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>
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.
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
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.
20 * This file is derived from virt/kvm/irq_comm.c.
23 * Yaozu (Eddie) Dong <Eddie.dong@intel.com>
24 * Alexander Graf <agraf@suse.de>
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>
34 struct kvm_irq_routing_table {
35 int chip[KVM_NR_IRQCHIPS][KVM_IRQCHIP_NUM_PINS];
38 * Array indexed by gsi. Each entry contains list of irq chips
39 * the gsi is connected to.
41 struct hlist_head map[0];
44 int kvm_irq_map_gsi(struct kvm *kvm,
45 struct kvm_kernel_irq_routing_entry *entries, int gsi)
47 struct kvm_irq_routing_table *irq_rt;
48 struct kvm_kernel_irq_routing_entry *e;
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) {
63 int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin)
65 struct kvm_irq_routing_table *irq_rt;
67 irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
68 return irq_rt->chip[irqchip][pin];
71 int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)
73 struct kvm_kernel_irq_routing_entry route;
75 if (!irqchip_in_kernel(kvm) || msi->flags != 0)
78 route.msi.address_lo = msi->address_lo;
79 route.msi.address_hi = msi->address_hi;
80 route.msi.data = msi->data;
82 return kvm_set_msi(&route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1, false);
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
91 int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
94 struct kvm_kernel_irq_routing_entry irq_set[KVM_NR_IRQCHIPS];
97 trace_kvm_set_irq(irq, level, irq_source_id);
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.
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);
109 r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level,
114 ret = r + ((ret < 0) ? 0 : ret);
120 static void free_irq_routing_table(struct kvm_irq_routing_table *rt)
127 for (i = 0; i < rt->nr_rt_entries; ++i) {
128 struct kvm_kernel_irq_routing_entry *e;
129 struct hlist_node *n;
131 hlist_for_each_entry_safe(e, n, &rt->map[i], link) {
140 void kvm_free_irq_routing(struct kvm *kvm)
142 /* Called only during vm destruction. Nobody can use the pointer
144 struct kvm_irq_routing_table *rt = rcu_access_pointer(kvm->irq_routing);
145 free_irq_routing_table(rt);
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)
153 struct kvm_kernel_irq_routing_entry *ei;
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.
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)
167 r = kvm_set_routing_entry(e, ue);
170 if (e->type == KVM_IRQ_ROUTING_IRQCHIP)
171 rt->chip[e->irqchip.irqchip][e->irqchip.pin] = e->gsi;
173 hlist_add_head(&e->link, &rt->map[e->gsi]);
179 int kvm_set_irq_routing(struct kvm *kvm,
180 const struct kvm_irq_routing_entry *ue,
184 struct kvm_irq_routing_table *new, *old;
185 u32 i, j, nr_rt_entries = 0;
188 for (i = 0; i < nr; ++i) {
189 if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
191 nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
196 new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head)),
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;
207 for (i = 0; i < nr; ++i) {
208 struct kvm_kernel_irq_routing_entry *e;
211 e = kzalloc(sizeof(*e), GFP_KERNEL);
218 r = setup_routing_entry(new, e, ue);
224 mutex_lock(&kvm->irq_lock);
225 old = kvm->irq_routing;
226 rcu_assign_pointer(kvm->irq_routing, new);
227 kvm_irq_routing_update(kvm);
228 mutex_unlock(&kvm->irq_lock);
230 synchronize_srcu_expedited(&kvm->irq_srcu);
236 free_irq_routing_table(new);