags),
792					      sizeof(hv_hdr.message_flags));
793		if (r < 0)
794			return r;
795		return -EAGAIN;
796	}
797
798	r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn, src_msg, msg_off,
799				      sizeof(src_msg->header) +
800				      src_msg->header.payload_size);
801	if (r < 0)
802		return r;
803
804	r = synic_set_irq(synic, sint);
805	if (r < 0)
806		return r;
807	if (r == 0)
808		return -EFAULT;
809	return 0;
810}
811
812static int stimer_send_msg(struct kvm_vcpu_hv_stimer *stimer)
813{
814	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
815	struct hv_message *msg = &stimer->msg;
816	struct hv_timer_message_payload *payload =
817			(struct hv_timer_message_payload *)&msg->u.payload;
818
819	/*
820	 * To avoid piling up periodic ticks, don't retry message
821	 * delivery for them (within "lazy" lost ticks policy).
822	 */
823	bool no_retry = stimer->config.periodic;
824
825	payload->expiration_time = stimer->exp_time;
826	payload->delivery_time = get_time_ref_counter(vcpu->kvm);
827	return synic_deliver_msg(to_hv_synic(vcpu),
828				 stimer->config.sintx, msg,
829				 no_retry);
830}
831
832static int stimer_notify_direct(struct kvm_vcpu_hv_stimer *stimer)
833{
834	struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
835	struct kvm_lapic_irq irq = {
836		.delivery_mode = APIC_DM_FIXED,
837		.vector = stimer->config.apic_vector
838	};
839
840	if (lapic_in_kernel(vcpu))
841		return !kvm_apic_set_irq(vcpu, &irq, NULL);
842	return 0;
843}
844
845static void stimer_expiration(struct kvm_vcpu_hv_stimer *stimer)
846{
847	int r, direct = stimer->config.direct_mode;
848
849	stimer->msg_pending = true;
850	if (!direct)
851		r = stimer_send_msg(stimer);
852	else
853		r = stimer_notify_direct(stimer);
854	trace_kvm_hv_stimer_expiration(hv_stimer_to_vcpu(stimer)->vcpu_id,
855				       stimer->index, direct, r);
856	if (!r) {
857		stimer->msg_pending = false;
858		if (!(stimer->config.periodic))
859			stimer->config.enable = 0;
860	}
861}
862
863void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
864{
865	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
866	struct kvm_vcpu_hv_stimer *stimer;
867	u64 time_now, exp_time;
868	int i;
869
870	if (!hv_vcpu)
871		return;
872
873	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
874		if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) {
875			stimer = &hv_vcpu->stimer[i];
876			if (stimer->config.enable) {
877				exp_time = stimer->exp_time;
878
879				if (exp_time) {
880					time_now =
881						get_time_ref_counter(vcpu->kvm);
882					if (time_now >= exp_time)
883						stimer_expiration(stimer);
884				}
885
886				if ((stimer->config.enable) &&
887				    stimer->count) {
888					if (!stimer->msg_pending)
889						stimer_start(stimer);
890				} else
891					stimer_cleanup(stimer);
892			}
893		}
894}
895
896void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu)
897{
898	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
899	int i;
900
901	if (!hv_vcpu)
902		return;
903
904	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
905		stimer_cleanup(&hv_vcpu->stimer[i]);
906
907	kfree(hv_vcpu);
908	vcpu->arch.hyperv = NULL;
909}
910
911bool kvm_hv_assist_page_enabled(struct kvm_vcpu *vcpu)
912{
913	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
914
915	if (!hv_vcpu)
916		return false;
917
918	if (!(hv_vcpu->hv_vapic & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE))
919		return false;
920	return vcpu->arch.pv_eoi.msr_val & KVM_MSR_ENABLED;
921}
922EXPORT_SYMBOL_GPL(kvm_hv_assist_page_enabled);
923
924int kvm_hv_get_assist_page(struct kvm_vcpu *vcpu)
925{
926	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
927
928	if (!hv_vcpu || !kvm_hv_assist_page_enabled(vcpu))
929		return -EFAULT;
930
931	return kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data,
932				     &hv_vcpu->vp_assist_page, sizeof(struct hv_vp_assist_page));
933}
934EXPORT_SYMBOL_GPL(kvm_hv_get_assist_page);
935
936static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
937{
938	struct hv_message *msg = &stimer->msg;
939	struct hv_timer_message_payload *payload =
940			(struct hv_timer_message_payload *)&msg->u.payload;
941
942	memset(&msg->header, 0, sizeof(msg->header));
943	msg->header.message_type = HVMSG_TIMER_EXPIRED;
944	msg->header.payload_size = sizeof(*payload);
945
946	payload->timer_index = stimer->index;
947	payload->expiration_time = 0;
948	payload->delivery_time = 0;
949}
950
951static void stimer_init(struct kvm_vcpu_hv_stimer *stimer, int timer_index)
952{
953	memset(stimer, 0, sizeof(*stimer));
954	stimer->index = timer_index;
955	hrtimer_init(&stimer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
956	stimer->timer.function = stimer_timer_callback;
957	stimer_prepare_msg(stimer);
958}
959
960int kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
961{
962	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
963	int i;
964
965	if (hv_vcpu)
966		return 0;
967
968	hv_vcpu = kzalloc(sizeof(struct kvm_vcpu_hv), GFP_KERNEL_ACCOUNT);
969	if (!hv_vcpu)
970		return -ENOMEM;
971
972	vcpu->arch.hyperv = hv_vcpu;
973	hv_vcpu->vcpu = vcpu;
974
975	synic_init(&hv_vcpu->synic);
976
977	bitmap_zero(hv_vcpu->stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
978	for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
979		stimer_init(&hv_vcpu->stimer[i], i);
980
981	hv_vcpu->vp_index = vcpu->vcpu_idx;
982
983	for (i = 0; i < HV_NR_TLB_FLUSH_FIFOS; i++) {
984		INIT_KFIFO(hv_vcpu->tlb_flush_fifo[i].entries);
985		spin_lock_init(&hv_vcpu->tlb_flush_fifo[i].write_lock);
986	}
987
988	return 0;
989}
990
991int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages)
992{
993	struct kvm_vcpu_hv_synic *synic;
994	int r;
995
996	r = kvm_hv_vcpu_init(vcpu);
997	if (r)
998		return r;
999
1000	synic = to_hv_synic(vcpu);
1001
1002	synic->active = true;
1003	synic->dont_zero_synic_pages = dont_zero_synic_pages;
1004	synic->control = HV_SYNIC_CONTROL_ENABLE;
1005	return 0;
1006}
1007
1008static bool kvm_hv_msr_partition_wide(u32 msr)
1009{
1010	bool r = false;
1011
1012	switch (msr) {
1013	case HV_X64_MSR_GUEST_OS_ID:
1014	case HV_X64_MSR_HYPERCALL:
1015	case HV_X64_MSR_REFERENCE_TSC:
1016	case HV_X64_MSR_TIME_REF_COUNT:
1017	case HV_X64_MSR_CRASH_CTL:
1018	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1019	case HV_X64_MSR_RESET:
1020	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1021	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1022	case HV_X64_MSR_TSC_EMULATION_STATUS:
1023	case HV_X64_MSR_TSC_INVARIANT_CONTROL:
1024	case HV_X64_MSR_SYNDBG_OPTIONS:
1025	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1026		r = true;
1027		break;
1028	}
1029
1030	return r;
1031}
1032
1033static int kvm_hv_msr_get_crash_data(struct kvm *kvm, u32 index, u64 *pdata)
1034{
1035	struct kvm_hv *hv = to_kvm_hv(kvm);
1036	size_t size = ARRAY_SIZE(hv->hv_crash_param);
1037
1038	if (WARN_ON_ONCE(index >= size))
1039		return -EINVAL;
1040
1041	*pdata = hv->hv_crash_param[array_index_nospec(index, size)];
1042	return 0;
1043}
1044
1045static int kvm_hv_msr_get_crash_ctl(struct kvm *kvm, u64 *pdata)
1046{
1047	struct kvm_hv *hv = to_kvm_hv(kvm);
1048
1049	*pdata = hv->hv_crash_ctl;
1050	return 0;
1051}
1052
1053static int kvm_hv_msr_set_crash_ctl(struct kvm *kvm, u64 data)
1054{
1055	struct kvm_hv *hv = to_kvm_hv(kvm);
1056
1057	hv->hv_crash_ctl = data & HV_CRASH_CTL_CRASH_NOTIFY;
1058
1059	return 0;
1060}
1061
1062static int kvm_hv_msr_set_crash_data(struct kvm *kvm, u32 index, u64 data)
1063{
1064	struct kvm_hv *hv = to_kvm_hv(kvm);
1065	size_t size = ARRAY_SIZE(hv->hv_crash_param);
1066
1067	if (WARN_ON_ONCE(index >= size))
1068		return -EINVAL;
1069
1070	hv->hv_crash_param[array_index_nospec(index, size)] = data;
1071	return 0;
1072}
1073
1074/*
1075 * The kvmclock and Hyper-V TSC page use similar formulas, and converting
1076 * between them is possible:
1077 *
1078 * kvmclock formula:
1079 *    nsec = (ticks - tsc_timestamp) * tsc_to_system_mul * 2^(tsc_shift-32)
1080 *           + system_time
1081 *
1082 * Hyper-V formula:
1083 *    nsec/100 = ticks * scale / 2^64 + offset
1084 *
1085 * When tsc_timestamp = system_time = 0, offset is zero in the Hyper-V formula.
1086 * By dividing the kvmclock formula by 100 and equating what's left we get:
1087 *    ticks * scale / 2^64 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1088 *            scale / 2^64 =         tsc_to_system_mul * 2^(tsc_shift-32) / 100
1089 *            scale        =         tsc_to_system_mul * 2^(32+tsc_shift) / 100
1090 *
1091 * Now expand the kvmclock formula and divide by 100:
1092 *    nsec = ticks * tsc_to_system_mul * 2^(tsc_shift-32)
1093 *           - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32)
1094 *           + system_time
1095 *    nsec/100 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1096 *               - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1097 *               + system_time / 100
1098 *
1099 * Replace tsc_to_system_mul * 2^(tsc_shift-32) / 100 by scale / 2^64:
1100 *    nsec/100 = ticks * scale / 2^64
1101 *               - tsc_timestamp * scale / 2^64
1102 *               + system_time / 100
1103 *
1104 * Equate with the Hyper-V formula so that ticks * scale / 2^64 cancels out:
1105 *    offset = system_time / 100 - tsc_timestamp * scale / 2^64
1106 *
1107 * These two equivalencies are implemented in this function.
