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