Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * HyperV Detection code.
4 *
5 * Copyright (C) 2010, Novell, Inc.
6 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
7 */
8
9#include <linux/types.h>
10#include <linux/time.h>
11#include <linux/clocksource.h>
12#include <linux/init.h>
13#include <linux/export.h>
14#include <linux/hardirq.h>
15#include <linux/efi.h>
16#include <linux/interrupt.h>
17#include <linux/irq.h>
18#include <linux/kexec.h>
19#include <linux/i8253.h>
20#include <linux/random.h>
21#include <asm/processor.h>
22#include <asm/hypervisor.h>
23#include <asm/hyperv-tlfs.h>
24#include <asm/mshyperv.h>
25#include <asm/desc.h>
26#include <asm/irq_regs.h>
27#include <asm/i8259.h>
28#include <asm/apic.h>
29#include <asm/timer.h>
30#include <asm/reboot.h>
31#include <asm/nmi.h>
32#include <clocksource/hyperv_timer.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_stimer0_handler)(void);
40static void (*hv_kexec_handler)(void);
41static void (*hv_crash_handler)(struct pt_regs *regs);
42
43__visible void __irq_entry hyperv_vector_handler(struct pt_regs *regs)
44{
45 struct pt_regs *old_regs = set_irq_regs(regs);
46
47 entering_irq();
48 inc_irq_stat(irq_hv_callback_count);
49 if (vmbus_handler)
50 vmbus_handler();
51
52 if (ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED)
53 ack_APIC_irq();
54
55 exiting_irq();
56 set_irq_regs(old_regs);
57}
58
59void hv_setup_vmbus_irq(void (*handler)(void))
60{
61 vmbus_handler = handler;
62}
63
64void hv_remove_vmbus_irq(void)
65{
66 /* We have no way to deallocate the interrupt gate */
67 vmbus_handler = NULL;
68}
69EXPORT_SYMBOL_GPL(hv_setup_vmbus_irq);
70EXPORT_SYMBOL_GPL(hv_remove_vmbus_irq);
71
72/*
73 * Routines to do per-architecture handling of stimer0
74 * interrupts when in Direct Mode
75 */
76
77__visible void __irq_entry hv_stimer0_vector_handler(struct pt_regs *regs)
78{
79 struct pt_regs *old_regs = set_irq_regs(regs);
80
81 entering_irq();
82 inc_irq_stat(hyperv_stimer0_count);
83 if (hv_stimer0_handler)
84 hv_stimer0_handler();
85 add_interrupt_randomness(HYPERV_STIMER0_VECTOR, 0);
86 ack_APIC_irq();
87
88 exiting_irq();
89 set_irq_regs(old_regs);
90}
91
92int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void))
93{
94 *vector = HYPERV_STIMER0_VECTOR;
95 *irq = -1; /* Unused on x86/x64 */
96 hv_stimer0_handler = handler;
97 return 0;
98}
99EXPORT_SYMBOL_GPL(hv_setup_stimer0_irq);
100
101void hv_remove_stimer0_irq(int irq)
102{
103 /* We have no way to deallocate the interrupt gate */
104 hv_stimer0_handler = NULL;
105}
106EXPORT_SYMBOL_GPL(hv_remove_stimer0_irq);
107
108void hv_setup_kexec_handler(void (*handler)(void))
109{
110 hv_kexec_handler = handler;
111}
112EXPORT_SYMBOL_GPL(hv_setup_kexec_handler);
113
114void hv_remove_kexec_handler(void)
115{
116 hv_kexec_handler = NULL;
117}
118EXPORT_SYMBOL_GPL(hv_remove_kexec_handler);
119
120void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs))
121{
122 hv_crash_handler = handler;
123}
124EXPORT_SYMBOL_GPL(hv_setup_crash_handler);
125
126void hv_remove_crash_handler(void)
127{
128 hv_crash_handler = NULL;
129}
130EXPORT_SYMBOL_GPL(hv_remove_crash_handler);
131
132#ifdef CONFIG_KEXEC_CORE
133static void hv_machine_shutdown(void)
134{
135 if (kexec_in_progress && hv_kexec_handler)
136 hv_kexec_handler();
137 native_machine_shutdown();
138}
139
140static void hv_machine_crash_shutdown(struct pt_regs *regs)
141{
142 if (hv_crash_handler)
143 hv_crash_handler(regs);
144 native_machine_crash_shutdown(regs);
145}
146#endif /* CONFIG_KEXEC_CORE */
147#endif /* CONFIG_HYPERV */
