summaryrefslogtreecommitdiff
path: root/drivers/hv/hv.c
blob: 60dbd6cb4640cd6caeb36a8c07585660d812f3b9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
/*
 * Copyright (c) 2009, Microsoft Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307 USA.
 *
 * Authors:
 *   Haiyang Zhang <haiyangz@microsoft.com>
 *   Hank Janssen  <hjanssen@microsoft.com>
 *
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/hyperv.h>
#include <linux/version.h>
#include <linux/interrupt.h>
#include <linux/clockchips.h>
#include <asm/hyperv.h>
#include <asm/mshyperv.h>
#include "hyperv_vmbus.h"

/* The one and only */
struct hv_context hv_context = {
	.synic_initialized	= false,
	.hypercall_page		= NULL,
};

#define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */
#define HV_MAX_MAX_DELTA_TICKS 0xffffffff
#define HV_MIN_DELTA_TICKS 1

/*
 * query_hypervisor_info - Get version info of the windows hypervisor
 */
unsigned int host_info_eax;
unsigned int host_info_ebx;
unsigned int host_info_ecx;
unsigned int host_info_edx;

static int query_hypervisor_info(void)
{
	unsigned int eax;
	unsigned int ebx;
	unsigned int ecx;
	unsigned int edx;
	unsigned int max_leaf;
	unsigned int op;

	/*
	* Its assumed that this is called after confirming that Viridian
	* is present. Query id and revision.
	*/
	eax = 0;
	ebx = 0;
	ecx = 0;
	edx = 0;
	op = HVCPUID_VENDOR_MAXFUNCTION;
	cpuid(op, &eax, &ebx, &ecx, &edx);

	max_leaf = eax;

	if (max_leaf >= HVCPUID_VERSION) {
		eax = 0;
		ebx = 0;
		ecx = 0;
		edx = 0;
		op = HVCPUID_VERSION;
		cpuid(op, &eax, &ebx, &ecx, &edx);
		host_info_eax = eax;
		host_info_ebx = ebx;
		host_info_ecx = ecx;
		host_info_edx = edx;
	}
	return max_leaf;
}

/*
 * hv_do_hypercall- Invoke the specified hypercall
 */
u64 hv_do_hypercall(u64 control, void *input, void *output)
{
	u64 input_address = (input) ? virt_to_phys(input) : 0;
	u64 output_address = (output) ? virt_to_phys(output) : 0;
	void *hypercall_page = hv_context.hypercall_page;
#ifdef CONFIG_X86_64
	u64 hv_status = 0;

	if (!hypercall_page)
		return (u64)ULLONG_MAX;

	__asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
	__asm__ __volatile__("call *%3" : "=a" (hv_status) :
			     "c" (control), "d" (input_address),
			     "m" (hypercall_page));

	return hv_status;

#else

	u32 control_hi = control >> 32;
	u32 control_lo = control & 0xFFFFFFFF;
	u32 hv_status_hi = 1;
	u32 hv_status_lo = 1;
	u32 input_address_hi = input_address >> 32;
	u32 input_address_lo = input_address & 0xFFFFFFFF;
	u32 output_address_hi = output_address >> 32;
	u32 output_address_lo = output_address & 0xFFFFFFFF;

	if (!hypercall_page)
		return (u64)ULLONG_MAX;

	__asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
			      "=a"(hv_status_lo) : "d" (control_hi),
			      "a" (control_lo), "b" (input_address_hi),
			      "c" (input_address_lo), "D"(output_address_hi),
			      "S"(output_address_lo), "m" (hypercall_page));

	return hv_status_lo | ((u64)hv_status_hi << 32);
#endif /* !x86_64 */
}
EXPORT_SYMBOL_GPL(hv_do_hypercall);

#ifdef CONFIG_X86_64
static cycle_t read_hv_clock_tsc(struct clocksource *arg)
{
	cycle_t current_tick;
	struct ms_hyperv_tsc_page *tsc_pg = hv_context.tsc_page;

	if (tsc_pg->tsc_sequence != 0) {
		/*
		 * Use the tsc page to compute the value.
		 */

		while (1) {
			cycle_t tmp;
			u32 sequence = tsc_pg->tsc_sequence;
			u64 cur_tsc;
			u64 scale = tsc_pg->tsc_scale;
			s64 offset = tsc_pg->tsc_offset;

