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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// 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#include "xen.h"
18
19/*
20 * check if there are pending timer events
21 * to be processed.
22 */
23int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
24{
25 int r = 0;
26
27 if (lapic_in_kernel(vcpu))
28 r = apic_has_pending_timer(vcpu);
29 if (kvm_xen_timer_enabled(vcpu))
30 r += kvm_xen_has_pending_timer(vcpu);
31
32 return r;
33}
34
35/*
36 * check if there is a pending userspace external interrupt
37 */
38static int pending_userspace_extint(struct kvm_vcpu *v)
39{
40 return v->arch.pending_external_vector != -1;
41}
42
43/*
44 * check if there is pending interrupt from
45 * non-APIC source without intack.
46 */
47int kvm_cpu_has_extint(struct kvm_vcpu *v)
48{
49 /*
50 * FIXME: interrupt.injected represents an interrupt whose
51 * side-effects have already been applied (e.g. bit from IRR
52 * already moved to ISR). Therefore, it is incorrect to rely
53 * on interrupt.injected to know if there is a pending
54 * interrupt in the user-mode LAPIC.
55 * This leads to nVMX/nSVM not be able to distinguish
56 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on
57 * pending interrupt or should re-inject an injected
58 * interrupt.
59 */
60 if (!lapic_in_kernel(v))
61 return v->arch.interrupt.injected;
62
63 if (kvm_xen_has_interrupt(v))
64 return 1;
65
66 if (!kvm_apic_accept_pic_intr(v))
67 return 0;
68
69 if (irqchip_split(v->kvm))
70 return pending_userspace_extint(v);
71 else
72 return v->kvm->arch.vpic->output;
73}
74
75/*
76 * check if there is injectable interrupt:
77 * when virtual interrupt delivery enabled,
78 * interrupt from apic will handled by hardware,
79 * we don't need to check it here.
80 */
81int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
82{
83 if (kvm_cpu_has_extint(v))
84 return 1;
85
86 if (!is_guest_mode(v) && kvm_vcpu_apicv_active(v))
87 return 0;
88
89 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
90}
91EXPORT_SYMBOL_GPL(kvm_cpu_has_injectable_intr);
92
93/*
94 * check if there is pending interrupt without
95 * intack.
96 */
97int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
98{
99 if (kvm_cpu_has_extint(v))
100 return 1;
101
102 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
103}
104EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
105
106/*
107 * Read pending interrupt(from non-APIC source)
108 * vector and intack.
109 */
110static int kvm_cpu_get_extint(struct kvm_vcpu *v)
111{
112 if (!kvm_cpu_has_extint(v)) {
113 WARN_ON(!lapic_in_kernel(v));
114 return -1;
115 }
116
117 if (!lapic_in_kernel(v))
118 return v->arch.interrupt.nr;
119
120 if (kvm_xen_has_interrupt(v))
121 return v->kvm->arch.xen.upcall_vector;
122
123 if (irqchip_split(v->kvm)) {
124 int vector = v->arch.pending_external_vector;
125
126 v->arch.pending_external_vector = -1;
127 return vector;
128 } else
129 return kvm_pic_read_irq(v->kvm); /* PIC */
130}
131
132/*
133 * Read pending interrupt vector and intack.
134 */
135int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
136{
137 int vector = kvm_cpu_get_extint(v);
138 if (vector != -1)
139 return vector; /* PIC */
140
141 return kvm_get_apic_interrupt(v); /* APIC */
142}
143EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
144
145void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
146{
147 if (lapic_in_kernel(vcpu))
148 kvm_inject_apic_timer_irqs(vcpu);
149 if (kvm_xen_timer_enabled(vcpu))
150 kvm_xen_inject_timer_irqs(vcpu);
151}
152
153void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
154{
155 __kvm_migrate_apic_timer(vcpu);
156 __kvm_migrate_pit_timer(vcpu);
157 static_call_cond(kvm_x86_migrate_timers)(vcpu);
158}
159
160bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args)
161{
162 bool resample = args->flags & KVM_IRQFD_FLAG_RESAMPLE;
163
164 return resample ? irqchip_kernel(kvm) : irqchip_in_kernel(kvm);
165}
166
167bool kvm_arch_irqchip_in_kernel(struct kvm *kvm)
168{
169 return irqchip_in_kernel(kvm);
170}