Commit | Line | Data |
---|---|---|
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 | ||
5f94c174 LV |
22 | static int coalesced_mmio_in_range(struct kvm_io_device *this, |
23 | gpa_t addr, int len, int is_write) | |
24 | { | |
d76685c4 | 25 | struct kvm_coalesced_mmio_dev *dev = to_mmio(this); |
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 | ||
31 | if (!is_write) | |
32 | return 0; | |
33 | ||
34 | /* kvm->lock is taken by the caller and must be not released before | |
35 | * dev.read/write | |
36 | */ | |
37 | ||
38 | /* Are we able to batch it ? */ | |
39 | ||
40 | /* last is the first free entry | |
41 | * check if we don't meet the first used entry | |
42 | * there is always one unused entry in the buffer | |
43 | */ | |
105f8d40 AK |
44 | ring = dev->kvm->coalesced_mmio_ring; |
45 | avail = (ring->first - ring->last - 1) % KVM_COALESCED_MMIO_MAX; | |
46 | if (avail < 1) { | |
5f94c174 LV |
47 | /* full */ |
48 | return 0; | |
49 | } | |
50 | ||
51 | /* is it in a batchable area ? */ | |
52 | ||
53 | for (i = 0; i < dev->nb_zones; i++) { | |
54 | zone = &dev->zone[i]; | |
55 | ||
56 | /* (addr,len) is fully included in | |
57 | * (zone->addr, zone->size) | |
58 | */ | |
59 | ||
60 | if (zone->addr <= addr && | |
61 | addr + len <= zone->addr + zone->size) | |
62 | return 1; | |
63 | } | |
64 | return 0; | |
65 | } | |
66 | ||
67 | static void coalesced_mmio_write(struct kvm_io_device *this, | |
68 | gpa_t addr, int len, const void *val) | |
69 | { | |
d76685c4 | 70 | struct kvm_coalesced_mmio_dev *dev = to_mmio(this); |
5f94c174 LV |
71 | struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring; |
72 | ||
73 | /* kvm->lock must be taken by caller before call to in_range()*/ | |
74 | ||
75 | /* copy data in first free entry of the ring */ | |
76 | ||
77 | ring->coalesced_mmio[ring->last].phys_addr = addr; | |
78 | ring->coalesced_mmio[ring->last].len = len; | |
79 | memcpy(ring->coalesced_mmio[ring->last].data, val, len); | |
80 | smp_wmb(); | |
81 | ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX; | |
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 GH |
87 | |
88 | kfree(dev); | |
5f94c174 LV |
89 | } |
90 | ||
d76685c4 GH |
91 | static const struct kvm_io_device_ops coalesced_mmio_ops = { |
92 | .write = coalesced_mmio_write, | |
93 | .in_range = coalesced_mmio_in_range, | |
94 | .destructor = coalesced_mmio_destructor, | |
95 | }; | |
96 | ||
5f94c174 LV |
97 | int kvm_coalesced_mmio_init(struct kvm *kvm) |
98 | { | |
99 | struct kvm_coalesced_mmio_dev *dev; | |
100 | ||
101 | dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL); | |
102 | if (!dev) | |
103 | return -ENOMEM; | |
d76685c4 | 104 | kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops); |
5f94c174 LV |
105 | dev->kvm = kvm; |
106 | kvm->coalesced_mmio_dev = dev; | |
107 | kvm_io_bus_register_dev(&kvm->mmio_bus, &dev->dev); | |
108 | ||
109 | return 0; | |
110 | } | |
111 | ||
112 | int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm, | |
113 | struct kvm_coalesced_mmio_zone *zone) | |
114 | { | |
115 | struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev; | |
116 | ||
117 | if (dev == NULL) | |
118 | return -EINVAL; | |
119 | ||
120 | mutex_lock(&kvm->lock); | |
121 | if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) { | |
122 | mutex_unlock(&kvm->lock); | |
123 | return -ENOBUFS; | |
124 | } | |
125 | ||
126 | dev->zone[dev->nb_zones] = *zone; | |
127 | dev->nb_zones++; | |
128 | ||
129 | mutex_unlock(&kvm->lock); | |
130 | return 0; | |
131 | } | |
132 | ||
133 | int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm, | |
134 | struct kvm_coalesced_mmio_zone *zone) | |
135 | { | |
136 | int i; | |
137 | struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev; | |
138 | struct kvm_coalesced_mmio_zone *z; | |
139 | ||
140 | if (dev == NULL) | |
141 | return -EINVAL; | |
142 | ||
143 | mutex_lock(&kvm->lock); | |
144 | ||
145 | i = dev->nb_zones; | |
146 | while(i) { | |
147 | z = &dev->zone[i - 1]; | |
148 | ||
149 | /* unregister all zones | |
150 | * included in (zone->addr, zone->size) | |
151 | */ | |
152 | ||
153 | if (zone->addr <= z->addr && | |
154 | z->addr + z->size <= zone->addr + zone->size) { | |
155 | dev->nb_zones--; | |
156 | *z = dev->zone[dev->nb_zones]; | |
157 | } | |
158 | i--; | |
159 | } | |
160 | ||
161 | mutex_unlock(&kvm->lock); | |
162 | ||
163 | return 0; | |
164 | } |