xref: /linux/arch/x86/kvm/irq.c (revision f884ab15afdc5514e88105c92a4e2e1e6539869a)
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  */
34 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
35 {
36 	return apic_has_pending_timer(vcpu);
37 }
38 EXPORT_SYMBOL(kvm_cpu_has_pending_timer);
39 
40 /*
41  * check if there is pending interrupt from
42  * non-APIC source without intack.
43  */
44 static 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  */
58 int 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  */
76 int 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 }
86 EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
87 
88 /*
89  * Read pending interrupt(from non-APIC source)
90  * vector and intack.
91  */
92 static 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  */
102 int 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 
117 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
118 {
119 	kvm_inject_apic_timer_irqs(vcpu);
120 	/* TODO: PIT, RTC etc. */
121 }
122 EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);
123 
124 void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
125 {
126 	__kvm_migrate_apic_timer(vcpu);
127 	__kvm_migrate_pit_timer(vcpu);
128 }
129