diff options
Diffstat (limited to 'arch/x86/kernel/cpu/mshyperv.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mshyperv.c | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c new file mode 100644 index 000000000..021cd0677 --- /dev/null +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -0,0 +1,397 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * HyperV Detection code. + * + * Copyright (C) 2010, Novell, Inc. + * Author : K. Y. Srinivasan <ksrinivasan@novell.com> + */ + +#include <linux/types.h> +#include <linux/time.h> +#include <linux/clocksource.h> +#include <linux/init.h> +#include <linux/export.h> +#include <linux/hardirq.h> +#include <linux/efi.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/kexec.h> +#include <linux/i8253.h> +#include <linux/random.h> +#include <asm/processor.h> +#include <asm/hypervisor.h> +#include <asm/hyperv-tlfs.h> +#include <asm/mshyperv.h> +#include <asm/desc.h> +#include <asm/idtentry.h> +#include <asm/irq_regs.h> +#include <asm/i8259.h> +#include <asm/apic.h> +#include <asm/timer.h> +#include <asm/reboot.h> +#include <asm/nmi.h> +#include <clocksource/hyperv_timer.h> + +struct ms_hyperv_info ms_hyperv; +EXPORT_SYMBOL_GPL(ms_hyperv); + +#if IS_ENABLED(CONFIG_HYPERV) +static void (*vmbus_handler)(void); +static void (*hv_stimer0_handler)(void); +static void (*hv_kexec_handler)(void); +static void (*hv_crash_handler)(struct pt_regs *regs); + +DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + + inc_irq_stat(irq_hv_callback_count); + if (vmbus_handler) + vmbus_handler(); + + if (ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED) + ack_APIC_irq(); + + set_irq_regs(old_regs); +} + +int hv_setup_vmbus_irq(int irq, void (*handler)(void)) +{ + /* + * The 'irq' argument is ignored on x86/x64 because a hard-coded + * interrupt vector is used for Hyper-V interrupts. + */ + vmbus_handler = handler; + return 0; +} + +void hv_remove_vmbus_irq(void) +{ + /* We have no way to deallocate the interrupt gate */ + vmbus_handler = NULL; +} +EXPORT_SYMBOL_GPL(hv_setup_vmbus_irq); +EXPORT_SYMBOL_GPL(hv_remove_vmbus_irq); + +/* + * Routines to do per-architecture handling of stimer0 + * interrupts when in Direct Mode + */ +DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_stimer0) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + + inc_irq_stat(hyperv_stimer0_count); + if (hv_stimer0_handler) + hv_stimer0_handler(); + add_interrupt_randomness(HYPERV_STIMER0_VECTOR); + ack_APIC_irq(); + + set_irq_regs(old_regs); +} + +int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void)) +{ + *vector = HYPERV_STIMER0_VECTOR; + *irq = -1; /* Unused on x86/x64 */ + hv_stimer0_handler = handler; + return 0; +} +EXPORT_SYMBOL_GPL(hv_setup_stimer0_irq); + +void hv_remove_stimer0_irq(int irq) +{ + /* We have no way to deallocate the interrupt gate */ + hv_stimer0_handler = NULL; +} +EXPORT_SYMBOL_GPL(hv_remove_stimer0_irq); + +void hv_setup_kexec_handler(void (*handler)(void)) +{ + hv_kexec_handler = handler; +} +EXPORT_SYMBOL_GPL(hv_setup_kexec_handler); + +void hv_remove_kexec_handler(void) +{ + hv_kexec_handler = NULL; +} +EXPORT_SYMBOL_GPL(hv_remove_kexec_handler); + +void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)) +{ + hv_crash_handler = handler; +} +EXPORT_SYMBOL_GPL(hv_setup_crash_handler); + +void hv_remove_crash_handler(void) +{ + hv_crash_handler = NULL; +} +EXPORT_SYMBOL_GPL(hv_remove_crash_handler); + +#ifdef CONFIG_KEXEC_CORE +static void hv_machine_shutdown(void) +{ + if (kexec_in_progress && hv_kexec_handler) + hv_kexec_handler(); + + /* + * Call hv_cpu_die() on all the CPUs, otherwise later the hypervisor + * corrupts the old VP Assist Pages and can crash the kexec kernel. + */ + if (kexec_in_progress && hyperv_init_cpuhp > 0) + cpuhp_remove_state(hyperv_init_cpuhp); + + /* The function calls stop_other_cpus(). */ + native_machine_shutdown(); + + /* Disable the hypercall page when there is only 1 active CPU. */ + if (kexec_in_progress) + hyperv_cleanup(); +} + +static void hv_machine_crash_shutdown(struct pt_regs *regs) +{ + if (hv_crash_handler) + hv_crash_handler(regs); + + /* The function calls crash_smp_send_stop(). */ + native_machine_crash_shutdown(regs); + + /* Disable the hypercall page when there is only 1 active CPU. */ + hyperv_cleanup(); +} +#endif /* CONFIG_KEXEC_CORE */ +#endif /* CONFIG_HYPERV */ + +static uint32_t __init ms_hyperv_platform(void) +{ + u32 eax; + u32 hyp_signature[3]; + + if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) + return 0; + + cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS, + &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]); + + if (eax >= HYPERV_CPUID_MIN && + eax <= HYPERV_CPUID_MAX && + !memcmp("Microsoft Hv", hyp_signature, 12)) + return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS; + + return 0; +} + +static unsigned char hv_get_nmi_reason(void) +{ + return 0; +} + +#ifdef CONFIG_X86_LOCAL_APIC +/* + * Prior to WS2016 Debug-VM sends NMIs to all CPUs which makes + * it dificult to process CHANNELMSG_UNLOAD in case of crash. Handle + * unknown NMI on the first CPU which gets it. + */ +static int hv_nmi_unknown(unsigned int val, struct pt_regs *regs) +{ + static atomic_t nmi_cpu = ATOMIC_INIT(-1); + + if (!unknown_nmi_panic) + return NMI_DONE; + + if (atomic_cmpxchg(&nmi_cpu, -1, raw_smp_processor_id()) != -1) + return NMI_HANDLED; + + return NMI_DONE; +} +#endif + +static unsigned long hv_get_tsc_khz(void) +{ + unsigned long freq; + + rdmsrl(HV_X64_MSR_TSC_FREQUENCY, freq); + + return freq / 1000; +} + +#if defined(CONFIG_SMP) && IS_ENABLED(CONFIG_HYPERV) +static void __init hv_smp_prepare_boot_cpu(void) +{ + native_smp_prepare_boot_cpu(); +#if defined(CONFIG_X86_64) && defined(CONFIG_PARAVIRT_SPINLOCKS) + hv_init_spinlocks(); +#endif +} +#endif + +static void __init ms_hyperv_init_platform(void) +{ + int hv_host_info_eax; + int hv_host_info_ebx; + int hv_host_info_ecx; + int hv_host_info_edx; + +#ifdef CONFIG_PARAVIRT + pv_info.name = "Hyper-V"; +#endif + + /* + * Extract the features and hints + */ + ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES); + ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES); + ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO); + + pr_info("Hyper-V: features 0x%x, hints 0x%x, misc 0x%x\n", + ms_hyperv.features, ms_hyperv.hints, ms_hyperv.misc_features); + + ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS); + ms_hyperv.max_lp_index = cpuid_ebx(HYPERV_CPUID_IMPLEMENT_LIMITS); + + pr_debug("Hyper-V: max %u virtual processors, %u logical processors\n", + ms_hyperv.max_vp_index, ms_hyperv.max_lp_index); + + /* + * Extract host information. + */ + if (cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS) >= + HYPERV_CPUID_VERSION) { + hv_host_info_eax = cpuid_eax(HYPERV_CPUID_VERSION); + hv_host_info_ebx = cpuid_ebx(HYPERV_CPUID_VERSION); + hv_host_info_ecx = cpuid_ecx(HYPERV_CPUID_VERSION); + hv_host_info_edx = cpuid_edx(HYPERV_CPUID_VERSION); + + pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d\n", + hv_host_info_eax, hv_host_info_ebx >> 16, + hv_host_info_ebx & 0xFFFF, hv_host_info_ecx, + hv_host_info_edx >> 24, hv_host_info_edx & 0xFFFFFF); + } + + if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS && + ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) { + x86_platform.calibrate_tsc = hv_get_tsc_khz; + x86_platform.calibrate_cpu = hv_get_tsc_khz; + } + + if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) { + ms_hyperv.nested_features = + cpuid_eax(HYPERV_CPUID_NESTED_FEATURES); + } + + /* + * Hyper-V expects to get crash register data or kmsg when + * crash enlightment is available and system crashes. Set + * crash_kexec_post_notifiers to be true to make sure that + * calling crash enlightment interface before running kdump + * kernel. + */ + if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) + crash_kexec_post_notifiers = true; + +#ifdef CONFIG_X86_LOCAL_APIC + if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS && + ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) { + /* + * Get the APIC frequency. + */ + u64 hv_lapic_frequency; + + rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency); + hv_lapic_frequency = div_u64(hv_lapic_frequency, HZ); + lapic_timer_period = hv_lapic_frequency; + pr_info("Hyper-V: LAPIC Timer Frequency: %#x\n", + lapic_timer_period); + } + + register_nmi_handler(NMI_UNKNOWN, hv_nmi_unknown, NMI_FLAG_FIRST, + "hv_nmi_unknown"); +#endif + +#ifdef CONFIG_X86_IO_APIC + no_timer_check = 1; +#endif + +#if IS_ENABLED(CONFIG_HYPERV) && defined(CONFIG_KEXEC_CORE) + machine_ops.shutdown = hv_machine_shutdown; + machine_ops.crash_shutdown = hv_machine_crash_shutdown; +#endif + if (ms_hyperv.features & HV_ACCESS_TSC_INVARIANT) { + wrmsrl(HV_X64_MSR_TSC_INVARIANT_CONTROL, 0x1); + setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE); + } + + /* + * Generation 2 instances don't support reading the NMI status from + * 0x61 port. + */ + if (efi_enabled(EFI_BOOT)) + x86_platform.get_nmi_reason = hv_get_nmi_reason; + + /* + * Hyper-V VMs have a PIT emulation quirk such that zeroing the + * counter register during PIT shutdown restarts the PIT. So it + * continues to interrupt @18.2 HZ. Setting i8253_clear_counter + * to false tells pit_shutdown() not to zero the counter so that + * the PIT really is shutdown. Generation 2 VMs don't have a PIT, + * and setting this value has no effect. + */ + i8253_clear_counter_on_shutdown = false; + +#if IS_ENABLED(CONFIG_HYPERV) + /* + * Setup the hook to get control post apic initialization. + */ + x86_platform.apic_post_init = hyperv_init; + hyperv_setup_mmu_ops(); + /* Setup the IDT for hypervisor callback */ + alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_hyperv_callback); + + /* Setup the IDT for reenlightenment notifications */ + if (ms_hyperv.features & HV_ACCESS_REENLIGHTENMENT) { + alloc_intr_gate(HYPERV_REENLIGHTENMENT_VECTOR, + asm_sysvec_hyperv_reenlightenment); + } + + /* Setup the IDT for stimer0 */ + if (ms_hyperv.misc_features & HV_STIMER_DIRECT_MODE_AVAILABLE) { + alloc_intr_gate(HYPERV_STIMER0_VECTOR, + asm_sysvec_hyperv_stimer0); + } + +# ifdef CONFIG_SMP + smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu; +# endif + + /* + * Hyper-V doesn't provide irq remapping for IO-APIC. To enable x2apic, + * set x2apic destination mode to physcial mode when x2apic is available + * and Hyper-V IOMMU driver makes sure cpus assigned with IO-APIC irqs + * have 8-bit APIC id. + */ +# ifdef CONFIG_X86_X2APIC + if (x2apic_supported()) + x2apic_phys = 1; +# endif + + /* Register Hyper-V specific clocksource */ + hv_init_clocksource(); +#endif + /* + * TSC should be marked as unstable only after Hyper-V + * clocksource has been initialized. This ensures that the + * stability of the sched_clock is not altered. + */ + if (!(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT)) + mark_tsc_unstable("running on Hyper-V"); +} + +const __initconst struct hypervisor_x86 x86_hyper_ms_hyperv = { + .name = "Microsoft Hyper-V", + .detect = ms_hyperv_platform, + .type = X86_HYPER_MS_HYPERV, + .init.init_platform = ms_hyperv_init_platform, +}; |