			rdtscll(cur_tsc);
			/* current_tick = ((cur_tsc *scale) >> 64) + offset */
			asm("mulq %3"
				: "=d" (current_tick), "=a" (tmp)
				: "a" (cur_tsc), "r" (scale));

			current_tick += offset;
			if (tsc_pg->tsc_sequence == sequence)
				return current_tick;

			if (tsc_pg->tsc_sequence != 0)
				continue;
			/*
			 * Fallback using MSR method.
			 */
			break;
		}
	}
	rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
	return current_tick;
}

static struct clocksource hyperv_cs_tsc = {
		.name           = "hyperv_clocksource_tsc_page",
		.rating         = 425,
		.read           = read_hv_clock_tsc,
		.mask           = CLOCKSOURCE_MASK(64),
		.flags          = CLOCK_SOURCE_IS_CONTINUOUS,
};
#endif


/*
 * hv_init - Main initialization routine.
 *
 * This routine must be called before any other routines in here are called
 */
int hv_init(void)
{
	int max_leaf;
	union hv_x64_msr_hypercall_contents hypercall_msr;
	void *virtaddr = NULL;

	memset(hv_context.synic_event_page, 0, sizeof(void *) * NR_CPUS);
	memset(hv_context.synic_message_page, 0,
	       sizeof(void *) * NR_CPUS);
	memset(hv_context.post_msg_page, 0,
	       sizeof(void *) * NR_CPUS);
	memset(hv_context.vp_index, 0,
	       sizeof(int) * NR_CPUS);
	memset(hv_context.event_dpc, 0,
	       sizeof(void *) * NR_CPUS);
	memset(hv_context.msg_dpc, 0,
	       sizeof(void *) * NR_CPUS);
	memset(hv_context.clk_evt, 0,
	       sizeof(void *) * NR_CPUS);

	max_leaf = query_hypervisor_info();

	/*
	 * Write our OS ID.
	 */
	hv_context.guestid = generate_guest_id(0, LINUX_VERSION_CODE, 0);
	wrmsrl(HV_X64_MSR_GUEST_OS_ID, hv_context.guestid);

	/* See if the hypercall page is already set */
	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);

	virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);

	if (!virtaddr)
		goto cleanup;

	hypercall_msr.enable = 1;

	hypercall_msr.guest_physical_address = vmalloc_to_pfn(virtaddr);
	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);

	/* Confirm that hypercall page did get setup. */
	hypercall_msr.as_uint64 = 0;
	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);

	if (!hypercall_msr.enable)
		goto cleanup;

	hv_context.hypercall_page = virtaddr;

#ifdef CONFIG_X86_64
	if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
		union hv_x64_msr_hypercall_contents tsc_msr;
		void *va_tsc;

		va_tsc = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL);
		if (!va_tsc)
			goto cleanup;
		hv_context.tsc_page = va_tsc;

		rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);

		tsc_msr.enable = 1;
		tsc_msr.guest_physical_address = vmalloc_to_pfn(va_tsc);

		wrmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
		clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
	}
#endif
	return 0;

cleanup:
	if (virtaddr) {
		if (hypercall_msr.enable) {
			hypercall_msr.as_uint64 = 0;
			wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
		}

		vfree(virtaddr);
	}

	return -ENOTSUPP;
}

/*
 * hv_cleanup - Cleanup routine.
 *
 * This routine is called normally during driver unloading or exiting.
 */
void hv_cleanup(bool crash)
{
	union hv_x64_msr_hypercall_contents hypercall_msr;

	/* Reset our OS id */
	wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);

	if (hv_context.hypercall_page) {
		hypercall_msr.as_uint64 = 0;
		wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
		if (!crash)
			vfree(hv_context.hypercall_page);
		hv_context.hypercall_page = NULL;
	}

#ifdef CONFIG_X86_64
	/*
	 * Cleanup the TSC page based CS.
	 */
	if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
		/*
		 * Crash can happen in an interrupt context and unregistering
		 * a clocksource is impossible and redundant in this case.
		 */
		if (!oops_in_progress) {
			clocksource_change_rating(&hyperv_cs_tsc, 10);
			clocksource_unregister(&hyperv_cs_tsc);
		}

		hypercall_msr.as_uint64 = 0;
		wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64);
		if (!crash)
			vfree(hv_context.tsc_page);
		hv_context.tsc_page = NULL;
	}
#endif
}

