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Commit | Line | Data |
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5f94c174 LV |
1 | /* |
2 | * KVM coalesced MMIO | |
3 | * | |
4 | * Copyright (c) 2008 Bull S.A.S. | |
5 | * | |
6 | * Author: Laurent Vivier <Laurent.Vivier@bull.net> | |
7 | * | |
8 | */ | |
9 | ||
10 | #include "iodev.h" | |
11 | ||
12 | #include <linux/kvm_host.h> | |
13 | #include <linux/kvm.h> | |
14 | ||
15 | #include "coalesced_mmio.h" | |
16 | ||
d76685c4 GH |
17 | static inline struct kvm_coalesced_mmio_dev *to_mmio(struct kvm_io_device *dev) |
18 | { | |
19 | return container_of(dev, struct kvm_coalesced_mmio_dev, dev); | |
20 | } | |
21 | ||
bda9020e MT |
22 | static int coalesced_mmio_in_range(struct kvm_coalesced_mmio_dev *dev, |
23 | gpa_t addr, int len) | |
5f94c174 | 24 | { |
5f94c174 | 25 | struct kvm_coalesced_mmio_zone *zone; |
105f8d40 AK |
26 | struct kvm_coalesced_mmio_ring *ring; |
27 | unsigned avail; | |
5f94c174 LV |
28 | int i; |
29 | ||
5f94c174 LV |
30 | /* Are we able to batch it ? */ |
31 | ||
32 | /* last is the first free entry | |
33 | * check if we don't meet the first used entry | |
34 | * there is always one unused entry in the buffer | |
35 | */ | |
105f8d40 AK |
36 | ring = dev->kvm->coalesced_mmio_ring; |
37 | avail = (ring->first - ring->last - 1) % KVM_COALESCED_MMIO_MAX; | |
64a2268d | 38 | if (avail < KVM_MAX_VCPUS) { |
5f94c174 LV |
39 | /* full */ |
40 | return 0; | |
41 | } | |
42 | ||
43 | /* is it in a batchable area ? */ | |
44 | ||
45 | for (i = 0; i < dev->nb_zones; i++) { | |
46 | zone = &dev->zone[i]; | |
47 | ||
48 | /* (addr,len) is fully included in | |
49 | * (zone->addr, zone->size) | |
50 | */ | |
51 | ||
52 | if (zone->addr <= addr && | |
53 | addr + len <= zone->addr + zone->size) | |
54 | return 1; | |
55 | } | |
56 | return 0; | |
57 | } | |
58 | ||
bda9020e MT |
59 | static int coalesced_mmio_write(struct kvm_io_device *this, |
60 | gpa_t addr, int len, const void *val) | |
5f94c174 | 61 | { |
d76685c4 | 62 | struct kvm_coalesced_mmio_dev *dev = to_mmio(this); |
5f94c174 | 63 | struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring; |
bda9020e MT |
64 | if (!coalesced_mmio_in_range(dev, addr, len)) |
65 | return -EOPNOTSUPP; | |
5f94c174 | 66 | |
64a2268d | 67 | spin_lock(&dev->lock); |
5f94c174 LV |
68 | |
69 | /* copy data in first free entry of the ring */ | |
70 | ||
71 | ring->coalesced_mmio[ring->last].phys_addr = addr; | |
72 | ring->coalesced_mmio[ring->last].len = len; | |
73 | memcpy(ring->coalesced_mmio[ring->last].data, val, len); | |
74 | smp_wmb(); | |
75 | ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX; | |
64a2268d | 76 | spin_unlock(&dev->lock); |
bda9020e | 77 | return 0; |
5f94c174 LV |
78 | } |
79 | ||
80 | static void coalesced_mmio_destructor(struct kvm_io_device *this) | |
81 | { | |
d76685c4 | 82 | struct kvm_coalesced_mmio_dev *dev = to_mmio(this); |
787a660a GH |
83 | |
84 | kfree(dev); | |
5f94c174 LV |
85 | } |
86 | ||
d76685c4 GH |