1108 */
1109static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
1110					struct ms_hyperv_tsc_page *tsc_ref)
1111{
1112	u64 max_mul;
1113
1114	if (!(hv_clock->flags & PVCLOCK_TSC_STABLE_BIT))
1115		return false;
1116
1117	/*
1118	 * check if scale would overflow, if so we use the time ref counter
1119	 *    tsc_to_system_mul * 2^(tsc_shift+32) / 100 >= 2^64
1120	 *    tsc_to_system_mul / 100 >= 2^(32-tsc_shift)
1121	 *    tsc_to_system_mul >= 100 * 2^(32-tsc_shift)
1122	 */
1123	max_mul = 100ull << (32 - hv_clock->tsc_shift);
1124	if (hv_clock->tsc_to_system_mul >= max_mul)
1125		return false;
1126
1127	/*
1128	 * Otherwise compute the scale and offset according to the formulas
1129	 * derived above.
1130	 */
1131	tsc_ref->tsc_scale =
1132		mul_u64_u32_div(1ULL << (32 + hv_clock->tsc_shift),
1133				hv_clock->tsc_to_system_mul,
1134				100);
1135
1136	tsc_ref->tsc_offset = hv_clock->system_time;
1137	do_div(tsc_ref->tsc_offset, 100);
1138	tsc_ref->tsc_offset -=
1139		mul_u64_u64_shr(hv_clock->tsc_timestamp, tsc_ref->tsc_scale, 64);
1140	return true;
1141}
1142
1143/*
1144 * Don't touch TSC page values if the guest has opted for TSC emulation after
1145 * migration. KVM doesn't fully support reenlightenment notifications and TSC
1146 * access emulation and Hyper-V is known to expect the values in TSC page to
1147 * stay constant before TSC access emulation is disabled from guest side
1148 * (HV_X64_MSR_TSC_EMULATION_STATUS). KVM userspace is expected to preserve TSC
1149 * frequency and guest visible TSC value across migration (and prevent it when
1150 * TSC scaling is unsupported).
1151 */
1152static inline bool tsc_page_update_unsafe(struct kvm_hv *hv)
1153{
1154	return (hv->hv_tsc_page_status != HV_TSC_PAGE_GUEST_CHANGED) &&
1155		hv->hv_tsc_emulation_control;
1156}
1157
1158void kvm_hv_setup_tsc_page(struct kvm *kvm,
1159			   struct pvclock_vcpu_time_info *hv_clock)
1160{
1161	struct kvm_hv *hv = to_kvm_hv(kvm);
1162	u32 tsc_seq;
1163	u64 gfn;
1164
1165	BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
1166	BUILD_BUG_ON(offsetof(struct ms_hyperv_tsc_page, tsc_sequence) != 0);
1167
1168	mutex_lock(&hv->hv_lock);
1169
1170	if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN ||
1171	    hv->hv_tsc_page_status == HV_TSC_PAGE_SET ||
1172	    hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET)
1173		goto out_unlock;
1174
1175	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
1176		goto out_unlock;
1177
1178	gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
1179	/*
1180	 * Because the TSC parameters only vary when there is a
1181	 * change in the master clock, do not bother with caching.
1182	 */
1183	if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
1184				    &tsc_seq, sizeof(tsc_seq))))
1185		goto out_err;
1186
1187	if (tsc_seq && tsc_page_update_unsafe(hv)) {
1188		if (kvm_read_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1189			goto out_err;
1190
1191		hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1192		goto out_unlock;
1193	}
1194
1195	/*
1196	 * While we're computing and writing the parameters, force the
1197	 * guest to use the time reference count MSR.
1198	 */
1199	hv->tsc_ref.tsc_sequence = 0;
1200	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1201			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1202		goto out_err;
1203
1204	if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
1205		goto out_err;
1206
1207	/* Ensure sequence is zero before writing the rest of the struct.  */
1208	smp_wmb();
1209	if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1210		goto out_err;
1211
1212	/*
1213	 * Now switch to the TSC page mechanism by writing the sequence.
1214	 */
1215	tsc_seq++;
1216	if (tsc_seq == 0xFFFFFFFF || tsc_seq == 0)
1217		tsc_seq = 1;
1218
1219	/* Write the struct entirely before the non-zero sequence.  */
1220	smp_wmb();
1221
1222	hv->tsc_ref.tsc_sequence = tsc_seq;
1223	if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1224			    &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1225		goto out_err;
1226
1227	hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1228	goto out_unlock;
1229
1230out_err:
1231	hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN;
1232out_unlock:
1233	mutex_unlock(&hv->hv_lock);
1234}
1235
1236void kvm_hv_request_tsc_page_update(struct kvm *kvm)
1237{
1238	struct kvm_hv *hv = to_kvm_hv(kvm);
1239
1240	mutex_lock(&hv->hv_lock);
1241
1242	if (hv->hv_tsc_page_status == HV_TSC_PAGE_SET &&
1243	    !tsc_page_update_unsafe(hv))
1244		hv->hv_tsc_page_status = HV_TSC_PAGE_HOST_CHANGED;
1245
1246	mutex_unlock(&hv->hv_lock);
1247}
1248
1249static bool hv_check_msr_access(struct kvm_vcpu_hv *hv_vcpu, u32 msr)
1250{
1251	if (!hv_vcpu->enforce_cpuid)
1252		return true;
1253
1254	switch (msr) {
1255	case HV_X64_MSR_GUEST_OS_ID:
1256	case HV_X64_MSR_HYPERCALL:
1257		return hv_vcpu->cpuid_cache.features_eax &
1258			HV_MSR_HYPERCALL_AVAILABLE;
1259	case HV_X64_MSR_VP_RUNTIME:
1260		return hv_vcpu->cpuid_cache.features_eax &
1261			HV_MSR_VP_RUNTIME_AVAILABLE;
1262	case HV_X64_MSR_TIME_REF_COUNT:
1263		return hv_vcpu->cpuid_cache.features_eax &
1264			HV_MSR_TIME_REF_COUNT_AVAILABLE;
1265	case HV_X64_MSR_VP_INDEX:
1266		return hv_vcpu->cpuid_cache.features_eax &
1267			HV_MSR_VP_INDEX_AVAILABLE;
1268	case HV_X64_MSR_RESET:
1269		return hv_vcpu->cpuid_cache.features_eax &
1270			HV_MSR_RESET_AVAILABLE;
1271	case HV_X64_MSR_REFERENCE_TSC:
1272		return hv_vcpu->cpuid_cache.features_eax &
1273			HV_MSR_REFERENCE_TSC_AVAILABLE;
1274	case HV_X64_MSR_SCONTROL:
1275	case HV_X64_MSR_SVERSION:
1276	case HV_X64_MSR_SIEFP:
1277	case HV_X64_MSR_SIMP:
1278	case HV_X64_MSR_EOM:
1279	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1280		return hv_vcpu->cpuid_cache.features_eax &
1281			HV_MSR_SYNIC_AVAILABLE;
1282	case HV_X64_MSR_STIMER0_CONFIG:
1283	case HV_X64_MSR_STIMER1_CONFIG:
1284	case HV_X64_MSR_STIMER2_CONFIG:
1285	case HV_X64_MSR_STIMER3_CONFIG:
1286	case HV_X64_MSR_STIMER0_COUNT:
1287	case HV_X64_MSR_STIMER1_COUNT:
1288	case HV_X64_MSR_STIMER2_COUNT:
1289	case HV_X64_MSR_STIMER3_COUNT:
1290		return hv_vcpu->cpuid_cache.features_eax &
1291			HV_MSR_SYNTIMER_AVAILABLE;
1292	case HV_X64_MSR_EOI:
1293	case HV_X64_MSR_ICR:
1294	case HV_X64_MSR_TPR:
1295	case HV_X64_MSR_VP_ASSIST_PAGE:
1296		return hv_vcpu->cpuid_cache.features_eax &
1297			HV_MSR_APIC_ACCESS_AVAILABLE;
1298	case HV_X64_MSR_TSC_FREQUENCY:
1299	case HV_X64_MSR_APIC_FREQUENCY:
1300		return hv_vcpu->cpuid_cache.features_eax &
1301			HV_ACCESS_FREQUENCY_MSRS;
1302	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1303	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1304	case HV_X64_MSR_TSC_EMULATION_STATUS:
1305		return hv_vcpu->cpuid_cache.features_eax &
1306			HV_ACCESS_REENLIGHTENMENT;
1307	case HV_X64_MSR_TSC_INVARIANT_CONTROL:
1308		return hv_vcpu->cpuid_cache.features_eax &
1309			HV_ACCESS_TSC_INVARIANT;
1310	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1311	case HV_X64_MSR_CRASH_CTL:
1312		return hv_vcpu->cpuid_cache.features_edx &
1313			HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
1314	case HV_X64_MSR_SYNDBG_OPTIONS:
1315	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1316		return hv_vcpu->cpuid_cache.features_edx &
1317			HV_FEATURE_DEBUG_MSRS_AVAILABLE;
1318	default:
1319		break;
1320	}
1321
1322	return false;
1323}
1324
1325static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
1326			     bool host)
1327{
1328	struct kvm *kvm = vcpu->kvm;
1329	struct kvm_hv *hv = to_kvm_hv(kvm);
1330
1331	if (unlikely(!host && !hv_check_msr_access(to_hv_vcpu(vcpu), msr)))
1332		return 1;
1333
1334	switch (msr) {
1335	case HV_X64_MSR_GUEST_OS_ID:
1336		hv->hv_guest_os_id = data;
1337		/* setting guest os id to zero disables hypercall page */
1338		if (!hv->hv_guest_os_id)
1339			hv->hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
1340		break;
1341	case HV_X64_MSR_HYPERCALL: {
1342		u8 instructions[9];
1343		int i = 0;
1344		u64 addr;
1345
1346		/* if guest os id is not set hypercall should remain disabled */
1347		if (!hv->hv_guest_os_id)
1348			break;
1349		if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
1350			hv->hv_hypercall = data;
1351			break;
1352		}
1353
1354		/*
1355		 * If Xen and Hyper-V hypercalls are both enabled, disambiguate
1356		 * the same way Xen itself does, by setting the bit 31 of EAX
1357		 * which is RsvdZ in the 32-bit Hyper-V hypercall ABI and just
1358		 * going to be clobbered on 64-bit.
