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 | { |
5f94c174 | 27 | struct kvm_coalesced_mmio_zone *zone; |
105f8d40 AK |
28 | struct kvm_coalesced_mmio_ring *ring; |
29 | unsigned avail; | |
5f94c174 LV |
30 | int i; |
31 | ||
5f94c174 LV |
32 | /* Are we able to batch it ? */ |
33 | ||
34 | /* last is the first free entry | |
35 | * check if we don't meet the first used entry | |
36 | * there is always one unused entry in the buffer | |
37 | */ | |
105f8d40 AK |
38 | ring = dev->kvm->coalesced_mmio_ring; |
39 | avail = (ring->first - ring->last - 1) % KVM_COALESCED_MMIO_MAX; | |
64a2268d | 40 | if (avail < KVM_MAX_VCPUS) { |
5f94c174 LV |
41 | /* full */ |
42 | return 0; | |
43 | } | |
44 | ||
45 | /* is it in a batchable area ? */ | |
46 | ||
47 | for (i = 0; i < dev->nb_zones; i++) { | |
48 | zone = &dev->zone[i]; | |
49 | ||
50 | /* (addr,len) is fully included in | |
51 | * (zone->addr, zone->size) | |
52 | */ | |
53 | ||
54 | if (zone->addr <= addr && | |
55 | addr + len <= zone->addr + zone->size) | |
56 | return 1; | |
57 | } | |
58 | return 0; | |
59 | } | |
60 | ||
bda9020e MT |
61 | static int coalesced_mmio_write(struct kvm_io_device *this, |
62 | gpa_t addr, int len, const void *val) | |
5f94c174 | 63 | { |
d76685c4 | 64 | struct kvm_coalesced_mmio_dev *dev = to_mmio(this); |
5f94c174 | 65 | struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring; |
bda9020e MT |
66 | if (!coalesced_mmio_in_range(dev, addr, len)) |
67 | return -EOPNOTSUPP; | |
5f94c174 | 68 | |
64a2268d | 69 | spin_lock(&dev->lock); |
5f94c174 LV |
70 | |
71 | /* copy data in first free entry of the ring */ | |
72 | ||
73 | ring->coalesced_mmio[ring->last].phys_addr = addr; | |
74 | ring->coalesced_mmio[ring->last].len = len; | |
75 | memcpy(ring->coalesced_mmio[ring->last].data, val, len); | |
76 | smp_wmb(); | |
77 | ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX; | |
64a2268d | 78 | spin_unlock(&dev->lock); |
bda9020e | 79 | return 0; |
5f94c174 LV |
80 | } |
81 | ||
82 | static void coalesced_mmio_destructor(struct kvm_io_device *this) | |
83 | { | |
d76685c4 | 84 | struct kvm_coalesced_mmio_dev *dev = to_mmio(this); |
787a660a GH |
85 | |
86 | kfree(dev); | |
5f94c174 LV |
87 | } |
88 | ||
d76685c4 GH |
89 | static const struct kvm_io_device_ops coalesced_mmio_ops = { |
90 | .write = coalesced_mmio_write, | |
d76685c4 GH |
91 | .destructor = coalesced_mmio_destructor, |
92 | }; | |
93 | ||
5f94c174 LV |
94 | int kvm_coalesced_mmio_init(struct kvm *kvm) |
95 | { | |
96 | struct kvm_coalesced_mmio_dev *dev; | |
980da6ce | 97 | struct page *page; |
090b7aff | 98 | int ret; |
5f94c174 | 99 | |
980da6ce AK |
100 | ret = -ENOMEM; |
101 | page = alloc_page(GFP_KERNEL | __GFP_ZERO); | |
102 | if (!page) | |
103 | goto out_err; | |
104 | kvm->coalesced_mmio_ring = page_address(page); | |
105 | ||
106 | ret = -ENOMEM; | |
5f94c174 LV |
107 | dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL); |
108 | if (!dev) | |
980da6ce | 109 | goto out_free_page; |
64a2268d | 110 | spin_lock_init(&dev->lock); |
d76685c4 | 111 | kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops); |
5f94c174 LV |
112 | dev->kvm = kvm; |
113 | kvm->coalesced_mmio_dev = dev; | |
5f94c174 | 114 | |
79fac95e | 115 | mutex_lock(&kvm->slots_lock); |
e93f8a0f | 116 | ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, &dev->dev); |
79fac95e | 117 | mutex_unlock(&kvm->slots_lock); |
090b7aff | 118 | if (ret < 0) |
980da6ce AK |
119 | goto out_free_dev; |
120 | ||
121 | return ret; | |
090b7aff | 122 | |
980da6ce | 123 | out_free_dev: |
6ce5a090 | 124 | kvm->coalesced_mmio_dev = NULL; |
980da6ce AK |
125 | kfree(dev); |
126 | out_free_page: | |
6ce5a090 | 127 | kvm->coalesced_mmio_ring = NULL; |
980da6ce AK |
128 | __free_page(page); |
129 | out_err: | |
090b7aff | 130 | return ret; |
5f94c174 LV |
131 | } |
132 | ||
980da6ce AK |
133 | void kvm_coalesced_mmio_free(struct kvm *kvm) |
134 | { | |
135 | if (kvm->coalesced_mmio_ring) | |
136 | free_page((unsigned long)kvm->coalesced_mmio_ring); | |
137 | } | |
138 | ||
5f94c174 | 139 | int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm, |
43db6697 | 140 | struct kvm_coalesced_mmio_zone *zone) |
5f94c174 LV |
141 | { |
142 | struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev; | |
143 | ||
144 | if (dev == NULL) | |
a87fa355 | 145 | return -ENXIO; |
5f94c174 | 146 | |
79fac95e | 147 | mutex_lock(&kvm->slots_lock); |
5f94c174 | 148 | if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) { |
79fac95e | 149 | mutex_unlock(&kvm->slots_lock); |
5f94c174 LV |
150 | return -ENOBUFS; |
151 | } | |
152 | ||
153 | dev->zone[dev->nb_zones] = *zone; | |
154 | dev->nb_zones++; | |
155 | ||
79fac95e | 156 | mutex_unlock(&kvm->slots_lock); |
5f94c174 LV |
157 | return 0; |
158 | } | |
159 | ||
160 | int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm, | |
161 | struct kvm_coalesced_mmio_zone *zone) | |
162 | { | |
163 | int i; | |
164 | struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev; | |
165 | struct kvm_coalesced_mmio_zone *z; | |
166 | ||
167 | if (dev == NULL) | |
a87fa355 | 168 | return -ENXIO; |
5f94c174 | 169 | |
79fac95e | 170 | mutex_lock(&kvm->slots_lock); |
5f94c174 LV |
171 | |
172 | i = dev->nb_zones; | |
43db6697 | 173 | while (i) { |
5f94c174 LV |
174 | z = &dev->zone[i - 1]; |
175 | ||
176 | /* unregister all zones | |
177 | * included in (zone->addr, zone->size) | |
178 | */ | |
179 | ||
180 | if (zone->addr <= z->addr && | |
181 | z->addr + z->size <= zone->addr + zone->size) { | |
182 | dev->nb_zones--; | |
183 | *z = dev->zone[dev->nb_zones]; | |
184 | } | |
185 | i--; | |
186 | } | |
187 | ||
79fac95e | 188 | mutex_unlock(&kvm->slots_lock); |
5f94c174 LV |
189 | |
190 | return 0; | |
191 | } |