linux/arch/x86/kernel/cpu/mshyperv.c
K. Y. Srinivasan 213ff44ae4 x86/hyper-V: Allocate the IDT entry early in boot
Allocate the hypervisor callback IDT entry early in the boot sequence.

The previous code would allocate the entry as part of registering the handler
when the vmbus driver loaded, and this caused a problem for the IDT cleanup
that Thomas is working on for v4.15.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: apw@canonical.com
Cc: devel@linuxdriverproject.org
Cc: gregkh@linuxfoundation.org
Cc: jasowang@redhat.com
Cc: olaf@aepfle.de
Link: http://lkml.kernel.org/r/20170908231557.2419-1-kys@exchange.microsoft.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-13 11:02:26 +02:00

263 lines
6.5 KiB
C

/*
* 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;
}
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_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(HVCPUID_IMPLEMENTATION_LIMITS);
ms_hyperv.max_lp_index = cpuid_ebx(HVCPUID_IMPLEMENTATION_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(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("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);
#endif
}
const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
.name = "Microsoft Hyper-V",
.detect = ms_hyperv_platform,
.init_platform = ms_hyperv_init_platform,
};
EXPORT_SYMBOL(x86_hyper_ms_hyperv);