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1/*
2 * HyperV Detection code.
3 *
4 * Copyright (C) 2010, Novell, Inc.
5 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; version 2 of the License.
10 *
11 */
12
13#include <linux/types.h>
14#include <linux/time.h>
15#include <linux/clocksource.h>
16#include <linux/module.h>
17#include <asm/processor.h>
18#include <asm/hypervisor.h>
19#include <asm/hyperv.h>
20#include <asm/mshyperv.h>
21
22struct ms_hyperv_info ms_hyperv;
23EXPORT_SYMBOL_GPL(ms_hyperv);
24
25static bool __init ms_hyperv_platform(void)
26{
27 u32 eax;
28 u32 hyp_signature[3];
29
30 if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
31 return false;
32
33 cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
34 &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
35
36 return eax >= HYPERV_CPUID_MIN &&
37 eax <= HYPERV_CPUID_MAX &&
38 !memcmp("Microsoft Hv", hyp_signature, 12);
39}
40
41static cycle_t read_hv_clock(struct clocksource *arg)
42{
43 cycle_t current_tick;
44 /*
45 * Read the partition counter to get the current tick count. This count
46 * is set to 0 when the partition is created and is incremented in
47 * 100 nanosecond units.
48 */
49 rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
50 return current_tick;
51}
52
53static struct clocksource hyperv_cs = {
54 .name = "hyperv_clocksource",
55 .rating = 400, /* use this when running on Hyperv*/
56 .read = read_hv_clock,
57 .mask = CLOCKSOURCE_MASK(64),
58};
59
60static void __init ms_hyperv_init_platform(void)
61{
62 /*
63 * Extract the features and hints
64 */
65 ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
66 ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
67
68 printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
69 ms_hyperv.features, ms_hyperv.hints);
70
71 clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);
72}
73
74const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
75 .name = "Microsoft HyperV",
76 .detect = ms_hyperv_platform,
77 .init_platform = ms_hyperv_init_platform,
78};
79EXPORT_SYMBOL(x86_hyper_ms_hyperv);
1/*
2 * HyperV Detection code.
3 *
4 * Copyright (C) 2010, Novell, Inc.
5 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; version 2 of the License.
10 *
11 */
12
13#include <linux/types.h>
14#include <linux/time.h>
15#include <linux/clocksource.h>
16#include <linux/module.h>
17#include <linux/hardirq.h>
18#include <linux/efi.h>
19#include <linux/interrupt.h>
20#include <linux/irq.h>
21#include <linux/kexec.h>
22#include <asm/processor.h>
23#include <asm/hypervisor.h>
24#include <asm/hyperv.h>
25#include <asm/mshyperv.h>
26#include <asm/desc.h>
27#include <asm/idle.h>
28#include <asm/irq_regs.h>
29#include <asm/i8259.h>
30#include <asm/apic.h>
31#include <asm/timer.h>
32#include <asm/reboot.h>
33
34struct ms_hyperv_info ms_hyperv;
35EXPORT_SYMBOL_GPL(ms_hyperv);
36
37#if IS_ENABLED(CONFIG_HYPERV)
38static void (*vmbus_handler)(void);
39static void (*hv_kexec_handler)(void);
40static void (*hv_crash_handler)(struct pt_regs *regs);
41
42void hyperv_vector_handler(struct pt_regs *regs)
43{
44 struct pt_regs *old_regs = set_irq_regs(regs);
45
46 entering_irq();
47 inc_irq_stat(irq_hv_callback_count);
48 if (vmbus_handler)
49 vmbus_handler();
50
51 exiting_irq();
52 set_irq_regs(old_regs);
53}
54
55void hv_setup_vmbus_irq(void (*handler)(void))
56{
57 vmbus_handler = handler;
58 /*
59 * Setup the IDT for hypervisor callback. Prevent reallocation
60 * at module reload.