1359		 */
1360		if (kvm_xen_hypercall_enabled(kvm)) {
1361			/* orl $0x80000000, %eax */
1362			instructions[i++] = 0x0d;
1363			instructions[i++] = 0x00;
1364			instructions[i++] = 0x00;
1365			instructions[i++] = 0x00;
1366			instructions[i++] = 0x80;
1367		}
1368
1369		/* vmcall/vmmcall */
1370		static_call(kvm_x86_patch_hypercall)(vcpu, instructions + i);
1371		i += 3;
1372
1373		/* ret */
1374		((unsigned char *)instructions)[i++] = 0xc3;
1375
1376		addr = data & HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_MASK;
1377		if (kvm_vcpu_write_guest(vcpu, addr, instructions, i))
1378			return 1;
1379		hv->hv_hypercall = data;
1380		break;
1381	}
1382	case HV_X64_MSR_REFERENCE_TSC:
1383		hv->hv_tsc_page = data;
1384		if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE) {
1385			if (!host)
1386				hv->hv_tsc_page_status = HV_TSC_PAGE_GUEST_CHANGED;
1387			else
1388				hv->hv_tsc_page_status = HV_TSC_PAGE_HOST_CHANGED;
1389			kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
1390		} else {
1391			hv->hv_tsc_page_status = HV_TSC_PAGE_UNSET;
1392		}
1393		break;
1394	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1395		return kvm_hv_msr_set_crash_data(kvm,
1396						 msr - HV_X64_MSR_CRASH_P0,
1397						 data);
1398	case HV_X64_MSR_CRASH_CTL:
1399		if (host)
1400			return kvm_hv_msr_set_crash_ctl(kvm, data);
1401
1402		if (data & HV_CRASH_CTL_CRASH_NOTIFY) {
1403			vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx 0x%llx)\n",
1404				   hv->hv_crash_param[0],
1405				   hv->hv_crash_param[1],
1406				   hv->hv_crash_param[2],
1407				   hv->hv_crash_param[3],
1408				   hv->hv_crash_param[4]);
1409
1410			/* Send notification about crash to user space */
1411			kvm_make_request(KVM_REQ_HV_CRASH, vcpu);
1412		}
1413		break;
1414	case HV_X64_MSR_RESET:
1415		if (data == 1) {
1416			vcpu_debug(vcpu, "hyper-v reset requested\n");
1417			kvm_make_request(KVM_REQ_HV_RESET, vcpu);
1418		}
1419		break;
1420	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1421		hv->hv_reenlightenment_control = data;
1422		break;
1423	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1424		hv->hv_tsc_emulation_control = data;
1425		break;
1426	case HV_X64_MSR_TSC_EMULATION_STATUS:
1427		if (data && !host)
1428			return 1;
1429
1430		hv->hv_tsc_emulation_status = data;
1431		break;
1432	case HV_X64_MSR_TIME_REF_COUNT:
1433		/* read-only, but still ignore it if host-initiated */
1434		if (!host)
1435			return 1;
1436		break;
1437	case HV_X64_MSR_TSC_INVARIANT_CONTROL:
1438		/* Only bit 0 is supported */
1439		if (data & ~HV_EXPOSE_INVARIANT_TSC)
1440			return 1;
1441
1442		/* The feature can't be disabled from the guest */
1443		if (!host && hv->hv_invtsc_control && !data)
1444			return 1;
1445
1446		hv->hv_invtsc_control = data;
1447		break;
1448	case HV_X64_MSR_SYNDBG_OPTIONS:
1449	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1450		return syndbg_set_msr(vcpu, msr, data, host);
1451	default:
1452		kvm_pr_unimpl_wrmsr(vcpu, msr, data);
1453		return 1;
1454	}
1455	return 0;
1456}
1457
1458/* Calculate cpu time spent by current task in 100ns units */
1459static u64 current_task_runtime_100ns(void)
1460{
1461	u64 utime, stime;
1462
1463	task_cputime_adjusted(current, &utime, &stime);
1464
1465	return div_u64(utime + stime, 100);
1466}
1467
1468static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1469{
1470	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1471
1472	if (unlikely(!host && !hv_check_msr_access(hv_vcpu, msr)))
1473		return 1;
1474
1475	switch (msr) {
1476	case HV_X64_MSR_VP_INDEX: {
1477		struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1478		u32 new_vp_index = (u32)data;
1479
1480		if (!host || new_vp_index >= KVM_MAX_VCPUS)
1481			return 1;
1482
1483		if (new_vp_index == hv_vcpu->vp_index)
1484			return 0;
1485
1486		/*
1487		 * The VP index is initialized to vcpu_index by
1488		 * kvm_hv_vcpu_postcreate so they initially match.  Now the
1489		 * VP index is changing, adjust num_mismatched_vp_indexes if
1490		 * it now matches or no longer matches vcpu_idx.
1491		 */
1492		if (hv_vcpu->vp_index == vcpu->vcpu_idx)
1493			atomic_inc(&hv->num_mismatched_vp_indexes);
1494		else if (new_vp_index == vcpu->vcpu_idx)
1495			atomic_dec(&hv->num_mismatched_vp_indexes);
1496
1497		hv_vcpu->vp_index = new_vp_index;
1498		break;
1499	}
1500	case HV_X64_MSR_VP_ASSIST_PAGE: {
1501		u64 gfn;
1502		unsigned long addr;
1503
1504		if (!(data & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE)) {
1505			hv_vcpu->hv_vapic = data;
1506			if (kvm_lapic_set_pv_eoi(vcpu, 0, 0))
1507				return 1;
1508			break;
1509		}
1510		gfn = data >> HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT;
1511		addr = kvm_vcpu_gfn_to_hva(vcpu, gfn);
1512		if (kvm_is_error_hva(addr))
1513			return 1;
1514
1515		/*
1516		 * Clear apic_assist portion of struct hv_vp_assist_page
1517		 * only, there can be valuable data in the rest which needs
1518		 * to be preserved e.g. on migration.
1519		 */
1520		if (__put_user(0, (u32 __user *)addr))
1521			return 1;
1522		hv_vcpu->hv_vapic = data;
1523		kvm_vcpu_mark_page_dirty(vcpu, gfn);
1524		if (kvm_lapic_set_pv_eoi(vcpu,
1525					    gfn_to_gpa(gfn) | KVM_MSR_ENABLED,
1526					    sizeof(struct hv_vp_assist_page)))
1527			return 1;
1528		break;
1529	}
1530	case HV_X64_MSR_EOI:
1531		return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
1532	case HV_X64_MSR_ICR:
1533		return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
1534	case HV_X64_MSR_TPR:
1535		return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
1536	case HV_X64_MSR_VP_RUNTIME:
1537		if (!host)
1538			return 1;
1539		hv_vcpu->runtime_offset = data - current_task_runtime_100ns();
1540		break;
1541	case HV_X64_MSR_SCONTROL:
1542	case HV_X64_MSR_SVERSION:
1543	case HV_X64_MSR_SIEFP:
1544	case HV_X64_MSR_SIMP:
1545	case HV_X64_MSR_EOM:
1546	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1547		return synic_set_msr(to_hv_synic(vcpu), msr, data, host);
1548	case HV_X64_MSR_STIMER0_CONFIG:
1549	case HV_X64_MSR_STIMER1_CONFIG:
1550	case HV_X64_MSR_STIMER2_CONFIG:
1551	case HV_X64_MSR_STIMER3_CONFIG: {
1552		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1553
1554		return stimer_set_config(to_hv_stimer(vcpu, timer_index),
1555					 data, host);
1556	}
1557	case HV_X64_MSR_STIMER0_COUNT:
1558	case HV_X64_MSR_STIMER1_COUNT:
1559	case HV_X64_MSR_STIMER2_COUNT:
1560	case HV_X64_MSR_STIMER3_COUNT: {
1561		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1562
1563		return stimer_set_count(to_hv_stimer(vcpu, timer_index),
1564					data, host);
1565	}
1566	case HV_X64_MSR_TSC_FREQUENCY:
1567	case HV_X64_MSR_APIC_FREQUENCY:
1568		/* read-only, but still ignore it if host-initiated */
1569		if (!host)
1570			return 1;
1571		break;
1572	default:
1573		kvm_pr_unimpl_wrmsr(vcpu, msr, data);
1574		return 1;
1575	}
1576
1577	return 0;
1578}
1579
1580static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1581			     bool host)
1582{
1583	u64 data = 0;
1584	struct kvm *kvm = vcpu->kvm;
1585	struct kvm_hv *hv = to_kvm_hv(kvm);
1586
1587	if (unlikely(!host && !hv_check_msr_access(to_hv_vcpu(vcpu), msr)))
1588		return 1;
1589
1590	switch (msr) {
1591	case HV_X64_MSR_GUEST_OS_ID:
1592		data = hv->hv_guest_os_id;
1593		break;
1594	case HV_X64_MSR_HYPERCALL:
1595		data = hv->hv_hypercall;
1596		break;
1597	case HV_X64_MSR_TIME_REF_COUNT:
1598		data = get_time_ref_counter(kvm);
1599		break;
1600	case HV_X64_MSR_REFERENCE_TSC:
1601		data = hv->hv_tsc_page;
1602		break;
1603	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1604		return kvm_hv_msr_get_crash_data(kvm,
1605						 msr - HV_X64_MSR_CRASH_P0,
1606						 pdata);
1607	case HV_X64_MSR_CRASH_CTL:
1608		return kvm_hv_msr_get_crash_ctl(kvm, pdata);
1609	case HV_X64_MSR_RESET:
1610		data = 0;
1611		break;
1612	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1613		data = hv->hv_reenlightenment_control;
1614		break;
1615	case HV_X64_MSR_TSC_EMULATION_CONTROL:
1616		data = hv->hv_tsc_emulation_control;
1617		break;
1618	case HV_X64_MSR_TSC_EMULATION_STATUS:
1619		data = hv->hv_tsc_emulation_status;
1620		break;
1621	case HV_X64_MSR_TSC_INVARIANT_CONTROL:
1622		data = hv->hv_invtsc_control;
1623		break;
1624	case HV_X64_MSR_SYNDBG_OPTIONS:
