From afca4d95dd7d7936d46a0ff02169cc40f534a6a3 Mon Sep 17 00:00:00 2001 From: Michael Kelley Date: Wed, 14 Jul 2021 11:34:45 -0700 Subject: Drivers: hv: Make portions of Hyper-V init code be arch neutral The code to allocate and initialize the hv_vp_index array is architecture neutral. Similarly, the code to allocate and populate the hypercall input and output arg pages is architecture neutral. Move both sets of code out from arch/x86 and into utility functions in drivers/hv/hv_common.c that can be shared by Hyper-V initialization on ARM64. No functional changes. However, the allocation of the hypercall input and output arg pages is done differently so that the size is always the Hyper-V page size, even if not the same as the guest page size (such as with ARM64's 64K page size). Signed-off-by: Michael Kelley Link: https://lore.kernel.org/r/1626287687-2045-2-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu --- drivers/hv/hv_common.c | 138 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) (limited to 'drivers/hv') diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c index 7f42da98d377..e836002bc0ce 100644 --- a/drivers/hv/hv_common.c +++ b/drivers/hv/hv_common.c @@ -15,9 +15,147 @@ #include #include #include +#include +#include #include #include +/* + * 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; + + /* + * 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) -- cgit