61 */
62 if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
63 alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
64 hyperv_callback_vector);
65}
66
67void hv_remove_vmbus_irq(void)
68{
69 /* We have no way to deallocate the interrupt gate */
70 vmbus_handler = NULL;
71}
72EXPORT_SYMBOL_GPL(hv_setup_vmbus_irq);
73EXPORT_SYMBOL_GPL(hv_remove_vmbus_irq);
74
75void hv_setup_kexec_handler(void (*handler)(void))
76{
77 hv_kexec_handler = handler;
78}
79EXPORT_SYMBOL_GPL(hv_setup_kexec_handler);
80
81void hv_remove_kexec_handler(void)
82{
83 hv_kexec_handler = NULL;
84}
85EXPORT_SYMBOL_GPL(hv_remove_kexec_handler);
86
87void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs))
88{
89 hv_crash_handler = handler;
90}
91EXPORT_SYMBOL_GPL(hv_setup_crash_handler);
92
93void hv_remove_crash_handler(void)
94{
95 hv_crash_handler = NULL;
96}
97EXPORT_SYMBOL_GPL(hv_remove_crash_handler);
98
99#ifdef CONFIG_KEXEC_CORE
100static void hv_machine_shutdown(void)
101{
102 if (kexec_in_progress && hv_kexec_handler)
103 hv_kexec_handler();
104 native_machine_shutdown();
105}
106
107static void hv_machine_crash_shutdown(struct pt_regs *regs)
108{
109 if (hv_crash_handler)
110 hv_crash_handler(regs);
111 native_machine_crash_shutdown(regs);
112}
113#endif /* CONFIG_KEXEC_CORE */
114#endif /* CONFIG_HYPERV */
115
116static uint32_t __init ms_hyperv_platform(void)
117{
118 u32 eax;
119 u32 hyp_signature[3];
120
121 if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
122 return 0;
123
124 cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
125 &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
126
127 if (eax >= HYPERV_CPUID_MIN &&
128 eax <= HYPERV_CPUID_MAX &&
129 !memcmp("Microsoft Hv", hyp_signature, 12))
130 return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS;
131
132 return 0;
133}
134
135static cycle_t read_hv_clock(struct clocksource *arg)
136{
137 cycle_t current_tick;
138 /*
139 * Read the partition counter to get the current tick count. This count
140 * is set to 0 when the partition is created and is incremented in
141 * 100 nanosecond units.
142 */
143 rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
144 return current_tick;
145}
146
147static struct clocksource hyperv_cs = {
148 .name = "hyperv_clocksource",
149 .rating = 400, /* use this when running on Hyperv*/
150 .read = read_hv_clock,
151 .mask = CLOCKSOURCE_MASK(64),
152 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
153};
154
155static unsigned char hv_get_nmi_reason(void)
156{
157 return 0;
158}
159
160static void __init ms_hyperv_init_platform(void)
161{
162 /*
163 * Extract the features and hints
164 */
165 ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
166 ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES);
167 ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
168
169 pr_info("HyperV: features 0x%x, hints 0x%x\n",
170 ms_hyperv.features, ms_hyperv.hints);
171
172#ifdef CONFIG_X86_LOCAL_APIC
173 if (ms_hyperv.features & HV_X64_MSR_APIC_FREQUENCY_AVAILABLE) {
174 /*
175 * Get the APIC frequency.
176 */
177 u64 hv_lapic_frequency;
178
179 rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency);
180 hv_lapic_frequency = div_u64(hv_lapic_frequency, HZ);
181 lapic_timer_frequency = hv_lapic_frequency;
182 pr_info("HyperV: LAPIC Timer Frequency: %#x\n",
183 lapic_timer_frequency);
184 }
185#endif
186
187 if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
188 clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);
189
190#ifdef CONFIG_X86_IO_APIC
191 no_timer_check = 1;
192#endif
193
194#if IS_ENABLED(CONFIG_HYPERV) && defined(CONFIG_KEXEC_CORE)
195 machine_ops.shutdown = hv_machine_shutdown;
196 machine_ops.crash_shutdown = hv_machine_crash_shutdown;
197#endif
198 mark_tsc_unstable("running on Hyper-V");
199
200 /*
201 * Generation 2 instances don't support reading the NMI status from
202 * 0x61 port.
203 */
204 if (efi_enabled(EFI_BOOT))
205 x86_platform.get_nmi_reason = hv_get_nmi_reason;
206}
207
208const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
209 .name = "Microsoft HyperV",
210 .detect = ms_hyperv_platform,
211 .init_platform = ms_hyperv_init_platform,
212};
213EXPORT_SYMBOL(x86_hyper_ms_hyperv);