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 | ||
af669ac6 | 11 | #include <kvm/iodev.h> |
5f94c174 LV |
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 | { |
2b3c246a SL |
27 | /* is it in a batchable area ? |
28 | * (addr,len) is fully included in | |
29 | * (zone->addr, zone->size) | |
30 | */ | |
1a214246 DC |
31 | if (len < 0) |
32 | return 0; | |
33 | if (addr + len < addr) | |
34 | return 0; | |
35 | if (addr < dev->zone.addr) | |
36 | return 0; | |
37 | if (addr + len > dev->zone.addr + dev->zone.size) | |
38 | return 0; | |
39 | return 1; | |
5f94c174 LV |
40 | } |
41 | ||
c298125f SL |
42 | static int coalesced_mmio_has_room(struct kvm_coalesced_mmio_dev *dev) |
43 | { | |
44 | struct kvm_coalesced_mmio_ring *ring; | |
45 | unsigned avail; | |
46 | ||
47 | /* Are we able to batch it ? */ | |
48 | ||
49 | /* last is the first free entry | |
50 | * check if we don't meet the first used entry | |
51 | * there is always one unused entry in the buffer | |
52 | */ | |
53 | ring = dev->kvm->coalesced_mmio_ring; | |
54 | avail = (ring->first - ring->last - 1) % KVM_COALESCED_MMIO_MAX; | |
55 | if (avail == 0) { | |
56 | /* full */ | |
57 | return 0; | |
58 | } | |
59 | ||
60 | return 1; | |
61 | } | |
62 | ||
e32edf4f NN |
63 | static int coalesced_mmio_write(struct kvm_vcpu *vcpu, |
64 | struct kvm_io_device *this, gpa_t addr, | |
65 | int len, const void *val) | |
5f94c174 | 66 | { |
d76685c4 | 67 | struct kvm_coalesced_mmio_dev *dev = to_mmio(this); |
5f94c174 | 68 | struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring; |
c298125f | 69 | |
bda9020e MT |
70 | if (!coalesced_mmio_in_range(dev, addr, len)) |
71 | return -EOPNOTSUPP; | |
5f94c174 | 72 | |
2b3c246a | 73 | spin_lock(&dev->kvm->ring_lock); |
5f94c174 | 74 | |
c298125f | 75 | if (!coalesced_mmio_has_room(dev)) { |
2b3c246a | 76 | spin_unlock(&dev->kvm->ring_lock); |
c298125f SL |
77 | return -EOPNOTSUPP; |
78 | } | |
79 | ||
5f94c174 LV |
80 | /* copy data in first free entry of the ring */ |
81 | ||
82 | ring->coalesced_mmio[ring->last].phys_addr = addr; | |
83 | ring->coalesced_mmio[ring->last].len = len; | |
84 | memcpy(ring->coalesced_mmio[ring->last].data, val, len); | |
85 | smp_wmb(); | |
86 | ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX; | |
2b3c246a | 87 | spin_unlock(&dev->kvm->ring_lock); |
bda9020e | 88 | return 0; |
5f94c174 LV |
89 | } |
90 | ||
91 | static void coalesced_mmio_destructor(struct kvm_io_device *this) | |
92 | { | |
d76685c4 | 93 | struct kvm_coalesced_mmio_dev *dev = to_mmio(this); |
787a660a | 94 | |
2b3c246a SL |
95 | list_del(&dev->list); |
96 | ||
787a660a | 97 | kfree(dev); |
5f94c174 LV |
98 | } |
99 | ||
d76685c4 GH |
100 | static const struct kvm_io_device_ops coalesced_mmio_ops = { |
101 | .write = coalesced_mmio_write, | |
d76685c4 GH |
102 | .destructor = coalesced_mmio_destructor, |
103 | }; | |
104 | ||
5f94c174 LV |
105 | int kvm_coalesced_mmio_init(struct kvm *kvm) |
106 | { | |
980da6ce | 107 | struct page *page; |
090b7aff | 108 | int ret; |
5f94c174 | 109 | |
980da6ce AK |
110 | ret = -ENOMEM; |
111 | page = alloc_page(GFP_KERNEL | __GFP_ZERO); | |
112 | if (!page) | |
113 | goto out_err; | |
980da6ce | 114 | |
2b3c246a SL |
115 | ret = 0; |
116 | kvm->coalesced_mmio_ring = page_address(page); | |
980da6ce | 117 | |
2b3c246a SL |
118 | /* |
119 | * We're using this spinlock to sync access to the coalesced ring. | |
120 | * The list doesn't need it's own lock since device registration and | |
121 | * unregistration should only happen when kvm->slots_lock is held. | |
122 | */ | |
123 | spin_lock_init(&kvm->ring_lock); | |
124 | INIT_LIST_HEAD(&kvm->coalesced_zones); | |
090b7aff | 125 | |
980da6ce | 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 | 138 | { |
2b3c246a SL |
139 | int ret; |
140 | struct kvm_coalesced_mmio_dev *dev; | |
5f94c174 | 141 | |
2b3c246a SL |
142 | dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL); |
143 | if (!dev) | |
144 | return -ENOMEM; | |
145 | ||
146 | kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops); | |
147 | dev->kvm = kvm; | |
148 | dev->zone = *zone; | |
5f94c174 | 149 | |
79fac95e | 150 | mutex_lock(&kvm->slots_lock); |
743eeb0b SL |
151 | ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, zone->addr, |
152 | zone->size, &dev->dev); | |
2b3c246a SL |
153 | if (ret < 0) |
154 | goto out_free_dev; | |
155 | list_add_tail(&dev->list, &kvm->coalesced_zones); | |
156 | mutex_unlock(&kvm->slots_lock); | |
5f94c174 | 157 | |
aac5c422 | 158 | return 0; |
5f94c174 | 159 | |
2b3c246a | 160 | out_free_dev: |
79fac95e | 161 | mutex_unlock(&kvm->slots_lock); |
2b3c246a SL |
162 | kfree(dev); |
163 | ||
aac5c422 | 164 | return ret; |
5f94c174 LV |
165 | } |
166 | ||
167 | int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm, | |
168 | struct kvm_coalesced_mmio_zone *zone) | |
169 | { | |
2b3c246a | 170 | struct kvm_coalesced_mmio_dev *dev, *tmp; |
5f94c174 | 171 | |
79fac95e | 172 | mutex_lock(&kvm->slots_lock); |
5f94c174 | 173 | |
2b3c246a SL |
174 | list_for_each_entry_safe(dev, tmp, &kvm->coalesced_zones, list) |
175 | if (coalesced_mmio_in_range(dev, zone->addr, zone->size)) { | |
176 | kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &dev->dev); | |
177 | kvm_iodevice_destructor(&dev->dev); | |
5f94c174 | 178 | } |
5f94c174 | 179 | |
79fac95e | 180 | mutex_unlock(&kvm->slots_lock); |
5f94c174 LV |
181 | |
182 | return 0; | |
183 | } |