xref: /linux/arch/x86/kvm/lapic.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
1 
2 /*
3  * Local APIC virtualization
4  *
5  * Copyright (C) 2006 Qumranet, Inc.
6  * Copyright (C) 2007 Novell
7  * Copyright (C) 2007 Intel
8  * Copyright 2009 Red Hat, Inc. and/or its affilates.
9  *
10  * Authors:
11  *   Dor Laor <dor.laor@qumranet.com>
12  *   Gregory Haskins <ghaskins@novell.com>
13  *   Yaozu (Eddie) Dong <eddie.dong@intel.com>
14  *
15  * Based on Xen 3.1 code, Copyright (c) 2004, Intel Corporation.
16  *
17  * This work is licensed under the terms of the GNU GPL, version 2.  See
18  * the COPYING file in the top-level directory.
19  */
20 
21 #include <linux/kvm_host.h>
22 #include <linux/kvm.h>
23 #include <linux/mm.h>
24 #include <linux/highmem.h>
25 #include <linux/smp.h>
26 #include <linux/hrtimer.h>
27 #include <linux/io.h>
28 #include <linux/module.h>
29 #include <linux/math64.h>
30 #include <linux/slab.h>
31 #include <asm/processor.h>
32 #include <asm/msr.h>
33 #include <asm/page.h>
34 #include <asm/current.h>
35 #include <asm/apicdef.h>
36 #include <asm/atomic.h>
37 #include "kvm_cache_regs.h"
38 #include "irq.h"
39 #include "trace.h"
40 #include "x86.h"
41 
42 #ifndef CONFIG_X86_64
43 #define mod_64(x, y) ((x) - (y) * div64_u64(x, y))
44 #else
45 #define mod_64(x, y) ((x) % (y))
46 #endif
47 
48 #define PRId64 "d"
49 #define PRIx64 "llx"
50 #define PRIu64 "u"
51 #define PRIo64 "o"
52 
53 #define APIC_BUS_CYCLE_NS 1
54 
55 /* #define apic_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg) */
56 #define apic_debug(fmt, arg...)
57 
58 #define APIC_LVT_NUM			6
59 /* 14 is the version for Xeon and Pentium 8.4.8*/
60 #define APIC_VERSION			(0x14UL | ((APIC_LVT_NUM - 1) << 16))
61 #define LAPIC_MMIO_LENGTH		(1 << 12)
62 /* followed define is not in apicdef.h */
63 #define APIC_SHORT_MASK			0xc0000
64 #define APIC_DEST_NOSHORT		0x0
65 #define APIC_DEST_MASK			0x800
66 #define MAX_APIC_VECTOR			256
67 
68 #define VEC_POS(v) ((v) & (32 - 1))
69 #define REG_POS(v) (((v) >> 5) << 4)
70 
71 static inline u32 apic_get_reg(struct kvm_lapic *apic, int reg_off)
72 {
73 	return *((u32 *) (apic->regs + reg_off));
74 }
75 
76 static inline void apic_set_reg(struct kvm_lapic *apic, int reg_off, u32 val)
77 {
78 	*((u32 *) (apic->regs + reg_off)) = val;
79 }
80 
81 static inline int apic_test_and_set_vector(int vec, void *bitmap)
82 {
83 	return test_and_set_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
84 }
85 
86 static inline int apic_test_and_clear_vector(int vec, void *bitmap)
87 {
88 	return test_and_clear_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
89 }
90 
91 static inline void apic_set_vector(int vec, void *bitmap)
92 {
93 	set_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
94 }
95 
96 static inline void apic_clear_vector(int vec, void *bitmap)
97 {
98 	clear_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
99 }
100 
101 static inline int apic_hw_enabled(struct kvm_lapic *apic)
102 {
103 	return (apic)->vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE;
104 }
105 
106 static inline int  apic_sw_enabled(struct kvm_lapic *apic)
107 {
108 	return apic_get_reg(apic, APIC_SPIV) & APIC_SPIV_APIC_ENABLED;
109 }
110 
111 static inline int apic_enabled(struct kvm_lapic *apic)
112 {
113 	return apic_sw_enabled(apic) &&	apic_hw_enabled(apic);
114 }
115 
116 #define LVT_MASK	\
117 	(APIC_LVT_MASKED | APIC_SEND_PENDING | APIC_VECTOR_MASK)
118 
119 #define LINT_MASK	\
120 	(LVT_MASK | APIC_MODE_MASK | APIC_INPUT_POLARITY | \
121 	 APIC_LVT_REMOTE_IRR | APIC_LVT_LEVEL_TRIGGER)
122 
123 static inline int kvm_apic_id(struct kvm_lapic *apic)
124 {
125 	return (apic_get_reg(apic, APIC_ID) >> 24) & 0xff;
126 }
127 
128 static inline int apic_lvt_enabled(struct kvm_lapic *apic, int lvt_type)
129 {
130 	return !(apic_get_reg(apic, lvt_type) & APIC_LVT_MASKED);
131 }
132 
133 static inline int apic_lvt_vector(struct kvm_lapic *apic, int lvt_type)
134 {
135 	return apic_get_reg(apic, lvt_type) & APIC_VECTOR_MASK;
136 }
137 
138 static inline int apic_lvtt_period(struct kvm_lapic *apic)
139 {
140 	return apic_get_reg(apic, APIC_LVTT) & APIC_LVT_TIMER_PERIODIC;
141 }
142 
143 static inline int apic_lvt_nmi_mode(u32 lvt_val)
144 {
145 	return (lvt_val & (APIC_MODE_MASK | APIC_LVT_MASKED)) == APIC_DM_NMI;
146 }
147 
148 void kvm_apic_set_version(struct kvm_vcpu *vcpu)
149 {
150 	struct kvm_lapic *apic = vcpu->arch.apic;
151 	struct kvm_cpuid_entry2 *feat;
152 	u32 v = APIC_VERSION;
153 
154 	if (!irqchip_in_kernel(vcpu->kvm))
155 		return;
156 
157 	feat = kvm_find_cpuid_entry(apic->vcpu, 0x1, 0);
158 	if (feat && (feat->ecx & (1 << (X86_FEATURE_X2APIC & 31))))
159 		v |= APIC_LVR_DIRECTED_EOI;
160 	apic_set_reg(apic, APIC_LVR, v);
161 }
162 
163 static inline int apic_x2apic_mode(struct kvm_lapic *apic)
164 {
165 	return apic->vcpu->arch.apic_base & X2APIC_ENABLE;
166 }
167 
168 static unsigned int apic_lvt_mask[APIC_LVT_NUM] = {
169 	LVT_MASK | APIC_LVT_TIMER_PERIODIC,	/* LVTT */
170 	LVT_MASK | APIC_MODE_MASK,	/* LVTTHMR */
