xref: /linux/arch/x86/kvm/irq.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
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  */
34 int 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 }
41 EXPORT_SYMBOL(kvm_cpu_has_pending_timer);
42 
43 /*
44  * check if there is a pending userspace external interrupt
45  */
46 static 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  */
55 static 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  */
74 int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
75 {
76 	if (!lapic_in_kernel(v))
77 		return v->arch.interrupt.pending;
78 
79 	if (kvm_cpu_has_extint(v))
80 		return 1;
81 
82 	if (kvm_vcpu_apicv_active(v))
83 		return 0;
84 
85 	return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
86 }
87 
88 /*
89  * check if there is pending interrupt without
90  * intack.
91  */
92 int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
93 {
94 	if (!lapic_in_kernel(v))
95 		return v->arch.interrupt.pending;
96 
97 	if (kvm_cpu_has_extint(v))
98 		return 1;
99 
100 	return kvm_apic_has_interrupt(v) != -1;	/* LAPIC */
101 }
102 EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
103 
104 /*
105  * Read pending interrupt(from non-APIC source)
106  * vector and intack.
107  */
108 static int kvm_cpu_get_extint(struct kvm_vcpu *v)
109 {
110 	if (kvm_cpu_has_extint(v)) {
111 		if (irqchip_split(v->kvm)) {
112 			int vector = v->arch.pending_external_vector;
113 
114 			v->arch.pending_external_vector = -1;
115 			return vector;
116 		} else
117 			return kvm_pic_read_irq(v->kvm); /* PIC */
118 	} else
119 		return -1;
120 }
121 
122 /*
123  * Read pending interrupt vector and intack.
124  */
125 int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
126 {
127 	int vector;
128 
129 	if (!lapic_in_kernel(v))
130 		return v->arch.interrupt.nr;
131 
132 	vector = kvm_cpu_get_extint(v);
133 
134 	if (vector != -1)
135 		return vector;			/* PIC */
136 
137 	return kvm_get_apic_interrupt(v);	/* APIC */
138 }
139 EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
140 
141 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
142 {
143 	if (lapic_in_kernel(vcpu))
144 		kvm_inject_apic_timer_irqs(vcpu);
145 }
146 EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);
147 
148 void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
149 {
150 	__kvm_migrate_apic_timer(vcpu);
151 	__kvm_migrate_pit_timer(vcpu);
152 }
153