blob: 71a39f3621baa39f25f567029ef41e9e8374e612 [file] [log] [blame]
/*
* 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/module.h>
#include <linux/hardirq.h>
#include <linux/interrupt.h>
#include <asm/processor.h>
#include <asm/hypervisor.h>
#include <asm/hyperv.h>
#include <asm/mshyperv.h>
#include <asm/desc.h>
#include <asm/idle.h>
#include <asm/irq_regs.h>
struct ms_hyperv_info ms_hyperv;
EXPORT_SYMBOL_GPL(ms_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 cycle_t read_hv_clock(struct clocksource *arg)
{
cycle_t current_tick;
/*
* Read the partition counter to get the current tick count. This count
* is set to 0 when the partition is created and is incremented in
* 100 nanosecond units.
*/
rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
return current_tick;
}
static struct clocksource hyperv_cs = {
.name = "hyperv_clocksource",
.rating = 400, /* use this when running on Hyperv*/
.read = read_hv_clock,
.mask = CLOCKSOURCE_MASK(64),
};
static void __init ms_hyperv_init_platform(void)
{
/*
* Extract the features and hints
*/
ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
ms_hyperv.features, ms_hyperv.hints);
if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);
}
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);
#if IS_ENABLED(CONFIG_HYPERV)
static int vmbus_irq = -1;
static irq_handler_t vmbus_isr;
void hv_register_vmbus_handler(int irq, irq_handler_t handler)
{
/*
* Setup the IDT for hypervisor callback.
*/
alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector);
vmbus_irq = irq;
vmbus_isr = handler;
}
void hyperv_vector_handler(struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
struct irq_desc *desc;
irq_enter();
exit_idle();
desc = irq_to_desc(vmbus_irq);
if (desc)
generic_handle_irq_desc(vmbus_irq, desc);
irq_exit();
set_irq_regs(old_regs);
}
#else
void hv_register_vmbus_handler(int irq, irq_handler_t handler)
{
}
#endif
EXPORT_SYMBOL_GPL(hv_register_vmbus_handler);