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 #include <asm/apic.h> 14 #include <asm/cpufeatures.h> 15 #include <asm/desc.h> 16 #include <asm/hypervisor.h> 17 #include <asm/idtentry.h> 18 #include <asm/irq_regs.h> 19 20 static u32 __init acrn_detect(void) 21 { 22 return hypervisor_cpuid_base("ACRNACRNACRN", 0); 23 } 24 25 static void __init acrn_init_platform(void) 26 { 27 /* Setup the IDT for ACRN hypervisor callback */ 28 alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_acrn_hv_callback); 29 } 30 31 static bool acrn_x2apic_available(void) 32 { 33 return boot_cpu_has(X86_FEATURE_X2APIC); 34 } 35 36 static void (*acrn_intr_handler)(void); 37 38 DEFINE_IDTENTRY_SYSVEC(sysvec_acrn_hv_callback) 39 { 40 struct pt_regs *old_regs = set_irq_regs(regs); 41 42 /* 43 * The hypervisor requires that the APIC EOI should be acked. 44 * If the APIC EOI is not acked, the APIC ISR bit for the 45 * HYPERVISOR_CALLBACK_VECTOR will not be cleared and then it 46 * will block the interrupt whose vector is lower than 47 * HYPERVISOR_CALLBACK_VECTOR. 48 */ 49 ack_APIC_irq(); 50 inc_irq_stat(irq_hv_callback_count); 51 52 if (acrn_intr_handler) 53 acrn_intr_handler(); 54 55 set_irq_regs(old_regs); 56 } 57 58 const __initconst struct hypervisor_x86 x86_hyper_acrn = { 59 .name = "ACRN", 60 .detect = acrn_detect, 61 .type = X86_HYPER_ACRN, 62 .init.init_platform = acrn_init_platform, 63 .init.x2apic_available = acrn_x2apic_available, 64 }; 65