1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * irqchip.c: Common API for in kernel interrupt controllers |
4 | * Copyright (c) 2007, Intel Corporation. |
5 | * Copyright 2010 Red Hat, Inc. and/or its affiliates. |
6 | * Copyright (c) 2013, Alexander Graf <agraf@suse.de> |
7 | * |
8 | * This file is derived from virt/kvm/irq_comm.c. |
9 | * |
10 | * Authors: |
11 | * Yaozu (Eddie) Dong <Eddie.dong@intel.com> |
12 | * Alexander Graf <agraf@suse.de> |
13 | */ |
14 | |
15 | #include <linux/kvm_host.h> |
16 | #include <linux/slab.h> |
17 | #include <linux/srcu.h> |
18 | #include <linux/export.h> |
19 | #include <trace/events/kvm.h> |
20 | |
21 | int kvm_irq_map_gsi(struct kvm *kvm, |
22 | struct kvm_kernel_irq_routing_entry *entries, int gsi) |
23 | { |
24 | struct kvm_irq_routing_table *irq_rt; |
25 | struct kvm_kernel_irq_routing_entry *e; |
26 | int n = 0; |
27 | |
28 | irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu, |
29 | lockdep_is_held(&kvm->irq_lock)); |
30 | if (irq_rt && gsi < irq_rt->nr_rt_entries) { |
31 | hlist_for_each_entry(e, &irq_rt->map[gsi], link) { |
32 | entries[n] = *e; |
33 | ++n; |
34 | } |
35 | } |
36 | |
37 | return n; |
38 | } |
39 | |
40 | int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin) |
41 | { |
42 | struct kvm_irq_routing_table *irq_rt; |
43 | |
44 | irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu); |
45 | return irq_rt->chip[irqchip][pin]; |
46 | } |
47 | |
48 | int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi) |
49 | { |
50 | struct kvm_kernel_irq_routing_entry route; |
51 | |
52 | if (!kvm_arch_irqchip_in_kernel(kvm) || (msi->flags & ~KVM_MSI_VALID_DEVID)) |
53 | return -EINVAL; |
54 | |
55 | route.msi.address_lo = msi->address_lo; |
56 | route.msi.address_hi = msi->address_hi; |
57 | route.msi.data = msi->data; |
58 | route.msi.flags = msi->flags; |
59 | route.msi.devid = msi->devid; |
60 | |
61 | return kvm_set_msi(irq_entry: &route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, level: 1, line_status: false); |
62 | } |
63 | |
64 | /* |
65 | * Return value: |
66 | * < 0 Interrupt was ignored (masked or not delivered for other reasons) |
67 | * = 0 Interrupt was coalesced (previous irq is still pending) |
68 | * > 0 Number of CPUs interrupt was delivered to |
69 | */ |
70 | int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level, |
71 | bool line_status) |
72 | { |
73 | struct kvm_kernel_irq_routing_entry irq_set[KVM_NR_IRQCHIPS]; |
74 | int ret = -1, i, idx; |
75 | |
76 | trace_kvm_set_irq(gsi: irq, level, irq_source_id); |
77 | |
78 | /* Not possible to detect if the guest uses the PIC or the |
79 | * IOAPIC. So set the bit in both. The guest will ignore |
80 | * writes to the unused one. |
81 | */ |
82 | idx = srcu_read_lock(ssp: &kvm->irq_srcu); |
83 | i = kvm_irq_map_gsi(kvm, entries: irq_set, gsi: irq); |
84 | srcu_read_unlock(ssp: &kvm->irq_srcu, idx); |
85 | |
86 | while (i--) { |
87 | int r; |
88 | r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level, |
89 | line_status); |
90 | if (r < 0) |
91 | continue; |
92 | |
93 | ret = r + ((ret < 0) ? 0 : ret); |
94 | } |
95 | |
96 | return ret; |
97 | } |
98 | |
99 | static void free_irq_routing_table(struct kvm_irq_routing_table *rt) |
100 | { |
101 | int i; |
102 | |
103 | if (!rt) |
104 | return; |
105 | |
106 | for (i = 0; i < rt->nr_rt_entries; ++i) { |
107 | struct kvm_kernel_irq_routing_entry *e; |
108 | struct hlist_node *n; |
109 | |
110 | hlist_for_each_entry_safe(e, n, &rt->map[i], link) { |
111 | hlist_del(n: &e->link); |
112 | kfree(objp: e); |
113 | } |
114 | } |
115 | |
116 | kfree(objp: rt); |
117 | } |
