blob: a6ec206f36ba2f16f43c90680535ff6bcc45d56f [file] [log] [blame]
Laurent Vivier5f94c172008-05-30 16:05:54 +02001/*
2 * KVM coalesced MMIO
3 *
4 * Copyright (c) 2008 Bull S.A.S.
Avi Kivity221d0592010-05-23 18:37:00 +03005 * Copyright 2009 Red Hat, Inc. and/or its affiliates.
Laurent Vivier5f94c172008-05-30 16:05:54 +02006 *
7 * Author: Laurent Vivier <Laurent.Vivier@bull.net>
8 *
9 */
10
11#include "iodev.h"
12
13#include <linux/kvm_host.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/slab.h>
Laurent Vivier5f94c172008-05-30 16:05:54 +020015#include <linux/kvm.h>
16
17#include "coalesced_mmio.h"
18
Gregory Haskinsd76685c2009-06-01 12:54:50 -040019static 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
Michael S. Tsirkinbda90202009-06-29 22:24:32 +030024static int coalesced_mmio_in_range(struct kvm_coalesced_mmio_dev *dev,
25 gpa_t addr, int len)
Laurent Vivier5f94c172008-05-30 16:05:54 +020026{
Sasha Levin2b3c2462011-07-20 20:59:00 +030027 /* is it in a batchable area ?
28 * (addr,len) is fully included in
29 * (zone->addr, zone->size)
30 */
Laurent Vivier5f94c172008-05-30 16:05:54 +020031
Sasha Levin2b3c2462011-07-20 20:59:00 +030032 return (dev->zone.addr <= addr &&
33 addr + len <= dev->zone.addr + dev->zone.size);
Laurent Vivier5f94c172008-05-30 16:05:54 +020034}
35
Sasha Levinc2981252011-07-18 17:17:14 +030036static int coalesced_mmio_has_room(struct kvm_coalesced_mmio_dev *dev)
37{
38 struct kvm_coalesced_mmio_ring *ring;
39 unsigned avail;
40
41 /* Are we able to batch it ? */
42
43 /* last is the first free entry
44 * check if we don't meet the first used entry
45 * there is always one unused entry in the buffer
46 */
47 ring = dev->kvm->coalesced_mmio_ring;
48 avail = (ring->first - ring->last - 1) % KVM_COALESCED_MMIO_MAX;
49 if (avail == 0) {
50 /* full */
51 return 0;
52 }
53
54 return 1;
55}
56
Michael S. Tsirkinbda90202009-06-29 22:24:32 +030057static int coalesced_mmio_write(struct kvm_io_device *this,
58 gpa_t addr, int len, const void *val)
Laurent Vivier5f94c172008-05-30 16:05:54 +020059{
Gregory Haskinsd76685c2009-06-01 12:54:50 -040060 struct kvm_coalesced_mmio_dev *dev = to_mmio(this);
Laurent Vivier5f94c172008-05-30 16:05:54 +020061 struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring;
Sasha Levinc2981252011-07-18 17:17:14 +030062
Michael S. Tsirkinbda90202009-06-29 22:24:32 +030063 if (!coalesced_mmio_in_range(dev, addr, len))
64 return -EOPNOTSUPP;
Laurent Vivier5f94c172008-05-30 16:05:54 +020065
Sasha Levin2b3c2462011-07-20 20:59:00 +030066 spin_lock(&dev->kvm->ring_lock);
Laurent Vivier5f94c172008-05-30 16:05:54 +020067
Sasha Levinc2981252011-07-18 17:17:14 +030068 if (!coalesced_mmio_has_room(dev)) {
Sasha Levin2b3c2462011-07-20 20:59:00 +030069 spin_unlock(&dev->kvm->ring_lock);
Sasha Levinc2981252011-07-18 17:17:14 +030070 return -EOPNOTSUPP;
71 }
72
Laurent Vivier5f94c172008-05-30 16:05:54 +020073 /* copy data in first free entry of the ring */
74
75 ring->coalesced_mmio[ring->last].phys_addr = addr;
76 ring->coalesced_mmio[ring->last].len = len;
77 memcpy(ring->coalesced_mmio[ring->last].data, val, len);
78 smp_wmb();
79 ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX;
Sasha Levin2b3c2462011-07-20 20:59:00 +030080 spin_unlock(&dev->kvm->ring_lock);
Michael S. Tsirkinbda90202009-06-29 22:24:32 +030081 return 0;
Laurent Vivier5f94c172008-05-30 16:05:54 +020082}
83
84static void coalesced_mmio_destructor(struct kvm_io_device *this)
85{
Gregory Haskinsd76685c2009-06-01 12:54:50 -040086 struct kvm_coalesced_mmio_dev *dev = to_mmio(this);
Gregory Haskins787a6602009-06-01 12:54:45 -040087
Sasha Levin2b3c2462011-07-20 20:59:00 +030088 list_del(&dev->list);
89
Gregory Haskins787a6602009-06-01 12:54:45 -040090 kfree(dev);
Laurent Vivier5f94c172008-05-30 16:05:54 +020091}
92
Gregory Haskinsd76685c2009-06-01 12:54:50 -040093static const struct kvm_io_device_ops coalesced_mmio_ops = {
94 .write = coalesced_mmio_write,
Gregory Haskinsd76685c2009-06-01 12:54:50 -040095 .destructor = coalesced_mmio_destructor,
96};
97
Laurent Vivier5f94c172008-05-30 16:05:54 +020098int kvm_coalesced_mmio_init(struct kvm *kvm)
99{
Avi Kivity980da6c2009-12-20 15:13:43 +0200100 struct page *page;
Gregory Haskins090b7af2009-07-07 17:08:44 -0400101 int ret;
Laurent Vivier5f94c172008-05-30 16:05:54 +0200102
Avi Kivity980da6c2009-12-20 15:13:43 +0200103 ret = -ENOMEM;
104 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
105 if (!page)
106 goto out_err;
Sasha Levin2b3c2462011-07-20 20:59:00 +0300107
108 ret = 0;
Avi Kivity980da6c2009-12-20 15:13:43 +0200109 kvm->coalesced_mmio_ring = page_address(page);
110
Sasha Levin2b3c2462011-07-20 20:59:00 +0300111 /*
112 * We're using this spinlock to sync access to the coalesced ring.
