aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/kvm/irq.c
blob: faa264822cee3c658280d122cc3495fc93587cf5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/*
 * irq.c: API for in kernel interrupt controller
 * Copyright (c) 2007, Intel Corporation.
 * Copyright 2009 Red Hat, Inc. and/or its affiliates.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307 USA.
 * Authors:
 *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
 *
 */

#include <linux/export.h>
#include <linux/kvm_host.h>

#include "irq.h"
#include "i8254.h"
#include "x86.h"

/*
 * check if there are pending timer events
 * to be processed.
 */
int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
{
	if (lapic_in_kernel(vcpu))
		return apic_has_pending_timer(vcpu);

	return 0;
}
EXPORT_SYMBOL(kvm_cpu_has_pending_timer);

/*
 * check if there is a pending userspace external interrupt
 */
static int pending_userspace_extint(struct kvm_vcpu *v)
{
	return v->arch.pending_external_vector != -1;
}

/*
 * check if there is pending interrupt from
 * non-APIC source without intack.
 */
static int kvm_cpu_has_extint(struct kvm_vcpu *v)
{
	u8 accept = kvm_apic_accept_pic_intr(v);

	if (accept) {
		if (irqchip_split(v->kvm))
			return pending_userspace_extint(v);
		else
			return v->kvm->arch.vpic->output;
	} else
		return 0;
}

/*
 * check if there is injectable interrupt:
 * when virtual interrupt delivery enabled,
 * interrupt from apic will handled by hardware,
 * we don't need to check it here.
 */
int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
{
	/*
	 * FIXME: interrupt.injected represents an interrupt that it's
	 * side-effects have already been applied (e.g. bit from IRR
	 * already moved to ISR). Therefore, it is incorrect to rely
	 * on interrupt.injected to know if there is a pending
	 * interrupt in the user-mode LAPIC.
	 * This leads to nVMX/nSVM not be able to distinguish
	 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on
	 * pending interrupt or should re-inject an injected
	 * interrupt.
	 */
	if (!lapic_in_kernel(v))
		return v->arch.interrupt.injected;

	if (kvm_cpu_has_extint(v))
		return 1;

	if (!is_guest_mode(v) && kvm_vcpu_apicv_active(v))
		return 0;

	return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
}

/*
 * check if there is pending interrupt without
 * intack.
 */
int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
{
	/*
	 * FIXME: interrupt.injected represents an interrupt that it's
	 * side-effects have already been applied (e.g. bit from IRR
	 * already moved to ISR). Therefore, it is incorrect to rely
	 * on interrupt.injected to know if there is a pending
	 * interrupt in the user-mode LAPIC.
	 * This leads to nVMX/nSVM not be able to distinguish
	 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on
	 * pending interrupt or should re-inject an injected
	 * interrupt.
	 */
	if (!lapic_in_kernel(v))
		return v->arch.interrupt.injected;

	if (kvm_cpu_has_extint(v))
		return 1;

	return kvm_apic_has_interrupt(v) != -1;	/* LAPIC */
}
EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);

/*
 * Read pending interrupt(from non-APIC source)
 * vector and intack.
 */
static int kvm_cpu_get_extint(struct kvm_vcpu *v)
{
	if (kvm_cpu_has_extint(v)) {
		if (irqchip_split(v->kvm)) {
			int vector = v->arch.pending_external_vector;

			v->arch.pending_external_vector = -1;
			return vector;
		} else
			return kvm_pic_read_irq(v->kvm); /* PIC */
	} else
		return -1;
}

/*
 * Read pending interrupt vector and intack.
 */
int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
{
	int vector;

	if (!lapic_in_kernel(v))
		return v->arch.interrupt.nr;

	vector = kvm_cpu_get_extint(v);

	if (vector != -1)
		return vector;			/* PIC */

	return kvm_get_apic_interrupt(v);	/* APIC */
}
EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);

void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
{
	if (lapic_in_kernel(vcpu))
		kvm_inject_apic_timer_irqs(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);

void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
{
	__kvm_migrate_apic_timer(vcpu);
	__kvm_migrate_pit_timer(vcpu);
}