171 	LVT_MASK | APIC_MODE_MASK,	/* LVTPC */
172 	LINT_MASK, LINT_MASK,	/* LVT0-1 */
173 	LVT_MASK		/* LVTERR */
174 };
175 
176 static int find_highest_vector(void *bitmap)
177 {
178 	u32 *word = bitmap;
179 	int word_offset = MAX_APIC_VECTOR >> 5;
180 
181 	while ((word_offset != 0) && (word[(--word_offset) << 2] == 0))
182 		continue;
183 
184 	if (likely(!word_offset && !word[0]))
185 		return -1;
186 	else
187 		return fls(word[word_offset << 2]) - 1 + (word_offset << 5);
188 }
189 
190 static inline int apic_test_and_set_irr(int vec, struct kvm_lapic *apic)
191 {
192 	apic->irr_pending = true;
193 	return apic_test_and_set_vector(vec, apic->regs + APIC_IRR);
194 }
195 
196 static inline int apic_search_irr(struct kvm_lapic *apic)
197 {
198 	return find_highest_vector(apic->regs + APIC_IRR);
199 }
200 
201 static inline int apic_find_highest_irr(struct kvm_lapic *apic)
202 {
203 	int result;
204 
205 	if (!apic->irr_pending)
206 		return -1;
207 
208 	result = apic_search_irr(apic);
209 	ASSERT(result == -1 || result >= 16);
210 
211 	return result;
212 }
213 
214 static inline void apic_clear_irr(int vec, struct kvm_lapic *apic)
215 {
216 	apic->irr_pending = false;
217 	apic_clear_vector(vec, apic->regs + APIC_IRR);
218 	if (apic_search_irr(apic) != -1)
219 		apic->irr_pending = true;
220 }
221 
222 int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu)
223 {
224 	struct kvm_lapic *apic = vcpu->arch.apic;
225 	int highest_irr;
226 
227 	/* This may race with setting of irr in __apic_accept_irq() and
228 	 * value returned may be wrong, but kvm_vcpu_kick() in __apic_accept_irq
229 	 * will cause vmexit immediately and the value will be recalculated
230 	 * on the next vmentry.
231 	 */
232 	if (!apic)
233 		return 0;
234 	highest_irr = apic_find_highest_irr(apic);
235 
236 	return highest_irr;
237 }
238 
239 static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
240 			     int vector, int level, int trig_mode);
241 
242 int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq)
243 {
244 	struct kvm_lapic *apic = vcpu->arch.apic;
245 
246 	return __apic_accept_irq(apic, irq->delivery_mode, irq->vector,
247 			irq->level, irq->trig_mode);
248 }
249 
250 static inline int apic_find_highest_isr(struct kvm_lapic *apic)
251 {
252 	int result;
253 
254 	result = find_highest_vector(apic->regs + APIC_ISR);
255 	ASSERT(result == -1 || result >= 16);
256 
257 	return result;
258 }
259 
260 static void apic_update_ppr(struct kvm_lapic *apic)
261 {
262 	u32 tpr, isrv, ppr;
263 	int isr;
264 
265 	tpr = apic_get_reg(apic, APIC_TASKPRI);
266 	isr = apic_find_highest_isr(apic);
267 	isrv = (isr != -1) ? isr : 0;
268 
269 	if ((tpr & 0xf0) >= (isrv & 0xf0))
270 		ppr = tpr & 0xff;
271 	else
272 		ppr = isrv & 0xf0;
273 
274 	apic_debug("vlapic %p, ppr 0x%x, isr 0x%x, isrv 0x%x",
275 		   apic, ppr, isr, isrv);
276 
277 	apic_set_reg(apic, APIC_PROCPRI, ppr);
278 }
279 
280 static void apic_set_tpr(struct kvm_lapic *apic, u32 tpr)
281 {
282 	apic_set_reg(apic, APIC_TASKPRI, tpr);
283 	apic_update_ppr(apic);
284 }
285 
286 int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u16 dest)
287 {
288 	return dest == 0xff || kvm_apic_id(apic) == dest;
289 }
290 
291 int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u8 mda)
292 {
293 	int result = 0;
294 	u32 logical_id;
295 
296 	if (apic_x2apic_mode(apic)) {
297 		logical_id = apic_get_reg(apic, APIC_LDR);
298 		return logical_id & mda;
299 	}
300 
301 	logical_id = GET_APIC_LOGICAL_ID(apic_get_reg(apic, APIC_LDR));
302 
303 	switch (apic_get_reg(apic, APIC_DFR)) {
304 	case APIC_DFR_FLAT:
305 		if (logical_id & mda)
306 			result = 1;
307 		break;
308 	case APIC_DFR_CLUSTER:
309 		if (((logical_id >> 4) == (mda >> 0x4))
310 		    && (logical_id & mda & 0xf))
311 			result = 1;
312 		break;
313 	default:
314 		printk(KERN_WARNING "Bad DFR vcpu %d: %08x\n",
315 		       apic->vcpu->vcpu_id, apic_get_reg(apic, APIC_DFR));
316 		break;
317 	}
318 
319 	return result;
320 }
321 
322 int kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,
323 			   int short_hand, int dest, int dest_mode)
324 {
325 	int result = 0;
326 	struct kvm_lapic *target = vcpu->arch.apic;
327 
328 	apic_debug("target %p, source %p, dest 0x%x, "
329 		   "dest_mode 0x%x, short_hand 0x%x\n",
330 		   target, source, dest, dest_mode, short_hand);
331 
332 	ASSERT(target);
333 	switch (short_hand) {
334 	case APIC_DEST_NOSHORT:
335 		if (dest_mode == 0)
336 			/* Physical mode. */
337 			result = kvm_apic_match_physical_addr(target, dest);
338 		else
339 			/* Logical mode. */
340 			result = kvm_apic_match_logical_addr(target, dest);
341 		break;
342 	case APIC_DEST_SELF:
343 		result = (target == source);
344 		break;
345 	case APIC_DEST_ALLINC:
346 		result = 1;
347 		break;
348 	case APIC_DEST_ALLBUT:
349 		result = (target != source);
350 		break;
351 	default:
352 		printk(KERN_WARNING "Bad dest shorthand value %x\n",
353 		       short_hand);
354 		break;
355 	}
356 
357 	return result;
358 }
359 
360 /*
361  * Add a pending IRQ into lapic.
