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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/hv/hv_common.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/hv/hv_common.c')
-rw-r--r-- | drivers/hv/hv_common.c | 321 |
1 files changed, 321 insertions, 0 deletions
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c new file mode 100644 index 000000000..ae68298c0 --- /dev/null +++ b/drivers/hv/hv_common.c @@ -0,0 +1,321 @@ +// 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 <mikelley@microsoft.com> + */ + +#include <linux/types.h> +#include <linux/acpi.h> +#include <linux/export.h> +#include <linux/bitfield.h> +#include <linux/cpumask.h> +#include <linux/panic_notifier.h> +#include <linux/ptrace.h> +#include <linux/slab.h> +#include <linux/dma-map-ops.h> +#include <asm/hyperv-tlfs.h> +#include <asm/mshyperv.h> + +/* + * hv_root_partition and ms_hyperv 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 two 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(hv_root_partition); + +struct ms_hyperv_info __weak ms_hyperv; +EXPORT_SYMBOL_GPL(ms_hyperv); + +u32 *hv_vp_index; +EXPORT_SYMBOL_GPL(hv_vp_index); + +u32 hv_max_vp_index; +EXPORT_SYMBOL_GPL(hv_max_vp_index); + +void * __percpu *hyperv_pcpu_input_arg; +EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg); + +void * __percpu *hyperv_pcpu_output_arg; +EXPORT_SYMBOL_GPL(hyperv_pcpu_output_arg); + +/* + * 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) +{ + kfree(hv_vp_index); + hv_vp_index = NULL; + + free_percpu(hyperv_pcpu_output_arg); + hyperv_pcpu_output_arg = NULL; + + free_percpu(hyperv_pcpu_input_arg); + hyperv_pcpu_input_arg = NULL; +} + +int __init hv_common_init(void) +{ + int i; + + /* + * 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; + pr_info("Hyper-V: enabling crash_kexec_post_notifiers\n"); + } + + /* + * Allocate the per-CPU state for the hypercall input arg. + * If this allocation fails, we will not be able to setup + * (per-CPU) hypercall input page and thus this failure is + * fatal on Hyper-V. + */ + hyperv_pcpu_input_arg = alloc_percpu(void *); + BUG_ON(!hyperv_pcpu_input_arg); + + /* Allocate the per-CPU state for output arg for root */ + if (hv_root_partition) { + hyperv_pcpu_output_arg = alloc_percpu(void *); + BUG_ON(!hyperv_pcpu_output_arg); + } + + hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index), + GFP_KERNEL); + if (!hv_vp_index) { + hv_common_free(); + return -ENOMEM; + } + + for (i = 0; i < num_possible_cpus(); i++) + hv_vp_index[i] = VP_INVAL; + + return 0; +} + +/* + * 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) +{ + void **inputarg, **outputarg; + u64 msr_vp_index; + gfp_t flags; + int pgcount = hv_root_partition ? 2 : 1; + + /* hv_cpu_init() can be called with IRQs disabled from hv_resume() */ + flags = irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL; + + inputarg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg); + *inputarg = kmalloc(pgcount * HV_HYP_PAGE_SIZE, flags); + if (!(*inputarg)) + return -ENOMEM; + + if (hv_root_partition) { + outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg); + *outputarg = (char *)(*inputarg) + HV_HYP_PAGE_SIZE; + } + + msr_vp_index = hv_get_register(HV_REGISTER_VP_INDEX); + + hv_vp_index[cpu] = msr_vp_index; + + if (msr_vp_index > hv_max_vp_index) + hv_max_vp_index = msr_vp_index; + + return 0; +} + +int hv_common_cpu_die(unsigned int cpu) +{ + unsigned long flags; + void **inputarg, **outputarg; + void *mem; + + local_irq_save(flags); + + inputarg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg); + mem = *inputarg; + *inputarg = NULL; + + if (hv_root_partition) { + outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg); + *outputarg = NULL; + } + + local_irq_restore(flags); + + kfree(mem); + + return 0; +} + +/* Bit mask of the extended capability to query: see HV_EXT_CAPABILITY_xxx */ +bool hv_query_ext_cap(u64 cap_query) +{ + /* + * The address of the 'hv_extended_cap' variable will be used as an + * output parameter to the hypercall below and so it should be + * compatible with 'virt_to_phys'. Which means, it's address should be + * directly mapped. Use 'static' to keep it compatible; stack variables + * can be virtually mapped, making them incompatible with + * 'virt_to_phys'. + * Hypercall input/output addresses should also be 8-byte aligned. + */ + static u64 hv_extended_cap __aligned(8); + static bool hv_extended_cap_queried; + u64 status; + + /* + * Querying extended capabilities is an extended hypercall. Check if the + * partition supports extended hypercall, first. + */ + if (!(ms_hyperv.priv_high & HV_ENABLE_EXTENDED_HYPERCALLS)) + return false; + + /* Extended capabilities do not change at runtime. */ + if (hv_extended_cap_queried) + return hv_extended_cap & cap_query; + + status = hv_do_hypercall(HV_EXT_CALL_QUERY_CAPABILITIES, NULL, + &hv_extended_cap); + + /* + * The query extended capabilities hypercall should not fail under + * any normal circumstances. Avoid repeatedly making the hypercall, on + * error. + */ + hv_extended_cap_queried = true; + if (!hv_result_success(status)) { + pr_err("Hyper-V: Extended query capabilities hypercall failed 0x%llx\n", + status); + return false; + } + + return hv_extended_cap & cap_query; +} +EXPORT_SYMBOL_GPL(hv_query_ext_cap); + +void hv_setup_dma_ops(struct device *dev, bool coherent) +{ + /* + * Hyper-V does not offer a vIOMMU in the guest + * VM, so pass 0/NULL for the IOMMU settings + */ + arch_setup_dma_ops(dev, 0, 0, NULL, coherent); +} +EXPORT_SYMBOL_GPL(hv_setup_dma_ops); + +bool hv_is_hibernation_supported(void) +{ + return !hv_root_partition && acpi_sleep_state_supported(ACPI_STATE_S4); +} +EXPORT_SYMBOL_GPL(hv_is_hibernation_supported); + +/* + * 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) +{ + return hv_get_register(HV_REGISTER_TIME_REF_COUNT); +} + +u64 (*hv_read_reference_counter)(void) = __hv_read_ref_counter; +EXPORT_SYMBOL_GPL(hv_read_reference_counter); + +/* 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) +{ + return false; +} +EXPORT_SYMBOL_GPL(hv_is_isolation_supported); + +bool __weak hv_isolation_type_snp(void) +{ + return false; +} +EXPORT_SYMBOL_GPL(hv_isolation_type_snp); + +void __weak hv_setup_vmbus_handler(void (*handler)(void)) +{ +} +EXPORT_SYMBOL_GPL(hv_setup_vmbus_handler); + +void __weak hv_remove_vmbus_handler(void) +{ +} +EXPORT_SYMBOL_GPL(hv_remove_vmbus_handler); + +void __weak hv_setup_kexec_handler(void (*handler)(void)) +{ +} +EXPORT_SYMBOL_GPL(hv_setup_kexec_handler); + +void __weak hv_remove_kexec_handler(void) +{ +} +EXPORT_SYMBOL_GPL(hv_remove_kexec_handler); + +void __weak hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)) +{ +} +EXPORT_SYMBOL_GPL(hv_setup_crash_handler); + +void __weak hv_remove_crash_handler(void) +{ +} +EXPORT_SYMBOL_GPL(hv_remove_crash_handler); + +void __weak hyperv_cleanup(void) +{ +} +EXPORT_SYMBOL_GPL(hyperv_cleanup); + +u64 __weak hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size) +{ + return HV_STATUS_INVALID_PARAMETER; +} +EXPORT_SYMBOL_GPL(hv_ghcb_hypercall); + +void __weak *hv_map_memory(void *addr, unsigned long size) +{ + return NULL; +} +EXPORT_SYMBOL_GPL(hv_map_memory); + +void __weak hv_unmap_memory(void *addr) +{ +} +EXPORT_SYMBOL_GPL(hv_unmap_memory); |