xref: /openbmc/linux/arch/x86/kvm/irq.c (revision 2c684d89)
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 a pending userspace external interrupt
42  */
43 static int pending_userspace_extint(struct kvm_vcpu *v)
44 {
45 	return v->arch.pending_external_vector != -1;
46 }
47 
48 /*
49  * check if there is pending interrupt from
50  * non-APIC source without intack.
51  */
52 static int kvm_cpu_has_extint(struct kvm_vcpu *v)
53 {
54 	u8 accept = kvm_apic_accept_pic_intr(v);
55 
56 	if (accept) {
57 		if (irqchip_split(v->kvm))
58 			return pending_userspace_extint(v);
59 		else
60 			return pic_irqchip(v->kvm)->output;
61 	} else
62 		return 0;
63 }
64 
65 /*
66  * check if there is injectable interrupt:
67  * when virtual interrupt delivery enabled,
68  * interrupt from apic will handled by hardware,
69  * we don't need to check it here.
70  */
71 int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
72 {
73 	if (!lapic_in_kernel(v))
74 		return v->arch.interrupt.pending;
75 
76 	if (kvm_cpu_has_extint(v))
77 		return 1;
78 
79 	if (kvm_vcpu_apic_vid_enabled(v))
80 		return 0;
81 
82 	return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
83 }
84 
85 /*
86  * check if there is pending interrupt without
87  * intack.
88  */
89 int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
90 {
91 	if (!lapic_in_kernel(v))
92 		return v->arch.interrupt.pending;
93 
94 	if (kvm_cpu_has_extint(v))
95 		return 1;
96 
97 	return kvm_apic_has_interrupt(v) != -1;	/* LAPIC */
98 }
99 EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
100 
101 /*
102  * Read pending interrupt(from non-APIC source)
103  * vector and intack.
104  */
105 static int kvm_cpu_get_extint(struct kvm_vcpu *v)
106 {
107 	if (kvm_cpu_has_extint(v)) {
108 		if (irqchip_split(v->kvm)) {
109 			int vector = v->arch.pending_external_vector;
110 
111 			v->arch.pending_external_vector = -1;
112 			return vector;
113 		} else
114 			return kvm_pic_read_irq(v->kvm); /* PIC */
115 	} else
116 		return -1;
117 }
118 
119 /*
120  * Read pending interrupt vector and intack.
121  */
122 int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
123 {
124 	int vector;
125 
126 	if (!lapic_in_kernel(v))
127 		return v->arch.interrupt.nr;
128 
129 	vector = kvm_cpu_get_extint(v);
130 
131 	if (vector != -1)
132 		return vector;			/* PIC */
133 
134 	return kvm_get_apic_interrupt(v);	/* APIC */
135 }
136 EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
137 
138 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
139 {
140 	kvm_inject_apic_timer_irqs(vcpu);
141 	/* TODO: PIT, RTC etc. */
142 }
143 EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);
144 
145 void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
146 {
147 	__kvm_migrate_apic_timer(vcpu);
148 	__kvm_migrate_pit_timer(vcpu);
149 }
150