1625	case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1626		return syndbg_get_msr(vcpu, msr, pdata, host);
1627	default:
1628		kvm_pr_unimpl_rdmsr(vcpu, msr);
1629		return 1;
1630	}
1631
1632	*pdata = data;
1633	return 0;
1634}
1635
1636static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1637			  bool host)
1638{
1639	u64 data = 0;
1640	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1641
1642	if (unlikely(!host && !hv_check_msr_access(hv_vcpu, msr)))
1643		return 1;
1644
1645	switch (msr) {
1646	case HV_X64_MSR_VP_INDEX:
1647		data = hv_vcpu->vp_index;
1648		break;
1649	case HV_X64_MSR_EOI:
1650		return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
1651	case HV_X64_MSR_ICR:
1652		return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
1653	case HV_X64_MSR_TPR:
1654		return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
1655	case HV_X64_MSR_VP_ASSIST_PAGE:
1656		data = hv_vcpu->hv_vapic;
1657		break;
1658	case HV_X64_MSR_VP_RUNTIME:
1659		data = current_task_runtime_100ns() + hv_vcpu->runtime_offset;
1660		break;
1661	case HV_X64_MSR_SCONTROL:
1662	case HV_X64_MSR_SVERSION:
1663	case HV_X64_MSR_SIEFP:
1664	case HV_X64_MSR_SIMP:
1665	case HV_X64_MSR_EOM:
1666	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1667		return synic_get_msr(to_hv_synic(vcpu), msr, pdata, host);
1668	case HV_X64_MSR_STIMER0_CONFIG:
1669	case HV_X64_MSR_STIMER1_CONFIG:
1670	case HV_X64_MSR_STIMER2_CONFIG:
1671	case HV_X64_MSR_STIMER3_CONFIG: {
1672		int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1673
1674		return stimer_get_config(to_hv_stimer(vcpu, timer_index),
1675					 pdata);
1676	}
1677	case HV_X64_MSR_STIMER0_COUNT:
1678	case HV_X64_MSR_STIMER1_COUNT:
1679	case HV_X64_MSR_STIMER2_COUNT:
1680	case HV_X64_MSR_STIMER3_COUNT: {
1681		int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1682
1683		return stimer_get_count(to_hv_stimer(vcpu, timer_index),
1684					pdata);
1685	}
1686	case HV_X64_MSR_TSC_FREQUENCY:
1687		data = (u64)vcpu->arch.virtual_tsc_khz * 1000;
1688		break;
1689	case HV_X64_MSR_APIC_FREQUENCY:
1690		data = APIC_BUS_FREQUENCY;
1691		break;
1692	default:
1693		kvm_pr_unimpl_rdmsr(vcpu, msr);
1694		return 1;
1695	}
1696	*pdata = data;
1697	return 0;
1698}
1699
1700int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1701{
1702	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1703
1704	if (!host && !vcpu->arch.hyperv_enabled)
1705		return 1;
1706
1707	if (kvm_hv_vcpu_init(vcpu))
1708		return 1;
1709
1710	if (kvm_hv_msr_partition_wide(msr)) {
1711		int r;
1712
1713		mutex_lock(&hv->hv_lock);
1714		r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
1715		mutex_unlock(&hv->hv_lock);
1716		return r;
1717	} else
1718		return kvm_hv_set_msr(vcpu, msr, data, host);
1719}
1720
1721int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
1722{
1723	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1724
1725	if (!host && !vcpu->arch.hyperv_enabled)
1726		return 1;
1727
1728	if (kvm_hv_vcpu_init(vcpu))
1729		return 1;
1730
1731	if (kvm_hv_msr_partition_wide(msr)) {
1732		int r;
1733
1734		mutex_lock(&hv->hv_lock);
1735		r = kvm_hv_get_msr_pw(vcpu, msr, pdata, host);
1736		mutex_unlock(&hv->hv_lock);
1737		return r;
1738	} else
1739		return kvm_hv_get_msr(vcpu, msr, pdata, host);
1740}
1741
1742static void sparse_set_to_vcpu_mask(struct kvm *kvm, u64 *sparse_banks,
1743				    u64 valid_bank_mask, unsigned long *vcpu_mask)
1744{
1745	struct kvm_hv *hv = to_kvm_hv(kvm);
1746	bool has_mismatch = atomic_read(&hv->num_mismatched_vp_indexes);
1747	u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1748	struct kvm_vcpu *vcpu;
1749	int bank, sbank = 0;
1750	unsigned long i;
1751	u64 *bitmap;
1752
1753	BUILD_BUG_ON(sizeof(vp_bitmap) >
1754		     sizeof(*vcpu_mask) * BITS_TO_LONGS(KVM_MAX_VCPUS));
1755
1756	/*
1757	 * If vp_index == vcpu_idx for all vCPUs, fill vcpu_mask directly, else
1758	 * fill a temporary buffer and manually test each vCPU's VP index.
1759	 */
1760	if (likely(!has_mismatch))
1761		bitmap = (u64 *)vcpu_mask;
1762	else
1763		bitmap = vp_bitmap;
1764
1765	/*
1766	 * Each set of 64 VPs is packed into sparse_banks, with valid_bank_mask
1767	 * having a '1' for each bank that exists in sparse_banks.  Sets must
1768	 * be in ascending order, i.e. bank0..bankN.
1769	 */
1770	memset(bitmap, 0, sizeof(vp_bitmap));
1771	for_each_set_bit(bank, (unsigned long *)&valid_bank_mask,
1772			 KVM_HV_MAX_SPARSE_VCPU_SET_BITS)
1773		bitmap[bank] = sparse_banks[sbank++];
1774
1775	if (likely(!has_mismatch))
1776		return;
1777
1778	bitmap_zero(vcpu_mask, KVM_MAX_VCPUS);
1779	kvm_for_each_vcpu(i, vcpu, kvm) {
1780		if (test_bit(kvm_hv_get_vpindex(vcpu), (unsigned long *)vp_bitmap))
1781			__set_bit(i, vcpu_mask);
1782	}
1783}
1784
1785static bool hv_is_vp_in_sparse_set(u32 vp_id, u64 valid_bank_mask, u64 sparse_banks[])
1786{
1787	int valid_bit_nr = vp_id / HV_VCPUS_PER_SPARSE_BANK;
1788	unsigned long sbank;
1789
1790	if (!test_bit(valid_bit_nr, (unsigned long *)&valid_bank_mask))
1791		return false;
1792
1793	/*
1794	 * The index into the sparse bank is the number of preceding bits in
1795	 * the valid mask.  Optimize for VMs with <64 vCPUs by skipping the
1796	 * fancy math if there can't possibly be preceding bits.
1797	 */
1798	if (valid_bit_nr)
1799		sbank = hweight64(valid_bank_mask & GENMASK_ULL(valid_bit_nr - 1, 0));
1800	else
1801		sbank = 0;
1802
1803	return test_bit(vp_id % HV_VCPUS_PER_SPARSE_BANK,
1804			(unsigned long *)&sparse_banks[sbank]);
1805}
1806
1807struct kvm_hv_hcall {
1808	/* Hypercall input data */
1809	u64 param;
1810	u64 ingpa;
1811	u64 outgpa;
1812	u16 code;
1813	u16 var_cnt;
1814	u16 rep_cnt;
1815	u16 rep_idx;
1816	bool fast;
1817	bool rep;
1818	sse128_t xmm[HV_HYPERCALL_MAX_XMM_REGISTERS];
1819
1820	/*
1821	 * Current read offset when KVM reads hypercall input data gradually,
1822	 * either offset in bytes from 'ingpa' for regular hypercalls or the
1823	 * number of already consumed 'XMM halves' for 'fast' hypercalls.
1824	 */
1825	union {
1826		gpa_t data_offset;
1827		int consumed_xmm_halves;
1828	};
1829};
1830
1831
1832static int kvm_hv_get_hc_data(struct kvm *kvm, struct kvm_hv_hcall *hc,
1833			      u16 orig_cnt, u16 cnt_cap, u64 *data)
1834{
1835	/*
1836	 * Preserve the original count when ignoring entries via a "cap", KVM
1837	 * still needs to validate the guest input (though the non-XMM path
1838	 * punts on the checks).
1839	 */
1840	u16 cnt = min(orig_cnt, cnt_cap);
1841	int i, j;
1842
1843	if (hc->fast) {
1844		/*
1845		 * Each XMM holds two sparse banks, but do not count halves that
1846		 * have already been consumed for hypercall parameters.
1847		 */
1848		if (orig_cnt > 2 * HV_HYPERCALL_MAX_XMM_REGISTERS - hc->consumed_xmm_halves)
1849			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1850
1851		for (i = 0; i < cnt; i++) {
1852			j = i + hc->consumed_xmm_halves;
1853			if (j % 2)
1854				data[i] = sse128_hi(hc->xmm[j / 2]);
1855			else
1856				data[i] = sse128_lo(hc->xmm[j / 2]);
1857		}
1858		return 0;
1859	}
1860
1861	return kvm_read_guest(kvm, hc->ingpa + hc->data_offset, data,
1862			      cnt * sizeof(*data));
1863}
1864
1865static u64 kvm_get_sparse_vp_set(struct kvm *kvm, struct kvm_hv_hcall *hc,
1866				 u64 *sparse_banks)
1867{
1868	if (hc->var_cnt > HV_MAX_SPARSE_VCPU_BANKS)
1869		return -EINVAL;
1870
1871	/* Cap var_cnt to ignore banks that cannot contain a legal VP index. */
1872	return kvm_hv_get_hc_data(kvm, hc, hc->var_cnt, KVM_HV_MAX_SPARSE_VCPU_SET_BITS,
1873				  sparse_banks);
1874}
1875
1876static int kvm_hv_get_tlb_flush_entries(struct kvm *kvm, struct kvm_hv_hcall *hc, u64 entries[])
1877{
1878	return kvm_hv_get_hc_data(kvm, hc, hc->rep_cnt, hc->rep_cnt, entries);
1879}
1880
1881static void hv_tlb_flush_enqueue(struct kvm_vcpu *vcpu,
1882				 struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo,
1883				 u64 *entries, int count)
1884{
1885	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1886	u64 flush_all_entry = KVM_HV_TLB_FLUSHALL_ENTRY;
1887
1888	if (!hv_vcpu)
1889		return;
1890
1891	spin_lock(&tlb_flush_fifo->write_lock);
1892
1893	/*
1894	 * All entries should fit on the fifo leaving one free for 'flush all'
1895	 * entry in case another request comes in. In case there's not enough
1896	 * space, just put 'flush all' entry there.
