KVM: do not treat noslot pfn as a error pfn
[deliverable/linux.git] / virt / kvm / iommu.c
CommitLineData
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1/*
2 * Copyright (c) 2006, Intel Corporation.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15 * Place - Suite 330, Boston, MA 02111-1307 USA.
16 *
17 * Copyright (C) 2006-2008 Intel Corporation
18 * Copyright IBM Corporation, 2008
221d059d
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19 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
20 *
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21 * Author: Allen M. Kay <allen.m.kay@intel.com>
22 * Author: Weidong Han <weidong.han@intel.com>
23 * Author: Ben-Ami Yassour <benami@il.ibm.com>
24 */
25
26#include <linux/list.h>
27#include <linux/kvm_host.h>
51441d43 28#include <linux/module.h>
62c476c7 29#include <linux/pci.h>
799fd8b2 30#include <linux/stat.h>
62c476c7 31#include <linux/dmar.h>
19de40a8 32#include <linux/iommu.h>
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33#include <linux/intel-iommu.h>
34
90ab5ee9 35static bool allow_unsafe_assigned_interrupts;
3f68b031
AW
36module_param_named(allow_unsafe_assigned_interrupts,
37 allow_unsafe_assigned_interrupts, bool, S_IRUGO | S_IWUSR);
38MODULE_PARM_DESC(allow_unsafe_assigned_interrupts,
39 "Enable device assignment on platforms without interrupt remapping support.");
40
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41static int kvm_iommu_unmap_memslots(struct kvm *kvm);
42static void kvm_iommu_put_pages(struct kvm *kvm,
43 gfn_t base_gfn, unsigned long npages);
44
d5661048
XG
45static pfn_t kvm_pin_pages(struct kvm_memory_slot *slot, gfn_t gfn,
46 unsigned long size)
fcd95807
JR
47{
48 gfn_t end_gfn;
49 pfn_t pfn;
50
d5661048 51 pfn = gfn_to_pfn_memslot(slot, gfn);
fcd95807
JR
52 end_gfn = gfn + (size >> PAGE_SHIFT);
53 gfn += 1;
54
81c52c56 55 if (is_error_noslot_pfn(pfn))
fcd95807
JR
56 return pfn;
57
58 while (gfn < end_gfn)
d5661048 59 gfn_to_pfn_memslot(slot, gfn++);
fcd95807
JR
60
61 return pfn;
62}
63
3ad26d81 64int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
62c476c7 65{
fcd95807 66 gfn_t gfn, end_gfn;
62c476c7 67 pfn_t pfn;
fcd95807 68 int r = 0;
19de40a8 69 struct iommu_domain *domain = kvm->arch.iommu_domain;
522c68c4 70 int flags;
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71
72 /* check if iommu exists and in use */
73 if (!domain)
74 return 0;
75
fcd95807
JR
76 gfn = slot->base_gfn;
77 end_gfn = gfn + slot->npages;
78
522c68c4
SY
79 flags = IOMMU_READ | IOMMU_WRITE;
80 if (kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY)
81 flags |= IOMMU_CACHE;
82
fcd95807
JR
83
84 while (gfn < end_gfn) {
85 unsigned long page_size;
86
87 /* Check if already mapped */
88 if (iommu_iova_to_phys(domain, gfn_to_gpa(gfn))) {
89 gfn += 1;
90 continue;
91 }
92
93 /* Get the page size we could use to map */
94 page_size = kvm_host_page_size(kvm, gfn);
95
96 /* Make sure the page_size does not exceed the memslot */
97 while ((gfn + (page_size >> PAGE_SHIFT)) > end_gfn)
98 page_size >>= 1;
99
100 /* Make sure gfn is aligned to the page size we want to map */
101 while ((gfn << PAGE_SHIFT) & (page_size - 1))
102 page_size >>= 1;
103
104 /*
105 * Pin all pages we are about to map in memory. This is
106 * important because we unmap and unpin in 4kb steps later.
