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 | ||
17 | static int coalesced_mmio_in_range(struct kvm_io_device *this, | |
18 | gpa_t addr, int len, int is_write) | |
19 | { | |
20 | struct kvm_coalesced_mmio_dev *dev = | |
21 | (struct kvm_coalesced_mmio_dev*)this->private; | |
22 | struct kvm_coalesced_mmio_zone *zone; | |
23 | int next; | |
24 | int i; | |
25 | ||
26 | if (!is_write) | |
27 | return 0; | |
28 | ||
29 | /* kvm->lock is taken by the caller and must be not released before | |
30 | * dev.read/write | |
31 | */ | |
32 | ||
33 | /* Are we able to batch it ? */ | |
34 | ||
35 | /* last is the first free entry | |
36 | * check if we don't meet the first used entry | |
37 | * there is always one unused entry in the buffer | |
38 | */ | |
39 | ||
40 | next = (dev->kvm->coalesced_mmio_ring->last + 1) % | |
41 | KVM_COALESCED_MMIO_MAX; | |
42 | if (next == dev->kvm->coalesced_mmio_ring->first) { | |
43 | /* full */ | |
44 | return 0; | |
45 | } | |
46 | ||
47 | /* is it in a batchable area ? */ | |
48 | ||
49 | for (i = 0; i < dev->nb_zones; i++) { | |
50 | zone = &dev->zone[i]; | |
51 | ||
52 | /* (addr,len) is fully included in | |
53 | * (zone->addr, zone->size) | |
54 | */ | |
55 | ||
56 | if (zone->addr <= addr && | |
57 | addr + len <= zone->addr + zone->size) | |
58 | return 1; | |
59 | } | |
60 | return 0; | |
61 | } | |
62 | ||
63 | static void coalesced_mmio_write(struct kvm_io_device *this, | |
64 | gpa_t addr, int len, const void *val) | |
65 | { | |
66 | struct kvm_coalesced_mmio_dev *dev = | |
67 | (struct kvm_coalesced_mmio_dev*)this->private; | |
68 | struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring; | |
69 | ||
70 | /* kvm->lock must be taken by caller before call to in_range()*/ | |
71 | ||
72 | /* copy data in first free entry of the ring */ | |
73 | ||
74 | ring->coalesced_mmio[ring->last].phys_addr = addr; | |
75 | ring->coalesced_mmio[ring->last].len = len; | |
76 | memcpy(ring->coalesced_mmio[ring->last].data, val, len); | |
77 | smp_wmb(); | |
78 | ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX; | |
79 | } | |
80 | ||
81 | static void coalesced_mmio_destructor(struct kvm_io_device *this) | |
82 | { | |
83 | kfree(this); | |
84 | } | |
85 | ||
86 | int kvm_coalesced_mmio_init(struct kvm *kvm) | |
87 | { | |
88 | struct kvm_coalesced_mmio_dev *dev; | |
89 | ||
90 | dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL); | |
91 | if (!dev) | |
92 | return -ENOMEM; | |
93 | dev->dev.write = coalesced_mmio_write; | |
94 | dev->dev.in_range = coalesced_mmio_in_range; | |
95 | dev->dev.destructor = coalesced_mmio_destructor; | |
96 | dev->dev.private = dev; | |
97 | dev->kvm = kvm; | |
98 | kvm->coalesced_mmio_dev = dev; | |
99 | kvm_io_bus_register_dev(&kvm->mmio_bus, &dev->dev); | |
100 | ||
101 | return 0; | |
102 | } | |
103 | ||
104 | int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm, | |
105 | struct kvm_coalesced_mmio_zone *zone) | |
106 | { | |
107 | struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev; | |
108 | ||
109 | if (dev == NULL) | |
110 | return -EINVAL; | |
111 | ||
112 | mutex_lock(&kvm->lock); | |
113 | if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) { | |
114 | mutex_unlock(&kvm->lock); | |
115 | return -ENOBUFS; | |
116 | } | |
117 | ||
118 | dev->zone[dev->nb_zones] = *zone; | |
119 | dev->nb_zones++; | |
120 | ||
121 | mutex_unlock(&kvm->lock); | |
122 | return 0; | |
123 | } | |
124 | ||
125 | int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm, | |
126 | struct kvm_coalesced_mmio_zone *zone) | |
127 | { | |
128 | int i; | |
129 | struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev; | |
130 | struct kvm_coalesced_mmio_zone *z; | |
131 | ||
132 | if (dev == NULL) | |
133 | return -EINVAL; | |
134 | ||
135 | mutex_lock(&kvm->lock); | |
136 | ||
137 | i = dev->nb_zones; | |
138 | while(i) { | |
139 | z = &dev->zone[i - 1]; | |
140 | ||
141 | /* unregister all zones | |
142 | * included in (zone->addr, zone->size) | |
143 | */ | |
144 | ||
145 | if (zone->addr <= z->addr && | |
146 | z->addr + z->size <= zone->addr + zone->size) { | |
147 | dev->nb_zones--; | |
148 | *z = dev->zone[dev->nb_zones]; | |
149 | } | |
150 | i--; | |
151 | } | |
152 | ||
153 | mutex_unlock(&kvm->lock); | |
154 | ||
155 | return 0; | |
156 | } |