bc2b0331e0
Starting with win8, vmbus interrupts can be delivered on any VCPU in the guest and furthermore can be concurrently active on multiple VCPUs. Support this interrupt delivery model by setting up a separate IDT entry for Hyper-V vmbus. interrupts. I would like to thank Jan Beulich <JBeulich@suse.com> and Thomas Gleixner <tglx@linutronix.de>, for their help. In this version of the patch, based on the feedback, I have merged the IDT vector for Xen and Hyper-V and made the necessary adjustments. Furhermore, based on Jan's feedback I have added the necessary compilation switches. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Link: http://lkml.kernel.org/r/1359940959-32168-3-git-send-email-kys@microsoft.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
131 lines
3.1 KiB
C
131 lines
3.1 KiB
C
/*
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* HyperV Detection code.
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*
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* Copyright (C) 2010, Novell, Inc.
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* Author : K. Y. Srinivasan <ksrinivasan@novell.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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*/
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#include <linux/types.h>
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#include <linux/time.h>
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#include <linux/clocksource.h>
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#include <linux/module.h>
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#include <linux/hardirq.h>
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#include <linux/interrupt.h>
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#include <asm/processor.h>
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#include <asm/hypervisor.h>
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#include <asm/hyperv.h>
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#include <asm/mshyperv.h>
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#include <asm/desc.h>
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#include <asm/idle.h>
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#include <asm/irq_regs.h>
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struct ms_hyperv_info ms_hyperv;
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EXPORT_SYMBOL_GPL(ms_hyperv);
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static bool __init ms_hyperv_platform(void)
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{
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u32 eax;
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u32 hyp_signature[3];
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if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
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return false;
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/*
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* Xen emulates Hyper-V to support enlightened Windows.
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* Check to see first if we are on a Xen Hypervisor.
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*/
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if (xen_cpuid_base())
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return false;
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cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
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&eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
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return eax >= HYPERV_CPUID_MIN &&
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eax <= HYPERV_CPUID_MAX &&
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!memcmp("Microsoft Hv", hyp_signature, 12);
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}
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static cycle_t read_hv_clock(struct clocksource *arg)
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{
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cycle_t current_tick;
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/*
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* Read the partition counter to get the current tick count. This count
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* is set to 0 when the partition is created and is incremented in
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* 100 nanosecond units.
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*/
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rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
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return current_tick;
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}
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static struct clocksource hyperv_cs = {
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.name = "hyperv_clocksource",
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.rating = 400, /* use this when running on Hyperv*/
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.read = read_hv_clock,
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.mask = CLOCKSOURCE_MASK(64),
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};
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static void __init ms_hyperv_init_platform(void)
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{
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/*
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* Extract the features and hints
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*/
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ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
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ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
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printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
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ms_hyperv.features, ms_hyperv.hints);
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if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
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clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);
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#if IS_ENABLED(CONFIG_HYPERV)
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/*
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* Setup the IDT for hypervisor callback.
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*/
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alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector);
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#endif
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}
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const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
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.name = "Microsoft HyperV",
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.detect = ms_hyperv_platform,
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.init_platform = ms_hyperv_init_platform,
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};
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EXPORT_SYMBOL(x86_hyper_ms_hyperv);
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#if IS_ENABLED(CONFIG_HYPERV)
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static int vmbus_irq = -1;
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static irq_handler_t vmbus_isr;
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void hv_register_vmbus_handler(int irq, irq_handler_t handler)
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{
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vmbus_irq = irq;
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vmbus_isr = handler;
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}
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void hyperv_vector_handler(struct pt_regs *regs)
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{
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struct pt_regs *old_regs = set_irq_regs(regs);
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struct irq_desc *desc;
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irq_enter();
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exit_idle();
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desc = irq_to_desc(vmbus_irq);
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if (desc)
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generic_handle_irq_desc(vmbus_irq, desc);
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irq_exit();
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set_irq_regs(old_regs);
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}
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#else
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void hv_register_vmbus_handler(int irq, irq_handler_t handler)
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{
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}
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#endif
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EXPORT_SYMBOL_GPL(hv_register_vmbus_handler);
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