aboutsummaryrefslogtreecommitdiff
path: root/virt/kvm/irqchip.c
blob: d7ea8e20dae4ee9b353441e5e342a6279d1485d6 (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
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
/*
 * irqchip.c: Common API for in kernel interrupt controllers
 * Copyright (c) 2007, Intel Corporation.
 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
 * Copyright (c) 2013, Alexander Graf <agraf@suse.de>
 *
 * 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.
 *
 * This file is derived from virt/kvm/irq_comm.c.
 *
 * Authors:
 *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
 *   Alexander Graf <agraf@suse.de>
 */

#include <linux/kvm_host.h>
#include <linux/slab.h>
#include <linux/srcu.h>
#include <linux/export.h>
#include <trace/events/kvm.h>
#include "irq.h"

struct kvm_irq_routing_table {
	int chip[KVM_NR_IRQCHIPS][KVM_IRQCHIP_NUM_PINS];
	u32 nr_rt_entries;
	/*
	 * Array indexed by gsi. Each entry contains list of irq chips
	 * the gsi is connected to.
	 */
	struct hlist_head map[0];
};

int kvm_irq_map_gsi(struct kvm *kvm,
		    struct kvm_kernel_irq_routing_entry *entries, int gsi)
{
	struct kvm_irq_routing_table *irq_rt;
	struct kvm_kernel_irq_routing_entry *e;
	int n = 0;

	irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
					lockdep_is_held(&kvm->irq_lock));
	if (gsi < irq_rt->nr_rt_entries) {
		hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
			entries[n] = *e;
			++n;
		}
	}

	return n;
}

int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin)
{
	struct kvm_irq_routing_table *irq_rt;

	irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
	return irq_rt->chip[irqchip][pin];
}

int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)
{
	struct kvm_kernel_irq_routing_entry route;

	if (!irqchip_in_kernel(kvm) || msi->flags != 0)
		return -EINVAL;

	route.msi.address_lo = msi->address_lo;
	route.msi.address_hi = msi->address_hi;
	route.msi.data = msi->data;

	return kvm_set_msi(&route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1, false);
}

/*
 * Return value:
 *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
 *  = 0   Interrupt was coalesced (previous irq is still pending)
 *  > 0   Number of CPUs interrupt was delivered to
 */
int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
		bool line_status)
{
	struct kvm_kernel_irq_routing_entry irq_set[KVM_NR_IRQCHIPS];
	int ret = -1, i, idx;

	trace_kvm_set_irq(irq, level, irq_source_id);

	/* Not possible to detect if the guest uses the PIC or the
	 * IOAPIC.  So set the bit in both. The guest will ignore
	 * writes to the unused one.
	 */
	idx = srcu_read_lock(&kvm->irq_srcu);
	i = kvm_irq_map_gsi(kvm, irq_set, irq);
	srcu_read_unlock(&kvm->irq_srcu, idx);

	while (i--) {
		int r;
		r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level,
				   line_status);
		if (r < 0)
			continue;

		ret = r + ((ret < 0) ? 0 : ret);
	}

	return ret;
}

static void free_irq_routing_table(struct kvm_irq_routing_table *rt)
{
	int i;

	if (!rt)
		return;

	for (i = 0; i < rt->nr_rt_entries; ++i) {
		struct kvm_kernel_irq_routing_entry *e;
		struct hlist_node *n;

		hlist_for_each_entry_safe(e, n, &rt->map[i], link) {
			hlist_del(&e->link);
			kfree(e);
		}
	}

	kfree(rt);
}

void kvm_free_irq_routing(struct kvm *kvm)
{
	/* Called only during vm destruction. Nobody can use the pointer
	   at this stage */
	struct kvm_irq_routing_table *rt = rcu_access_pointer(kvm->irq_routing);
	free_irq_routing_table(rt);
}

static int setup_routing_entry(struct kvm_irq_routing_table *rt,
			       struct kvm_kernel_irq_routing_entry *e,
			       const struct kvm_irq_routing_entry *ue)
{
	int r = -EINVAL;
	struct kvm_kernel_irq_routing_entry *ei;

	/*
	 * Do not allow GSI to be mapped to the same irqchip more than once.
	 * Allow only one to one mapping between GSI and MSI.
	 */
	hlist_for_each_entry(ei, &rt->map[ue->gsi], link)
		if (ei->type == KVM_IRQ_ROUTING_MSI ||
		    ue->type == KVM_IRQ_ROUTING_MSI ||
		    ue->u.irqchip.irqchip == ei->irqchip.irqchip)
			return r;

	e->gsi = ue->gsi;
	e->type = ue->type;
	r = kvm_set_routing_entry(e, ue);
	if (r)
		goto out;
	if (e->type == KVM_IRQ_ROUTING_IRQCHIP)
		rt->chip[e->irqchip.irqchip][e->irqchip.pin] = e->gsi;

	hlist_add_head(&e->link, &rt->map[e->gsi]);
	r = 0;
out:
	return r;
}

int kvm_set_irq_routing(struct kvm *kvm,
			const struct kvm_irq_routing_entry *ue,
			unsigned nr,
			unsigned flags)
{
	struct kvm_irq_routing_table *new, *old;
	u32 i, j, nr_rt_entries = 0;
	int r;

	for (i = 0; i < nr; ++i) {
		if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
			return -EINVAL;
		nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
	}

	nr_rt_entries += 1;

	new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head)),
		      GFP_KERNEL);

	if (!new)
		return -ENOMEM;

	new->nr_rt_entries = nr_rt_entries;
	for (i = 0; i < KVM_NR_IRQCHIPS; i++)
		for (j = 0; j < KVM_IRQCHIP_NUM_PINS; j++)
			new->chip[i][j] = -1;

	for (i = 0; i < nr; ++i) {
		struct kvm_kernel_irq_routing_entry *e;

		r = -ENOMEM;
		e = kzalloc(sizeof(*e), GFP_KERNEL);
		if (!e)
			goto out;

		r = -EINVAL;
		if (ue->flags) {
			kfree(e);
			goto out;
		}
		r = setup_routing_entry(new, e, ue);
		if (r) {
			kfree(e);
			goto out;
		}
		++ue;
	}

	mutex_lock(&kvm->irq_lock);
	old = kvm->irq_routing;
	rcu_assign_pointer(kvm->irq_routing, new);
	kvm_irq_routing_update(kvm);
	mutex_unlock(&kvm->irq_lock);

	synchronize_srcu_expedited(&kvm->irq_srcu);

	new = old;
	r = 0;

out:
	free_irq_routing_table(new);

	return r;
}