362  * Return 1 if successfully added and 0 if discarded.
363  */
364 static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
365 			     int vector, int level, int trig_mode)
366 {
367 	int result = 0;
368 	struct kvm_vcpu *vcpu = apic->vcpu;
369 
370 	switch (delivery_mode) {
371 	case APIC_DM_LOWEST:
372 		vcpu->arch.apic_arb_prio++;
373 	case APIC_DM_FIXED:
374 		/* FIXME add logic for vcpu on reset */
375 		if (unlikely(!apic_enabled(apic)))
376 			break;
377 
378 		if (trig_mode) {
379 			apic_debug("level trig mode for vector %d", vector);
380 			apic_set_vector(vector, apic->regs + APIC_TMR);
381 		} else
382 			apic_clear_vector(vector, apic->regs + APIC_TMR);
383 
384 		result = !apic_test_and_set_irr(vector, apic);
385 		trace_kvm_apic_accept_irq(vcpu->vcpu_id, delivery_mode,
386 					  trig_mode, vector, !result);
387 		if (!result) {
388 			if (trig_mode)
389 				apic_debug("level trig mode repeatedly for "
390 						"vector %d", vector);
391 			break;
392 		}
393 
394 		kvm_vcpu_kick(vcpu);
395 		break;
396 
397 	case APIC_DM_REMRD:
398 		printk(KERN_DEBUG "Ignoring delivery mode 3\n");
399 		break;
400 
401 	case APIC_DM_SMI:
402 		printk(KERN_DEBUG "Ignoring guest SMI\n");
403 		break;
404 
405 	case APIC_DM_NMI:
406 		result = 1;
407 		kvm_inject_nmi(vcpu);
408 		kvm_vcpu_kick(vcpu);
409 		break;
410 
411 	case APIC_DM_INIT:
412 		if (level) {
413 			result = 1;
414 			if (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE)
415 				printk(KERN_DEBUG
416 				       "INIT on a runnable vcpu %d\n",
417 				       vcpu->vcpu_id);
418 			vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED;
419 			kvm_vcpu_kick(vcpu);
420 		} else {
421 			apic_debug("Ignoring de-assert INIT to vcpu %d\n",
422 				   vcpu->vcpu_id);
423 		}
424 		break;
425 
426 	case APIC_DM_STARTUP:
427 		apic_debug("SIPI to vcpu %d vector 0x%02x\n",
428 			   vcpu->vcpu_id, vector);
429 		if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
430 			result = 1;
431 			vcpu->arch.sipi_vector = vector;
432 			vcpu->arch.mp_state = KVM_MP_STATE_SIPI_RECEIVED;
433 			kvm_vcpu_kick(vcpu);
434 		}
435 		break;
436 
437 	case APIC_DM_EXTINT:
438 		/*
439 		 * Should only be called by kvm_apic_local_deliver() with LVT0,
440 		 * before NMI watchdog was enabled. Already handled by
441 		 * kvm_apic_accept_pic_intr().
442 		 */
443 		break;
444 
445 	default:
446 		printk(KERN_ERR "TODO: unsupported delivery mode %x\n",
447 		       delivery_mode);
448 		break;
449 	}
450 	return result;
451 }
452 
453 int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2)
454 {
455 	return vcpu1->arch.apic_arb_prio - vcpu2->arch.apic_arb_prio;
456 }
457 
458 static void apic_set_eoi(struct kvm_lapic *apic)
459 {
460 	int vector = apic_find_highest_isr(apic);
461 	int trigger_mode;
462 	/*
463 	 * Not every write EOI will has corresponding ISR,
464 	 * one example is when Kernel check timer on setup_IO_APIC
465 	 */
466 	if (vector == -1)
467 		return;
468 
469 	apic_clear_vector(vector, apic->regs + APIC_ISR);
470 	apic_update_ppr(apic);
471 
472 	if (apic_test_and_clear_vector(vector, apic->regs + APIC_TMR))
473 		trigger_mode = IOAPIC_LEVEL_TRIG;
474 	else
475 		trigger_mode = IOAPIC_EDGE_TRIG;
476 	if (!(apic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI))
477 		kvm_ioapic_update_eoi(apic->vcpu->kvm, vector, trigger_mode);
478 }
479 
480 static void apic_send_ipi(struct kvm_lapic *apic)
481 {
482 	u32 icr_low = apic_get_reg(apic, APIC_ICR);
483 	u32 icr_high = apic_get_reg(apic, APIC_ICR2);
484 	struct kvm_lapic_irq irq;
485 
486 	irq.vector = icr_low & APIC_VECTOR_MASK;
487 	irq.delivery_mode = icr_low & APIC_MODE_MASK;
488 	irq.dest_mode = icr_low & APIC_DEST_MASK;
489 	irq.level = icr_low & APIC_INT_ASSERT;
490 	irq.trig_mode = icr_low & APIC_INT_LEVELTRIG;
491 	irq.shorthand = icr_low & APIC_SHORT_MASK;
492 	if (apic_x2apic_mode(apic))
493 		irq.dest_id = icr_high;
494 	else
495 		irq.dest_id = GET_APIC_DEST_FIELD(icr_high);
496 
497 	trace_kvm_apic_ipi(icr_low, irq.dest_id);
498 
499 	apic_debug("icr_high 0x%x, icr_low 0x%x, "
500 		   "short_hand 0x%x, dest 0x%x, trig_mode 0x%x, level 0x%x, "
501 		   "dest_mode 0x%x, delivery_mode 0x%x, vector 0x%x\n",
502 		   icr_high, icr_low, irq.shorthand, irq.dest_id,
503 		   irq.trig_mode, irq.level, irq.dest_mode, irq.delivery_mode,
504 		   irq.vector);
505 
506 	kvm_irq_delivery_to_apic(apic->vcpu->kvm, apic, &irq);
507 }
508 
