Merge tag 'drm-fixes-for-v4.16-rc2' of git://people.freedesktop.org/~airlied/linux
[sfrench/cifs-2.6.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 int kvm_irq_map_gsi(struct kvm *kvm,
35                     struct kvm_kernel_irq_routing_entry *entries, int gsi)
36 {
37         struct kvm_irq_routing_table *irq_rt;
38         struct kvm_kernel_irq_routing_entry *e;
39         int n = 0;
40
41         irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
42                                         lockdep_is_held(&kvm->irq_lock));
43         if (irq_rt && gsi < irq_rt->nr_rt_entries) {
44                 hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
45                         entries[n] = *e;
46                         ++n;
47                 }
48         }
49
50         return n;
51 }
52
53 int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin)
54 {
55         struct kvm_irq_routing_table *irq_rt;
56
57         irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
58         return irq_rt->chip[irqchip][pin];
59 }
60
61 int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)
62 {
63         struct kvm_kernel_irq_routing_entry route;
64
65         if (!irqchip_in_kernel(kvm) || (msi->flags & ~KVM_MSI_VALID_DEVID))
66                 return -EINVAL;
67
68         route.msi.address_lo = msi->address_lo;
69         route.msi.address_hi = msi->address_hi;
70         route.msi.data = msi->data;
71         route.msi.flags = msi->flags;
72         route.msi.devid = msi->devid;
73
74         return kvm_set_msi(&route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1, false);
75 }
76
77 /*
78  * Return value:
79  *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
80  *  = 0   Interrupt was coalesced (previous irq is still pending)
81  *  > 0   Number of CPUs interrupt was delivered to
82  */
83 int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
84                 bool line_status)
85 {
86         struct kvm_kernel_irq_routing_entry irq_set[KVM_NR_IRQCHIPS];
87         int ret = -1, i, idx;
88
89         trace_kvm_set_irq(irq, level, irq_source_id);
90
91         /* Not possible to detect if the guest uses the PIC or the
92          * IOAPIC.  So set the bit in both. The guest will ignore
93          * writes to the unused one.
94          */
95         idx = srcu_read_lock(&kvm->irq_srcu);
96         i = kvm_irq_map_gsi(kvm, irq_set, irq);
97         srcu_read_unlock(&kvm->irq_srcu, idx);
98
99         while (i--) {
100                 int r;
101                 r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level,
102                                    line_status);
103                 if (r < 0)
104                         continue;
105
106                 ret = r + ((ret < 0) ? 0 : ret);
107         }
108
109         return ret;
110 }
111
112 static void free_irq_routing_table(struct kvm_irq_routing_table *rt)
113 {
114         int i;
115
116         if (!rt)
117                 return;
118
119         for (i = 0; i < rt->nr_rt_entries; ++i) {
120                 struct kvm_kernel_irq_routing_entry *e;
121                 struct hlist_node *n;
122
123                 hlist_for_each_entry_safe(e, n, &rt->map[i], link) {
124                         hlist_del(&e->link);
125                         kfree(e);
126                 }
127         }
128
129         kfree(rt);
130 }
131
132 void kvm_free_irq_routing(struct kvm *kvm)
133 {
134         /* Called only during vm destruction. Nobody can use the pointer
135            at this stage */
136         struct kvm_irq_routing_table *rt = rcu_access_pointer(kvm->irq_routing);
137         free_irq_routing_table(rt);
138 }
139
140 static int setup_routing_entry(struct kvm *kvm,
141                                struct kvm_irq_routing_table *rt,
142                                struct kvm_kernel_irq_routing_entry *e,
143                                const struct kvm_irq_routing_entry *ue)
144 {
145         struct kvm_kernel_irq_routing_entry *ei;
146         int r;
147
148         /*
149          * Do not allow GSI to be mapped to the same irqchip more than once.
150          * Allow only one to one mapping between GSI and non-irqchip routing.
151          */
152         hlist_for_each_entry(ei, &rt->map[ue->gsi], link)
153                 if (ei->type != KVM_IRQ_ROUTING_IRQCHIP ||
154                     ue->type != KVM_IRQ_ROUTING_IRQCHIP ||
155                     ue->u.irqchip.irqchip == ei->irqchip.irqchip)
156                         return -EINVAL;
157
158         e->gsi = ue->gsi;
159         e->type = ue->type;
160         r = kvm_set_routing_entry(kvm, e, ue);
161         if (r)
162                 return r;
163         if (e->type == KVM_IRQ_ROUTING_IRQCHIP)
164                 rt->chip[e->irqchip.irqchip][e->irqchip.pin] = e->gsi;
165
166         hlist_add_head(&e->link, &rt->map[e->gsi]);
167
168         return 0;
169 }
170
171 void __attribute__((weak)) kvm_arch_irq_routing_update(struct kvm *kvm)
172 {
173 }
174
175 bool __weak kvm_arch_can_set_irq_routing(struct kvm *kvm)
176 {
177         return true;
178 }
179
180 int kvm_set_irq_routing(struct kvm *kvm,
181                         const struct kvm_irq_routing_entry *ue,
182                         unsigned nr,
183                         unsigned flags)
184 {
185         struct kvm_irq_routing_table *new, *old;
186         struct kvm_kernel_irq_routing_entry *e;
187         u32 i, j, nr_rt_entries = 0;
188         int r;
189
190         for (i = 0; i < nr; ++i) {
191                 if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
192                         return -EINVAL;
193                 nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
194         }
195
196         nr_rt_entries += 1;
197
198         new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head)),
199                       GFP_KERNEL);
200
201         if (!new)
202                 return -ENOMEM;
203
204         new->nr_rt_entries = nr_rt_entries;
205         for (i = 0; i < KVM_NR_IRQCHIPS; i++)
206                 for (j = 0; j < KVM_IRQCHIP_NUM_PINS; j++)
207                         new->chip[i][j] = -1;
208
209         for (i = 0; i < nr; ++i) {
210                 r = -ENOMEM;
211                 e = kzalloc(sizeof(*e), GFP_KERNEL);
212                 if (!e)
213                         goto out;
214
215                 r = -EINVAL;
216                 switch (ue->type) {
217                 case KVM_IRQ_ROUTING_MSI:
218                         if (ue->flags & ~KVM_MSI_VALID_DEVID)
219                                 goto free_entry;
220                         break;
221                 default:
222                         if (ue->flags)
223                                 goto free_entry;
224                         break;
225                 }
226                 r = setup_routing_entry(kvm, new, e, ue);
227                 if (r)
228                         goto free_entry;
229                 ++ue;
230         }
231
232         mutex_lock(&kvm->irq_lock);
233         old = rcu_dereference_protected(kvm->irq_routing, 1);
234         rcu_assign_pointer(kvm->irq_routing, new);
235         kvm_irq_routing_update(kvm);
236         kvm_arch_irq_routing_update(kvm);
237         mutex_unlock(&kvm->irq_lock);
238
239         kvm_arch_post_irq_routing_update(kvm);
240
241         synchronize_srcu_expedited(&kvm->irq_srcu);
242
243         new = old;
244         r = 0;
245         goto out;
246
247 free_entry:
248         kfree(e);
249 out:
250         free_irq_routing_table(new);
251
252         return r;
253 }