// SPDX-License-Identifier: GPL-2.0-only /* * HyperV Detection code. * * Copyright (C) 2010, Novell, Inc. * Author : K. Y. Srinivasan <[email protected]> */ #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/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> #include <asm/numa.h> #include <asm/svm.h> /* Is Linux running as the root partition? */ bool hv_root_partition; /* Is Linux running on nested Microsoft Hypervisor */ bool hv_nested; struct ms_hyperv_info ms_hyperv; /* Used in modules via hv_do_hypercall(): see arch/x86/include/asm/mshyperv.h */ bool hyperv_paravisor_present __ro_after_init; EXPORT_SYMBOL_GPL(…); #if IS_ENABLED(CONFIG_HYPERV) static inline unsigned int hv_get_nested_msr(unsigned int reg) { … } u64 hv_get_non_nested_msr(unsigned int reg) { … } EXPORT_SYMBOL_GPL(…); void hv_set_non_nested_msr(unsigned int reg, u64 value) { … } EXPORT_SYMBOL_GPL(…); u64 hv_get_msr(unsigned int reg) { … } EXPORT_SYMBOL_GPL(…); void hv_set_msr(unsigned int reg, u64 value) { … } EXPORT_SYMBOL_GPL(…); 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) { … } void hv_setup_vmbus_handler(void (*handler)(void)) { … } void hv_remove_vmbus_handler(void) { … } /* * Routines to do per-architecture handling of stimer0 * interrupts when in Direct Mode */ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_stimer0) { … } /* For x86/x64, override weak placeholders in hyperv_timer.c */ void hv_setup_stimer0_handler(void (*handler)(void)) { … } void hv_remove_stimer0_handler(void) { … } void hv_setup_kexec_handler(void (*handler)(void)) { … } void hv_remove_kexec_handler(void) { … } void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)) { … } void hv_remove_crash_handler(void) { … } #ifdef CONFIG_KEXEC_CORE static void hv_machine_shutdown(void) { … } #endif /* CONFIG_KEXEC_CORE */ #ifdef CONFIG_CRASH_DUMP static void hv_machine_crash_shutdown(struct pt_regs *regs) { … } #endif /* CONFIG_CRASH_DUMP */ #endif /* CONFIG_HYPERV */ static uint32_t __init ms_hyperv_platform(void) { … } #ifdef CONFIG_X86_LOCAL_APIC /* * Prior to WS2016 Debug-VM sends NMIs to all CPUs which makes * it difficult 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) { … } #endif static unsigned long hv_get_tsc_khz(void) { … } #if defined(CONFIG_SMP) && IS_ENABLED(CONFIG_HYPERV) static void __init hv_smp_prepare_boot_cpu(void) { … } static void __init hv_smp_prepare_cpus(unsigned int max_cpus) { … } #endif /* * When a fully enlightened TDX VM runs on Hyper-V, the firmware sets the * HW_REDUCED flag: refer to acpi_tb_create_local_fadt(). Consequently ttyS0 * interrupts can't work because request_irq() -> ... -> irq_to_desc() returns * NULL for ttyS0. This happens because mp_config_acpi_legacy_irqs() sees a * nr_legacy_irqs() of 0, so it doesn't initialize the array 'mp_irqs[]', and * later setup_IO_APIC_irqs() -> find_irq_entry() fails to find the legacy irqs * from the array and hence doesn't create the necessary irq description info. * * Clone arch/x86/kernel/acpi/boot.c: acpi_generic_reduced_hw_init() here, * except don't change 'legacy_pic', which keeps its default value * 'default_legacy_pic'. This way, mp_config_acpi_legacy_irqs() sees a non-zero * nr_legacy_irqs() and eventually serial console interrupts works properly. */ static void __init reduced_hw_init(void) { … } int hv_get_hypervisor_version(union hv_hypervisor_version_info *info) { … } static void __init ms_hyperv_init_platform(void) { … } static bool __init ms_hyperv_x2apic_available(void) { … } /* * If ms_hyperv_msi_ext_dest_id() returns true, hyperv_prepare_irq_remapping() * returns -ENODEV and the Hyper-V IOMMU driver is not used; instead, the * generic support of the 15-bit APIC ID is used: see __irq_msi_compose_msg(). * * Note: for a VM on Hyper-V, the I/O-APIC is the only device which * (logically) generates MSIs directly to the system APIC irq domain. * There is no HPET, and PCI MSI/MSI-X interrupts are remapped by the * pci-hyperv host bridge. * * Note: for a Hyper-V root partition, this will always return false. * The hypervisor doesn't expose these HYPERV_CPUID_VIRT_STACK_* cpuids by * default, they are implemented as intercepts by the Windows Hyper-V stack. * Even a nested root partition (L2 root) will not get them because the * nested (L1) hypervisor filters them out. */ static bool __init ms_hyperv_msi_ext_dest_id(void) { … } #ifdef CONFIG_AMD_MEM_ENCRYPT static void hv_sev_es_hcall_prepare(struct ghcb *ghcb, struct pt_regs *regs) { … } static bool hv_sev_es_hcall_finish(struct ghcb *ghcb, struct pt_regs *regs) { … } #endif const __initconst struct hypervisor_x86 x86_hyper_ms_hyperv = …;
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