Merge remote-tracking branch 'mvebu/for-next'
[karo-tx-linux.git] / virt / kvm / irqchip.c
1 /*
2  * irqchip.c: Common API for in kernel interrupt controllers
3  * Copyright (c) 2007, Intel Corporation.
4  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
5  * Copyright (c) 2013, Alexander Graf <agraf@suse.de>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
18  * Place - Suite 330, Boston, MA 02111-1307 USA.
19  *
20  * This file is derived from virt/kvm/irq_comm.c.
21  *
22  * Authors:
23  *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
24  *   Alexander Graf <agraf@suse.de>
25  */
26
27 #include <linux/kvm_host.h>
28 #include <linux/slab.h>
29 #include <linux/srcu.h>
30 #include <linux/export.h>
31 #include <trace/events/kvm.h>
32 #include "irq.h"
33
34 struct kvm_irq_routing_table {
35         int chip[KVM_NR_IRQCHIPS][KVM_IRQCHIP_NUM_PINS];
36         u32 nr_rt_entries;
37         /*
38          * Array indexed by gsi. Each entry contains list of irq chips
39          * the gsi is connected to.
40          */
41         struct hlist_head map[0];
42 };
43
44 int kvm_irq_map_gsi(struct kvm *kvm,
45                     struct kvm_kernel_irq_routing_entry *entries, int gsi)
46 {
47         struct kvm_irq_routing_table *irq_rt;
48         struct kvm_kernel_irq_routing_entry *e;
49         int n = 0;
50
51         irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
52                                         lockdep_is_held(&kvm->irq_lock));
53         if (gsi < irq_rt->nr_rt_entries) {
54                 hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
55                         entries[n] = *e;
56                         ++n;
57                 }
58         }
59
60         return n;
61 }
62
63 int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin)
64 {
65         struct kvm_irq_routing_table *irq_rt;
66
67         irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
68         return irq_rt->chip[irqchip][pin];
69 }
70
71 int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)
72 {
73         struct kvm_kernel_irq_routing_entry route;
74
75         if (!irqchip_in_kernel(kvm) || msi->flags != 0)
76                 return -EINVAL;
77
78         route.msi.address_lo = msi->address_lo;
79         route.msi.address_hi = msi->address_hi;
80         route.msi.data = msi->data;
81
82         return kvm_set_msi(&route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1, false);
83 }
84
85 /*
86  * Return value:
87  *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
88  *  = 0   Interrupt was coalesced (previous irq is still pending)
89  *  > 0   Number of CPUs interrupt was delivered to
90  */
91 int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
92                 bool line_status)
93 {
94         struct kvm_kernel_irq_routing_entry irq_set[KVM_NR_IRQCHIPS];
95         int ret = -1, i, idx;
96
97         trace_kvm_set_irq(irq, level, irq_source_id);
98
99         /* Not possible to detect if the guest uses the PIC or the
100          * IOAPIC.  So set the bit in both. The guest will ignore
101          * writes to the unused one.
102          */
103         idx = srcu_read_lock(&kvm->irq_srcu);
104         i = kvm_irq_map_gsi(kvm, irq_set, irq);
105         srcu_read_unlock(&kvm->irq_srcu, idx);
106
107         while (i--) {
108                 int r;
109                 r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level,
110                                    line_status);
111                 if (r < 0)
112                         continue;
113
114                 ret = r + ((ret < 0) ? 0 : ret);
115         }
116
117         return ret;
118 }
119
120 static void free_irq_routing_table(struct kvm_irq_routing_table *rt)
121 {
122         int i;
123
124         if (!rt)
125                 return;
126
127         for (i = 0; i < rt->nr_rt_entries; ++i) {
128                 struct kvm_kernel_irq_routing_entry *e;
129                 struct hlist_node *n;
130
131                 hlist_for_each_entry_safe(e, n, &rt->map[i], link) {
132                         hlist_del(&e->link);
133                         kfree(e);
134                 }
135         }
136
137         kfree(rt);
138 }
139
140 void kvm_free_irq_routing(struct kvm *kvm)
141 {
142         /* Called only during vm destruction. Nobody can use the pointer
143            at this stage */
144         struct kvm_irq_routing_table *rt = rcu_access_pointer(kvm->irq_routing);
145         free_irq_routing_table(rt);
146 }
147
148 static int setup_routing_entry(struct kvm_irq_routing_table *rt,
149                                struct kvm_kernel_irq_routing_entry *e,
150                                const struct kvm_irq_routing_entry *ue)
151 {
152         int r = -EINVAL;
153         struct kvm_kernel_irq_routing_entry *ei;
154
155         /*
156          * Do not allow GSI to be mapped to the same irqchip more than once.
157          * Allow only one to one mapping between GSI and MSI.
158          */
159         hlist_for_each_entry(ei, &rt->map[ue->gsi], link)
160                 if (ei->type == KVM_IRQ_ROUTING_MSI ||
161                     ue->type == KVM_IRQ_ROUTING_MSI ||
162                     ue->u.irqchip.irqchip == ei->irqchip.irqchip)
163                         return r;
164
165         e->gsi = ue->gsi;
166         e->type = ue->type;
167         r = kvm_set_routing_entry(e, ue);
168         if (r)
169                 goto out;
170         if (e->type == KVM_IRQ_ROUTING_IRQCHIP)
171                 rt->chip[e->irqchip.irqchip][e->irqchip.pin] = e->gsi;
172
173         hlist_add_head(&e->link, &rt->map[e->gsi]);
174         r = 0;
175 out:
176         return r;
177 }
178
179 int kvm_set_irq_routing(struct kvm *kvm,
180                         const struct kvm_irq_routing_entry *ue,
181                         unsigned nr,
182                         unsigned flags)
183 {
184         struct kvm_irq_routing_table *new, *old;
185         u32 i, j, nr_rt_entries = 0;
186         int r;
187
188         for (i = 0; i < nr; ++i) {
189                 if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
190                         return -EINVAL;
191                 nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
192         }
193
194         nr_rt_entries += 1;
195
196         new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head)),
197                       GFP_KERNEL);
198
199         if (!new)
200                 return -ENOMEM;
201
202         new->nr_rt_entries = nr_rt_entries;
203         for (i = 0; i < KVM_NR_IRQCHIPS; i++)
204                 for (j = 0; j < KVM_IRQCHIP_NUM_PINS; j++)
205                         new->chip[i][j] = -1;
206
207         for (i = 0; i < nr; ++i) {
208                 struct kvm_kernel_irq_routing_entry *e;
209
210                 r = -ENOMEM;
211                 e = kzalloc(sizeof(*e), GFP_KERNEL);
212                 if (!e)
213                         goto out;
214
215                 r = -EINVAL;
216                 if (ue->flags) {
217                         kfree(e);
218                         goto out;
219                 }
220                 r = setup_routing_entry(new, e, ue);
221                 if (r) {
222                         kfree(e);
223                         goto out;
224                 }
225                 ++ue;
226         }
227
228         mutex_lock(&kvm->irq_lock);
229         old = kvm->irq_routing;
230         rcu_assign_pointer(kvm->irq_routing, new);
231         kvm_irq_routing_update(kvm);
232         mutex_unlock(&kvm->irq_lock);
233
234         synchronize_srcu_expedited(&kvm->irq_srcu);
235
236         new = old;
237         r = 0;
238
239 out:
240         free_irq_routing_table(new);
241
242         return r;
243 }