113 * The list doesn't need it's own lock since device registration and
114 * unregistration should only happen when kvm->slots_lock is held.
115 */
116 spin_lock_init(&kvm->ring_lock);
117 INIT_LIST_HEAD(&kvm->coalesced_zones);
Laurent Vivier5f94c172008-05-30 16:05:54 +0200118
Avi Kivity980da6c2009-12-20 15:13:43 +0200119out_err:
120 return ret;
121}
122
123void kvm_coalesced_mmio_free(struct kvm *kvm)
124{
125 if (kvm->coalesced_mmio_ring)
126 free_page((unsigned long)kvm->coalesced_mmio_ring);
Laurent Vivier5f94c172008-05-30 16:05:54 +0200127}
128
129int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
Jochen Maes43db6692010-02-08 11:29:33 +0100130 struct kvm_coalesced_mmio_zone *zone)
Laurent Vivier5f94c172008-05-30 16:05:54 +0200131{
Sasha Levin2b3c2462011-07-20 20:59:00 +0300132 int ret;
133 struct kvm_coalesced_mmio_dev *dev;
134
135 dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL);
136 if (!dev)
137 return -ENOMEM;
138
139 kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops);
140 dev->kvm = kvm;
141 dev->zone = *zone;
142
143 mutex_lock(&kvm->slots_lock);
Sasha Levin743eeb02011-07-27 16:00:48 +0300144 ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, zone->addr,
145 zone->size, &dev->dev);
Sasha Levin2b3c2462011-07-20 20:59:00 +0300146 if (ret < 0)
147 goto out_free_dev;
148 list_add_tail(&dev->list, &kvm->coalesced_zones);
149 mutex_unlock(&kvm->slots_lock);
150
151 return ret;
152
153out_free_dev:
154 mutex_unlock(&kvm->slots_lock);
155
156 kfree(dev);
Laurent Vivier5f94c172008-05-30 16:05:54 +0200157
158 if (dev == NULL)
Wei Yongjuna87fa352010-03-12 12:59:06 +0800159 return -ENXIO;
Laurent Vivier5f94c172008-05-30 16:05:54 +0200160
Laurent Vivier5f94c172008-05-30 16:05:54 +0200161 return 0;
162}
163
164int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
165 struct kvm_coalesced_mmio_zone *zone)
166{
Sasha Levin2b3c2462011-07-20 20:59:00 +0300167 struct kvm_coalesced_mmio_dev *dev, *tmp;
Laurent Vivier5f94c172008-05-30 16:05:54 +0200168
Marcelo Tosatti79fac952009-12-23 14:35:26 -0200169 mutex_lock(&kvm->slots_lock);
Laurent Vivier5f94c172008-05-30 16:05:54 +0200170
Sasha Levin2b3c2462011-07-20 20:59:00 +0300171 list_for_each_entry_safe(dev, tmp, &kvm->coalesced_zones, list)
172 if (coalesced_mmio_in_range(dev, zone->addr, zone->size)) {
173 kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &dev->dev);
174 kvm_iodevice_destructor(&dev->dev);
Laurent Vivier5f94c172008-05-30 16:05:54 +0200175 }
Laurent Vivier5f94c172008-05-30 16:05:54 +0200176
Marcelo Tosatti79fac952009-12-23 14:35:26 -0200177 mutex_unlock(&kvm->slots_lock);
Laurent Vivier5f94c172008-05-30 16:05:54 +0200178
179 return 0;
180}