509 static u32 apic_get_tmcct(struct kvm_lapic *apic)
510 {
511 	ktime_t remaining;
512 	s64 ns;
513 	u32 tmcct;
514 
515 	ASSERT(apic != NULL);
516 
517 	/* if initial count is 0, current count should also be 0 */
518 	if (apic_get_reg(apic, APIC_TMICT) == 0)
519 		return 0;
520 
521 	remaining = hrtimer_get_remaining(&apic->lapic_timer.timer);
522 	if (ktime_to_ns(remaining) < 0)
523 		remaining = ktime_set(0, 0);
524 
525 	ns = mod_64(ktime_to_ns(remaining), apic->lapic_timer.period);
526 	tmcct = div64_u64(ns,
527 			 (APIC_BUS_CYCLE_NS * apic->divide_count));
528 
529 	return tmcct;
530 }
531 
532 static void __report_tpr_access(struct kvm_lapic *apic, bool write)
533 {
534 	struct kvm_vcpu *vcpu = apic->vcpu;
535 	struct kvm_run *run = vcpu->run;
536 
537 	kvm_make_request(KVM_REQ_REPORT_TPR_ACCESS, vcpu);
538 	run->tpr_access.rip = kvm_rip_read(vcpu);
539 	run->tpr_access.is_write = write;
540 }
541 
542 static inline void report_tpr_access(struct kvm_lapic *apic, bool write)
543 {
544 	if (apic->vcpu->arch.tpr_access_reporting)
545 		__report_tpr_access(apic, write);
546 }
547 
548 static u32 __apic_read(struct kvm_lapic *apic, unsigned int offset)
549 {
550 	u32 val = 0;
551 
552 	if (offset >= LAPIC_MMIO_LENGTH)
553 		return 0;
554 
555 	switch (offset) {
556 	case APIC_ID:
557 		if (apic_x2apic_mode(apic))
558 			val = kvm_apic_id(apic);
559 		else
560 			val = kvm_apic_id(apic) << 24;
561 		break;
562 	case APIC_ARBPRI:
563 		printk(KERN_WARNING "Access APIC ARBPRI register "
564 		       "which is for P6\n");
565 		break;
566 
567 	case APIC_TMCCT:	/* Timer CCR */
568 		val = apic_get_tmcct(apic);
569 		break;
570 
571 	case APIC_TASKPRI:
572 		report_tpr_access(apic, false);
573 		/* fall thru */
574 	default:
575 		apic_update_ppr(apic);
576 		val = apic_get_reg(apic, offset);
577 		break;
578 	}
579 
580 	return val;
581 }
582 
583 static inline struct kvm_lapic *to_lapic(struct kvm_io_device *dev)
584 {
585 	return container_of(dev, struct kvm_lapic, dev);
586 }
587 
588 static int apic_reg_read(struct kvm_lapic *apic, u32 offset, int len,
589 		void *data)
590 {
591 	unsigned char alignment = offset & 0xf;
592 	u32 result;
593 	/* this bitmask has a bit cleared for each reserver register */
594 	static const u64 rmask = 0x43ff01ffffffe70cULL;
595 
596 	if ((alignment + len) > 4) {
597 		apic_debug("KVM_APIC_READ: alignment error %x %d\n",
598 			   offset, len);
599 		return 1;
600 	}
601 
602 	if (offset > 0x3f0 || !(rmask & (1ULL << (offset >> 4)))) {
603 		apic_debug("KVM_APIC_READ: read reserved register %x\n",
604 			   offset);
605 		return 1;
606 	}
607 
608 	result = __apic_read(apic, offset & ~0xf);
609 
610 	trace_kvm_apic_read(offset, result);
611 
612 	switch (len) {
613 	case 1:
614 	case 2:
615 	case 4:
616 		memcpy(data, (char *)&result + alignment, len);
617 		break;
618 	default:
619 		printk(KERN_ERR "Local APIC read with len = %x, "
620 		       "should be 1,2, or 4 instead\n", len);
621 		break;
622 	}
623 	return 0;
624 }
625 
626 static int apic_mmio_in_range(struct kvm_lapic *apic, gpa_t addr)
627 {
628 	return apic_hw_enabled(apic) &&
629 	    addr >= apic->base_address &&
630 	    addr < apic->base_address + LAPIC_MMIO_LENGTH;
631 }
632 
633 static int apic_mmio_read(struct kvm_io_device *this,
634 			   gpa_t address, int len, void *data)
635 {
636 	struct kvm_lapic *apic = to_lapic(this);
637 	u32 offset = address - apic->base_address;
638 
639 	if (!apic_mmio_in_range(apic, address))
640 		return -EOPNOTSUPP;
641 
642 	apic_reg_read(apic, offset, len, data);
643 
644 	return 0;
645 }
646 
647 static void update_divide_count(struct kvm_lapic *apic)
648 {
649 	u32 tmp1, tmp2, tdcr;
650 
651 	tdcr = apic_get_reg(apic, APIC_TDCR);
652 	tmp1 = tdcr & 0xf;
653 	tmp2 = ((tmp1 & 0x3) | ((tmp1 & 0x8) >> 1)) + 1;
654 	apic->divide_count = 0x1 << (tmp2 & 0x7);
655 
656 	apic_debug("timer divide count is 0x%x\n",
657 				   apic->divide_count);
658 }
659 
660 static void start_apic_timer(struct kvm_lapic *apic)
661 {
662 	ktime_t now = apic->lapic_timer.timer.base->get_time();
663 
664 	apic->lapic_timer.period = (u64)apic_get_reg(apic, APIC_TMICT) *
665 		    APIC_BUS_CYCLE_NS * apic->divide_count;
666 	atomic_set(&apic->lapic_timer.pending, 0);
667 
668 	if (!apic->lapic_timer.period)
669 		return;
670 	/*
671 	 * Do not allow the guest to program periodic timers with small
672 	 * interval, since the hrtimers are not throttled by the host
673 	 * scheduler.
