arch/x86/kernel/cpu/acrn.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * ACRN detection support
   4  *
   5  * Copyright (C) 2019 Intel Corporation. All rights reserved.
   6  *
   7  * Jason Chen CJ <jason.cj.chen@intel.com>
   8  * Zhao Yakui <yakui.zhao@intel.com>
   9  *
  10  */
  11
  12 #include <linux/interrupt.h>
  13
  14 #include <asm/acrn.h>
  15 #include <asm/apic.h>
  16 #include <asm/cpufeatures.h>
  17 #include <asm/desc.h>
  18 #include <asm/hypervisor.h>
  19 #include <asm/idtentry.h>
  20 #include <asm/irq_regs.h>
  21
  22 static u32 __init acrn_detect(void)
  23 {
  24         return acrn_cpuid_base();
  25 }
  26
  27 static void __init acrn_init_platform(void)
  28 {
  29         /* Install system interrupt handler for ACRN hypervisor callback */
  30         sysvec_install(HYPERVISOR_CALLBACK_VECTOR, sysvec_acrn_hv_callback);
  31
  32         x86_platform.calibrate_tsc = acrn_get_tsc_khz;
  33         x86_platform.calibrate_cpu = acrn_get_tsc_khz;
  34 }
  35
  36 static bool acrn_x2apic_available(void)
  37 {
  38         return boot_cpu_has(X86_FEATURE_X2APIC);
  39 }
  40
  41 static void (*acrn_intr_handler)(void);
  42
  43 DEFINE_IDTENTRY_SYSVEC(sysvec_acrn_hv_callback)
  44 {
  45         struct pt_regs *old_regs = set_irq_regs(regs);
  46
  47         /*
  48          * The hypervisor requires that the APIC EOI should be acked.
  49          * If the APIC EOI is not acked, the APIC ISR bit for the
  50          * HYPERVISOR_CALLBACK_VECTOR will not be cleared and then it
  51          * will block the interrupt whose vector is lower than
  52          * HYPERVISOR_CALLBACK_VECTOR.
  53          */
  54         apic_eoi();
  55         inc_irq_stat(irq_hv_callback_count);
  56
  57         if (acrn_intr_handler)
  58                 acrn_intr_handler();
  59
  60         set_irq_regs(old_regs);
  61 }
  62
  63 void acrn_setup_intr_handler(void (*handler)(void))
  64 {
  65         acrn_intr_handler = handler;
  66 }
  67 EXPORT_SYMBOL_GPL(acrn_setup_intr_handler);
  68
  69 void acrn_remove_intr_handler(void)
  70 {
  71         acrn_intr_handler = NULL;
  72 }
  73 EXPORT_SYMBOL_GPL(acrn_remove_intr_handler);
  74
  75 const __initconst struct hypervisor_x86 x86_hyper_acrn = {
  76         .name                   = "ACRN",
  77         .detect                 = acrn_detect,
  78         .type                   = X86_HYPER_ACRN,
  79         .init.init_platform     = acrn_init_platform,
  80         .init.x2apic_available  = acrn_x2apic_available,
  81 };