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         /* Setup the IDT for ACRN hypervisor callback */
  30         alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_acrn_hv_callback);
  31 }
  32
  33 static bool acrn_x2apic_available(void)
  34 {
  35         return boot_cpu_has(X86_FEATURE_X2APIC);
  36 }
  37
  38 static void (*acrn_intr_handler)(void);
  39
  40 DEFINE_IDTENTRY_SYSVEC(sysvec_acrn_hv_callback)
  41 {
  42         struct pt_regs *old_regs = set_irq_regs(regs);
  43
  44         /*
  45          * The hypervisor requires that the APIC EOI should be acked.
  46          * If the APIC EOI is not acked, the APIC ISR bit for the
  47          * HYPERVISOR_CALLBACK_VECTOR will not be cleared and then it
  48          * will block the interrupt whose vector is lower than
  49          * HYPERVISOR_CALLBACK_VECTOR.
  50          */
  51         ack_APIC_irq();
  52         inc_irq_stat(irq_hv_callback_count);
  53
  54         if (acrn_intr_handler)
  55                 acrn_intr_handler();
  56
  57         set_irq_regs(old_regs);
  58 }
  59
  60 void acrn_setup_intr_handler(void (*handler)(void))
  61 {
  62         acrn_intr_handler = handler;
  63 }
  64 EXPORT_SYMBOL_GPL(acrn_setup_intr_handler);
  65
  66 void acrn_remove_intr_handler(void)
  67 {
  68         acrn_intr_handler = NULL;
  69 }
  70 EXPORT_SYMBOL_GPL(acrn_remove_intr_handler);
  71
  72 const __initconst struct hypervisor_x86 x86_hyper_acrn = {
  73         .name                   = "ACRN",
  74         .detect                 = acrn_detect,
  75         .type                   = X86_HYPER_ACRN,
  76         .init.init_platform     = acrn_init_platform,
  77         .init.x2apic_available  = acrn_x2apic_available,
  78 };