1897	 */
1898	if (count && entries && count < kfifo_avail(&tlb_flush_fifo->entries)) {
1899		WARN_ON(kfifo_in(&tlb_flush_fifo->entries, entries, count) != count);
1900		goto out_unlock;
1901	}
1902
1903	/*
1904	 * Note: full fifo always contains 'flush all' entry, no need to check the
1905	 * return value.
1906	 */
1907	kfifo_in(&tlb_flush_fifo->entries, &flush_all_entry, 1);
1908
1909out_unlock:
1910	spin_unlock(&tlb_flush_fifo->write_lock);
1911}
1912
1913int kvm_hv_vcpu_flush_tlb(struct kvm_vcpu *vcpu)
1914{
1915	struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo;
1916	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1917	u64 entries[KVM_HV_TLB_FLUSH_FIFO_SIZE];
1918	int i, j, count;
1919	gva_t gva;
1920
1921	if (!tdp_enabled || !hv_vcpu)
1922		return -EINVAL;
1923
1924	tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(vcpu, is_guest_mode(vcpu));
1925
1926	count = kfifo_out(&tlb_flush_fifo->entries, entries, KVM_HV_TLB_FLUSH_FIFO_SIZE);
1927
1928	for (i = 0; i < count; i++) {
1929		if (entries[i] == KVM_HV_TLB_FLUSHALL_ENTRY)
1930			goto out_flush_all;
1931
1932		/*
1933		 * Lower 12 bits of 'address' encode the number of additional
1934		 * pages to flush.
1935		 */
1936		gva = entries[i] & PAGE_MASK;
1937		for (j = 0; j < (entries[i] & ~PAGE_MASK) + 1; j++)
1938			static_call(kvm_x86_flush_tlb_gva)(vcpu, gva + j * PAGE_SIZE);
1939
1940		++vcpu->stat.tlb_flush;
1941	}
1942	return 0;
1943
1944out_flush_all:
1945	kfifo_reset_out(&tlb_flush_fifo->entries);
1946
1947	/* Fall back to full flush. */
1948	return -ENOSPC;
1949}
1950
1951static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
1952{
1953	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1954	u64 *sparse_banks = hv_vcpu->sparse_banks;
1955	struct kvm *kvm = vcpu->kvm;
1956	struct hv_tlb_flush_ex flush_ex;
1957	struct hv_tlb_flush flush;
1958	DECLARE_BITMAP(vcpu_mask, KVM_MAX_VCPUS);
1959	struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo;
1960	/*
1961	 * Normally, there can be no more than 'KVM_HV_TLB_FLUSH_FIFO_SIZE'
1962	 * entries on the TLB flush fifo. The last entry, however, needs to be
1963	 * always left free for 'flush all' entry which gets placed when
1964	 * there is not enough space to put all the requested entries.
1965	 */
1966	u64 __tlb_flush_entries[KVM_HV_TLB_FLUSH_FIFO_SIZE - 1];
1967	u64 *tlb_flush_entries;
1968	u64 valid_bank_mask;
1969	struct kvm_vcpu *v;
1970	unsigned long i;
1971	bool all_cpus;
1972
1973	/*
1974	 * The Hyper-V TLFS doesn't allow more than HV_MAX_SPARSE_VCPU_BANKS
1975	 * sparse banks. Fail the build if KVM's max allowed number of
1976	 * vCPUs (>4096) exceeds this limit.
1977	 */
1978	BUILD_BUG_ON(KVM_HV_MAX_SPARSE_VCPU_SET_BITS > HV_MAX_SPARSE_VCPU_BANKS);
1979
1980	/*
1981	 * 'Slow' hypercall's first parameter is the address in guest's memory
1982	 * where hypercall parameters are placed. This is either a GPA or a
1983	 * nested GPA when KVM is handling the call from L2 ('direct' TLB
1984	 * flush).  Translate the address here so the memory can be uniformly
1985	 * read with kvm_read_guest().
1986	 */
1987	if (!hc->fast && is_guest_mode(vcpu)) {
1988		hc->ingpa = translate_nested_gpa(vcpu, hc->ingpa, 0, NULL);
1989		if (unlikely(hc->ingpa == INVALID_GPA))
1990			return HV_STATUS_INVALID_HYPERCALL_INPUT;
1991	}
1992
1993	if (hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST ||
1994	    hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE) {
1995		if (hc->fast) {
1996			flush.address_space = hc->ingpa;
1997			flush.flags = hc->outgpa;
1998			flush.processor_mask = sse128_lo(hc->xmm[0]);
1999			hc->consumed_xmm_halves = 1;
2000		} else {
2001			if (unlikely(kvm_read_guest(kvm, hc->ingpa,
2002						    &flush, sizeof(flush))))
2003				return HV_STATUS_INVALID_HYPERCALL_INPUT;
2004			hc->data_offset = sizeof(flush);
2005		}
2006
2007		trace_kvm_hv_flush_tlb(flush.processor_mask,
2008				       flush.address_space, flush.flags,
2009				       is_guest_mode(vcpu));
2010
2011		valid_bank_mask = BIT_ULL(0);
2012		sparse_banks[0] = flush.processor_mask;
2013
2014		/*
2015		 * Work around possible WS2012 bug: it sends hypercalls
2016		 * with processor_mask = 0x0 and HV_FLUSH_ALL_PROCESSORS clear,
2017		 * while also expecting us to flush something and crashing if
2018		 * we don't. Let's treat processor_mask == 0 same as
2019		 * HV_FLUSH_ALL_PROCESSORS.
2020		 */
2021		all_cpus = (flush.flags & HV_FLUSH_ALL_PROCESSORS) ||
2022			flush.processor_mask == 0;
2023	} else {
2024		if (hc->fast) {
2025			flush_ex.address_space = hc->ingpa;
2026			flush_ex.flags = hc->outgpa;
2027			memcpy(&flush_ex.hv_vp_set,
2028			       &hc->xmm[0], sizeof(hc->xmm[0]));
2029			hc->consumed_xmm_halves = 2;
2030		} else {
2031			if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush_ex,
2032						    sizeof(flush_ex))))
2033				return HV_STATUS_INVALID_HYPERCALL_INPUT;
2034			hc->data_offset = sizeof(flush_ex);
2035		}
2036
2037		trace_kvm_hv_flush_tlb_ex(flush_ex.hv_vp_set.valid_bank_mask,
2038					  flush_ex.hv_vp_set.format,
2039					  flush_ex.address_space,
2040					  flush_ex.flags, is_guest_mode(vcpu));
2041
2042		valid_bank_mask = flush_ex.hv_vp_set.valid_bank_mask;
2043		all_cpus = flush_ex.hv_vp_set.format !=
2044			HV_GENERIC_SET_SPARSE_4K;
2045
2046		if (hc->var_cnt != hweight64(valid_bank_mask))
2047			return HV_STATUS_INVALID_HYPERCALL_INPUT;
2048
2049		if (!all_cpus) {
2050			if (!hc->var_cnt)
2051				goto ret_success;
2052
2053			if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks))
2054				return HV_STATUS_INVALID_HYPERCALL_INPUT;
2055		}
2056
2057		/*
2058		 * Hyper-V TLFS doesn't explicitly forbid non-empty sparse vCPU
2059		 * banks (and, thus, non-zero 'var_cnt') for the 'all vCPUs'
2060		 * case (HV_GENERIC_SET_ALL).  Always adjust data_offset and
2061		 * consumed_xmm_halves to make sure TLB flush entries are read
2062		 * from the correct offset.
2063		 */
2064		if (hc->fast)
2065			hc->consumed_xmm_halves += hc->var_cnt;
2066		else
2067			hc->data_offset += hc->var_cnt * sizeof(sparse_banks[0]);
2068	}
2069
2070	if (hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE ||
2071	    hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX ||
2072	    hc->rep_cnt > ARRAY_SIZE(__tlb_flush_entries)) {
2073		tlb_flush_entries = NULL;
2074	} else {
2075		if (kvm_hv_get_tlb_flush_entries(kvm, hc, __tlb_flush_entries))
2076			return HV_STATUS_INVALID_HYPERCALL_INPUT;
2077		tlb_flush_entries = __tlb_flush_entries;
2078	}
2079
2080	/*
2081	 * vcpu->arch.cr3 may not be up-to-date for running vCPUs so we can't
2082	 * analyze it here, flush TLB regardless of the specified address space.