674 	 */
675 	if (apic_lvtt_period(apic)) {
676 		if (apic->lapic_timer.period < NSEC_PER_MSEC/2)
677 			apic->lapic_timer.period = NSEC_PER_MSEC/2;
678 	}
679 
680 	hrtimer_start(&apic->lapic_timer.timer,
681 		      ktime_add_ns(now, apic->lapic_timer.period),
682 		      HRTIMER_MODE_ABS);
683 
684 	apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016"
685 			   PRIx64 ", "
686 			   "timer initial count 0x%x, period %lldns, "
687 			   "expire @ 0x%016" PRIx64 ".\n", __func__,
688 			   APIC_BUS_CYCLE_NS, ktime_to_ns(now),
689 			   apic_get_reg(apic, APIC_TMICT),
690 			   apic->lapic_timer.period,
691 			   ktime_to_ns(ktime_add_ns(now,
692 					apic->lapic_timer.period)));
693 }
694 
695 static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val)
696 {
697 	int nmi_wd_enabled = apic_lvt_nmi_mode(apic_get_reg(apic, APIC_LVT0));
698 
699 	if (apic_lvt_nmi_mode(lvt0_val)) {
700 		if (!nmi_wd_enabled) {
701 			apic_debug("Receive NMI setting on APIC_LVT0 "
702 				   "for cpu %d\n", apic->vcpu->vcpu_id);
703 			apic->vcpu->kvm->arch.vapics_in_nmi_mode++;
704 		}
705 	} else if (nmi_wd_enabled)
706 		apic->vcpu->kvm->arch.vapics_in_nmi_mode--;
707 }
708 
709 static int apic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
710 {
711 	int ret = 0;
712 
713 	trace_kvm_apic_write(reg, val);
714 
715 	switch (reg) {
716 	case APIC_ID:		/* Local APIC ID */
717 		if (!apic_x2apic_mode(apic))
718 			apic_set_reg(apic, APIC_ID, val);
719 		else
720 			ret = 1;
721 		break;
722 
723 	case APIC_TASKPRI:
724 		report_tpr_access(apic, true);
725 		apic_set_tpr(apic, val & 0xff);
726 		break;
727 
728 	case APIC_EOI:
729 		apic_set_eoi(apic);
730 		break;
731 
732 	case APIC_LDR:
733 		if (!apic_x2apic_mode(apic))
734 			apic_set_reg(apic, APIC_LDR, val & APIC_LDR_MASK);
735 		else
736 			ret = 1;
737 		break;
738 
739 	case APIC_DFR:
740 		if (!apic_x2apic_mode(apic))
741 			apic_set_reg(apic, APIC_DFR, val | 0x0FFFFFFF);
742 		else
743 			ret = 1;
744 		break;
745 
746 	case APIC_SPIV: {
747 		u32 mask = 0x3ff;
748 		if (apic_get_reg(apic, APIC_LVR) & APIC_LVR_DIRECTED_EOI)
749 			mask |= APIC_SPIV_DIRECTED_EOI;
750 		apic_set_reg(apic, APIC_SPIV, val & mask);
751 		if (!(val & APIC_SPIV_APIC_ENABLED)) {
752 			int i;
753 			u32 lvt_val;
754 
755 			for (i = 0; i < APIC_LVT_NUM; i++) {
756 				lvt_val = apic_get_reg(apic,
757 						       APIC_LVTT + 0x10 * i);
758 				apic_set_reg(apic, APIC_LVTT + 0x10 * i,
759 					     lvt_val | APIC_LVT_MASKED);
760 			}
761 			atomic_set(&apic->lapic_timer.pending, 0);
762 
763 		}
764 		break;
765 	}
766 	case APIC_ICR:
767 		/* No delay here, so we always clear the pending bit */
768 		apic_set_reg(apic, APIC_ICR, val & ~(1 << 12));
769 		apic_send_ipi(apic);
770 		break;
771 
772 	case APIC_ICR2:
773 		if (!apic_x2apic_mode(apic))
774 			val &= 0xff000000;
775 		apic_set_reg(apic, APIC_ICR2, val);
776 		break;
777 
778 	case APIC_LVT0:
779 		apic_manage_nmi_watchdog(apic, val);
780 	case APIC_LVTT:
781 	case APIC_LVTTHMR:
782 	case APIC_LVTPC:
783 	case APIC_LVT1:
784 	case APIC_LVTERR:
785 		/* TODO: Check vector */
786 		if (!apic_sw_enabled(apic))
787 			val |= APIC_LVT_MASKED;
788 
789 		val &= apic_lvt_mask[(reg - APIC_LVTT) >> 4];
790 		apic_set_reg(apic, reg, val);
791 
792 		break;
793 
794 	case APIC_TMICT:
795 		hrtimer_cancel(&apic->lapic_timer.timer);
796 		apic_set_reg(apic, APIC_TMICT, val);
797 		start_apic_timer(apic);
798 		break;
799 
800 	case APIC_TDCR:
801 		if (val & 4)
802 			printk(KERN_ERR "KVM_WRITE:TDCR %x\n", val);
803 		apic_set_reg(apic, APIC_TDCR, val);
804 		update_divide_count(apic);
805 		break;
806 
807 	case APIC_ESR:
808 		if (apic_x2apic_mode(apic) && val != 0) {
809 			printk(KERN_ERR "KVM_WRITE:ESR not zero %x\n", val);
810 			ret = 1;
811 		}
812 		break;
813 
814 	case APIC_SELF_IPI:
815 		if (apic_x2apic_mode(apic)) {
816 			apic_reg_write(apic, APIC_ICR, 0x40000 | (val & 0xff));
817 		} else
818 			ret = 1;
819 		break;
820 	default:
821 		ret = 1;
822 		break;
823 	}
824 	if (ret)
825 		apic_debug("Local APIC Write to read-only register %x\n", reg);
826 	return ret;
827 }
828 
829 static int apic_mmio_write(struct kvm_io_device *this,
830 			    gpa_t address, int len, const void *data)
831 {
832 	struct kvm_lapic *apic = to_lapic(this);
833 	unsigned int offset = address - apic->base_address;
834 	u32 val;
835 
836 	if (!apic_mmio_in_range(apic, address))
837 		return -EOPNOTSUPP;
838 
839 	/*
840 	 * APIC register must be aligned on 128-bits boundary.