/*
 * hv_post_message - Post a message using the hypervisor message IPC.
 *
 * This involves a hypercall.
 */
int hv_post_message(union hv_connection_id connection_id,
		  enum hv_message_type message_type,
		  void *payload, size_t payload_size)
{

	struct hv_input_post_message *aligned_msg;
	u64 status;

	if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
		return -EMSGSIZE;

	aligned_msg = (struct hv_input_post_message *)
			hv_context.post_msg_page[get_cpu()];

	aligned_msg->connectionid = connection_id;
	aligned_msg->reserved = 0;
	aligned_msg->message_type = message_type;
	aligned_msg->payload_size = payload_size;
	memcpy((void *)aligned_msg->payload, payload, payload_size);

	status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);

	put_cpu();
	return status & 0xFFFF;
}

static int hv_ce_set_next_event(unsigned long delta,
				struct clock_event_device *evt)
{
	cycle_t current_tick;

	WARN_ON(!clockevent_state_oneshot(evt));

	rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
	current_tick += delta;
	wrmsrl(HV_X64_MSR_STIMER0_COUNT, current_tick);
	return 0;
}

static int hv_ce_shutdown(struct clock_event_device *evt)
{
	wrmsrl(HV_X64_MSR_STIMER0_COUNT, 0);
	wrmsrl(HV_X64_MSR_STIMER0_CONFIG, 0);

	return 0;
}

static int hv_ce_set_oneshot(struct clock_event_device *evt)
{
	union hv_timer_config timer_cfg;

	timer_cfg.enable = 1;
	timer_cfg.auto_enable = 1;
	timer_cfg.sintx = VMBUS_MESSAGE_SINT;
	wrmsrl(HV_X64_MSR_STIMER0_CONFIG, timer_cfg.as_uint64);

	return 0;
}

static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu)
{
	dev->name = "Hyper-V clockevent";
	dev->features = CLOCK_EVT_FEAT_ONESHOT;
	dev->cpumask = cpumask_of(cpu);
	dev->rating = 1000;
	/*
	 * Avoid settint dev->owner = THIS_MODULE deliberately as doing so will
	 * result in clockevents_config_and_register() taking additional
	 * references to the hv_vmbus module making it impossible to unload.
	 */

	dev->set_state_shutdown = hv_ce_shutdown;
	dev->set_state_oneshot = hv_ce_set_oneshot;
	dev->set_next_event = hv_ce_set_next_event;
}


int hv_synic_alloc(void)
{
	size_t size = sizeof(struct tasklet_struct);
	size_t ced_size = sizeof(struct clock_event_device);
	int cpu;

	hv_context.hv_numa_map = kzalloc(sizeof(struct cpumask) * nr_node_ids,
					 GFP_ATOMIC);
	if (hv_context.hv_numa_map == NULL) {
		pr_err("Unable to allocate NUMA map\n");
		goto err;
	}

	for_each_online_cpu(cpu) {
		hv_context.event_dpc[cpu] = kmalloc(size, GFP_ATOMIC);
		if (hv_context.event_dpc[cpu] == NULL) {
			pr_err("Unable to allocate event dpc\n");
			goto err;
		}
		tasklet_init(hv_context.event_dpc[cpu], vmbus_on_event, cpu);

		hv_context.msg_dpc[cpu] = kmalloc(size, GFP_ATOMIC);
		if (hv_context.msg_dpc[cpu] == NULL) {
			pr_err("Unable to allocate event dpc\n");
			goto err;
		}
		tasklet_init(hv_context.msg_dpc[cpu], vmbus_on_msg_dpc, cpu);

		hv_context.clk_evt[cpu] = kzalloc(ced_size, GFP_ATOMIC);
		if (hv_context.clk_evt[cpu] == NULL) {
			pr_err("Unable to allocate clock event device\n");
			goto err;
		}

		hv_init_clockevent_device(hv_context.clk_evt[cpu], cpu);

		hv_context.synic_message_page[cpu] =
			(void *)get_zeroed_page(GFP_ATOMIC);

		if (hv_context.synic_message_page[cpu] == NULL) {
			pr_err("Unable to allocate SYNIC message page\n");
			goto err;
		}

		hv_context.synic_event_page[cpu] =
			(void *)get_zeroed_page(GFP_ATOMIC);

		if (hv_context.synic_event_page[cpu] == NULL) {
			pr_err("Unable to allocate SYNIC event page\n");
			goto err;
		}

		hv_context.post_msg_page[cpu] =
			(void *)get_zeroed_page(GFP_ATOMIC);