2083	 */
2084	if (all_cpus && !is_guest_mode(vcpu)) {
2085		kvm_for_each_vcpu(i, v, kvm) {
2086			tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(v, false);
2087			hv_tlb_flush_enqueue(v, tlb_flush_fifo,
2088					     tlb_flush_entries, hc->rep_cnt);
2089		}
2090
2091		kvm_make_all_cpus_request(kvm, KVM_REQ_HV_TLB_FLUSH);
2092	} else if (!is_guest_mode(vcpu)) {
2093		sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask, vcpu_mask);
2094
2095		for_each_set_bit(i, vcpu_mask, KVM_MAX_VCPUS) {
2096			v = kvm_get_vcpu(kvm, i);
2097			if (!v)
2098				continue;
2099			tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(v, false);
2100			hv_tlb_flush_enqueue(v, tlb_flush_fifo,
2101					     tlb_flush_entries, hc->rep_cnt);
2102		}
2103
2104		kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask);
2105	} else {
2106		struct kvm_vcpu_hv *hv_v;
2107
2108		bitmap_zero(vcpu_mask, KVM_MAX_VCPUS);
2109
2110		kvm_for_each_vcpu(i, v, kvm) {
2111			hv_v = to_hv_vcpu(v);
2112
2113			/*
2114			 * The following check races with nested vCPUs entering/exiting
2115			 * and/or migrating between L1's vCPUs, however the only case when
2116			 * KVM *must* flush the TLB is when the target L2 vCPU keeps
2117			 * running on the same L1 vCPU from the moment of the request until
2118			 * kvm_hv_flush_tlb() returns. TLB is fully flushed in all other
2119			 * cases, e.g. when the target L2 vCPU migrates to a different L1
2120			 * vCPU or when the corresponding L1 vCPU temporary switches to a
2121			 * different L2 vCPU while the request is being processed.
2122			 */
2123			if (!hv_v || hv_v->nested.vm_id != hv_vcpu->nested.vm_id)
2124				continue;
2125
2126			if (!all_cpus &&
2127			    !hv_is_vp_in_sparse_set(hv_v->nested.vp_id, valid_bank_mask,
2128						    sparse_banks))
2129				continue;
2130
2131			__set_bit(i, vcpu_mask);
2132			tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(v, true);
2133			hv_tlb_flush_enqueue(v, tlb_flush_fifo,
2134					     tlb_flush_entries, hc->rep_cnt);
2135		}
2136
2137		kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask);
2138	}
2139
2140ret_success:
2141	/* We always do full TLB flush, set 'Reps completed' = 'Rep Count' */
2142	return (u64)HV_STATUS_SUCCESS |
2143		((u64)hc->rep_cnt << HV_HYPERCALL_REP_COMP_OFFSET);
2144}
2145
2146static void kvm_hv_send_ipi_to_many(struct kvm *kvm, u32 vector,
2147				    u64 *sparse_banks, u64 valid_bank_mask)
2148{
2149	struct kvm_lapic_irq irq = {
2150		.delivery_mode = APIC_DM_FIXED,
2151		.vector = vector
2152	};
2153	struct kvm_vcpu *vcpu;
2154	unsigned long i;
2155
2156	kvm_for_each_vcpu(i, vcpu, kvm) {
2157		if (sparse_banks &&
2158		    !hv_is_vp_in_sparse_set(kvm_hv_get_vpindex(vcpu),
2159					    valid_bank_mask, sparse_banks))
2160			continue;
2161
2162		/* We fail only when APIC is disabled */
2163		kvm_apic_set_irq(vcpu, &irq, NULL);
2164	}
2165}
2166
2167static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
2168{
2169	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
2170	u64 *sparse_banks = hv_vcpu->sparse_banks;
2171	struct kvm *kvm = vcpu->kvm;
2172	struct hv_send_ipi_ex send_ipi_ex;
2173	struct hv_send_ipi send_ipi;
2174	u64 valid_bank_mask;
2175	u32 vector;
2176	bool all_cpus;
2177
2178	if (hc->code == HVCALL_SEND_IPI) {
2179		if (!hc->fast) {
2180			if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi,
2181						    sizeof(send_ipi))))
2182				return HV_STATUS_INVALID_HYPERCALL_INPUT;
2183			sparse_banks[0] = send_ipi.cpu_mask;
2184			vector = send_ipi.vector;
2185		} else {
2186			/* 'reserved' part of hv_send_ipi should be 0 */
2187			if (unlikely(hc->ingpa >> 32 != 0))
2188				return HV_STATUS_INVALID_HYPERCALL_INPUT;
2189			sparse_banks[0] = hc->outgpa;
2190			vector = (u32)hc->ingpa;
2191		}
2192		all_cpus = false;
2193		valid_bank_mask = BIT_ULL(0);
2194
2195		trace_kvm_hv_send_ipi(vector, sparse_banks[0]);
2196	} else {
2197		if (!hc->fast) {
2198			if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi_ex,
2199						    sizeof(send_ipi_ex))))
2200				return HV_STATUS_INVALID_HYPERCALL_INPUT;
2201		} else {
2202			send_ipi_ex.vector = (u32)hc->ingpa;
2203			send_ipi_ex.vp_set.format = hc->outgpa;
2204			send_ipi_ex.vp_set.valid_bank_mask = sse128_lo(hc->xmm[0]);
2205		}
2206
2207		trace_kvm_hv_send_ipi_ex(send_ipi_ex.vector,
2208					 send_ipi_ex.vp_set.format,
2209					 send_ipi_ex.vp_set.valid_bank_mask);
2210
2211		vector = send_ipi_ex.vector;
2212		valid_bank_mask = send_ipi_ex.vp_set.valid_bank_mask;
2213		all_cpus = send_ipi_ex.vp_set.format == HV_GENERIC_SET_ALL;
2214
2215		if (hc->var_cnt != hweight64(valid_bank_mask))
2216			return HV_STATUS_INVALID_HYPERCALL_INPUT;
2217
2218		if (all_cpus)
2219			goto check_and_send_ipi;
2220
2221		if (!hc->var_cnt)
2222			goto ret_success;
2223
2224		if (!hc->fast)
2225			hc->data_offset = offsetof(struct hv_send_ipi_ex,
2226						   vp_set.bank_contents);
2227		else
2228			hc->consumed_xmm_halves = 1;
2229
2230		if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks))
2231			return HV_STATUS_INVALID_HYPERCALL_INPUT;
2232	}
2233
2234check_and_send_ipi:
2235	if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR))
2236		return HV_STATUS_INVALID_HYPERCALL_INPUT;
2237
2238	if (all_cpus)
2239		kvm_hv_send_ipi_to_many(kvm, vector, NULL, 0);
2240	else
2241		kvm_hv_send_ipi_to_many(kvm, vector, sparse_banks, valid_bank_mask);
2242
2243ret_success:
2244	return HV_STATUS_SUCCESS;
2245}
2246
2247void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu, bool hyperv_enabled)
2248{
2249	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
2250	struct kvm_cpuid_entry2 *entry;
2251
2252	vcpu->arch.hyperv_enabled = hyperv_enabled;
2253
2254	if (!hv_vcpu) {
2255		/*
2256		 * KVM should have already allocated kvm_vcpu_hv if Hyper-V is
2257		 * enabled in CPUID.
2258		 */
2259		WARN_ON_ONCE(vcpu->arch.hyperv_enabled);
2260		return;
2261	}
2262
2263	memset(&hv_vcpu->cpuid_cache, 0, sizeof(hv_vcpu->cpuid_cache));
2264
2265	if (!vcpu->arch.hyperv_enabled)
2266		return;
2267
2268	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_FEATURES);
2269	if (entry) {
2270		hv_vcpu->cpuid_cache.features_eax = entry->eax;
2271		hv_vcpu->cpuid_cache.features_ebx = entry->ebx;
2272		hv_vcpu->cpuid_cache.features_edx = entry->edx;
2273	}
2274
2275	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_ENLIGHTMENT_INFO);
2276	if (entry) {
2277		hv_vcpu->cpuid_cache.enlightenments_eax = entry->eax;
2278		hv_vcpu->cpuid_cache.enlightenments_ebx = entry->ebx;
2279	}
2280
2281	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES);
2282	if (entry)
2283		hv_vcpu->cpuid_cache.syndbg_cap_eax = entry->eax;
2284
2285	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_NESTED_FEATURES);
2286	if (entry) {
2287		hv_vcpu->cpuid_cache.nested_eax = entry->eax;
2288		hv_vcpu->cpuid_cache.nested_ebx = entry->ebx;
2289	}
2290}
2291
2292int kvm_hv_set_enforce_cpuid(struct kvm_vcpu *vcpu, bool enforce)
2293{
2294	struct kvm_vcpu_hv *hv_vcpu;
2295	int ret = 0;
2296
2297	if (!to_hv_vcpu(vcpu)) {
2298		if (enforce) {
2299			ret = kvm_hv_vcpu_init(vcpu);
2300			if (ret)
2301				return ret;
2302		} else {
2303			return 0;
2304		}
2305	}
2306
2307	hv_vcpu = to_hv_vcpu(vcpu);
2308	hv_vcpu->enforce_cpuid = enforce;
2309
2310	return ret;
2311}
2312
2313static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
2314{
2315	bool longmode;
2316
2317	longmode = is_64_bit_hypercall(vcpu);
2318	if (longmode)
2319		kvm_rax_write(vcpu, result);
2320	else {
2321		kvm_rdx_write(vcpu, result >> 32);
2322		kvm_rax_write(vcpu, result & 0xffffffff);
2323	}
2324}
2325
2326static int kvm_hv_hypercall_complete(struct kvm_vcpu *vcpu, u64 result)
2327{
2328	u32 tlb_lock_count = 0;
2329	int ret;
2330
2331	if (hv_result_success(result) && is_guest_mode(vcpu) &&
2332	    kvm_hv_is_tlb_flush_hcall(vcpu) &&
2333	    kvm_read_guest(vcpu->kvm, to_hv_vcpu(vcpu)->nested.pa_page_gpa,
2334			   &tlb_lock_count, sizeof(tlb_lock_count)))
2335		result = HV_STATUS_INVALID_HYPERCALL_INPUT;
2336
2337	trace_kvm_hv_hypercall_done(result);
2338	kvm_hv_hypercall_set_result(vcpu, result);
2339	++vcpu->stat.hypercalls;
2340
2341	ret = kvm_skip_emulated_instruction(vcpu);
2342
2343	if (tlb_lock_count)
2344		kvm_x86_ops.nested_ops->hv_inject_synthetic_vmexit_post_tlb_flush(vcpu);
2345
2346	return ret;
2347}
2348
2349static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
2350{
2351	return kvm_hv_hypercall_complete(vcpu, vcpu->run->hyperv.u.hcall.result);
2352}
2353
2354static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
2355{
2356	struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
2357	struct eventfd_ctx *eventfd;
2358
2359	if (unlikely(!hc->fast)) {
2360		int ret;
2361		gpa_t gpa = hc->ingpa;
2362
2363		if ((gpa & (__alignof__(hc->ingpa) - 1)) ||
2364		    offset_in_page(gpa) + sizeof(hc->ingpa) > PAGE_SIZE)
2365			return HV_STATUS_INVALID_ALIGNMENT;
2366
2367		ret = kvm_vcpu_read_guest(vcpu, gpa,
2368					  &hc->ingpa, sizeof(hc->ingpa));
2369		if (ret < 0)
2370			return HV_STATUS_INVALID_ALIGNMENT;
2371	}
2372
2373	/*
2374	 * Per spec, bits 32-47 contain the extra "flag number".  However, we
2375	 * have no use for it, and in all known usecases it is zero, so just
2376	 * report lookup failure if it isn't.
