| 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 | |
| 34 | struct ms_hyperv_info ms_hyperv; |
| 35 | EXPORT_SYMBOL_GPL(ms_hyperv); |
| 36 | |
| 37 | #if IS_ENABLED(CONFIG_HYPERV) |
| 38 | static void (*vmbus_handler)(void); |
| 39 | static void (*hv_kexec_handler)(void); |
| 40 | static void (*hv_crash_handler)(struct pt_regs *regs); |
| 41 | |
| 42 | void 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 | |
| 55 | void 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 | |
| 67 | void hv_remove_vmbus_irq(void) |
| 68 | { |
| 69 | /* We have no way to deallocate the interrupt gate */ |
| 70 | vmbus_handler = NULL; |
| 71 | } |
| 72 | EXPORT_SYMBOL_GPL(hv_setup_vmbus_irq); |
| 73 | EXPORT_SYMBOL_GPL(hv_remove_vmbus_irq); |
| 74 | |
| 75 | void hv_setup_kexec_handler(void (*handler)(void)) |
| 76 | { |
| 77 | hv_kexec_handler = handler; |
| 78 | } |
| 79 | EXPORT_SYMBOL_GPL(hv_setup_kexec_handler); |
| 80 | |
| 81 | void hv_remove_kexec_handler(void) |
| 82 | { |
| 83 | hv_kexec_handler = NULL; |
| 84 | } |
| 85 | EXPORT_SYMBOL_GPL(hv_remove_kexec_handler); |
| 86 | |
| 87 | void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)) |
| 88 | { |
| 89 | hv_crash_handler = handler; |
| 90 | } |
| 91 | EXPORT_SYMBOL_GPL(hv_setup_crash_handler); |
| 92 | |
| 93 | void hv_remove_crash_handler(void) |
| 94 | { |
| 95 | hv_crash_handler = NULL; |
| 96 | } |
| 97 | EXPORT_SYMBOL_GPL(hv_remove_crash_handler); |
| 98 | |
| 99 | #ifdef CONFIG_KEXEC_CORE |
| 100 | static void hv_machine_shutdown(void) |
| 101 | { |
| 102 | if (kexec_in_progress && hv_kexec_handler) |
| 103 | hv_kexec_handler(); |
| 104 | native_machine_shutdown(); |
| 105 | } |
| 106 | |
| 107 | static 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 | |
| 116 | static 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 | |
| 135 | static 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 | |
| 147 | static 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 | |
| 155 | static unsigned char hv_get_nmi_reason(void) |
| 156 | { |
| 157 | return 0; |
| 158 | } |
| 159 | |
| 160 | static 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 | |
| 208 | const __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 | }; |
| 213 | EXPORT_SYMBOL(x86_hyper_ms_hyperv); |