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 */
kvm_cpu_has_pending_timer(struct kvm_vcpu * vcpu)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 */
pending_userspace_extint(struct kvm_vcpu * v)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 */
kvm_cpu_has_extint(struct kvm_vcpu * v)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 */
kvm_cpu_has_injectable_intr(struct kvm_vcpu * v)74 int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
75 {
76 /*
77 * FIXME: interrupt.injected represents an interrupt that it's
78 * side-effects have already been applied (e.g. bit from IRR
79 * already moved to ISR). Therefore, it is incorrect to rely
80 * on interrupt.injected to know if there is a pending
81 * interrupt in the user-mode LAPIC.
82 * This leads to nVMX/nSVM not be able to distinguish
83 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on
84 * pending interrupt or should re-inject an injected
85 * interrupt.
86 */
87 if (!lapic_in_kernel(v))
88 return v->arch.interrupt.injected;
89
90 if (kvm_cpu_has_extint(v))
91 return 1;
92
93 if (!is_guest_mode(v) && kvm_vcpu_apicv_active(v))
94 return 0;
95
96 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
97 }
98
99 /*
100 * check if there is pending interrupt without
101 * intack.
102 */
kvm_cpu_has_interrupt(struct kvm_vcpu * v)103 int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
104 {
105 /*
106 * FIXME: interrupt.injected represents an interrupt that it's
107 * side-effects have already been applied (e.g. bit from IRR
108 * already moved to ISR). Therefore, it is incorrect to rely
109 * on interrupt.injected to know if there is a pending
110 * interrupt in the user-mode LAPIC.
111 * This leads to nVMX/nSVM not be able to distinguish
112 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on
113 * pending interrupt or should re-inject an injected
114 * interrupt.
115 */
116 if (!lapic_in_kernel(v))
117 return v->arch.interrupt.injected;
118
119 if (kvm_cpu_has_extint(v))
120 return 1;
121
122 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
123 }
124 EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
125
126 /*
127 * Read pending interrupt(from non-APIC source)
128 * vector and intack.
129 */
kvm_cpu_get_extint(struct kvm_vcpu * v)130 static int kvm_cpu_get_extint(struct kvm_vcpu *v)
131 {
132 if (kvm_cpu_has_extint(v)) {
133 if (irqchip_split(v->kvm)) {
134 int vector = v->arch.pending_external_vector;
135
136 v->arch.pending_external_vector = -1;
137 return vector;
138 } else
139 return kvm_pic_read_irq(v->kvm); /* PIC */
140 } else
141 return -1;
142 }
143
144 /*
145 * Read pending interrupt vector and intack.
146 */
kvm_cpu_get_interrupt(struct kvm_vcpu * v)147 int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
148 {
149 int vector;
150
151 if (!lapic_in_kernel(v))
152 return v->arch.interrupt.nr;
153
154 vector = kvm_cpu_get_extint(v);
155
156 if (vector != -1)
157 return vector; /* PIC */
158
159 return kvm_get_apic_interrupt(v); /* APIC */
160 }
161 EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
162
kvm_inject_pending_timer_irqs(struct kvm_vcpu * vcpu)163 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
164 {
165 if (lapic_in_kernel(vcpu))
166 kvm_inject_apic_timer_irqs(vcpu);
167 }
168 EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);
169
__kvm_migrate_timers(struct kvm_vcpu * vcpu)170 void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
171 {
172 __kvm_migrate_apic_timer(vcpu);
173 __kvm_migrate_pit_timer(vcpu);
174 }
175