		if (hv_context.post_msg_page[cpu] == NULL) {
			pr_err("Unable to allocate post msg page\n");
			goto err;
		}
	}

	return 0;
err:
	return -ENOMEM;
}

static void hv_synic_free_cpu(int cpu)
{
	kfree(hv_context.event_dpc[cpu]);
	kfree(hv_context.msg_dpc[cpu]);
	kfree(hv_context.clk_evt[cpu]);
	if (hv_context.synic_event_page[cpu])
		free_page((unsigned long)hv_context.synic_event_page[cpu]);
	if (hv_context.synic_message_page[cpu])
		free_page((unsigned long)hv_context.synic_message_page[cpu]);
	if (hv_context.post_msg_page[cpu])
		free_page((unsigned long)hv_context.post_msg_page[cpu]);
}

void hv_synic_free(void)
{
	int cpu;

	kfree(hv_context.hv_numa_map);
	for_each_online_cpu(cpu)
		hv_synic_free_cpu(cpu);
}

/*
 * hv_synic_init - Initialize the Synthethic Interrupt Controller.
 *
 * If it is already initialized by another entity (ie x2v shim), we need to
 * retrieve the initialized message and event pages.  Otherwise, we create and
 * initialize the message and event pages.
 */
void hv_synic_init(void *arg)
{
	u64 version;
	union hv_synic_simp simp;
	union hv_synic_siefp siefp;
	union hv_synic_sint shared_sint;
	union hv_synic_scontrol sctrl;
	u64 vp_index;

	int cpu = smp_processor_id();

	if (!hv_context.hypercall_page)
		return;

	/* Check the version */
	rdmsrl(HV_X64_MSR_SVERSION, version);

	/* Setup the Synic's message page */
	rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
	simp.simp_enabled = 1;
	simp.base_simp_gpa = virt_to_phys(hv_context.synic_message_page[cpu])
		>> PAGE_SHIFT;

	wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);

	/* Setup the Synic's event page */
	rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
	siefp.siefp_enabled = 1;
	siefp.base_siefp_gpa = virt_to_phys(hv_context.synic_event_page[cpu])
		>> PAGE_SHIFT;

	wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);

	/* Setup the shared SINT. */
	rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);

	shared_sint.as_uint64 = 0;
	shared_sint.vector = HYPERVISOR_CALLBACK_VECTOR;
	shared_sint.masked = false;
	shared_sint.auto_eoi = true;

	wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);

	/* Enable the global synic bit */
	rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
	sctrl.enable = 1;

	wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);

	hv_context.synic_initialized = true;

	/*
	 * Setup the mapping between Hyper-V's notion
	 * of cpuid and Linux' notion of cpuid.
	 * This array will be indexed using Linux cpuid.
	 */
	rdmsrl(HV_X64_MSR_VP_INDEX, vp_index);
	hv_context.vp_index[cpu] = (u32)vp_index;

	INIT_LIST_HEAD(&hv_context.percpu_list[cpu]);

	/*
	 * Register the per-cpu clockevent source.
	 */
	if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE)
		clockevents_config_and_register(hv_context.clk_evt[cpu],
						HV_TIMER_FREQUENCY,
						HV_MIN_DELTA_TICKS,
						HV_MAX_MAX_DELTA_TICKS);
	return;
}

/*
 * hv_synic_clockevents_cleanup - Cleanup clockevent devices
 */
void hv_synic_clockevents_cleanup(void)
{
	int cpu;

	if (!(ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE))
		return;

	for_each_online_cpu(cpu)
		clockevents_unbind_device(hv_context.clk_evt[cpu], cpu);
}

/*
 * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 */
void hv_synic_cleanup(void *arg)
{
	union hv_synic_sint shared_sint;
	union hv_synic_simp simp;
	union hv_synic_siefp siefp;
	union hv_synic_scontrol sctrl;
	int cpu = smp_processor_id();

	if (!hv_context.synic_initialized)
		return;

	/* Turn off clockevent device */
	if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE)
		hv_ce_shutdown(hv_context.clk_evt[cpu]);

	rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);

	shared_sint.masked = 1;

	/* Need to correctly cleanup in the case of SMP!!! */
	/* Disable the interrupt */
	wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);

	rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
	simp.simp_enabled = 0;
	simp.base_simp_gpa = 0;

	wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);

	rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
	siefp.siefp_enabled = 0;
	siefp.base_siefp_gpa = 0;

	wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);

	/* Disable the global synic bit */
	rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
	sctrl.enable = 0;
	wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
}