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);