KVM: x86: Clear apic tsc-deadline after deadline
[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 struct kvm_irq_routing_table {
35         int chip[KVM_NR_IRQCHIPS][KVM_IRQCHIP_NUM_PINS];
36         struct kvm_kernel_irq_routing_entry *rt_entries;
37         u32 nr_rt_entries;
38         /*
39          * Array indexed by gsi. Each entry contains list of irq chips
40          * the gsi is connected to.
41          */
42         struct hlist_head map[0];
43 };
44
45 int kvm_irq_map_gsi(struct kvm *kvm,
46                     struct kvm_kernel_irq_routing_entry *entries, int gsi)
47 {
48         struct kvm_irq_routing_table *irq_rt;
49         struct kvm_kernel_irq_routing_entry *e;
50         int n = 0;
51
52         irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
53                                         lockdep_is_held(&kvm->irq_lock));
54         if (gsi < irq_rt->nr_rt_entries) {
55                 hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
56                         entries[n] = *e;
57                         ++n;
58                 }
59         }
60
61         return n;
62 }
63
64 int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin)
65 {
66         struct kvm_irq_routing_table *irq_rt;
67
68         irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
69         return irq_rt->chip[irqchip][pin];
70 }
71
72 int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)
73 {
74         struct kvm_kernel_irq_routing_entry route;
75
76         if (!irqchip_in_kernel(kvm) || msi->flags != 0)
77                 return -EINVAL;
78
79         route.msi.address_lo = msi->address_lo;
80         route.msi.address_hi = msi->address_hi;
81         route.msi.data = msi->data;
82
83         return kvm_set_msi(&route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1, false);
84 }
85
86 /*
87  * Return value:
88  *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
89  *  = 0   Interrupt was coalesced (previous irq is still pending)
90  *  > 0   Number of CPUs interrupt was delivered to
91  */
92 int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
93                 bool line_status)
94 {
95         struct kvm_kernel_irq_routing_entry irq_set[KVM_NR_IRQCHIPS];
96         int ret = -1, i, idx;
97
98         trace_kvm_set_irq(irq, level, irq_source_id);
99
100         /* Not possible to detect if the guest uses the PIC or the
101          * IOAPIC.  So set the bit in both. The guest will ignore
102          * writes to the unused one.
103          */
104         idx = srcu_read_lock(&kvm->irq_srcu);
105         i = kvm_irq_map_gsi(kvm, irq_set, irq);
106         srcu_read_unlock(&kvm->irq_srcu, idx);
107
108         while(i--) {
109                 int r;
110                 r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level,
111                                    line_status);
112                 if (r < 0)
113                         continue;
114
115                 ret = r + ((ret < 0) ? 0 : ret);
116         }
117
118         return ret;
119 }
120
121 void kvm_free_irq_routing(struct kvm *kvm)
122 {
123         /* Called only during vm destruction. Nobody can use the pointer
124            at this stage */
125         kfree(kvm->irq_routing);
126 }
127
128 static int setup_routing_entry(struct kvm_irq_routing_table *rt,
129                                struct kvm_kernel_irq_routing_entry *e,
130                                const struct kvm_irq_routing_entry *ue)
131 {
132         int r = -EINVAL;
133         struct kvm_kernel_irq_routing_entry *ei;
134
135         /*
136          * Do not allow GSI to be mapped to the same irqchip more than once.
137          * Allow only one to one mapping between GSI and MSI.
138          */
139         hlist_for_each_entry(ei, &rt->map[ue->gsi], link)
140                 if (ei->type == KVM_IRQ_ROUTING_MSI ||
141                     ue->type == KVM_IRQ_ROUTING_MSI ||
142                     ue->u.irqchip.irqchip == ei->irqchip.irqchip)
143                         return r;
144
145         e->gsi = ue->gsi;
146         e->type = ue->type;
147         r = kvm_set_routing_entry(e, ue);
148         if (r)
149                 goto out;
150         if (e->type == KVM_IRQ_ROUTING_IRQCHIP)
151                 rt->chip[e->irqchip.irqchip][e->irqchip.pin] = e->gsi;
152
153         hlist_add_head(&e->link, &rt->map[e->gsi]);
154         r = 0;
155 out:
156         return r;
157 }
158
159 int kvm_set_irq_routing(struct kvm *kvm,
160                         const struct kvm_irq_routing_entry *ue,
161                         unsigned nr,
162                         unsigned flags)
163 {
164         struct kvm_irq_routing_table *new, *old;
165         u32 i, j, nr_rt_entries = 0;
166         int r;
167
168         for (i = 0; i < nr; ++i) {
169                 if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
170                         return -EINVAL;
171                 nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
172         }
173
174         nr_rt_entries += 1;
175
176         new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head))
177                       + (nr * sizeof(struct kvm_kernel_irq_routing_entry)),
178                       GFP_KERNEL);
179
180         if (!new)
181                 return -ENOMEM;
182
183         new->rt_entries = (void *)&new->map[nr_rt_entries];
184
185         new->nr_rt_entries = nr_rt_entries;
186         for (i = 0; i < KVM_NR_IRQCHIPS; i++)
187                 for (j = 0; j < KVM_IRQCHIP_NUM_PINS; j++)
188                         new->chip[i][j] = -1;
189
190         for (i = 0; i < nr; ++i) {
191                 r = -EINVAL;
192                 if (ue->flags)
193                         goto out;
194                 r = setup_routing_entry(new, &new->rt_entries[i], ue);
195                 if (r)
196                         goto out;
197                 ++ue;
198         }
199
200         mutex_lock(&kvm->irq_lock);
201         old = kvm->irq_routing;
202         rcu_assign_pointer(kvm->irq_routing, new);
203         kvm_irq_routing_update(kvm);
204         mutex_unlock(&kvm->irq_lock);
205
206         synchronize_srcu_expedited(&kvm->irq_srcu);
207
208         new = old;
209         r = 0;
210
211 out:
212         kfree(new);
213         return r;
214 }