arch/x86/kernel/cpu/mshyperv.c - third_party/linux - Git at Google

 /*
  * 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-tlfs.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_stimer0_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;
 }

 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);

 /*
  * Routines to do per-architecture handling of stimer0
  * interrupts when in Direct Mode
  */

 __visible void __irq_entry hv_stimer0_vector_handler(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);

 	entering_irq();
 	inc_irq_stat(hyperv_stimer0_count);
 	if (hv_stimer0_handler)
 		hv_stimer0_handler();
 	ack_APIC_irq();

 	exiting_irq();
 	set_irq_regs(old_regs);
 }

 int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void))
 {
 	*vector = HYPERV_STIMER0_VECTOR;
 	*irq = 0;   /* Unused on x86/x64 */
 	hv_stimer0_handler = handler;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(hv_setup_stimer0_irq);

 void hv_remove_stimer0_irq(int irq)
 {
 	/* We have no way to deallocate the interrupt gate */
 	hv_stimer0_handler = NULL;
 }
 EXPORT_SYMBOL_GPL(hv_remove_stimer0_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_CORE
 static 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("Hyper-V: features 0x%x, hints 0x%x\n",
 		ms_hyperv.features, ms_hyperv.hints);

 	ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS);
 	ms_hyperv.max_lp_index = cpuid_ebx(HYPERV_CPUID_IMPLEMENT_LIMITS);

 	pr_debug("Hyper-V: max %u virtual processors, %u logical processors\n",
 		 ms_hyperv.max_vp_index, ms_hyperv.max_lp_index);

 	/*
 	 * Extract host information.
 	 */
 	if (cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS) >=
 	    HYPERV_CPUID_VERSION) {
 		hv_host_info_eax = cpuid_eax(HYPERV_CPUID_VERSION);
 		hv_host_info_ebx = cpuid_ebx(HYPERV_CPUID_VERSION);
 		hv_host_info_ecx = cpuid_ecx(HYPERV_CPUID_VERSION);
 		hv_host_info_edx = cpuid_edx(HYPERV_CPUID_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;
 	}

 	if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) {
 		ms_hyperv.nested_features =
 			cpuid_eax(HYPERV_CPUID_NESTED_FEATURES);
 	}

 #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("Hyper-V: 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;
 	hyperv_setup_mmu_ops();
 	/* Setup the IDT for hypervisor callback */
 	alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector);

 	/* Setup the IDT for reenlightenment notifications */
 	if (ms_hyperv.features & HV_X64_ACCESS_REENLIGHTENMENT)
 		alloc_intr_gate(HYPERV_REENLIGHTENMENT_VECTOR,
 				hyperv_reenlightenment_vector);

 	/* Setup the IDT for stimer0 */
 	if (ms_hyperv.misc_features & HV_X64_STIMER_DIRECT_MODE_AVAILABLE)
 		alloc_intr_gate(HYPERV_STIMER0_VECTOR,
 				hv_stimer0_callback_vector);
 #endif
 }

 const __initconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
 	.name			= "Microsoft Hyper-V",
 	.detect			= ms_hyperv_platform,
 	.type			= X86_HYPER_MS_HYPERV,
 	.init.init_platform	= ms_hyperv_init_platform,
 };
	/*
	* 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-tlfs.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_stimer0_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;
	}

	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);

	/*
	* Routines to do per-architecture handling of stimer0
	* interrupts when in Direct Mode
	*/

	__visible void __irq_entry hv_stimer0_vector_handler(struct pt_regs *regs)
	{
	struct pt_regs *old_regs = set_irq_regs(regs);

	entering_irq();
	inc_irq_stat(hyperv_stimer0_count);
	if (hv_stimer0_handler)
	hv_stimer0_handler();
	ack_APIC_irq();

	exiting_irq();
	set_irq_regs(old_regs);
	}

	int hv_setup_stimer0_irq(int irq, int vector, void (*handler)(void))
	{
	*vector = HYPERV_STIMER0_VECTOR;
	irq = 0; / Unused on x86/x64 */
	hv_stimer0_handler = handler;
	return 0;
	}
	EXPORT_SYMBOL_GPL(hv_setup_stimer0_irq);

	void hv_remove_stimer0_irq(int irq)
	{
	/* We have no way to deallocate the interrupt gate */
	hv_stimer0_handler = NULL;
	}
	EXPORT_SYMBOL_GPL(hv_remove_stimer0_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_CORE
	static 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("Hyper-V: features 0x%x, hints 0x%x\n",
	ms_hyperv.features, ms_hyperv.hints);

	ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS);
	ms_hyperv.max_lp_index = cpuid_ebx(HYPERV_CPUID_IMPLEMENT_LIMITS);

	pr_debug("Hyper-V: max %u virtual processors, %u logical processors\n",
	ms_hyperv.max_vp_index, ms_hyperv.max_lp_index);

	/*
	* Extract host information.
	*/
	if (cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS) >=
	HYPERV_CPUID_VERSION) {
	hv_host_info_eax = cpuid_eax(HYPERV_CPUID_VERSION);
	hv_host_info_ebx = cpuid_ebx(HYPERV_CPUID_VERSION);
	hv_host_info_ecx = cpuid_ecx(HYPERV_CPUID_VERSION);
	hv_host_info_edx = cpuid_edx(HYPERV_CPUID_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;
	}

	if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) {
	ms_hyperv.nested_features =
	cpuid_eax(HYPERV_CPUID_NESTED_FEATURES);
	}

	#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("Hyper-V: 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;
	hyperv_setup_mmu_ops();
	/* Setup the IDT for hypervisor callback */
	alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector);

	/* Setup the IDT for reenlightenment notifications */
	if (ms_hyperv.features & HV_X64_ACCESS_REENLIGHTENMENT)
	alloc_intr_gate(HYPERV_REENLIGHTENMENT_VECTOR,
	hyperv_reenlightenment_vector);

	/* Setup the IDT for stimer0 */
	if (ms_hyperv.misc_features & HV_X64_STIMER_DIRECT_MODE_AVAILABLE)
	alloc_intr_gate(HYPERV_STIMER0_VECTOR,
	hv_stimer0_callback_vector);
	#endif
	}

	const __initconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
	.name = "Microsoft Hyper-V",
	.detect = ms_hyperv_platform,
	.type = X86_HYPER_MS_HYPERV,
	.init.init_platform = ms_hyperv_init_platform,
	};