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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * irq.c: API for in kernel interrupt controller
4 * Copyright (c) 2007, Intel Corporation.
5 * Copyright 2009 Red Hat, Inc. and/or its affiliates.
6 *
7 * Authors:
8 * Yaozu (Eddie) Dong <Eddie.dong@intel.com>
9 */
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/export.h>
13#include <linux/kvm_host.h>
14
15#include "irq.h"
16#include "i8254.h"
17#include "x86.h"
18#include "xen.h"
19
20/*
21 * check if there are pending timer events
22 * to be processed.
23 */
24int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
25{
26 int r = 0;
27
28 if (lapic_in_kernel(vcpu))
29 r = apic_has_pending_timer(vcpu);
30 if (kvm_xen_timer_enabled(vcpu))
31 r += kvm_xen_has_pending_timer(vcpu);
32
33 return r;
34}
35
36/*
37 * check if there is a pending userspace external interrupt
38 */
39static int pending_userspace_extint(struct kvm_vcpu *v)
40{
41 return v->arch.pending_external_vector != -1;
42}
43
44/*
45 * check if there is pending interrupt from
46 * non-APIC source without intack.
47 */
48int kvm_cpu_has_extint(struct kvm_vcpu *v)
49{
50 /*
51 * FIXME: interrupt.injected represents an interrupt whose
52 * side-effects have already been applied (e.g. bit from IRR
53 * already moved to ISR). Therefore, it is incorrect to rely
54 * on interrupt.injected to know if there is a pending
55 * interrupt in the user-mode LAPIC.
56 * This leads to nVMX/nSVM not be able to distinguish
57 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on
58 * pending interrupt or should re-inject an injected
59 * interrupt.
60 */
61 if (!lapic_in_kernel(v))
62 return v->arch.interrupt.injected;
63
64 if (kvm_xen_has_interrupt(v))
65 return 1;
66
67 if (!kvm_apic_accept_pic_intr(v))
68 return 0;
69
70 if (irqchip_split(v->kvm))
71 return pending_userspace_extint(v);
72 else
73 return v->kvm->arch.vpic->output;
74}
75
76/*
77 * check if there is injectable interrupt:
78 * when virtual interrupt delivery enabled,
79 * interrupt from apic will handled by hardware,
80 * we don't need to check it here.
81 */
82int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
83{
84 if (kvm_cpu_has_extint(v))
85 return 1;
86
87 if (!is_guest_mode(v) && kvm_vcpu_apicv_active(v))
88 return 0;
89
90 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
91}
92EXPORT_SYMBOL_GPL(kvm_cpu_has_injectable_intr);
93
94/*
95 * check if there is pending interrupt without
96 * intack.
97 */
98int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
99{
100 if (kvm_cpu_has_extint(v))
101 return 1;
102
103 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
104}
105EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
106
107/*
108 * Read pending interrupt(from non-APIC source)
109 * vector and intack.
110 */
111int kvm_cpu_get_extint(struct kvm_vcpu *v)
112{
113 if (!kvm_cpu_has_extint(v)) {
114 WARN_ON(!lapic_in_kernel(v));
115 return -1;
116 }
117
118 if (!lapic_in_kernel(v))
119 return v->arch.interrupt.nr;
120
121#ifdef CONFIG_KVM_XEN
122 if (kvm_xen_has_interrupt(v))
123 return v->kvm->arch.xen.upcall_vector;
124#endif
125
126 if (irqchip_split(v->kvm)) {
127 int vector = v->arch.pending_external_vector;
128
129 v->arch.pending_external_vector = -1;
130 return vector;
131 } else
132 return kvm_pic_read_irq(v->kvm); /* PIC */
133}
134EXPORT_SYMBOL_GPL(kvm_cpu_get_extint);
135
136/*
137 * Read pending interrupt vector and intack.
138 */
139int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
140{
141 int vector = kvm_cpu_get_extint(v);
142 if (vector != -1)
143 return vector; /* PIC */
144
145 vector = kvm_apic_has_interrupt(v); /* APIC */
146 if (vector != -1)
147 kvm_apic_ack_interrupt(v, vector);
148
149 return vector;
150}
151
152void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
153{
154 if (lapic_in_kernel(vcpu))
155 kvm_inject_apic_timer_irqs(vcpu);
156 if (kvm_xen_timer_enabled(vcpu))
157 kvm_xen_inject_timer_irqs(vcpu);
158}
159
160void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
161{
162 __kvm_migrate_apic_timer(vcpu);
163 __kvm_migrate_pit_timer(vcpu);
164 kvm_x86_call(migrate_timers)(vcpu);
165}
166
167bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args)
168{
169 bool resample = args->flags & KVM_IRQFD_FLAG_RESAMPLE;
170
171 return resample ? irqchip_kernel(kvm) : irqchip_in_kernel(kvm);
172}
173
174bool kvm_arch_irqchip_in_kernel(struct kvm *kvm)
175{
176 return irqchip_in_kernel(kvm);
177}
1/*
2 * irq.c: API for in kernel interrupt controller
3 * Copyright (c) 2007, Intel Corporation.