118 | |
119 | void kvm_free_irq_routing(struct kvm *kvm) |
120 | { |
121 | /* Called only during vm destruction. Nobody can use the pointer |
122 | at this stage */ |
123 | struct kvm_irq_routing_table *rt = rcu_access_pointer(kvm->irq_routing); |
124 | free_irq_routing_table(rt); |
125 | } |
126 | |
127 | static int setup_routing_entry(struct kvm *kvm, |
128 | struct kvm_irq_routing_table *rt, |
129 | struct kvm_kernel_irq_routing_entry *e, |
130 | const struct kvm_irq_routing_entry *ue) |
131 | { |
132 | struct kvm_kernel_irq_routing_entry *ei; |
133 | int r; |
134 | u32 gsi = array_index_nospec(ue->gsi, KVM_MAX_IRQ_ROUTES); |
135 | |
136 | /* |
137 | * Do not allow GSI to be mapped to the same irqchip more than once. |
138 | * Allow only one to one mapping between GSI and non-irqchip routing. |
139 | */ |
140 | hlist_for_each_entry(ei, &rt->map[gsi], link) |
141 | if (ei->type != KVM_IRQ_ROUTING_IRQCHIP || |
142 | ue->type != KVM_IRQ_ROUTING_IRQCHIP || |
143 | ue->u.irqchip.irqchip == ei->irqchip.irqchip) |
144 | return -EINVAL; |
145 | |
146 | e->gsi = gsi; |
147 | e->type = ue->type; |
148 | r = kvm_set_routing_entry(kvm, e, ue); |
149 | if (r) |
150 | return r; |
151 | if (e->type == KVM_IRQ_ROUTING_IRQCHIP) |
152 | rt->chip[e->irqchip.irqchip][e->irqchip.pin] = e->gsi; |
153 | |
154 | hlist_add_head(n: &e->link, h: &rt->map[e->gsi]); |
155 | |
156 | return 0; |
157 | } |
158 | |
159 | void __attribute__((weak)) kvm_arch_irq_routing_update(struct kvm *kvm) |
160 | { |
161 | } |
162 | |
163 | bool __weak kvm_arch_can_set_irq_routing(struct kvm *kvm) |
164 | { |
165 | return true; |
166 | } |
167 | |
168 | int kvm_set_irq_routing(struct kvm *kvm, |
169 | const struct kvm_irq_routing_entry *ue, |
170 | unsigned nr, |
171 | unsigned flags) |
172 | { |
173 | struct kvm_irq_routing_table *new, *old; |
174 | struct kvm_kernel_irq_routing_entry *e; |
175 | u32 i, j, nr_rt_entries = 0; |
176 | int r; |
177 | |
178 | for (i = 0; i < nr; ++i) { |
179 | if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES) |
180 | return -EINVAL; |
181 | nr_rt_entries = max(nr_rt_entries, ue[i].gsi); |
182 | } |
183 | |
184 | nr_rt_entries += 1; |
185 | |
186 | new = kzalloc(struct_size(new, map, nr_rt_entries), GFP_KERNEL_ACCOUNT); |
187 | if (!new) |
188 | return -ENOMEM; |
189 | |
190 | new->nr_rt_entries = nr_rt_entries; |
191 | for (i = 0; i < KVM_NR_IRQCHIPS; i++) |
192 | for (j = 0; j < KVM_IRQCHIP_NUM_PINS; j++) |
193 | new->chip[i][j] = -1; |
194 | |
195 | for (i = 0; i < nr; ++i) { |
196 | r = -ENOMEM; |
197 | e = kzalloc(size: sizeof(*e), GFP_KERNEL_ACCOUNT); |
198 | if (!e) |
199 | goto out; |
200 | |
201 | r = -EINVAL; |
202 | switch (ue->type) { |
203 | case KVM_IRQ_ROUTING_MSI: |
204 | if (ue->flags & ~KVM_MSI_VALID_DEVID) |
205 | goto free_entry; |
206 | break; |
207 | default: |
208 | if (ue->flags) |
209 | goto free_entry; |
210 | break; |
211 | } |
212 | r = setup_routing_entry(kvm, rt: new, e, ue); |
213 | if (r) |
214 | goto free_entry; |
215 | ++ue; |
216 | } |
217 | |
218 | mutex_lock(&kvm->irq_lock); |
219 | old = rcu_dereference_protected(kvm->irq_routing, 1); |
220 | rcu_assign_pointer(kvm->irq_routing, new); |
221 | kvm_irq_routing_update(kvm); |
222 | kvm_arch_irq_routing_update(kvm); |
223 | mutex_unlock(lock: &kvm->irq_lock); |
224 | |
225 | kvm_arch_post_irq_routing_update(kvm); |
226 | |
227 | synchronize_srcu_expedited(ssp: &kvm->irq_srcu); |
228 | |
229 | new = old; |
230 | r = 0; |
231 | goto out; |
232 | |
233 | free_entry: |
234 | kfree(objp: e); |
235 | out: |
236 | free_irq_routing_table(rt: new); |
237 | |
238 | return r; |
239 | } |
240 | |