841 	 * 32/64/128 bits registers must be accessed thru 32 bits.
842 	 * Refer SDM 8.4.1
843 	 */
844 	if (len != 4 || (offset & 0xf)) {
845 		/* Don't shout loud, $infamous_os would cause only noise. */
846 		apic_debug("apic write: bad size=%d %lx\n", len, (long)address);
847 		return 0;
848 	}
849 
850 	val = *(u32*)data;
851 
852 	/* too common printing */
853 	if (offset != APIC_EOI)
854 		apic_debug("%s: offset 0x%x with length 0x%x, and value is "
855 			   "0x%x\n", __func__, offset, len, val);
856 
857 	apic_reg_write(apic, offset & 0xff0, val);
858 
859 	return 0;
860 }
861 
862 void kvm_free_lapic(struct kvm_vcpu *vcpu)
863 {
864 	if (!vcpu->arch.apic)
865 		return;
866 
867 	hrtimer_cancel(&vcpu->arch.apic->lapic_timer.timer);
868 
869 	if (vcpu->arch.apic->regs_page)
870 		__free_page(vcpu->arch.apic->regs_page);
871 
872 	kfree(vcpu->arch.apic);
873 }
874 
875 /*
876  *----------------------------------------------------------------------
877  * LAPIC interface
878  *----------------------------------------------------------------------
879  */
880 
881 void kvm_lapic_set_tpr(struct kvm_vcpu *vcpu, unsigned long cr8)
882 {
883 	struct kvm_lapic *apic = vcpu->arch.apic;
884 
885 	if (!apic)
886 		return;
887 	apic_set_tpr(apic, ((cr8 & 0x0f) << 4)
888 		     | (apic_get_reg(apic, APIC_TASKPRI) & 4));
889 }
890 
891 u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu)
892 {
893 	struct kvm_lapic *apic = vcpu->arch.apic;
894 	u64 tpr;
895 
896 	if (!apic)
897 		return 0;
898 	tpr = (u64) apic_get_reg(apic, APIC_TASKPRI);
899 
900 	return (tpr & 0xf0) >> 4;
901 }
902 
903 void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
904 {
905 	struct kvm_lapic *apic = vcpu->arch.apic;
906 
907 	if (!apic) {
908 		value |= MSR_IA32_APICBASE_BSP;
909 		vcpu->arch.apic_base = value;
910 		return;
911 	}
912 
913 	if (!kvm_vcpu_is_bsp(apic->vcpu))
914 		value &= ~MSR_IA32_APICBASE_BSP;
915 
916 	vcpu->arch.apic_base = value;
917 	if (apic_x2apic_mode(apic)) {
918 		u32 id = kvm_apic_id(apic);
919 		u32 ldr = ((id & ~0xf) << 16) | (1 << (id & 0xf));
920 		apic_set_reg(apic, APIC_LDR, ldr);
921 	}
922 	apic->base_address = apic->vcpu->arch.apic_base &
923 			     MSR_IA32_APICBASE_BASE;
924 
925 	/* with FSB delivery interrupt, we can restart APIC functionality */
926 	apic_debug("apic base msr is 0x%016" PRIx64 ", and base address is "
927 		   "0x%lx.\n", apic->vcpu->arch.apic_base, apic->base_address);
928 
929 }
930 
931 void kvm_lapic_reset(struct kvm_vcpu *vcpu)
932 {
933 	struct kvm_lapic *apic;
934 	int i;
935 
936 	apic_debug("%s\n", __func__);
937 
938 	ASSERT(vcpu);
939 	apic = vcpu->arch.apic;
940 	ASSERT(apic != NULL);
941 
942 	/* Stop the timer in case it's a reset to an active apic */
943 	hrtimer_cancel(&apic->lapic_timer.timer);
944 
945 	apic_set_reg(apic, APIC_ID, vcpu->vcpu_id << 24);
946 	kvm_apic_set_version(apic->vcpu);
947 
948 	for (i = 0; i < APIC_LVT_NUM; i++)
949 		apic_set_reg(apic, APIC_LVTT + 0x10 * i, APIC_LVT_MASKED);
950 	apic_set_reg(apic, APIC_LVT0,
951 		     SET_APIC_DELIVERY_MODE(0, APIC_MODE_EXTINT));
952 
953 	apic_set_reg(apic, APIC_DFR, 0xffffffffU);
954 	apic_set_reg(apic, APIC_SPIV, 0xff);
955 	apic_set_reg(apic, APIC_TASKPRI, 0);
956 	apic_set_reg(apic, APIC_LDR, 0);
957 	apic_set_reg(apic, APIC_ESR, 0);
958 	apic_set_reg(apic, APIC_ICR, 0);
959 	apic_set_reg(apic, APIC_ICR2, 0);
960 	apic_set_reg(apic, APIC_TDCR, 0);
961 	apic_set_reg(apic, APIC_TMICT, 0);
962 	for (i = 0; i < 8; i++) {
963 		apic_set_reg(apic, APIC_IRR + 0x10 * i, 0);
964 		apic_set_reg(apic, APIC_ISR + 0x10 * i, 0);
965 		apic_set_reg(apic, APIC_TMR + 0x10 * i, 0);
966 	}
967 	apic->irr_pending = false;
968 	update_divide_count(apic);
969 	atomic_set(&apic->lapic_timer.pending, 0);
970 	if (kvm_vcpu_is_bsp(vcpu))
971 		vcpu->arch.apic_base |= MSR_IA32_APICBASE_BSP;
972 	apic_update_ppr(apic);
973 
974 	vcpu->arch.apic_arb_prio = 0;
975 
976 	apic_debug(KERN_INFO "%s: vcpu=%p, id=%d, base_msr="
977 		   "0x%016" PRIx64 ", base_address=0x%0lx.\n", __func__,
978 		   vcpu, kvm_apic_id(apic),
979 		   vcpu->arch.apic_base, apic->base_address);
980 }
981 
982 bool kvm_apic_present(struct kvm_vcpu *vcpu)
983 {
984 	return vcpu->arch.apic && apic_hw_enabled(vcpu->arch.apic);
