summaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/mshyperv.h
blob: 530f448fddafff3297f0e97d697309f1a2cf15bf (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
#ifndef _ASM_X86_MSHYPER_H
#define _ASM_X86_MSHYPER_H

#include <linux/types.h>
#include <linux/atomic.h>
#include <linux/nmi.h>
#include <asm/io.h>
#include <asm/hyperv.h>

/*
 * The below CPUID leaves are present if VersionAndFeatures.HypervisorPresent
 * is set by CPUID(HVCPUID_VERSION_FEATURES).
 */
enum hv_cpuid_function {
	HVCPUID_VERSION_FEATURES		= 0x00000001,
	HVCPUID_VENDOR_MAXFUNCTION		= 0x40000000,
	HVCPUID_INTERFACE			= 0x40000001,

	/*
	 * The remaining functions depend on the value of
	 * HVCPUID_INTERFACE
	 */
	HVCPUID_VERSION				= 0x40000002,
	HVCPUID_FEATURES			= 0x40000003,
	HVCPUID_ENLIGHTENMENT_INFO		= 0x40000004,
	HVCPUID_IMPLEMENTATION_LIMITS		= 0x40000005,
};

struct ms_hyperv_info {
	u32 features;
	u32 misc_features;
	u32 hints;
	u32 max_vp_index;
	u32 max_lp_index;
};

extern struct ms_hyperv_info ms_hyperv;

/*
 * Declare the MSR used to setup pages used to communicate with the hypervisor.
 */
union hv_x64_msr_hypercall_contents {
	u64 as_uint64;
	struct {
		u64 enable:1;
		u64 reserved:11;
		u64 guest_physical_address:52;
	};
};

/*
 * TSC page layout.
 */

struct ms_hyperv_tsc_page {
	volatile u32 tsc_sequence;
	u32 reserved1;
	volatile u64 tsc_scale;
	volatile s64 tsc_offset;
	u64 reserved2[509];
};

/*
 * The guest OS needs to register the guest ID with the hypervisor.
 * The guest ID is a 64 bit entity and the structure of this ID is
 * specified in the Hyper-V specification:
 *
 * msdn.microsoft.com/en-us/library/windows/hardware/ff542653%28v=vs.85%29.aspx
 *
 * While the current guideline does not specify how Linux guest ID(s)
 * need to be generated, our plan is to publish the guidelines for
 * Linux and other guest operating systems that currently are hosted
 * on Hyper-V. The implementation here conforms to this yet
 * unpublished guidelines.
 *
 *
 * Bit(s)
 * 63 - Indicates if the OS is Open Source or not; 1 is Open Source
 * 62:56 - Os Type; Linux is 0x100
 * 55:48 - Distro specific identification
 * 47:16 - Linux kernel version number
 * 15:0  - Distro specific identification
 *
 *
 */

#define HV_LINUX_VENDOR_ID              0x8100

/*
 * Generate the guest ID based on the guideline described above.
 */

static inline  __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
				       __u64 d_info2)
{
	__u64 guest_id = 0;

	guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
	guest_id |= (d_info1 << 48);
	guest_id |= (kernel_version << 16);
	guest_id |= d_info2;

	return guest_id;
}


/* Free the message slot and signal end-of-message if required */
static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
{
	/*
	 * On crash we're reading some other CPU's message page and we need
	 * to be careful: this other CPU may already had cleared the header
	 * and the host may already had delivered some other message there.
	 * In case we blindly write msg->header.message_type we're going
	 * to lose it. We can still lose a message of the same type but
	 * we count on the fact that there can only be one
	 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages
	 * on crash.
	 */
	if (cmpxchg(&msg->header.message_type, old_msg_type,
		    HVMSG_NONE) != old_msg_type)
		return;

	/*
	 * Make sure the write to MessageType (ie set to
	 * HVMSG_NONE) happens before we read the
	 * MessagePending and EOMing. Otherwise, the EOMing
	 * will not deliver any more messages since there is
	 * no empty slot
	 */
	mb();

	if (msg->header.message_flags.msg_pending) {
		/*
		 * This will cause message queue rescan to
		 * possibly deliver another msg from the
		 * hypervisor
		 */
		wrmsrl(HV_X64_MSR_EOM, 0);
	}
}