87 | static const struct kvm_io_device_ops coalesced_mmio_ops = { |
88 | .write = coalesced_mmio_write, | |
d76685c4 GH |
89 | .destructor = coalesced_mmio_destructor, |
90 | }; | |
91 | ||
5f94c174 LV |
92 | int kvm_coalesced_mmio_init(struct kvm *kvm) |
93 | { | |
94 | struct kvm_coalesced_mmio_dev *dev; | |
980da6ce | 95 | struct page *page; |
090b7aff | 96 | int ret; |
5f94c174 | 97 | |
980da6ce AK |
98 | ret = -ENOMEM; |
99 | page = alloc_page(GFP_KERNEL | __GFP_ZERO); | |
100 | if (!page) | |
101 | goto out_err; | |
102 | kvm->coalesced_mmio_ring = page_address(page); | |
103 | ||
104 | ret = -ENOMEM; | |
5f94c174 LV |
105 | dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL); |
106 | if (!dev) | |
980da6ce | 107 | goto out_free_page; |
64a2268d | 108 | spin_lock_init(&dev->lock); |
d76685c4 | 109 | kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops); |
5f94c174 LV |
110 | dev->kvm = kvm; |
111 | kvm->coalesced_mmio_dev = dev; | |
5f94c174 | 112 | |
e93f8a0f MT |
113 | down_write(&kvm->slots_lock); |
114 | ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, &dev->dev); | |
115 | up_write(&kvm->slots_lock); | |
090b7aff | 116 | if (ret < 0) |
980da6ce AK |
117 | goto out_free_dev; |
118 | ||
119 | return ret; | |
090b7aff | 120 | |
980da6ce AK |
121 | out_free_dev: |
122 | kfree(dev); | |
123 | out_free_page: | |
124 | __free_page(page); | |
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 LV |
135 | int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm, |
136 | struct kvm_coalesced_mmio_zone *zone) | |
137 | { | |
138 | struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev; | |
139 | ||
140 | if (dev == NULL) | |
141 | return -EINVAL; | |
142 | ||
d5c2dcc3 | 143 | down_write(&kvm->slots_lock); |
5f94c174 | 144 | if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) { |
d5c2dcc3 | 145 | up_write(&kvm->slots_lock); |
5f94c174 LV |
146 | return -ENOBUFS; |
147 | } | |
148 | ||
149 | dev->zone[dev->nb_zones] = *zone; | |
150 | dev->nb_zones++; | |
151 | ||
d5c2dcc3 | 152 | up_write(&kvm->slots_lock); |
5f94c174 LV |
153 | return 0; |
154 | } | |
155 | ||
156 | int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm, | |
157 | struct kvm_coalesced_mmio_zone *zone) | |
158 | { | |
159 | int i; | |
160 | struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev; | |
161 | struct kvm_coalesced_mmio_zone *z; | |
162 | ||
163 | if (dev == NULL) | |
164 | return -EINVAL; | |
165 | ||
d5c2dcc3 | 166 | down_write(&kvm->slots_lock); |
5f94c174 LV |
167 | |
168 | i = dev->nb_zones; | |
169 | while(i) { | |
170 | z = &dev->zone[i - 1]; | |
171 | ||
172 | /* unregister all zones | |
173 | * included in (zone->addr, zone->size) | |
174 | */ | |
175 | ||
176 | if (zone->addr <= z->addr && | |
177 | z->addr + z->size <= zone->addr + zone->size) { | |
178 | dev->nb_zones--; | |
179 | *z = dev->zone[dev->nb_zones]; | |
180 | } | |
181 | i--; | |
182 | } | |
183 | ||
d5c2dcc3 | 184 | up_write(&kvm->slots_lock); |
5f94c174 LV |
185 | |
186 | return 0; | |
187 | } |