985 }
986 
987 int kvm_lapic_enabled(struct kvm_vcpu *vcpu)
988 {
989 	return kvm_apic_present(vcpu) && apic_sw_enabled(vcpu->arch.apic);
990 }
991 
992 /*
993  *----------------------------------------------------------------------
994  * timer interface
995  *----------------------------------------------------------------------
996  */
997 
998 static bool lapic_is_periodic(struct kvm_timer *ktimer)
999 {
1000 	struct kvm_lapic *apic = container_of(ktimer, struct kvm_lapic,
1001 					      lapic_timer);
1002 	return apic_lvtt_period(apic);
1003 }
1004 
1005 int apic_has_pending_timer(struct kvm_vcpu *vcpu)
1006 {
1007 	struct kvm_lapic *lapic = vcpu->arch.apic;
1008 
1009 	if (lapic && apic_enabled(lapic) && apic_lvt_enabled(lapic, APIC_LVTT))
1010 		return atomic_read(&lapic->lapic_timer.pending);
1011 
1012 	return 0;
1013 }
1014 
1015 static int kvm_apic_local_deliver(struct kvm_lapic *apic, int lvt_type)
1016 {
1017 	u32 reg = apic_get_reg(apic, lvt_type);
1018 	int vector, mode, trig_mode;
1019 
1020 	if (apic_hw_enabled(apic) && !(reg & APIC_LVT_MASKED)) {
1021 		vector = reg & APIC_VECTOR_MASK;
1022 		mode = reg & APIC_MODE_MASK;
1023 		trig_mode = reg & APIC_LVT_LEVEL_TRIGGER;
1024 		return __apic_accept_irq(apic, mode, vector, 1, trig_mode);
1025 	}
1026 	return 0;
1027 }
1028 
1029 void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu)
1030 {
1031 	struct kvm_lapic *apic = vcpu->arch.apic;
1032 
1033 	if (apic)
1034 		kvm_apic_local_deliver(apic, APIC_LVT0);
1035 }
1036 
1037 static struct kvm_timer_ops lapic_timer_ops = {
1038 	.is_periodic = lapic_is_periodic,
1039 };
1040 
1041 static const struct kvm_io_device_ops apic_mmio_ops = {
1042 	.read     = apic_mmio_read,
1043 	.write    = apic_mmio_write,
1044 };
1045 
1046 int kvm_create_lapic(struct kvm_vcpu *vcpu)
1047 {
1048 	struct kvm_lapic *apic;
1049 
1050 	ASSERT(vcpu != NULL);
1051 	apic_debug("apic_init %d\n", vcpu->vcpu_id);
1052 
1053 	apic = kzalloc(sizeof(*apic), GFP_KERNEL);
1054 	if (!apic)
1055 		goto nomem;
1056 
1057 	vcpu->arch.apic = apic;
1058 
1059 	apic->regs_page = alloc_page(GFP_KERNEL);
1060 	if (apic->regs_page == NULL) {
1061 		printk(KERN_ERR "malloc apic regs error for vcpu %x\n",
1062 		       vcpu->vcpu_id);
1063 		goto nomem_free_apic;
1064 	}
1065 	apic->regs = page_address(apic->regs_page);
1066 	memset(apic->regs, 0, PAGE_SIZE);
1067 	apic->vcpu = vcpu;
1068 
1069 	hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
1070 		     HRTIMER_MODE_ABS);
1071 	apic->lapic_timer.timer.function = kvm_timer_fn;
1072 	apic->lapic_timer.t_ops = &lapic_timer_ops;
1073 	apic->lapic_timer.kvm = vcpu->kvm;
1074 	apic->lapic_timer.vcpu = vcpu;
1075 
1076 	apic->base_address = APIC_DEFAULT_PHYS_BASE;
1077 	vcpu->arch.apic_base = APIC_DEFAULT_PHYS_BASE;
1078 
1079 	kvm_lapic_reset(vcpu);
1080 	kvm_iodevice_init(&apic->dev, &apic_mmio_ops);
1081 
1082 	return 0;
1083 nomem_free_apic:
1084 	kfree(apic);
1085 nomem:
1086 	return -ENOMEM;
1087 }
1088 
1089 int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu)
1090 {
1091 	struct kvm_lapic *apic = vcpu->arch.apic;
1092 	int highest_irr;
1093 
1094 	if (!apic || !apic_enabled(apic))
1095 		return -1;
1096 
1097 	apic_update_ppr(apic);
1098 	highest_irr = apic_find_highest_irr(apic);
1099 	if ((highest_irr == -1) ||
1100 	    ((highest_irr & 0xF0) <= apic_get_reg(apic, APIC_PROCPRI)))
1101 		return -1;
1102 	return highest_irr;
1103 }
1104 
1105 int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu)
1106 {
1107 	u32 lvt0 = apic_get_reg(vcpu->arch.apic, APIC_LVT0);
1108 	int r = 0;
1109 
1110 	if (!apic_hw_enabled(vcpu->arch.apic))
1111 		r = 1;
1112 	if ((lvt0 & APIC_LVT_MASKED) == 0 &&
1113 	    GET_APIC_DELIVERY_MODE(lvt0) == APIC_MODE_EXTINT)
1114 		r = 1;
1115 	return r;
1116 }
1117 
1118 void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu)
1119 {
1120 	struct kvm_lapic *apic = vcpu->arch.apic;
1121 
1122 	if (apic && atomic_read(&apic->lapic_timer.pending) > 0) {
1123 		if (kvm_apic_local_deliver(apic, APIC_LVTT))
1124 			atomic_dec(&apic->lapic_timer.pending);
1125 	}
1126 }
1127 
1128 int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu)
1129 {
1130 	int vector = kvm_apic_has_interrupt(vcpu);
1131 	struct kvm_lapic *apic = vcpu->arch.apic;
