// SPDX-License-Identifier: GPL-2.0 /* * Architecture neutral utility routines for interacting with * Hyper-V. This file is specifically for code that must be * built-in to the kernel image when CONFIG_HYPERV is set * (vs. being in a module) because it is called from architecture * specific code under arch/. * * Copyright (C) 2021, Microsoft, Inc. * * Author : Michael Kelley <[email protected]> */ #include <linux/types.h> #include <linux/acpi.h> #include <linux/export.h> #include <linux/bitfield.h> #include <linux/cpumask.h> #include <linux/sched/task_stack.h> #include <linux/panic_notifier.h> #include <linux/ptrace.h> #include <linux/random.h> #include <linux/efi.h> #include <linux/kdebug.h> #include <linux/kmsg_dump.h> #include <linux/sizes.h> #include <linux/slab.h> #include <linux/dma-map-ops.h> #include <linux/set_memory.h> #include <asm/hyperv-tlfs.h> #include <asm/mshyperv.h> /* * hv_root_partition, ms_hyperv and hv_nested are defined here with other * Hyper-V specific globals so they are shared across all architectures and are * built only when CONFIG_HYPERV is defined. But on x86, * ms_hyperv_init_platform() is built even when CONFIG_HYPERV is not * defined, and it uses these three variables. So mark them as __weak * here, allowing for an overriding definition in the module containing * ms_hyperv_init_platform(). */ bool __weak hv_root_partition; EXPORT_SYMBOL_GPL(…); bool __weak hv_nested; EXPORT_SYMBOL_GPL(…); struct ms_hyperv_info __weak ms_hyperv; EXPORT_SYMBOL_GPL(…); u32 *hv_vp_index; EXPORT_SYMBOL_GPL(…); u32 hv_max_vp_index; EXPORT_SYMBOL_GPL(…); void * __percpu *hyperv_pcpu_input_arg; EXPORT_SYMBOL_GPL(…); void * __percpu *hyperv_pcpu_output_arg; EXPORT_SYMBOL_GPL(…); static void hv_kmsg_dump_unregister(void); static struct ctl_table_header *hv_ctl_table_hdr; /* * Hyper-V specific initialization and shutdown code that is * common across all architectures. Called from architecture * specific initialization functions. */ void __init hv_common_free(void) { … } /* * Functions for allocating and freeing memory with size and * alignment HV_HYP_PAGE_SIZE. These functions are needed because * the guest page size may not be the same as the Hyper-V page * size. We depend upon kmalloc() aligning power-of-two size * allocations to the allocation size boundary, so that the * allocated memory appears to Hyper-V as a page of the size * it expects. */ void *hv_alloc_hyperv_page(void) { … } EXPORT_SYMBOL_GPL(…); void *hv_alloc_hyperv_zeroed_page(void) { … } EXPORT_SYMBOL_GPL(…); void hv_free_hyperv_page(void *addr) { … } EXPORT_SYMBOL_GPL(…); static void *hv_panic_page; /* * Boolean to control whether to report panic messages over Hyper-V. * * It can be set via /proc/sys/kernel/hyperv_record_panic_msg */ static int sysctl_record_panic_msg = …; /* * sysctl option to allow the user to control whether kmsg data should be * reported to Hyper-V on panic. */ static struct ctl_table hv_ctl_table[] = …; static int hv_die_panic_notify_crash(struct notifier_block *self, unsigned long val, void *args); static struct notifier_block hyperv_die_report_block = …; static struct notifier_block hyperv_panic_report_block = …; /* * The following callback works both as die and panic notifier; its * goal is to provide panic information to the hypervisor unless the * kmsg dumper is used [see hv_kmsg_dump()], which provides more * information but isn't always available. * * Notice that both the panic/die report notifiers are registered only * if we have the capability HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE set. */ static int hv_die_panic_notify_crash(struct notifier_block *self, unsigned long val, void *args) { … } /* * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg * buffer and call into Hyper-V to transfer the data. */ static void hv_kmsg_dump(struct kmsg_dumper *dumper, struct kmsg_dump_detail *detail) { … } static struct kmsg_dumper hv_kmsg_dumper = …; static void hv_kmsg_dump_unregister(void) { … } static void hv_kmsg_dump_register(void) { … } int __init hv_common_init(void) { … } void __init ms_hyperv_late_init(void) { … } /* * Hyper-V specific initialization and die code for * individual CPUs that is common across all architectures. * Called by the CPU hotplug mechanism. */ int hv_common_cpu_init(unsigned int cpu) { … } int hv_common_cpu_die(unsigned int cpu) { … } /* Bit mask of the extended capability to query: see HV_EXT_CAPABILITY_xxx */ bool hv_query_ext_cap(u64 cap_query) { … } EXPORT_SYMBOL_GPL(…); void hv_setup_dma_ops(struct device *dev, bool coherent) { … } EXPORT_SYMBOL_GPL(…); bool hv_is_hibernation_supported(void) { … } EXPORT_SYMBOL_GPL(…); /* * Default function to read the Hyper-V reference counter, independent * of whether Hyper-V enlightened clocks/timers are being used. But on * architectures where it is used, Hyper-V enlightenment code in * hyperv_timer.c may override this function. */ static u64 __hv_read_ref_counter(void) { … } u64 (*hv_read_reference_counter)(void) = …; EXPORT_SYMBOL_GPL(…); /* These __weak functions provide default "no-op" behavior and * may be overridden by architecture specific versions. Architectures * for which the default "no-op" behavior is sufficient can leave * them unimplemented and not be cluttered with a bunch of stub * functions in arch-specific code. */ bool __weak hv_is_isolation_supported(void) { … } EXPORT_SYMBOL_GPL(…); bool __weak hv_isolation_type_snp(void) { … } EXPORT_SYMBOL_GPL(…); bool __weak hv_isolation_type_tdx(void) { … } EXPORT_SYMBOL_GPL(…); void __weak hv_setup_vmbus_handler(void (*handler)(void)) { … } EXPORT_SYMBOL_GPL(…); void __weak hv_remove_vmbus_handler(void) { … } EXPORT_SYMBOL_GPL(…); void __weak hv_setup_kexec_handler(void (*handler)(void)) { … } EXPORT_SYMBOL_GPL(…); void __weak hv_remove_kexec_handler(void) { … } EXPORT_SYMBOL_GPL(…); void __weak hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)) { … } EXPORT_SYMBOL_GPL(…); void __weak hv_remove_crash_handler(void) { … } EXPORT_SYMBOL_GPL(…); void __weak hyperv_cleanup(void) { … } EXPORT_SYMBOL_GPL(…); u64 __weak hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size) { … } EXPORT_SYMBOL_GPL(…); u64 __weak hv_tdx_hypercall(u64 control, u64 param1, u64 param2) { … } EXPORT_SYMBOL_GPL(…);
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