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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> | |
5a0e3ad6 | 13 | #include <linux/slab.h> |
5f94c174 LV |
14 | #include <linux/kvm.h> |
15 | ||
16 | #include "coalesced_mmio.h" | |
17 | ||
d76685c4 GH |
18 | static inline struct kvm_coalesced_mmio_dev *to_mmio(struct kvm_io_device *dev) |
19 | { | |
20 | return container_of(dev, struct kvm_coalesced_mmio_dev, dev); | |
21 | } | |
22 | ||
bda9020e MT |
23 | static int coalesced_mmio_in_range(struct kvm_coalesced_mmio_dev *dev, |
24 | gpa_t addr, int len) | |
5f94c174 | 25 | { |
5f94c174 | 26 | struct kvm_coalesced_mmio_zone *zone; |
105f8d40 AK |
27 | struct kvm_coalesced_mmio_ring *ring; |
28 | unsigned avail; | |
5f94c174 LV |
29 | int i; |
30 | ||
5f94c174 LV |
31 | /* Are we able to batch it ? */ |
32 | ||
33 | /* last is the first free entry | |
34 | * check if we don't meet the first used entry | |
35 | * there is always one unused entry in the buffer | |
36 | */ | |
105f8d40 AK |
37 | ring = dev->kvm->coalesced_mmio_ring; |
38 | avail = (ring->first - ring->last - 1) % KVM_COALESCED_MMIO_MAX; | |
64a2268d | 39 | if (avail < KVM_MAX_VCPUS) { |
5f94c174 LV |
40 | /* full */ |
41 | return 0; | |
42 | } | |
43 | ||
44 | /* is it in a batchable area ? */ | |
45 | ||
46 | for (i = 0; i < dev->nb_zones; i++) { | |
47 | zone = &dev->zone[i]; | |
48 | ||
49 | /* (addr,len) is fully included in | |
50 | * (zone->addr, zone->size) | |
51 | */ | |
52 | ||
53 | if (zone->addr <= addr && | |
54 | addr + len <= zone->addr + zone->size) | |
55 | return 1; | |
56 | } | |
57 | return 0; | |
58 | } | |
59 | ||
bda9020e MT |
60 | static int coalesced_mmio_write(struct kvm_io_device *this, |
61 | gpa_t addr, int len, const void *val) | |
5f94c174 | 62 | { |
d76685c4 | 63 | struct kvm_coalesced_mmio_dev *dev = to_mmio(this); |
5f94c174 | 64 | struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring; |
bda9020e MT |
65 | if (!coalesced_mmio_in_range(dev, addr, len)) |
66 | return -EOPNOTSUPP; | |
5f94c174 | 67 | |
64a2268d | 68 | spin_lock(&dev->lock); |
5f94c174 LV |
69 | |
70 | /* copy data in first free entry of the ring */ | |
71 | ||
72 | ring->coalesced_mmio[ring->last].phys_addr = addr; | |
73 | ring->coalesced_mmio[ring->last].len = len; | |
74 | memcpy(ring->coalesced_mmio[ring->last].data, val, len); | |
75 | smp_wmb(); | |
76 | ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX; | |
64a2268d | 77 | spin_unlock(&dev->lock); |
bda9020e | 78 | return 0; |
5f94c174 LV |
79 | } |
80 | ||
81 | static void coalesced_mmio_destructor(struct kvm_io_device *this) | |
82 | { | |
d76685c4 | 83 | struct kvm_coalesced_mmio_dev *dev = to_mmio(this); |
787a660a GH |
84 | |
85 | kfree(dev); | |
5f94c174 LV |
86 | } |
87 | ||
d76685c4 GH |
88 | static const struct kvm_io_device_ops coalesced_mmio_ops = { |
89 | .write = coalesced_mmio_write, | |
d76685c4 GH |
90 | .destructor = coalesced_mmio_destructor, |
91 | }; | |
92 | ||
5f94c174 LV |
93 | int kvm_coalesced_mmio_init(struct kvm *kvm) |
94 | { | |