2377	 */
2378	if (hc->ingpa & 0xffff00000000ULL)
2379		return HV_STATUS_INVALID_PORT_ID;
2380	/* remaining bits are reserved-zero */
2381	if (hc->ingpa & ~KVM_HYPERV_CONN_ID_MASK)
2382		return HV_STATUS_INVALID_HYPERCALL_INPUT;
2383
2384	/* the eventfd is protected by vcpu->kvm->srcu, but conn_to_evt isn't */
2385	rcu_read_lock();
2386	eventfd = idr_find(&hv->conn_to_evt, hc->ingpa);
2387	rcu_read_unlock();
2388	if (!eventfd)
2389		return HV_STATUS_INVALID_PORT_ID;
2390
2391	eventfd_signal(eventfd, 1);
2392	return HV_STATUS_SUCCESS;
2393}
2394
2395static bool is_xmm_fast_hypercall(struct kvm_hv_hcall *hc)
2396{
2397	switch (hc->code) {
2398	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2399	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2400	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2401	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2402	case HVCALL_SEND_IPI_EX:
2403		return true;
2404	}
2405
2406	return false;
2407}
2408
2409static void kvm_hv_hypercall_read_xmm(struct kvm_hv_hcall *hc)
2410{
2411	int reg;
2412
2413	kvm_fpu_get();
2414	for (reg = 0; reg < HV_HYPERCALL_MAX_XMM_REGISTERS; reg++)
2415		_kvm_read_sse_reg(reg, &hc->xmm[reg]);
2416	kvm_fpu_put();
2417}
2418
2419static bool hv_check_hypercall_access(struct kvm_vcpu_hv *hv_vcpu, u16 code)
2420{
2421	if (!hv_vcpu->enforce_cpuid)
2422		return true;
2423
2424	switch (code) {
2425	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
2426		return hv_vcpu->cpuid_cache.enlightenments_ebx &&
2427			hv_vcpu->cpuid_cache.enlightenments_ebx != U32_MAX;
2428	case HVCALL_POST_MESSAGE:
2429		return hv_vcpu->cpuid_cache.features_ebx & HV_POST_MESSAGES;
2430	case HVCALL_SIGNAL_EVENT:
2431		return hv_vcpu->cpuid_cache.features_ebx & HV_SIGNAL_EVENTS;
2432	case HVCALL_POST_DEBUG_DATA:
2433	case HVCALL_RETRIEVE_DEBUG_DATA:
2434	case HVCALL_RESET_DEBUG_SESSION:
2435		/*
2436		 * Return 'true' when SynDBG is disabled so the resulting code
2437		 * will be HV_STATUS_INVALID_HYPERCALL_CODE.
2438		 */
2439		return !kvm_hv_is_syndbg_enabled(hv_vcpu->vcpu) ||
2440			hv_vcpu->cpuid_cache.features_ebx & HV_DEBUGGING;
2441	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2442	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2443		if (!(hv_vcpu->cpuid_cache.enlightenments_eax &
2444		      HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
2445			return false;
2446		fallthrough;
2447	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2448	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2449		return hv_vcpu->cpuid_cache.enlightenments_eax &
2450			HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
2451	case HVCALL_SEND_IPI_EX:
2452		if (!(hv_vcpu->cpuid_cache.enlightenments_eax &
2453		      HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
2454			return false;
2455		fallthrough;
2456	case HVCALL_SEND_IPI:
2457		return hv_vcpu->cpuid_cache.enlightenments_eax &
2458			HV_X64_CLUSTER_IPI_RECOMMENDED;
2459	case HV_EXT_CALL_QUERY_CAPABILITIES ... HV_EXT_CALL_MAX:
2460		return hv_vcpu->cpuid_cache.features_ebx &
2461			HV_ENABLE_EXTENDED_HYPERCALLS;
2462	default:
2463		break;
2464	}
2465
2466	return true;
2467}
2468
2469int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
2470{
2471	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
2472	struct kvm_hv_hcall hc;
2473	u64 ret = HV_STATUS_SUCCESS;
2474
2475	/*
2476	 * hypercall generates UD from non zero cpl and real mode
2477	 * per HYPER-V spec
2478	 */
2479	if (static_call(kvm_x86_get_cpl)(vcpu) != 0 || !is_protmode(vcpu)) {
2480		kvm_queue_exception(vcpu, UD_VECTOR);
2481		return 1;
2482	}
2483
2484#ifdef CONFIG_X86_64
2485	if (is_64_bit_hypercall(vcpu)) {
2486		hc.param = kvm_rcx_read(vcpu);
2487		hc.ingpa = kvm_rdx_read(vcpu);
2488		hc.outgpa = kvm_r8_read(vcpu);
2489	} else
2490#endif
2491	{
2492		hc.param = ((u64)kvm_rdx_read(vcpu) << 32) |
2493			    (kvm_rax_read(vcpu) & 0xffffffff);
2494		hc.ingpa = ((u64)kvm_rbx_read(vcpu) << 32) |
2495			    (kvm_rcx_read(vcpu) & 0xffffffff);
2496		hc.outgpa = ((u64)kvm_rdi_read(vcpu) << 32) |
2497			     (kvm_rsi_read(vcpu) & 0xffffffff);
2498	}
2499
2500	hc.code = hc.param & 0xffff;
2501	hc.var_cnt = (hc.param & HV_HYPERCALL_VARHEAD_MASK) >> HV_HYPERCALL_VARHEAD_OFFSET;
2502	hc.fast = !!(hc.param & HV_HYPERCALL_FAST_BIT);
2503	hc.rep_cnt = (hc.param >> HV_HYPERCALL_REP_COMP_OFFSET) & 0xfff;
2504	hc.rep_idx = (hc.param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff;
2505	hc.rep = !!(hc.rep_cnt || hc.rep_idx);
2506
2507	trace_kvm_hv_hypercall(hc.code, hc.fast, hc.var_cnt, hc.rep_cnt,
2508			       hc.rep_idx, hc.ingpa, hc.outgpa);
2509
2510	if (unlikely(!hv_check_hypercall_access(hv_vcpu, hc.code))) {
2511		ret = HV_STATUS_ACCESS_DENIED;
2512		goto hypercall_complete;
2513	}
2514
2515	if (unlikely(hc.param & HV_HYPERCALL_RSVD_MASK)) {
2516		ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2517		goto hypercall_complete;
2518	}
2519
2520	if (hc.fast && is_xmm_fast_hypercall(&hc)) {
2521		if (unlikely(hv_vcpu->enforce_cpuid &&
2522			     !(hv_vcpu->cpuid_cache.features_edx &
2523			       HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE))) {
2524			kvm_queue_exception(vcpu, UD_VECTOR);
2525			return 1;
2526		}
2527
2528		kvm_hv_hypercall_read_xmm(&hc);
2529	}
2530
2531	switch (hc.code) {
2532	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
2533		if (unlikely(hc.rep || hc.var_cnt)) {
2534			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2535			break;
2536		}
2537		kvm_vcpu_on_spin(vcpu, true);
2538		break;
2539	case HVCALL_SIGNAL_EVENT:
2540		if (unlikely(hc.rep || hc.var_cnt)) {
2541			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2542			break;
2543		}
2544		ret = kvm_hvcall_signal_event(vcpu, &hc);
2545		if (ret != HV_STATUS_INVALID_PORT_ID)
2546			break;
2547		fallthrough;	/* maybe userspace knows this conn_id */
2548	case HVCALL_POST_MESSAGE:
2549		/* don't bother userspace if it has no way to handle it */
2550		if (unlikely(hc.rep || hc.var_cnt || !to_hv_synic(vcpu)->active)) {
2551			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2552			break;
2553		}
2554		goto hypercall_userspace_exit;
2555	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2556		if (unlikely(hc.var_cnt)) {
2557			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2558			break;
2559		}
2560		fallthrough;
2561	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2562		if (unlikely(!hc.rep_cnt || hc.rep_idx)) {
2563			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2564			break;
2565		}
2566		ret = kvm_hv_flush_tlb(vcpu, &hc);
2567		break;
2568	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2569		if (unlikely(hc.var_cnt)) {
2570			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2571			break;
2572		}
2573		fallthrough;
2574	case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2575		if (unlikely(hc.rep)) {
2576			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2577			break;
2578		}
2579		ret = kvm_hv_flush_tlb(vcpu, &hc);
2580		break;
2581	case HVCALL_SEND_IPI:
2582		if (unlikely(hc.var_cnt)) {
2583			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2584			break;
2585		}
2586		fallthrough;
2587	case HVCALL_SEND_IPI_EX:
2588		if (unlikely(hc.rep)) {
2589			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2590			break;
2591		}
2592		ret = kvm_hv_send_ipi(vcpu, &hc);
2593		break;
2594	case HVCALL_POST_DEBUG_DATA:
2595	case HVCALL_RETRIEVE_DEBUG_DATA:
2596		if (unlikely(hc.fast)) {
2597			ret = HV_STATUS_INVALID_PARAMETER;
2598			break;
2599		}
2600		fallthrough;
2601	case HVCALL_RESET_DEBUG_SESSION: {
2602		struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
2603
2604		if (!kvm_hv_is_syndbg_enabled(vcpu)) {
2605			ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2606			break;
2607		}
2608
2609		if (!(syndbg->options & HV_X64_SYNDBG_OPTION_USE_HCALLS)) {
2610			ret = HV_STATUS_OPERATION_DENIED;
2611			break;
2612		}