148
149static uint32_t __init ms_hyperv_platform(void)
150{
151 u32 eax;
152 u32 hyp_signature[3];
153
154 if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
155 return 0;
156
157 cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
158 &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
159
160 if (eax >= HYPERV_CPUID_MIN &&
161 eax <= HYPERV_CPUID_MAX &&
162 !memcmp("Microsoft Hv", hyp_signature, 12))
163 return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS;
164
165 return 0;
166}
167
168static unsigned char hv_get_nmi_reason(void)
169{
170 return 0;
171}
172
173#ifdef CONFIG_X86_LOCAL_APIC
174/*
175 * Prior to WS2016 Debug-VM sends NMIs to all CPUs which makes
176 * it dificult to process CHANNELMSG_UNLOAD in case of crash. Handle
177 * unknown NMI on the first CPU which gets it.
178 */
179static int hv_nmi_unknown(unsigned int val, struct pt_regs *regs)
180{
181 static atomic_t nmi_cpu = ATOMIC_INIT(-1);
182
183 if (!unknown_nmi_panic)
184 return NMI_DONE;
185
186 if (atomic_cmpxchg(&nmi_cpu, -1, raw_smp_processor_id()) != -1)
187 return NMI_HANDLED;
188
189 return NMI_DONE;
190}
191#endif
192
193static unsigned long hv_get_tsc_khz(void)
194{
195 unsigned long freq;
196
197 rdmsrl(HV_X64_MSR_TSC_FREQUENCY, freq);
198
199 return freq / 1000;
200}
201
202#if defined(CONFIG_SMP) && IS_ENABLED(CONFIG_HYPERV)
203static void __init hv_smp_prepare_boot_cpu(void)
204{
205 native_smp_prepare_boot_cpu();
206#if defined(CONFIG_X86_64) && defined(CONFIG_PARAVIRT_SPINLOCKS)
207 hv_init_spinlocks();
208#endif
209}
210#endif
211
212static void __init ms_hyperv_init_platform(void)
213{
214 int hv_host_info_eax;
215 int hv_host_info_ebx;
216 int hv_host_info_ecx;
217 int hv_host_info_edx;
218
219#ifdef CONFIG_PARAVIRT
220 pv_info.name = "Hyper-V";
221#endif
222
223 /*
224 * Extract the features and hints
225 */
226 ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
227 ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES);
228 ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
229
230 pr_info("Hyper-V: features 0x%x, hints 0x%x\n",
231 ms_hyperv.features, ms_hyperv.hints);
232
233 ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS);
234 ms_hyperv.max_lp_index = cpuid_ebx(HYPERV_CPUID_IMPLEMENT_LIMITS);
235
236 pr_debug("Hyper-V: max %u virtual processors, %u logical processors\n",
237 ms_hyperv.max_vp_index, ms_hyperv.max_lp_index);
238
239 /*
240 * Extract host information.
241 */
242 if (cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS) >=
243 HYPERV_CPUID_VERSION) {
244 hv_host_info_eax = cpuid_eax(HYPERV_CPUID_VERSION);
245 hv_host_info_ebx = cpuid_ebx(HYPERV_CPUID_VERSION);
246 hv_host_info_ecx = cpuid_ecx(HYPERV_CPUID_VERSION);
247 hv_host_info_edx = cpuid_edx(HYPERV_CPUID_VERSION);
248
249 pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d\n",
250 hv_host_info_eax, hv_host_info_ebx >> 16,
251 hv_host_info_ebx & 0xFFFF, hv_host_info_ecx,
252 hv_host_info_edx >> 24, hv_host_info_edx & 0xFFFFFF);
253 }
254
255 if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS &&
256 ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
257 x86_platform.calibrate_tsc = hv_get_tsc_khz;
258 x86_platform.calibrate_cpu = hv_get_tsc_khz;
259 }
260
261 if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) {
262 ms_hyperv.nested_features =
263 cpuid_eax(HYPERV_CPUID_NESTED_FEATURES);
264 }
265
266#ifdef CONFIG_X86_LOCAL_APIC
267 if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS &&
268 ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
269 /*
270 * Get the APIC frequency.
