Commit | Line | Data |
---|---|---|
5f94c174 LV |
1 | /* |
2 | * KVM coalesced MMIO | |
3 | * | |
4 | * Copyright (c) 2008 Bull S.A.S. | |
221d059d | 5 | * Copyright 2009 Red Hat, Inc. and/or its affiliates. |
5f94c174 LV |
6 | * |
7 | * Author: Laurent Vivier <Laurent.Vivier@bull.net> | |
8 | * | |
9 | */ | |
10 | ||
11 | #include "iodev.h" | |
12 | ||
13 | #include <linux/kvm_host.h> | |
5a0e3ad6 | 14 | #include <linux/slab.h> |
5f94c174 LV |
15 | #include <linux/kvm.h> |
16 | ||
17 | #include "coalesced_mmio.h" | |
18 | ||
d76685c4 GH |
19 | static inline struct kvm_coalesced_mmio_dev *to_mmio(struct kvm_io_device *dev) |
20 | { | |
21 | return container_of(dev, struct kvm_coalesced_mmio_dev, dev); | |
22 | } | |
23 | ||
bda9020e MT |
24 | static int coalesced_mmio_in_range(struct kvm_coalesced_mmio_dev *dev, |
25 | gpa_t addr, int len) | |
5f94c174 | 26 | { |
2b3c246a SL |
27 | /* is it in a batchable area ? |
28 | * (addr,len) is fully included in | |
29 | * (zone->addr, zone->size) | |
30 | */ | |
1a214246 DC |
31 | if (len < 0) |
32 | return 0; | |
33 | if (addr + len < addr) | |
34 | return 0; | |
35 | if (addr < dev->zone.addr) | |
36 | return 0; | |
37 | if (addr + len > dev->zone.addr + dev->zone.size) | |
38 | return 0; | |
39 | return 1; | |
5f94c174 LV |
40 | } |
41 | ||
c298125f SL |
42 | static int coalesced_mmio_has_room(struct kvm_coalesced_mmio_dev *dev) |
43 | { | |
44 | struct kvm_coalesced_mmio_ring *ring; | |
45 | unsigned avail; | |
46 | ||
47 | /* Are we able to batch it ? */ | |
48 | ||
49 | /* last is the first free entry | |
50 | * check if we don't meet the first used entry | |
51 | * there is always one unused entry in the buffer | |
52 | */ | |
53 | ring = dev->kvm->coalesced_mmio_ring; | |
54 | avail = (ring->first - ring->last - 1) % KVM_COALESCED_MMIO_MAX; | |
55 | if (avail == 0) { | |
56 | /* full */ | |
57 | return 0; | |
58 | } | |
59 | ||
60 | return 1; | |
61 | } | |
62 | ||
bda9020e MT |
63 | static int coalesced_mmio_write(struct kvm_io_device *this, |
64 | gpa_t addr, int len, const void *val) | |
5f94c174 | 65 | { |
d76685c4 | 66 | struct kvm_coalesced_mmio_dev *dev = to_mmio(this); |
5f94c174 | 67 | struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring; |
c298125f | 68 | |
bda9020e MT |
69 | if (!coalesced_mmio_in_range(dev, addr, len)) |
70 | return -EOPNOTSUPP; | |
5f94c174 | 71 | |
2b3c246a | 72 | spin_lock(&dev->kvm->ring_lock); |
5f94c174 | 73 | |
c298125f | 74 | if (!coalesced_mmio_has_room(dev)) { |
2b3c246a | 75 | spin_unlock(&dev->kvm->ring_lock); |
c298125f SL |
76 | return -EOPNOTSUPP; |
77 | } | |
78 | ||
5f94c174 LV |
79 | /* copy data in first free entry of the ring */ |
80 | ||
81 | ring->coalesced_mmio[ring->last].phys_addr = addr; | |
82 | ring->coalesced_mmio[ring->last].len = len; | |
83 | memcpy(ring->coalesced_mmio[ring->last].data, val, len); | |
84 | smp_wmb(); | |
85 | ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX; | |
2b3c246a | 86 | spin_unlock(&dev->kvm->ring_lock); |
bda9020e | 87 | return 0; |
5f94c174 LV |
88 | } |
89 | ||
90 | static void coalesced_mmio_destructor(struct kvm_io_device *this) | |
91 | { | |
d76685c4 | 92 | struct kvm_coalesced_mmio_dev *dev = to_mmio(this); |
787a660a | 93 | |
