/* * HyperV  Detection code. * * Copyright (C) 2010, Novell, Inc. * Author : K. Y. Srinivasan <ksrinivasan@novell.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * */ #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 <asm/processor.h>#include <asm/hypervisor.h>#include <asm/hyperv.h>#include <asm/mshyperv.h>#include <asm/desc.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> struct ms_hyperv_info ms_hyperv;EXPORT_SYMBOL_GPL(ms_hyperv); #if IS_ENABLED(CONFIG_HYPERV)static void (*vmbus_handler)(void);static void (*hv_kexec_handler)(void);static void (*hv_crash_handler)(struct pt_regs *regs); void hyperv_vector_handler(struct pt_regs *regs){	struct pt_regs *old_regs = set_irq_regs(regs); 	entering_irq();	inc_irq_stat(irq_hv_callback_count);	if (vmbus_handler)		vmbus_handler(); 	if (ms_hyperv.hints & HV_X64_DEPRECATING_AEOI_RECOMMENDED)		ack_APIC_irq(); 	exiting_irq();	set_irq_regs(old_regs);} void hv_setup_vmbus_irq(void (*handler)(void)){	vmbus_handler = handler;	/*	 * Setup the IDT for hypervisor callback. Prevent reallocation	 * at module reload.	 */	if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))		alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,				hyperv_callback_vector);} 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); 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_COREstatic void hv_machine_shutdown(void){	if (kexec_in_progress && hv_kexec_handler)		hv_kexec_handler();	native_machine_shutdown();} static void hv_machine_crash_shutdown(struct pt_regs *regs){	if (hv_crash_handler)		hv_crash_handler(regs);	native_machine_crash_shutdown(regs);}#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;} 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; 	/*	 * 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("HyperV: features 0x%x, hints 0x%x\n",		ms_hyperv.features, ms_hyperv.hints); 	/*	 * Extract host information.	 */	if (cpuid_eax(HVCPUID_VENDOR_MAXFUNCTION) >= HVCPUID_VERSION) {		hv_host_info_eax = cpuid_eax(HVCPUID_VERSION);		hv_host_info_ebx = cpuid_ebx(HVCPUID_VERSION);		hv_host_info_ecx = cpuid_ecx(HVCPUID_VERSION);		hv_host_info_edx = cpuid_edx(HVCPUID_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_X64_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;	} #ifdef CONFIG_X86_LOCAL_APIC	if (ms_hyperv.features & HV_X64_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_frequency = hv_lapic_frequency;		pr_info("HyperV: LAPIC Timer Frequency: %#x\n",			lapic_timer_frequency);	} 	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	mark_tsc_unstable("running on Hyper-V"); 	/*	 * 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; #if IS_ENABLED(CONFIG_HYPERV)	/*	 * Setup the hook to get control post apic initialization.	 */	x86_platform.apic_post_init = hyperv_init;#endif} const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {	.name			= "Microsoft HyperV",	.detect			= ms_hyperv_platform,	.init_platform		= ms_hyperv_init_platform,};EXPORT_SYMBOL(x86_hyper_ms_hyperv);