271 */
272 u64 hv_lapic_frequency;
273
274 rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency);
275 hv_lapic_frequency = div_u64(hv_lapic_frequency, HZ);
276 lapic_timer_period = hv_lapic_frequency;
277 pr_info("Hyper-V: LAPIC Timer Frequency: %#x\n",
278 lapic_timer_period);
279 }
280
281 register_nmi_handler(NMI_UNKNOWN, hv_nmi_unknown, NMI_FLAG_FIRST,
282 "hv_nmi_unknown");
283#endif
284
285#ifdef CONFIG_X86_IO_APIC
286 no_timer_check = 1;
287#endif
288
289#if IS_ENABLED(CONFIG_HYPERV) && defined(CONFIG_KEXEC_CORE)
290 machine_ops.shutdown = hv_machine_shutdown;
291 machine_ops.crash_shutdown = hv_machine_crash_shutdown;
292#endif
293 mark_tsc_unstable("running on Hyper-V");
294
295 /*
296 * Generation 2 instances don't support reading the NMI status from
297 * 0x61 port.
298 */
299 if (efi_enabled(EFI_BOOT))
300 x86_platform.get_nmi_reason = hv_get_nmi_reason;
301
302 /*
303 * Hyper-V VMs have a PIT emulation quirk such that zeroing the
304 * counter register during PIT shutdown restarts the PIT. So it
305 * continues to interrupt @18.2 HZ. Setting i8253_clear_counter
306 * to false tells pit_shutdown() not to zero the counter so that
307 * the PIT really is shutdown. Generation 2 VMs don't have a PIT,
308 * and setting this value has no effect.
309 */
310 i8253_clear_counter_on_shutdown = false;
311
312#if IS_ENABLED(CONFIG_HYPERV)
313 /*
314 * Setup the hook to get control post apic initialization.
315 */
316 x86_platform.apic_post_init = hyperv_init;
317 hyperv_setup_mmu_ops();
318 /* Setup the IDT for hypervisor callback */
319 alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector);
320
321 /* Setup the IDT for reenlightenment notifications */
322 if (ms_hyperv.features & HV_X64_ACCESS_REENLIGHTENMENT)
323 alloc_intr_gate(HYPERV_REENLIGHTENMENT_VECTOR,
324 hyperv_reenlightenment_vector);
325
326 /* Setup the IDT for stimer0 */
327 if (ms_hyperv.misc_features & HV_STIMER_DIRECT_MODE_AVAILABLE)
328 alloc_intr_gate(HYPERV_STIMER0_VECTOR,
329 hv_stimer0_callback_vector);
330
331# ifdef CONFIG_SMP
332 smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu;
333# endif
334
335 /*
336 * Hyper-V doesn't provide irq remapping for IO-APIC. To enable x2apic,
337 * set x2apic destination mode to physcial mode when x2apic is available
338 * and Hyper-V IOMMU driver makes sure cpus assigned with IO-APIC irqs
339 * have 8-bit APIC id.
340 */
341# ifdef CONFIG_X86_X2APIC
342 if (x2apic_supported())
343 x2apic_phys = 1;
344# endif
345
346 /* Register Hyper-V specific clocksource */
347 hv_init_clocksource();
348#endif
349}
350
351void hv_setup_sched_clock(void *sched_clock)
352{
353#ifdef CONFIG_PARAVIRT
354 pv_ops.time.sched_clock = sched_clock;
355#endif
356}
357
358const __initconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
359 .name = "Microsoft Hyper-V",
360 .detect = ms_hyperv_platform,
361 .type = X86_HYPER_MS_HYPERV,
362 .init.init_platform = ms_hyperv_init_platform,
363};
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);