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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
11#include <linux/export.h>
12#include <linux/kvm_host.h>
13
14#include "irq.h"
15#include "i8254.h"
16#include "x86.h"
17
18/*
19 * check if there are pending timer events
20 * to be processed.
21 */
22int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
23{
24 if (lapic_in_kernel(vcpu))
25 return apic_has_pending_timer(vcpu);
26
27 return 0;
28}
29EXPORT_SYMBOL(kvm_cpu_has_pending_timer);
30
31/*
32 * check if there is a pending userspace external interrupt
33 */
34static int pending_userspace_extint(struct kvm_vcpu *v)
35{
36 return v->arch.pending_external_vector != -1;
37}
38
39/*
40 * check if there is pending interrupt from
41 * non-APIC source without intack.
42 */
43static int kvm_cpu_has_extint(struct kvm_vcpu *v)
44{
45 u8 accept = kvm_apic_accept_pic_intr(v);
46
47 if (accept) {
48 if (irqchip_split(v->kvm))
49 return pending_userspace_extint(v);
50 else
51 return v->kvm->arch.vpic->output;
52 } else
53 return 0;
54}
55
56/*
57 * check if there is injectable interrupt:
58 * when virtual interrupt delivery enabled,
59 * interrupt from apic will handled by hardware,
60 * we don't need to check it here.
61 */
62int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
63{
64 /*
65 * FIXME: interrupt.injected represents an interrupt that it's
66 * side-effects have already been applied (e.g. bit from IRR
67 * already moved to ISR). Therefore, it is incorrect to rely
68 * on interrupt.injected to know if there is a pending
69 * interrupt in the user-mode LAPIC.
70 * This leads to nVMX/nSVM not be able to distinguish
71 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on
72 * pending interrupt or should re-inject an injected
73 * interrupt.
74 */
75 if (!lapic_in_kernel(v))
76 return v->arch.interrupt.injected;
77
78 if (kvm_cpu_has_extint(v))
79 return 1;
80
81 if (!is_guest_mode(v) && kvm_vcpu_apicv_active(v))
82 return 0;
83
84 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
85}
86EXPORT_SYMBOL_GPL(kvm_cpu_has_injectable_intr);
87
88/*
89 * check if there is pending interrupt without
90 * intack.
91 */
92int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
93{
94 /*
95 * FIXME: interrupt.injected represents an interrupt that it's
96 * side-effects have already been applied (e.g. bit from IRR
97 * already moved to ISR). Therefore, it is incorrect to rely
98 * on interrupt.injected to know if there is a pending
99 * interrupt in the user-mode LAPIC.
100 * This leads to nVMX/nSVM not be able to distinguish
101 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on
102 * pending interrupt or should re-inject an injected
103 * interrupt.
104 */
105 if (!lapic_in_kernel(v))
106 return v->arch.interrupt.injected;
107
108 if (kvm_cpu_has_extint(v))
109 return 1;
110
111 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
112}
113EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
114
115/*
116 * Read pending interrupt(from non-APIC source)
117 * vector and intack.
118 */
119static int kvm_cpu_get_extint(struct kvm_vcpu *v)
120{
121 if (kvm_cpu_has_extint(v)) {
122 if (irqchip_split(v->kvm)) {
123 int vector = v->arch.pending_external_vector;
124
125 v->arch.pending_external_vector = -1;
126 return vector;
127 } else
128 return kvm_pic_read_irq(v->kvm); /* PIC */
129 } else
130 return -1;
131}
132
133/*
134 * Read pending interrupt vector and intack.
135 */
136int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
137{
138 int vector;
139
140 if (!lapic_in_kernel(v))
141 return v->arch.interrupt.nr;
142
143 vector = kvm_cpu_get_extint(v);
144
145 if (vector != -1)
146 return vector; /* PIC */
147
148 return kvm_get_apic_interrupt(v); /* APIC */
149}
150EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
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}
157EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);
158
159void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
160{
161 __kvm_migrate_apic_timer(vcpu);
162 __kvm_migrate_pit_timer(vcpu);
163 if (kvm_x86_ops.migrate_timers)
164 kvm_x86_ops.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}
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/module.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 return apic_has_pending_timer(vcpu);
37}
38EXPORT_SYMBOL(kvm_cpu_has_pending_timer);
39
40/*
41 * check if there is pending interrupt from
42 * non-APIC source without intack.
43 */
44static int kvm_cpu_has_extint(struct kvm_vcpu *v)
45{
46 if (kvm_apic_accept_pic_intr(v))
47 return pic_irqchip(v->kvm)->output; /* PIC */
48 else
49 return 0;
50}
51
52/*
53 * check if there is injectable interrupt:
54 * when virtual interrupt delivery enabled,
55 * interrupt from apic will handled by hardware,
56 * we don't need to check it here.
57 */
58int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
59{
60 if (!irqchip_in_kernel(v->kvm))
61 return v->arch.interrupt.pending;
62
63 if (kvm_cpu_has_extint(v))
64 return 1;
65
66 if (kvm_apic_vid_enabled(v->kvm))
67 return 0;
68
69 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
70}
71
72/*
73 * check if there is pending interrupt without
74 * intack.
75 */
76int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
77{
78 if (!irqchip_in_kernel(v->kvm))
79 return v->arch.interrupt.pending;
80
81 if (kvm_cpu_has_extint(v))
82 return 1;
83
84 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
85}
86EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
87
88/*
89 * Read pending interrupt(from non-APIC source)
90 * vector and intack.
91 */
92static int kvm_cpu_get_extint(struct kvm_vcpu *v)
93{
94 if (kvm_cpu_has_extint(v))
95 return kvm_pic_read_irq(v->kvm); /* PIC */
96 return -1;
97}
98
99/*
100 * Read pending interrupt vector and intack.
101 */
102int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
103{
104 int vector;
105
106 if (!irqchip_in_kernel(v->kvm))
107 return v->arch.interrupt.nr;
108
109 vector = kvm_cpu_get_extint(v);
110
111 if (kvm_apic_vid_enabled(v->kvm) || vector != -1)
112 return vector; /* PIC */
113
114 return kvm_get_apic_interrupt(v); /* APIC */
115}
116
117void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
118{
119 kvm_inject_apic_timer_irqs(vcpu);
120 /* TODO: PIT, RTC etc. */
121}
122EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);
123
124void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
125{
126 __kvm_migrate_apic_timer(vcpu);
127 __kvm_migrate_pit_timer(vcpu);
128}