2613		goto hypercall_userspace_exit;
2614	}
2615	case HV_EXT_CALL_QUERY_CAPABILITIES ... HV_EXT_CALL_MAX:
2616		if (unlikely(hc.fast)) {
2617			ret = HV_STATUS_INVALID_PARAMETER;
2618			break;
2619		}
2620		goto hypercall_userspace_exit;
2621	default:
2622		ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2623		break;
2624	}
2625
2626hypercall_complete:
2627	return kvm_hv_hypercall_complete(vcpu, ret);
2628
2629hypercall_userspace_exit:
2630	vcpu->run->exit_reason = KVM_EXIT_HYPERV;
2631	vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
2632	vcpu->run->hyperv.u.hcall.input = hc.param;
2633	vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
2634	vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
2635	vcpu->arch.complete_userspace_io = kvm_hv_hypercall_complete_userspace;
2636	return 0;
2637}
2638
2639void kvm_hv_init_vm(struct kvm *kvm)
2640{
2641	struct kvm_hv *hv = to_kvm_hv(kvm);
2642
2643	mutex_init(&hv->hv_lock);
2644	idr_init(&hv->conn_to_evt);
2645}
2646
2647void kvm_hv_destroy_vm(struct kvm *kvm)
2648{
2649	struct kvm_hv *hv = to_kvm_hv(kvm);
2650	struct eventfd_ctx *eventfd;
2651	int i;
2652
2653	idr_for_each_entry(&hv->conn_to_evt, eventfd, i)
2654		eventfd_ctx_put(eventfd);
2655	idr_destroy(&hv->conn_to_evt);
2656}
2657
2658static int kvm_hv_eventfd_assign(struct kvm *kvm, u32 conn_id, int fd)
2659{
2660	struct kvm_hv *hv = to_kvm_hv(kvm);
2661	struct eventfd_ctx *eventfd;
2662	int ret;
2663
2664	eventfd = eventfd_ctx_fdget(fd);
2665	if (IS_ERR(eventfd))
2666		return PTR_ERR(eventfd);
2667
2668	mutex_lock(&hv->hv_lock);
2669	ret = idr_alloc(&hv->conn_to_evt, eventfd, conn_id, conn_id + 1,
2670			GFP_KERNEL_ACCOUNT);
2671	mutex_unlock(&hv->hv_lock);
2672
2673	if (ret >= 0)
2674		return 0;
2675
2676	if (ret == -ENOSPC)
2677		ret = -EEXIST;
2678	eventfd_ctx_put(eventfd);
2679	return ret;
2680}
2681
2682static int kvm_hv_eventfd_deassign(struct kvm *kvm, u32 conn_id)
2683{
2684	struct kvm_hv *hv = to_kvm_hv(kvm);
2685	struct eventfd_ctx *eventfd;
2686
2687	mutex_lock(&hv->hv_lock);
2688	eventfd = idr_remove(&hv->conn_to_evt, conn_id);
2689	mutex_unlock(&hv->hv_lock);
2690
2691	if (!eventfd)
2692		return -ENOENT;
2693
2694	synchronize_srcu(&kvm->srcu);
2695	eventfd_ctx_put(eventfd);
2696	return 0;
2697}
2698
2699int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args)
2700{
2701	if ((args->flags & ~KVM_HYPERV_EVENTFD_DEASSIGN) ||
2702	    (args->conn_id & ~KVM_HYPERV_CONN_ID_MASK))
2703		return -EINVAL;
2704
2705	if (args->flags == KVM_HYPERV_EVENTFD_DEASSIGN)
2706		return kvm_hv_eventfd_deassign(kvm, args->conn_id);
2707	return kvm_hv_eventfd_assign(kvm, args->conn_id, args->fd);
2708}
2709
2710int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
2711		     struct kvm_cpuid_entry2 __user *entries)
2712{
2713	uint16_t evmcs_ver = 0;
2714	struct kvm_cpuid_entry2 cpuid_entries[] = {
2715		{ .function = HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS },
2716		{ .function = HYPERV_CPUID_INTERFACE },
2717		{ .function = HYPERV_CPUID_VERSION },
2718		{ .function = HYPERV_CPUID_FEATURES },
2719		{ .function = HYPERV_CPUID_ENLIGHTMENT_INFO },
2720		{ .function = HYPERV_CPUID_IMPLEMENT_LIMITS },
2721		{ .function = HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS },
2722		{ .function = HYPERV_CPUID_SYNDBG_INTERFACE },
2723		{ .function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES	},
2724		{ .function = HYPERV_CPUID_NESTED_FEATURES },
2725	};
2726	int i, nent = ARRAY_SIZE(cpuid_entries);
2727
2728	if (kvm_x86_ops.nested_ops->get_evmcs_version)
2729		evmcs_ver = kvm_x86_ops.nested_ops->get_evmcs_version(vcpu);
2730
2731	if (cpuid->nent < nent)
2732		return -E2BIG;
2733
2734	if (cpuid->nent > nent)
2735		cpuid->nent = nent;
2736
2737	for (i = 0; i < nent; i++) {
2738		struct kvm_cpuid_entry2 *ent = &cpuid_entries[i];
2739		u32 signature[3];
2740
2741		switch (ent->function) {
2742		case HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS:
2743			memcpy(signature, "Linux KVM Hv", 12);
2744
2745			ent->eax = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES;
2746			ent->ebx = signature[0];
2747			ent->ecx = signature[1];
2748			ent->edx = signature[2];
2749			break;
2750
2751		case HYPERV_CPUID_INTERFACE:
2752			ent->eax = HYPERV_CPUID_SIGNATURE_EAX;
2753			break;
2754
2755		case HYPERV_CPUID_VERSION:
2756			/*
2757			 * We implement some Hyper-V 2016 functions so let's use
2758			 * this version.
2759			 */
2760			ent->eax = 0x00003839;
2761			ent->ebx = 0x000A0000;
2762			break;
2763
2764		case HYPERV_CPUID_FEATURES:
2765			ent->eax |= HV_MSR_VP_RUNTIME_AVAILABLE;
2766			ent->eax |= HV_MSR_TIME_REF_COUNT_AVAILABLE;
2767			ent->eax |= HV_MSR_SYNIC_AVAILABLE;
2768			ent->eax |= HV_MSR_SYNTIMER_AVAILABLE;
2769			ent->eax |= HV_MSR_APIC_ACCESS_AVAILABLE;
2770			ent->eax |= HV_MSR_HYPERCALL_AVAILABLE;
2771			ent->eax |= HV_MSR_VP_INDEX_AVAILABLE;
2772			ent->eax |= HV_MSR_RESET_AVAILABLE;
2773			ent->eax |= HV_MSR_REFERENCE_TSC_AVAILABLE;
2774			ent->eax |= HV_ACCESS_FREQUENCY_MSRS;
2775			ent->eax |= HV_ACCESS_REENLIGHTENMENT;
2776			ent->eax |= HV_ACCESS_TSC_INVARIANT;
2777
2778			ent->ebx |= HV_POST_MESSAGES;
2779			ent->ebx |= HV_SIGNAL_EVENTS;
2780			ent->ebx |= HV_ENABLE_EXTENDED_HYPERCALLS;
2781
2782			ent->edx |= HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE;
2783			ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
2784			ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
2785
2786			ent->ebx |= HV_DEBUGGING;
2787			ent->edx |= HV_X64_GUEST_DEBUGGING_AVAILABLE;
2788			ent->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
2789			ent->edx |= HV_FEATURE_EXT_GVA_RANGES_FLUSH;
2790
2791			/*
2792			 * Direct Synthetic timers only make sense with in-kernel
2793			 * LAPIC
2794			 */
2795			if (!vcpu || lapic_in_kernel(vcpu))
2796				ent->edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
2797
2798			break;
2799
2800		case HYPERV_CPUID_ENLIGHTMENT_INFO:
2801			ent->eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
2802			ent->eax |= HV_X64_APIC_ACCESS_RECOMMENDED;
2803			ent->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED;
2804			ent->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
2805			ent->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
2806			if (evmcs_ver)
2807				ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;
2808			if (!cpu_smt_possible())
2809				ent->eax |= HV_X64_NO_NONARCH_CORESHARING;
2810
2811			ent->eax |= HV_DEPRECATING_AEOI_RECOMMENDED;
2812			/*
2813			 * Default number of spinlock retry attempts, matches
2814			 * HyperV 2016.
2815			 */
2816			ent->ebx = 0x00000FFF;
2817
2818			break;
2819
2820		case HYPERV_CPUID_IMPLEMENT_LIMITS:
2821			/* Maximum number of virtual processors */
2822			ent->eax = KVM_MAX_VCPUS;
2823			/*
2824			 * Maximum number of logical processors, matches
2825			 * HyperV 2016.
2826			 */
2827			ent->ebx = 64;
2828
2829			break;
2830
2831		case HYPERV_CPUID_NESTED_FEATURES:
2832			ent->eax = evmcs_ver;
2833			ent->eax |= HV_X64_NESTED_DIRECT_FLUSH;
2834			ent->eax |= HV_X64_NESTED_MSR_BITMAP;
2835			ent->ebx |= HV_X64_NESTED_EVMCS1_PERF_GLOBAL_CTRL;
2836			break;
2837
2838		case HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS:
2839			memcpy(signature, "Linux KVM Hv", 12);
2840
2841			ent->eax = 0;
2842			ent->ebx = signature[0];
2843			ent->ecx = signature[1];
2844			ent->edx = signature[2];
2845			break;
2846
2847		case HYPERV_CPUID_SYNDBG_INTERFACE:
2848			memcpy(signature, "VS#1\0\0\0\0\0\0\0\0", 12);
2849			ent->eax = signature[0];
2850			break;
2851
2852		case HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES:
2853			ent->eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
2854			break;
2855
2856		default:
2857			break;
2858		}
2859	}
2860
2861	if (copy_to_user(entries, cpuid_entries,
2862			 nent * sizeof(struct kvm_cpuid_entry2)))
2863		return -EFAULT;
2864
2865	return 0;
2866}
2867