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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/idtentry.h>
27#include <asm/irq_regs.h>
28#include <asm/i8259.h>
29#include <asm/apic.h>
30#include <asm/timer.h>
31#include <asm/reboot.h>
32#include <asm/nmi.h>
33#include <clocksource/hyperv_timer.h>
34
35struct ms_hyperv_info ms_hyperv;
36EXPORT_SYMBOL_GPL(ms_hyperv);
37
38#if IS_ENABLED(CONFIG_HYPERV)
39static void (*vmbus_handler)(void);
40static void (*hv_stimer0_handler)(void);
41static void (*hv_kexec_handler)(void);
42static void (*hv_crash_handler)(struct pt_regs *regs);
43
44DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
45{
46 struct pt_regs *old_regs = set_irq_regs(regs);
47
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 set_irq_regs(old_regs);
56}
57
58void hv_setup_vmbus_irq(void (*handler)(void))
59{
60 vmbus_handler = handler;
61}
62
63void hv_remove_vmbus_irq(void)
64{
65 /* We have no way to deallocate the interrupt gate */
66 vmbus_handler = NULL;
67}
68EXPORT_SYMBOL_GPL(hv_setup_vmbus_irq);
69EXPORT_SYMBOL_GPL(hv_remove_vmbus_irq);
70
71/*
72 * Routines to do per-architecture handling of stimer0
73 * interrupts when in Direct Mode
74 */
75DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_stimer0)
76{
77 struct pt_regs *old_regs = set_irq_regs(regs);
78
79 inc_irq_stat(hyperv_stimer0_count);
80 if (hv_stimer0_handler)
81 hv_stimer0_handler();
82 add_interrupt_randomness(HYPERV_STIMER0_VECTOR, 0);
83 ack_APIC_irq();
84
85 set_irq_regs(old_regs);
86}
87
88int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void))
89{
90 *vector = HYPERV_STIMER0_VECTOR;
91 *irq = -1; /* Unused on x86/x64 */
92 hv_stimer0_handler = handler;
93 return 0;
94}
95EXPORT_SYMBOL_GPL(hv_setup_stimer0_irq);
96
97void hv_remove_stimer0_irq(int irq)
98{
99 /* We have no way to deallocate the interrupt gate */
100 hv_stimer0_handler = NULL;
101}
102EXPORT_SYMBOL_GPL(hv_remove_stimer0_irq);
103
104void hv_setup_kexec_handler(void (*handler)(void))
105{
106 hv_kexec_handler = handler;
107}
108EXPORT_SYMBOL_GPL(hv_setup_kexec_handler);
109
110void hv_remove_kexec_handler(void)
111{
112 hv_kexec_handler = NULL;
113}
114EXPORT_SYMBOL_GPL(hv_remove_kexec_handler);
115
116void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs))
117{
118 hv_crash_handler = handler;
119}
120EXPORT_SYMBOL_GPL(hv_setup_crash_handler);
121
122void hv_remove_crash_handler(void)
123{
124 hv_crash_handler = NULL;
125}
126EXPORT_SYMBOL_GPL(hv_remove_crash_handler);
127
128#ifdef CONFIG_KEXEC_CORE
129static void hv_machine_shutdown(void)
130{
131 if (kexec_in_progress && hv_kexec_handler)
132 hv_kexec_handler();
133 native_machine_shutdown();
134}
135
136static void hv_machine_crash_shutdown(struct pt_regs *regs)
137{
138 if (hv_crash_handler)
139 hv_crash_handler(regs);
140 native_machine_crash_shutdown(regs);
141}
142#endif /* CONFIG_KEXEC_CORE */
143#endif /* CONFIG_HYPERV */
144
145static uint32_t __init ms_hyperv_platform(void)
146{
147 u32 eax;
148 u32 hyp_signature[3];
149
150 if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
151 return 0;
152
153 cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
154 &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
155
156 if (eax >= HYPERV_CPUID_MIN &&
157 eax <= HYPERV_CPUID_MAX &&
158 !memcmp("Microsoft Hv", hyp_signature, 12))
159 return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS;
160
161 return 0;
162}
163
164static unsigned char hv_get_nmi_reason(void)
165{
166 return 0;
167}
168
169#ifdef CONFIG_X86_LOCAL_APIC
170/*
171 * Prior to WS2016 Debug-VM sends NMIs to all CPUs which makes
172 * it dificult to process CHANNELMSG_UNLOAD in case of crash. Handle
173 * unknown NMI on the first CPU which gets it.
