Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: 04d69cd7049b989100058dcb8d74ef6fb7c295e2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
/*
 * KVM coalesced MMIO
 *
 * Copyright (c) 2008 Bull S.A.S.
 *
 *  Author: Laurent Vivier <Laurent.Vivier@bull.net>
 *
 */

#include "iodev.h"

#include <linux/kvm_host.h>
#include <linux/kvm.h>

#include "coalesced_mmio.h"

static inline struct kvm_coalesced_mmio_dev *to_mmio(struct kvm_io_device *dev)
{
	return container_of(dev, struct kvm_coalesced_mmio_dev, dev);
}

static int coalesced_mmio_in_range(struct kvm_coalesced_mmio_dev *dev,
				   gpa_t addr, int len)
{
	struct kvm_coalesced_mmio_zone *zone;
	struct kvm_coalesced_mmio_ring *ring;
	unsigned avail;
	int i;

	/* Are we able to batch it ? */

	/* last is the first free entry
	 * check if we don't meet the first used entry
	 * there is always one unused entry in the buffer
	 */
	ring = dev->kvm->coalesced_mmio_ring;
	avail = (ring->first - ring->last - 1) % KVM_COALESCED_MMIO_MAX;
	if (avail < KVM_MAX_VCPUS) {
		/* full */
		return 0;
	}

	/* is it in a batchable area ? */

	for (i = 0; i < dev->nb_zones; i++) {
		zone = &dev->zone[i];

		/* (addr,len) is fully included in
		 * (zone->addr, zone->size)
		 */

		if (zone->addr <= addr &&
		    addr + len <= zone->addr + zone->size)
			return 1;
	}
	return 0;
}

static int coalesced_mmio_write(struct kvm_io_device *this,
				gpa_t addr, int len, const void *val)
{
	struct kvm_coalesced_mmio_dev *dev = to_mmio(this);
	struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring;
	if (!coalesced_mmio_in_range(dev, addr, len))
		return -EOPNOTSUPP;

	spin_lock(&dev->lock);

	/* copy data in first free entry of the ring */

	ring->coalesced_mmio[ring->last].phys_addr = addr;
	ring->coalesced_mmio[ring->last].len = len;
	memcpy(ring->coalesced_mmio[ring->last].data, val, len);
	smp_wmb();
	ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX;
	spin_unlock(&dev->lock);
	return 0;
}

static void coalesced_mmio_destructor(struct kvm_io_device *this)
{
	struct kvm_coalesced_mmio_dev *dev = to_mmio(this);

	kfree(dev);
}

static const struct kvm_io_device_ops coalesced_mmio_ops = {
	.write      = coalesced_mmio_write,
	.destructor = coalesced_mmio_destructor,
};

int kvm_coalesced_mmio_init(struct kvm *kvm)
{
	struct kvm_coalesced_mmio_dev *dev;
	int ret;

	dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL);
	if (!dev)
		return -ENOMEM;
	spin_lock_init(&dev->lock);
	kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops);
	dev->kvm = kvm;
	kvm->coalesced_mmio_dev = dev;

	ret = kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &dev->dev);
	if (ret < 0)
		kfree(dev);

	return ret;
}

int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
				         struct kvm_coalesced_mmio_zone *zone)
{
	struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev;

	if (dev == NULL)
		return -EINVAL;

	down_write(&kvm->slots_lock);
	if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) {
		up_write(&kvm->slots_lock);
		return -ENOBUFS;
	}

	dev->zone[dev->nb_zones] = *zone;
	dev->nb_zones++;

	up_write(&kvm->slots_lock);
	return 0;
}

int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
					   struct kvm_coalesced_mmio_zone *zone)
{
	int i;
	struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev;
	struct kvm_coalesced_mmio_zone *z;

	if (dev == NULL)
		return -EINVAL;

	down_write(&kvm->slots_lock);

	i = dev->nb_zones;
	while(i) {
		z = &dev->zone[i - 1];

		/* unregister all zones
		 * included in (zone->addr, zone->size)
		 */

		if (zone->addr <= z->addr &&
		    z->addr + z->size <= zone->addr + zone->size) {
			dev->nb_zones--;
			*z = dev->zone[dev->nb_zones];
		}
		i--;
	}

	up_write(&kvm->slots_lock);

	return 0;
}