#define hv_init_timer(timer, tick) wrmsrl(timer, tick)
#define hv_init_timer_config(config, val) wrmsrl(config, val)

#define hv_get_simp(val) rdmsrl(HV_X64_MSR_SIMP, val)
#define hv_set_simp(val) wrmsrl(HV_X64_MSR_SIMP, val)

#define hv_get_siefp(val) rdmsrl(HV_X64_MSR_SIEFP, val)
#define hv_set_siefp(val) wrmsrl(HV_X64_MSR_SIEFP, val)

#define hv_get_synic_state(val) rdmsrl(HV_X64_MSR_SCONTROL, val)
#define hv_set_synic_state(val) wrmsrl(HV_X64_MSR_SCONTROL, val)

#define hv_get_vp_index(index) rdmsrl(HV_X64_MSR_VP_INDEX, index)

#define hv_get_synint_state(int_num, val) rdmsrl(int_num, val)
#define hv_set_synint_state(int_num, val) wrmsrl(int_num, val)

void hyperv_callback_vector(void);
#ifdef CONFIG_TRACING
#define trace_hyperv_callback_vector hyperv_callback_vector
#endif
void hyperv_vector_handler(struct pt_regs *regs);
void hv_setup_vmbus_irq(void (*handler)(void));
void hv_remove_vmbus_irq(void);

void hv_setup_kexec_handler(void (*handler)(void));
void hv_remove_kexec_handler(void);
void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
void hv_remove_crash_handler(void);

#if IS_ENABLED(CONFIG_HYPERV)
extern struct clocksource *hyperv_cs;
extern void *hv_hypercall_pg;

static inline 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;
	u64 hv_status;

#ifdef CONFIG_X86_64
	if (!hv_hypercall_pg)
		return U64_MAX;

	__asm__ __volatile__("mov %4, %%r8\n"
			     "call *%5"
			     : "=a" (hv_status), ASM_CALL_CONSTRAINT,
			       "+c" (control), "+d" (input_address)
			     :  "r" (output_address), "m" (hv_hypercall_pg)
			     : "cc", "memory", "r8", "r9", "r10", "r11");
#else
	u32 input_address_hi = upper_32_bits(input_address);
	u32 input_address_lo = lower_32_bits(input_address);
	u32 output_address_hi = upper_32_bits(output_address);
	u32 output_address_lo = lower_32_bits(output_address);

	if (!hv_hypercall_pg)
		return U64_MAX;

	__asm__ __volatile__("call *%7"
			     : "=A" (hv_status),
			       "+c" (input_address_lo), ASM_CALL_CONSTRAINT
			     : "A" (control),
			       "b" (input_address_hi),
			       "D"(output_address_hi), "S"(output_address_lo),
			       "m" (hv_hypercall_pg)
			     : "cc", "memory");
#endif /* !x86_64 */
	return hv_status;
}

#define HV_HYPERCALL_RESULT_MASK	GENMASK_ULL(15, 0)
#define HV_HYPERCALL_FAST_BIT		BIT(16)
#define HV_HYPERCALL_VARHEAD_OFFSET	17
#define HV_HYPERCALL_REP_COMP_OFFSET	32
#define HV_HYPERCALL_REP_COMP_MASK	GENMASK_ULL(43, 32)
#define HV_HYPERCALL_REP_START_OFFSET	48
#define HV_HYPERCALL_REP_START_MASK	GENMASK_ULL(59, 48)

/* Fast hypercall with 8 bytes of input and no output */
static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)
{
	u64 hv_status, control = (u64)code | HV_HYPERCALL_FAST_BIT;

#ifdef CONFIG_X86_64
	{
		__asm__ __volatile__("call *%4"
				     : "=a" (hv_status), ASM_CALL_CONSTRAINT,
				       "+c" (control), "+d" (input1)
				     : "m" (hv_hypercall_pg)
				     : "cc", "r8", "r9", "r10", "r11");
	}
#else
	{
		u32 input1_hi = upper_32_bits(input1);
		u32 input1_lo = lower_32_bits(input1);