174 */
175static int hv_nmi_unknown(unsigned int val, struct pt_regs *regs)
176{
177 static atomic_t nmi_cpu = ATOMIC_INIT(-1);
178
179 if (!unknown_nmi_panic)
180 return NMI_DONE;
181
182 if (atomic_cmpxchg(&nmi_cpu, -1, raw_smp_processor_id()) != -1)
183 return NMI_HANDLED;
184
185 return NMI_DONE;
186}
187#endif
188
189static unsigned long hv_get_tsc_khz(void)
190{
191 unsigned long freq;
192
193 rdmsrl(HV_X64_MSR_TSC_FREQUENCY, freq);
194
195 return freq / 1000;
196}
197
198#if defined(CONFIG_SMP) && IS_ENABLED(CONFIG_HYPERV)
199static void __init hv_smp_prepare_boot_cpu(void)
200{
201 native_smp_prepare_boot_cpu();
202#if defined(CONFIG_X86_64) && defined(CONFIG_PARAVIRT_SPINLOCKS)
203 hv_init_spinlocks();
204#endif
205}
206#endif
207
208static void __init ms_hyperv_init_platform(void)
209{
210 int hv_host_info_eax;
211 int hv_host_info_ebx;
212 int hv_host_info_ecx;
213 int hv_host_info_edx;
214
215#ifdef CONFIG_PARAVIRT
216 pv_info.name = "Hyper-V";
217#endif
218
219 /*
220 * Extract the features and hints
221 */
222 ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
223 ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES);
224 ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
225
226 pr_info("Hyper-V: features 0x%x, hints 0x%x, misc 0x%x\n",
227 ms_hyperv.features, ms_hyperv.hints, ms_hyperv.misc_features);
228
229 ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS);
230 ms_hyperv.max_lp_index = cpuid_ebx(HYPERV_CPUID_IMPLEMENT_LIMITS);
231
232 pr_debug("Hyper-V: max %u virtual processors, %u logical processors\n",
233 ms_hyperv.max_vp_index, ms_hyperv.max_lp_index);
234
235 /*
236 * Extract host information.
237 */
238 if (cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS) >=
239 HYPERV_CPUID_VERSION) {
240 hv_host_info_eax = cpuid_eax(HYPERV_CPUID_VERSION);
241 hv_host_info_ebx = cpuid_ebx(HYPERV_CPUID_VERSION);
242 hv_host_info_ecx = cpuid_ecx(HYPERV_CPUID_VERSION);
243 hv_host_info_edx = cpuid_edx(HYPERV_CPUID_VERSION);
244
245 pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d\n",
246 hv_host_info_eax, hv_host_info_ebx >> 16,
247 hv_host_info_ebx & 0xFFFF, hv_host_info_ecx,
248 hv_host_info_edx >> 24, hv_host_info_edx & 0xFFFFFF);
249 }
250
251 if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS &&
252 ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
253 x86_platform.calibrate_tsc = hv_get_tsc_khz;
254 x86_platform.calibrate_cpu = hv_get_tsc_khz;
255 }
256
257 if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) {
258 ms_hyperv.nested_features =
259 cpuid_eax(HYPERV_CPUID_NESTED_FEATURES);
260 }
261
262 /*
263 * Hyper-V expects to get crash register data or kmsg when
264 * crash enlightment is available and system crashes. Set
265 * crash_kexec_post_notifiers to be true to make sure that
266 * calling crash enlightment interface before running kdump
267 * kernel.
