xref: /linux/arch/arm64/kvm/vgic/vgic-irqfd.c (revision d53b8e36925256097a08d7cb749198d85cbf9b2b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2015, 2016 ARM Ltd.
4  */
5 
6 #include <linux/kvm.h>
7 #include <linux/kvm_host.h>
8 #include <trace/events/kvm.h>
9 #include <kvm/arm_vgic.h>
10 #include "vgic.h"
11 
12 /*
13  * vgic_irqfd_set_irq: inject the IRQ corresponding to the
14  * irqchip routing entry
15  *
16  * This is the entry point for irqfd IRQ injection
17  */
18 static int vgic_irqfd_set_irq(struct kvm_kernel_irq_routing_entry *e,
19 			struct kvm *kvm, int irq_source_id,
20 			int level, bool line_status)
21 {
22 	unsigned int spi_id = e->irqchip.pin + VGIC_NR_PRIVATE_IRQS;
23 
24 	if (!vgic_valid_spi(kvm, spi_id))
25 		return -EINVAL;
26 	return kvm_vgic_inject_irq(kvm, NULL, spi_id, level, NULL);
27 }
28 
29 /**
30  * kvm_set_routing_entry: populate a kvm routing entry
31  * from a user routing entry
32  *
33  * @kvm: the VM this entry is applied to
34  * @e: kvm kernel routing entry handle
35  * @ue: user api routing entry handle
36  * return 0 on success, -EINVAL on errors.
37  */
38 int kvm_set_routing_entry(struct kvm *kvm,
39 			  struct kvm_kernel_irq_routing_entry *e,
40 			  const struct kvm_irq_routing_entry *ue)
41 {
42 	int r = -EINVAL;
43 
44 	switch (ue->type) {
45 	case KVM_IRQ_ROUTING_IRQCHIP:
46 		e->set = vgic_irqfd_set_irq;
47 		e->irqchip.irqchip = ue->u.irqchip.irqchip;
48 		e->irqchip.pin = ue->u.irqchip.pin;
49 		if ((e->irqchip.pin >= KVM_IRQCHIP_NUM_PINS) ||
50 		    (e->irqchip.irqchip >= KVM_NR_IRQCHIPS))
51 			goto out;
52 		break;
53 	case KVM_IRQ_ROUTING_MSI:
54 		e->set = kvm_set_msi;
55 		e->msi.address_lo = ue->u.msi.address_lo;
56 		e->msi.address_hi = ue->u.msi.address_hi;
57 		e->msi.data = ue->u.msi.data;
58 		e->msi.flags = ue->flags;
59 		e->msi.devid = ue->u.msi.devid;
60 		break;
61 	default:
62 		goto out;
63 	}
64 	r = 0;
65 out:
66 	return r;
67 }
68 
69 static void kvm_populate_msi(struct kvm_kernel_irq_routing_entry *e,
70 			     struct kvm_msi *msi)
71 {
72 	msi->address_lo = e->msi.address_lo;
73 	msi->address_hi = e->msi.address_hi;
74 	msi->data = e->msi.data;
75 	msi->flags = e->msi.flags;
76 	msi->devid = e->msi.devid;
77 }
78 
79 /*
80  * kvm_set_msi: inject the MSI corresponding to the
81  * MSI routing entry
82  *
83  * This is the entry point for irqfd MSI injection
84  * and userspace MSI injection.
85  */
86 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
87 		struct kvm *kvm, int irq_source_id,
88 		int level, bool line_status)
89 {
90 	struct kvm_msi msi;
91 
92 	if (!vgic_has_its(kvm))
93 		return -ENODEV;
94 
95 	if (!level)
96 		return -1;
97 
98 	kvm_populate_msi(e, &msi);
99 	return vgic_its_inject_msi(kvm, &msi);
100 }
101 
102 /*
103  * kvm_arch_set_irq_inatomic: fast-path for irqfd injection
104  */
105 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
106 			      struct kvm *kvm, int irq_source_id, int level,
107 			      bool line_status)
108 {
109 	if (!level)
110 		return -EWOULDBLOCK;
111 
112 	switch (e->type) {
113 	case KVM_IRQ_ROUTING_MSI: {
114 		struct kvm_msi msi;
115 
116 		if (!vgic_has_its(kvm))
117 			break;
118 
119 		kvm_populate_msi(e, &msi);
120 		return vgic_its_inject_cached_translation(kvm, &msi);
121 	}
122 
123 	case KVM_IRQ_ROUTING_IRQCHIP:
124 		/*
125 		 * Injecting SPIs is always possible in atomic context
126 		 * as long as the damn vgic is initialized.
127 		 */
128 		if (unlikely(!vgic_initialized(kvm)))
129 			break;
130 		return vgic_irqfd_set_irq(e, kvm, irq_source_id, 1, line_status);
131 	}
132 
133 	return -EWOULDBLOCK;
134 }
135 
136 int kvm_vgic_setup_default_irq_routing(struct kvm *kvm)
137 {
138 	struct kvm_irq_routing_entry *entries;
139 	struct vgic_dist *dist = &kvm->arch.vgic;
140 	u32 nr = dist->nr_spis;
141 	int i, ret;
142 
143 	entries = kcalloc(nr, sizeof(*entries), GFP_KERNEL_ACCOUNT);
144 	if (!entries)
145 		return -ENOMEM;
146 
147 	for (i = 0; i < nr; i++) {
148 		entries[i].gsi = i;
149 		entries[i].type = KVM_IRQ_ROUTING_IRQCHIP;
150 		entries[i].u.irqchip.irqchip = 0;
151 		entries[i].u.irqchip.pin = i;
152 	}
153 	ret = kvm_set_irq_routing(kvm, entries, nr, 0);
154 	kfree(entries);
155 	return ret;
156 }
157