		__asm__ __volatile__ ("call *%5"
				      : "=A"(hv_status),
					"+c"(input1_lo),
					ASM_CALL_CONSTRAINT
				      :	"A" (control),
					"b" (input1_hi),
					"m" (hv_hypercall_pg)
				      : "cc", "edi", "esi");
	}
#endif
		return hv_status;
}

/*
 * Rep hypercalls. Callers of this functions are supposed to ensure that
 * rep_count and varhead_size comply with Hyper-V hypercall definition.
 */
static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
				      void *input, void *output)
{
	u64 control = code;
	u64 status;
	u16 rep_comp;

	control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
	control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;

	do {
		status = hv_do_hypercall(control, input, output);
		if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
			return status;

		/* Bits 32-43 of status have 'Reps completed' data. */
		rep_comp = (status & HV_HYPERCALL_REP_COMP_MASK) >>
			HV_HYPERCALL_REP_COMP_OFFSET;

		control &= ~HV_HYPERCALL_REP_START_MASK;
		control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;

		touch_nmi_watchdog();
	} while (rep_comp < rep_count);

	return status;
}

/*
 * Hypervisor's notion of virtual processor ID is different from
 * Linux' notion of CPU ID. This information can only be retrieved
 * in the context of the calling CPU. Setup a map for easy access
 * to this information.
 */
extern u32 *hv_vp_index;
extern u32 hv_max_vp_index;

/**
 * hv_cpu_number_to_vp_number() - Map CPU to VP.
 * @cpu_number: CPU number in Linux terms
 *
 * This function returns the mapping between the Linux processor
 * number and the hypervisor's virtual processor number, useful
 * in making hypercalls and such that talk about specific
 * processors.
 *
 * Return: Virtual processor number in Hyper-V terms
 */
static inline int hv_cpu_number_to_vp_number(int cpu_number)
{
	return hv_vp_index[cpu_number];
}

void hyperv_init(void);
void hyperv_setup_mmu_ops(void);
void hyper_alloc_mmu(void);
void hyperv_report_panic(struct pt_regs *regs);
bool hv_is_hypercall_page_setup(void);
void hyperv_cleanup(void);
#else /* CONFIG_HYPERV */
static inline void hyperv_init(void) {}
static inline bool hv_is_hypercall_page_setup(void) { return false; }
static inline void hyperv_cleanup(void) {}
static inline void hyperv_setup_mmu_ops(void) {}
#endif /* CONFIG_HYPERV */

#ifdef CONFIG_HYPERV_TSCPAGE
struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
{
	u64 scale, offset, cur_tsc;
	u32 sequence;

	/*
	 * The protocol for reading Hyper-V TSC page is specified in Hypervisor
	 * Top-Level Functional Specification ver. 3.0 and above. To get the
	 * reference time we must do the following:
	 * - READ ReferenceTscSequence
	 *   A special '0' value indicates the time source is unreliable and we
	 *   need to use something else. The currently published specification
	 *   versions (up to 4.0b) contain a mistake and wrongly claim '-1'
	 *   instead of '0' as the special value, see commit c35b82ef0294.
	 * - ReferenceTime =
	 *        ((RDTSC() * ReferenceTscScale) >> 64) + ReferenceTscOffset
	 * - READ ReferenceTscSequence again. In case its value has changed
	 *   since our first reading we need to discard ReferenceTime and repeat
	 *   the whole sequence as the hypervisor was updating the page in
	 *   between.
	 */
	do {
		sequence = READ_ONCE(tsc_pg->tsc_sequence);
		if (!sequence)
			return U64_MAX;
		/*
		 * Make sure we read sequence before we read other values from
		 * TSC page.
		 */
		smp_rmb();

		scale = READ_ONCE(tsc_pg->tsc_scale);
		offset = READ_ONCE(tsc_pg->tsc_offset);
		cur_tsc = rdtsc_ordered();

		/*
		 * Make sure we read sequence after we read all other values
		 * from TSC page.
		 */
		smp_rmb();

	} while (READ_ONCE(tsc_pg->tsc_sequence) != sequence);

	return mul_u64_u64_shr(cur_tsc, scale, 64) + offset;
}

#else
static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
{
	return NULL;
}
#endif
#endif