4 * Copyright 2009 Red Hat, Inc. and/or its affiliates.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
17 * Place - Suite 330, Boston, MA 02111-1307 USA.
18 * Authors:
19 * Yaozu (Eddie) Dong <Eddie.dong@intel.com>
20 *
21 */
22
23#include <linux/export.h>
24#include <linux/kvm_host.h>
25
26#include "irq.h"
27#include "i8254.h"
28#include "x86.h"
29
30/*
31 * check if there are pending timer events
32 * to be processed.
33 */
34int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
35{
36 if (lapic_in_kernel(vcpu))
37 return apic_has_pending_timer(vcpu);
38
39 return 0;
40}
41EXPORT_SYMBOL(kvm_cpu_has_pending_timer);
42
43/*
44 * check if there is a pending userspace external interrupt
45 */
46static int pending_userspace_extint(struct kvm_vcpu *v)
47{
48 return v->arch.pending_external_vector != -1;
49}
50
51/*
52 * check if there is pending interrupt from
53 * non-APIC source without intack.
54 */
55static int kvm_cpu_has_extint(struct kvm_vcpu *v)
56{
57 u8 accept = kvm_apic_accept_pic_intr(v);
58
59 if (accept) {
60 if (irqchip_split(v->kvm))
61 return pending_userspace_extint(v);
62 else
63 return v->kvm->arch.vpic->output;
64 } else
65 return 0;
66}
67
68/*
69 * check if there is injectable interrupt:
70 * when virtual interrupt delivery enabled,
71 * interrupt from apic will handled by hardware,
72 * we don't need to check it here.
73 */
74int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
75{
76 /*
77 * FIXME: interrupt.injected represents an interrupt that it's
78 * side-effects have already been applied (e.g. bit from IRR
79 * already moved to ISR). Therefore, it is incorrect to rely
80 * on interrupt.injected to know if there is a pending
81 * interrupt in the user-mode LAPIC.
82 * This leads to nVMX/nSVM not be able to distinguish
83 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on
84 * pending interrupt or should re-inject an injected
85 * interrupt.
86 */
87 if (!lapic_in_kernel(v))
88 return v->arch.interrupt.injected;
89
90 if (kvm_cpu_has_extint(v))
91 return 1;
92
93 if (!is_guest_mode(v) && kvm_vcpu_apicv_active(v))
94 return 0;
95
96 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
97}
98
99/*
100 * check if there is pending interrupt without
101 * intack.
102 */
103int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
104{
105 /*
106 * FIXME: interrupt.injected represents an interrupt that it's
107 * side-effects have already been applied (e.g. bit from IRR
108 * already moved to ISR). Therefore, it is incorrect to rely
109 * on interrupt.injected to know if there is a pending
110 * interrupt in the user-mode LAPIC.
111 * This leads to nVMX/nSVM not be able to distinguish
112 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on
113 * pending interrupt or should re-inject an injected
114 * interrupt.
115 */
116 if (!lapic_in_kernel(v))
117 return v->arch.interrupt.injected;
118
119 if (kvm_cpu_has_extint(v))
120 return 1;
121
122 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
123}
124EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
125
126/*
127 * Read pending interrupt(from non-APIC source)
128 * vector and intack.
129 */
130static int kvm_cpu_get_extint(struct kvm_vcpu *v)
131{
132 if (kvm_cpu_has_extint(v)) {
133 if (irqchip_split(v->kvm)) {
134 int vector = v->arch.pending_external_vector;
135
136 v->arch.pending_external_vector = -1;
137 return vector;
138 } else
139 return kvm_pic_read_irq(v->kvm); /* PIC */
140 } else
141 return -1;
142}
143
144/*
145 * Read pending interrupt vector and intack.
146 */
147int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
148{
149 int vector;
150
151 if (!lapic_in_kernel(v))
152 return v->arch.interrupt.nr;
153
154 vector = kvm_cpu_get_extint(v);
155
156 if (vector != -1)
157 return vector; /* PIC */
158
159 return kvm_get_apic_interrupt(v); /* APIC */
160}
161EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
162
163void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
164{
165 if (lapic_in_kernel(vcpu))
166 kvm_inject_apic_timer_irqs(vcpu);
167}
168EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);
169
170void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
171{
172 __kvm_migrate_apic_timer(vcpu);
173 __kvm_migrate_pit_timer(vcpu);
174}