95 | struct kvm_coalesced_mmio_dev *dev; | |
980da6ce | 96 | struct page *page; |
090b7aff | 97 | int ret; |
5f94c174 | 98 | |
980da6ce AK |
99 | ret = -ENOMEM; |
100 | page = alloc_page(GFP_KERNEL | __GFP_ZERO); | |
101 | if (!page) | |
102 | goto out_err; | |
103 | kvm->coalesced_mmio_ring = page_address(page); | |
104 | ||
105 | ret = -ENOMEM; | |
5f94c174 LV |
106 | dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL); |
107 | if (!dev) | |
980da6ce | 108 | goto out_free_page; |
64a2268d | 109 | spin_lock_init(&dev->lock); |
d76685c4 | 110 | kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops); |
5f94c174 LV |
111 | dev->kvm = kvm; |
112 | kvm->coalesced_mmio_dev = dev; | |
5f94c174 | 113 | |
79fac95e | 114 | mutex_lock(&kvm->slots_lock); |
e93f8a0f | 115 | ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, &dev->dev); |
79fac95e | 116 | mutex_unlock(&kvm->slots_lock); |
090b7aff | 117 | if (ret < 0) |
980da6ce AK |
118 | goto out_free_dev; |
119 | ||
120 | return ret; | |
090b7aff | 121 | |
980da6ce AK |
122 | out_free_dev: |
123 | kfree(dev); | |
124 | out_free_page: | |
125 | __free_page(page); | |
126 | out_err: | |
090b7aff | 127 | return ret; |
5f94c174 LV |
128 | } |
129 | ||
980da6ce AK |
130 | void kvm_coalesced_mmio_free(struct kvm *kvm) |
131 | { | |
132 | if (kvm->coalesced_mmio_ring) | |
133 | free_page((unsigned long)kvm->coalesced_mmio_ring); | |
134 | } | |
135 | ||
5f94c174 | 136 | int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm, |
43db6697 | 137 | struct kvm_coalesced_mmio_zone *zone) |
5f94c174 LV |
138 | { |
139 | struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev; | |
140 | ||
141 | if (dev == NULL) | |
142 | return -EINVAL; | |
143 | ||
79fac95e | 144 | mutex_lock(&kvm->slots_lock); |
5f94c174 | 145 | if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) { |
79fac95e | 146 | mutex_unlock(&kvm->slots_lock); |
5f94c174 LV |
147 | return -ENOBUFS; |
148 | } | |
149 | ||
150 | dev->zone[dev->nb_zones] = *zone; | |
151 | dev->nb_zones++; | |
152 | ||
79fac95e | 153 | mutex_unlock(&kvm->slots_lock); |
5f94c174 LV |
154 | return 0; |
155 | } | |
156 | ||
157 | int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm, | |
158 | struct kvm_coalesced_mmio_zone *zone) | |
159 | { | |
160 | int i; | |
161 | struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev; | |
162 | struct kvm_coalesced_mmio_zone *z; | |
163 | ||
164 | if (dev == NULL) | |
165 | return -EINVAL; | |
166 | ||
79fac95e | 167 | mutex_lock(&kvm->slots_lock); |
5f94c174 LV |
168 | |
169 | i = dev->nb_zones; | |
43db6697 | 170 | while (i) { |
5f94c174 LV |
171 | z = &dev->zone[i - 1]; |
172 | ||
173 | /* unregister all zones | |
174 | * included in (zone->addr, zone->size) | |
175 | */ | |
176 | ||
177 | if (zone->addr <= z->addr && | |
178 | z->addr + z->size <= zone->addr + zone->size) { | |
179 | dev->nb_zones--; | |
180 | *z = dev->zone[dev->nb_zones]; | |
181 | } | |
182 | i--; | |
183 | } | |
184 | ||
79fac95e | 185 | mutex_unlock(&kvm->slots_lock); |
5f94c174 LV |
186 | |
187 | return 0; | |
188 | } |