2b3c246a SL |
94 | list_del(&dev->list); |
95 | ||
787a660a | 96 | kfree(dev); |
5f94c174 LV |
97 | } |
98 | ||
d76685c4 GH |
99 | static const struct kvm_io_device_ops coalesced_mmio_ops = { |
100 | .write = coalesced_mmio_write, | |
d76685c4 GH |
101 | .destructor = coalesced_mmio_destructor, |
102 | }; | |
103 | ||
5f94c174 LV |
104 | int kvm_coalesced_mmio_init(struct kvm *kvm) |
105 | { | |
980da6ce | 106 | struct page *page; |
090b7aff | 107 | int ret; |
5f94c174 | 108 | |
980da6ce AK |
109 | ret = -ENOMEM; |
110 | page = alloc_page(GFP_KERNEL | __GFP_ZERO); | |
111 | if (!page) | |
112 | goto out_err; | |
980da6ce | 113 | |
2b3c246a SL |
114 | ret = 0; |
115 | kvm->coalesced_mmio_ring = page_address(page); | |
980da6ce | 116 | |
2b3c246a SL |
117 | /* |
118 | * We're using this spinlock to sync access to the coalesced ring. | |
119 | * The list doesn't need it's own lock since device registration and | |
120 | * unregistration should only happen when kvm->slots_lock is held. | |
121 | */ | |
122 | spin_lock_init(&kvm->ring_lock); | |
123 | INIT_LIST_HEAD(&kvm->coalesced_zones); | |
090b7aff | 124 | |
980da6ce | 125 | out_err: |
090b7aff | 126 | return ret; |
5f94c174 LV |
127 | } |
128 | ||
980da6ce AK |
129 | void kvm_coalesced_mmio_free(struct kvm *kvm) |
130 | { | |
131 | if (kvm->coalesced_mmio_ring) | |
132 | free_page((unsigned long)kvm->coalesced_mmio_ring); | |
133 | } | |
134 | ||
5f94c174 | 135 | int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm, |
43db6697 | 136 | struct kvm_coalesced_mmio_zone *zone) |
5f94c174 | 137 | { |
2b3c246a SL |
138 | int ret; |
139 | struct kvm_coalesced_mmio_dev *dev; | |
5f94c174 | 140 | |
2b3c246a SL |
141 | dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL); |
142 | if (!dev) | |
143 | return -ENOMEM; | |
144 | ||
145 | kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops); | |
146 | dev->kvm = kvm; | |
147 | dev->zone = *zone; | |
5f94c174 | 148 | |
79fac95e | 149 | mutex_lock(&kvm->slots_lock); |
743eeb0b SL |
150 | ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, zone->addr, |
151 | zone->size, &dev->dev); | |
2b3c246a SL |
152 | if (ret < 0) |
153 | goto out_free_dev; | |
154 | list_add_tail(&dev->list, &kvm->coalesced_zones); | |
155 | mutex_unlock(&kvm->slots_lock); | |
5f94c174 | 156 | |
aac5c422 | 157 | return 0; |
5f94c174 | 158 | |
2b3c246a | 159 | out_free_dev: |
79fac95e | 160 | mutex_unlock(&kvm->slots_lock); |
2b3c246a SL |
161 | kfree(dev); |
162 | ||
aac5c422 | 163 | return ret; |
5f94c174 LV |
164 | } |
165 | ||
166 | int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm, | |
167 | struct kvm_coalesced_mmio_zone *zone) | |
168 | { | |
2b3c246a | 169 | struct kvm_coalesced_mmio_dev *dev, *tmp; |
5f94c174 | 170 | |
79fac95e | 171 | mutex_lock(&kvm->slots_lock); |
5f94c174 | 172 | |
2b3c246a SL |
173 | list_for_each_entry_safe(dev, tmp, &kvm->coalesced_zones, list) |
174 | if (coalesced_mmio_in_range(dev, zone->addr, zone->size)) { | |
175 | kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &dev->dev); | |
176 | kvm_iodevice_destructor(&dev->dev); | |
5f94c174 | 177 | } |
5f94c174 | 178 | |
79fac95e | 179 | mutex_unlock(&kvm->slots_lock); |
5f94c174 LV |
180 | |
181 | return 0; | |
182 | } |