268 */
269 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE)
270 crash_kexec_post_notifiers = true;
271
272#ifdef CONFIG_X86_LOCAL_APIC
273 if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS &&
274 ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
275 /*
276 * Get the APIC frequency.
277 */
278 u64 hv_lapic_frequency;
279
280 rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency);
281 hv_lapic_frequency = div_u64(hv_lapic_frequency, HZ);
282 lapic_timer_period = hv_lapic_frequency;
283 pr_info("Hyper-V: LAPIC Timer Frequency: %#x\n",
284 lapic_timer_period);
285 }
286
287 register_nmi_handler(NMI_UNKNOWN, hv_nmi_unknown, NMI_FLAG_FIRST,
288 "hv_nmi_unknown");
289#endif
290
291#ifdef CONFIG_X86_IO_APIC
292 no_timer_check = 1;
293#endif
294
295#if IS_ENABLED(CONFIG_HYPERV) && defined(CONFIG_KEXEC_CORE)
296 machine_ops.shutdown = hv_machine_shutdown;
297 machine_ops.crash_shutdown = hv_machine_crash_shutdown;
298#endif
299 if (ms_hyperv.features & HV_X64_ACCESS_TSC_INVARIANT) {
300 wrmsrl(HV_X64_MSR_TSC_INVARIANT_CONTROL, 0x1);
301 setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
302 } else {
303 mark_tsc_unstable("running on Hyper-V");
304 }
305
306 /*
307 * Generation 2 instances don't support reading the NMI status from
308 * 0x61 port.
309 */
310 if (efi_enabled(EFI_BOOT))
311 x86_platform.get_nmi_reason = hv_get_nmi_reason;
312
313 /*
314 * Hyper-V VMs have a PIT emulation quirk such that zeroing the
315 * counter register during PIT shutdown restarts the PIT. So it
316 * continues to interrupt @18.2 HZ. Setting i8253_clear_counter
317 * to false tells pit_shutdown() not to zero the counter so that
318 * the PIT really is shutdown. Generation 2 VMs don't have a PIT,
319 * and setting this value has no effect.
320 */
321 i8253_clear_counter_on_shutdown = false;
322
323#if IS_ENABLED(CONFIG_HYPERV)
324 /*
325 * Setup the hook to get control post apic initialization.
326 */
327 x86_platform.apic_post_init = hyperv_init;
328 hyperv_setup_mmu_ops();
329 /* Setup the IDT for hypervisor callback */
330 alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_hyperv_callback);
331
332 /* Setup the IDT for reenlightenment notifications */
333 if (ms_hyperv.features & HV_X64_ACCESS_REENLIGHTENMENT) {
334 alloc_intr_gate(HYPERV_REENLIGHTENMENT_VECTOR,
335 asm_sysvec_hyperv_reenlightenment);
336 }
337
338 /* Setup the IDT for stimer0 */
339 if (ms_hyperv.misc_features & HV_STIMER_DIRECT_MODE_AVAILABLE) {
340 alloc_intr_gate(HYPERV_STIMER0_VECTOR,
341 asm_sysvec_hyperv_stimer0);
342 }
343
344# ifdef CONFIG_SMP
345 smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu;
346# endif
347
348 /*
349 * Hyper-V doesn't provide irq remapping for IO-APIC. To enable x2apic,
350 * set x2apic destination mode to physcial mode when x2apic is available
351 * and Hyper-V IOMMU driver makes sure cpus assigned with IO-APIC irqs
352 * have 8-bit APIC id.
353 */
354# ifdef CONFIG_X86_X2APIC
355 if (x2apic_supported())
356 x2apic_phys = 1;
357# endif
358
359 /* Register Hyper-V specific clocksource */
360 hv_init_clocksource();
361#endif
362}
363
364const __initconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
365 .name = "Microsoft Hyper-V",
366 .detect = ms_hyperv_platform,
367 .type = X86_HYPER_MS_HYPERV,
368 .init.init_platform = ms_hyperv_init_platform,
369};
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);