1132 
1133 	if (vector == -1)
1134 		return -1;
1135 
1136 	apic_set_vector(vector, apic->regs + APIC_ISR);
1137 	apic_update_ppr(apic);
1138 	apic_clear_irr(vector, apic);
1139 	return vector;
1140 }
1141 
1142 void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu)
1143 {
1144 	struct kvm_lapic *apic = vcpu->arch.apic;
1145 
1146 	apic->base_address = vcpu->arch.apic_base &
1147 			     MSR_IA32_APICBASE_BASE;
1148 	kvm_apic_set_version(vcpu);
1149 
1150 	apic_update_ppr(apic);
1151 	hrtimer_cancel(&apic->lapic_timer.timer);
1152 	update_divide_count(apic);
1153 	start_apic_timer(apic);
1154 	apic->irr_pending = true;
1155 }
1156 
1157 void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu)
1158 {
1159 	struct kvm_lapic *apic = vcpu->arch.apic;
1160 	struct hrtimer *timer;
1161 
1162 	if (!apic)
1163 		return;
1164 
1165 	timer = &apic->lapic_timer.timer;
1166 	if (hrtimer_cancel(timer))
1167 		hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
1168 }
1169 
1170 void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu)
1171 {
1172 	u32 data;
1173 	void *vapic;
1174 
1175 	if (!irqchip_in_kernel(vcpu->kvm) || !vcpu->arch.apic->vapic_addr)
1176 		return;
1177 
1178 	vapic = kmap_atomic(vcpu->arch.apic->vapic_page, KM_USER0);
1179 	data = *(u32 *)(vapic + offset_in_page(vcpu->arch.apic->vapic_addr));
1180 	kunmap_atomic(vapic, KM_USER0);
1181 
1182 	apic_set_tpr(vcpu->arch.apic, data & 0xff);
1183 }
1184 
1185 void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu)
1186 {
1187 	u32 data, tpr;
1188 	int max_irr, max_isr;
1189 	struct kvm_lapic *apic;
1190 	void *vapic;
1191 
1192 	if (!irqchip_in_kernel(vcpu->kvm) || !vcpu->arch.apic->vapic_addr)
1193 		return;
1194 
1195 	apic = vcpu->arch.apic;
1196 	tpr = apic_get_reg(apic, APIC_TASKPRI) & 0xff;
1197 	max_irr = apic_find_highest_irr(apic);
1198 	if (max_irr < 0)
1199 		max_irr = 0;
1200 	max_isr = apic_find_highest_isr(apic);
1201 	if (max_isr < 0)
1202 		max_isr = 0;
1203 	data = (tpr & 0xff) | ((max_isr & 0xf0) << 8) | (max_irr << 24);
1204 
1205 	vapic = kmap_atomic(vcpu->arch.apic->vapic_page, KM_USER0);
1206 	*(u32 *)(vapic + offset_in_page(vcpu->arch.apic->vapic_addr)) = data;
1207 	kunmap_atomic(vapic, KM_USER0);
1208 }
1209 
1210 void kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr)
1211 {
1212 	if (!irqchip_in_kernel(vcpu->kvm))
1213 		return;
1214 
1215 	vcpu->arch.apic->vapic_addr = vapic_addr;
1216 }
1217 
1218 int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data)
1219 {
1220 	struct kvm_lapic *apic = vcpu->arch.apic;
1221 	u32 reg = (msr - APIC_BASE_MSR) << 4;
1222 
1223 	if (!irqchip_in_kernel(vcpu->kvm) || !apic_x2apic_mode(apic))
1224 		return 1;
1225 
1226 	/* if this is ICR write vector before command */
1227 	if (msr == 0x830)
1228 		apic_reg_write(apic, APIC_ICR2, (u32)(data >> 32));
1229 	return apic_reg_write(apic, reg, (u32)data);
1230 }
1231 
1232 int kvm_x2apic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
1233 {
1234 	struct kvm_lapic *apic = vcpu->arch.apic;
1235 	u32 reg = (msr - APIC_BASE_MSR) << 4, low, high = 0;
1236 
1237 	if (!irqchip_in_kernel(vcpu->kvm) || !apic_x2apic_mode(apic))
1238 		return 1;
1239 
1240 	if (apic_reg_read(apic, reg, 4, &low))
1241 		return 1;
1242 	if (msr == 0x830)
1243 		apic_reg_read(apic, APIC_ICR2, 4, &high);
1244 
1245 	*data = (((u64)high) << 32) | low;
1246 
1247 	return 0;
1248 }
1249 
1250 int kvm_hv_vapic_msr_write(struct kvm_vcpu *vcpu, u32 reg, u64 data)
1251 {
1252 	struct kvm_lapic *apic = vcpu->arch.apic;
1253 
1254 	if (!irqchip_in_kernel(vcpu->kvm))
1255 		return 1;
1256 
1257 	/* if this is ICR write vector before command */
1258 	if (reg == APIC_ICR)
1259 		apic_reg_write(apic, APIC_ICR2, (u32)(data >> 32));
1260 	return apic_reg_write(apic, reg, (u32)data);
1261 }
1262 
1263 int kvm_hv_vapic_msr_read(struct kvm_vcpu *vcpu, u32 reg, u64 *data)
1264 {
1265 	struct kvm_lapic *apic = vcpu->arch.apic;
1266 	u32 low, high = 0;
1267 
1268 	if (!irqchip_in_kernel(vcpu->kvm))
1269 		return 1;
1270 
1271 	if (apic_reg_read(apic, reg, 4, &low))
1272 		return 1;
1273 	if (reg == APIC_ICR)
1274 		apic_reg_read(apic, APIC_ICR2, 4, &high);
1275 
1276 	*data = (((u64)high) << 32) | low;
1277 
1278 	return 0;
1279 }
1280