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/init.h> 17 #include <linux/export.h> 18 #include <linux/hardirq.h> 19 #include <linux/efi.h> 20 #include <linux/interrupt.h> 21 #include <linux/irq.h> 22 #include <linux/kexec.h> 23 #include <asm/processor.h> 24 #include <asm/hypervisor.h> 25 #include <asm/hyperv-tlfs.h> 26 #include <asm/mshyperv.h> 27 #include <asm/desc.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 #include <asm/nmi.h> 34 35 struct ms_hyperv_info ms_hyperv; 36 EXPORT_SYMBOL_GPL(ms_hyperv); 37 38 #if IS_ENABLED(CONFIG_HYPERV) 39 static void (*vmbus_handler)(void); 40 static void (*hv_stimer0_handler)(void); 41 static void (*hv_kexec_handler)(void); 42 static void (*hv_crash_handler)(struct pt_regs *regs); 43 44 void hyperv_vector_handler(struct pt_regs *regs) 45 { 46 struct pt_regs *old_regs = set_irq_regs(regs); 47 48 entering_irq(); 49 inc_irq_stat(irq_hv_callback_count); 50 if (vmbus_handler) 51 vmbus_handler(); 52 53 if (ms_hyperv.hints & HV_X64_DEPRECATING_AEOI_RECOMMENDED) 54 ack_APIC_irq(); 55 56 exiting_irq(); 57 set_irq_regs(old_regs); 58 } 59 60 void hv_setup_vmbus_irq(void (*handler)(void)) 61 { 62 vmbus_handler = handler; 63 } 64 65 void hv_remove_vmbus_irq(void) 66 { 67 /* We have no way to deallocate the interrupt gate */ 68 vmbus_handler = NULL; 69 } 70 EXPORT_SYMBOL_GPL(hv_setup_vmbus_irq); 71 EXPORT_SYMBOL_GPL(hv_remove_vmbus_irq); 72 73 /* 74 * Routines to do per-architecture handling of stimer0 75 * interrupts when in Direct Mode 76 */ 77 78 __visible void __irq_entry hv_stimer0_vector_handler(struct pt_regs *regs) 79 { 80 struct pt_regs *old_regs = set_irq_regs(regs); 81 82 entering_irq(); 83 inc_irq_stat(hyperv_stimer0_count); 84 if (hv_stimer0_handler) 85 hv_stimer0_handler(); 86 ack_APIC_irq(); 87 88 exiting_irq(); 89 set_irq_regs(old_regs); 90 } 91 92 int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void)) 93 { 94 *vector = HYPERV_STIMER0_VECTOR; 95 *irq = 0; /* Unused on x86/x64 */ 96 hv_stimer0_handler = handler; 97 return 0; 98 } 99 EXPORT_SYMBOL_GPL(hv_setup_stimer0_irq); 100 101 void hv_remove_stimer0_irq(int irq) 102 { 103 /* We have no way to deallocate the interrupt gate */ 104 hv_stimer0_handler = NULL; 105 } 106 EXPORT_SYMBOL_GPL(hv_remove_stimer0_irq); 107 108 void hv_setup_kexec_handler(void (*handler)(void)) 109 { 110 hv_kexec_handler = handler; 111 } 112 EXPORT_SYMBOL_GPL(hv_setup_kexec_handler); 113 114 void hv_remove_kexec_handler(void) 115 { 116 hv_kexec_handler = NULL; 117 } 118 EXPORT_SYMBOL_GPL(hv_remove_kexec_handler); 119 120 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)) 121 { 122 hv_crash_handler = handler; 123 } 124 EXPORT_SYMBOL_GPL(hv_setup_crash_handler); 125 126 void hv_remove_crash_handler(void) 127 { 128 hv_crash_handler = NULL; 129 } 130 EXPORT_SYMBOL_GPL(hv_remove_crash_handler); 131 132 #ifdef CONFIG_KEXEC_CORE 133 static void hv_machine_shutdown(void) 134 { 135 if (kexec_in_progress && hv_kexec_handler) 136 hv_kexec_handler(); 137 native_machine_shutdown(); 138 } 139 140 static 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 */ 148 149 static 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 } 167 168 static 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 */ 179 static 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 192 193 static 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 static void __init ms_hyperv_init_platform(void) 203 { 204 int hv_host_info_eax; 205 int hv_host_info_ebx; 206 int hv_host_info_ecx; 207 int hv_host_info_edx; 208 209 /* 210 * Extract the features and hints 211 */ 212 ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES); 213 ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES); 214 ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO); 215 216 pr_info("Hyper-V: features 0x%x, hints 0x%x\n", 217 ms_hyperv.features, ms_hyperv.hints); 218 219 ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS); 220 ms_hyperv.max_lp_index = cpuid_ebx(HYPERV_CPUID_IMPLEMENT_LIMITS); 221 222 pr_debug("Hyper-V: max %u virtual processors, %u logical processors\n", 223 ms_hyperv.max_vp_index, ms_hyperv.max_lp_index); 224 225 /* 226 * Extract host information. 227 */ 228 if (cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS) >= 229 HYPERV_CPUID_VERSION) { 230 hv_host_info_eax = cpuid_eax(HYPERV_CPUID_VERSION); 231 hv_host_info_ebx = cpuid_ebx(HYPERV_CPUID_VERSION); 232 hv_host_info_ecx = cpuid_ecx(HYPERV_CPUID_VERSION); 233 hv_host_info_edx = cpuid_edx(HYPERV_CPUID_VERSION); 234 235 pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d\n", 236 hv_host_info_eax, hv_host_info_ebx >> 16, 237 hv_host_info_ebx & 0xFFFF, hv_host_info_ecx, 238 hv_host_info_edx >> 24, hv_host_info_edx & 0xFFFFFF); 239 } 240 241 if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS && 242 ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) { 243 x86_platform.calibrate_tsc = hv_get_tsc_khz; 244 x86_platform.calibrate_cpu = hv_get_tsc_khz; 245 } 246 247 if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) { 248 ms_hyperv.nested_features = 249 cpuid_eax(HYPERV_CPUID_NESTED_FEATURES); 250 } 251 252 #ifdef CONFIG_X86_LOCAL_APIC 253 if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS && 254 ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) { 255 /* 256 * Get the APIC frequency. 257 */ 258 u64 hv_lapic_frequency; 259 260 rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency); 261 hv_lapic_frequency = div_u64(hv_lapic_frequency, HZ); 262 lapic_timer_frequency = hv_lapic_frequency; 263 pr_info("Hyper-V: LAPIC Timer Frequency: %#x\n", 264 lapic_timer_frequency); 265 } 266 267 register_nmi_handler(NMI_UNKNOWN, hv_nmi_unknown, NMI_FLAG_FIRST, 268 "hv_nmi_unknown"); 269 #endif 270 271 #ifdef CONFIG_X86_IO_APIC 272 no_timer_check = 1; 273 #endif 274 275 #if IS_ENABLED(CONFIG_HYPERV) && defined(CONFIG_KEXEC_CORE) 276 machine_ops.shutdown = hv_machine_shutdown; 277 machine_ops.crash_shutdown = hv_machine_crash_shutdown; 278 #endif 279 mark_tsc_unstable("running on Hyper-V"); 280 281 /* 282 * Generation 2 instances don't support reading the NMI status from 283 * 0x61 port. 284 */ 285 if (efi_enabled(EFI_BOOT)) 286 x86_platform.get_nmi_reason = hv_get_nmi_reason; 287 288 #if IS_ENABLED(CONFIG_HYPERV) 289 /* 290 * Setup the hook to get control post apic initialization. 291 */ 292 x86_platform.apic_post_init = hyperv_init; 293 hyperv_setup_mmu_ops(); 294 /* Setup the IDT for hypervisor callback */ 295 alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector); 296 297 /* Setup the IDT for reenlightenment notifications */ 298 if (ms_hyperv.features & HV_X64_ACCESS_REENLIGHTENMENT) 299 alloc_intr_gate(HYPERV_REENLIGHTENMENT_VECTOR, 300 hyperv_reenlightenment_vector); 301 302 /* Setup the IDT for stimer0 */ 303 if (ms_hyperv.misc_features & HV_X64_STIMER_DIRECT_MODE_AVAILABLE) 304 alloc_intr_gate(HYPERV_STIMER0_VECTOR, 305 hv_stimer0_callback_vector); 306 #endif 307 } 308 309 const __initconst struct hypervisor_x86 x86_hyper_ms_hyperv = { 310 .name = "Microsoft Hyper-V", 311 .detect = ms_hyperv_platform, 312 .type = X86_HYPER_MS_HYPERV, 313 .init.init_platform = ms_hyperv_init_platform, 314 }; 315