107 */
d5661048 108 pfn = kvm_pin_pages(slot, gfn, page_size);
81c52c56 109 if (is_error_noslot_pfn(pfn)) {
fcd95807 110 gfn += 1;
62c476c7 111 continue;
fcd95807 112 }
62c476c7 113
fcd95807
JR
114 /* Map into IO address space */
115 r = iommu_map(domain, gfn_to_gpa(gfn), pfn_to_hpa(pfn),
7d3002cc 116 page_size, flags);
e5fcfc82 117 if (r) {
260782bc 118 printk(KERN_ERR "kvm_iommu_map_address:"
5689cc53 119 "iommu failed to map pfn=%llx\n", pfn);
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120 goto unmap_pages;
121 }
fcd95807
JR
122
123 gfn += page_size >> PAGE_SHIFT;
124
125
62c476c7 126 }
fcd95807 127
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128 return 0;
129
130unmap_pages:
fcd95807 131 kvm_iommu_put_pages(kvm, slot->base_gfn, gfn);
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132 return r;
133}
134
135static int kvm_iommu_map_memslots(struct kvm *kvm)
136{
be6ba0f0 137 int idx, r = 0;
46a26bf5 138 struct kvm_memslots *slots;
be6ba0f0 139 struct kvm_memory_slot *memslot;
62c476c7 140
95c87e2b 141 idx = srcu_read_lock(&kvm->srcu);
90d83dc3 142 slots = kvm_memslots(kvm);
46a26bf5 143
be6ba0f0
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144 kvm_for_each_memslot(memslot, slots) {
145 r = kvm_iommu_map_pages(kvm, memslot);
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146 if (r)
147 break;
148 }
95c87e2b 149 srcu_read_unlock(&kvm->srcu, idx);
682edb4c 150
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151 return r;
152}
153
260782bc
WH
154int kvm_assign_device(struct kvm *kvm,
155 struct kvm_assigned_dev_kernel *assigned_dev)
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156{
157 struct pci_dev *pdev = NULL;
19de40a8 158 struct iommu_domain *domain = kvm->arch.iommu_domain;
522c68c4 159 int r, last_flags;
62c476c7 160
260782bc
WH
161 /* check if iommu exists and in use */
162 if (!domain)
163 return 0;
164
165 pdev = assigned_dev->dev;
166 if (pdev == NULL)
62c476c7 167 return -ENODEV;
260782bc 168
19de40a8 169 r = iommu_attach_device(domain, &pdev->dev);
260782bc 170 if (r) {
d151f63f 171 dev_err(&pdev->dev, "kvm assign device failed ret %d", r);
260782bc 172 return r;
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173 }
174
522c68c4
SY
175 last_flags = kvm->arch.iommu_flags;
176 if (iommu_domain_has_cap(kvm->arch.iommu_domain,
177 IOMMU_CAP_CACHE_COHERENCY))
178 kvm->arch.iommu_flags |= KVM_IOMMU_CACHE_COHERENCY;
179
180 /* Check if need to update IOMMU page table for guest memory */
181 if ((last_flags ^ kvm->arch.iommu_flags) ==
182 KVM_IOMMU_CACHE_COHERENCY) {
183 kvm_iommu_unmap_memslots(kvm);
184 r = kvm_iommu_map_memslots(kvm);
185 if (r)
186 goto out_unmap;
187 }
188
6777829c
GR
189 pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
190
ab9f4ecb
ZE
191 printk(KERN_DEBUG "assign device %x:%x:%x.%x\n",
192 assigned_dev->host_segnr,
260782bc
WH
193 assigned_dev->host_busnr,
194 PCI_SLOT(assigned_dev->host_devfn),
195 PCI_FUNC(assigned_dev->host_devfn));
62c476c7 196
260782bc 197 return 0;
522c68c4
SY
198out_unmap:
199 kvm_iommu_unmap_memslots(kvm);
200 return r;
260782bc 201}
62c476c7 202
0a920356
WH
203int kvm_deassign_device(struct kvm *kvm,
204 struct kvm_assigned_dev_kernel *assigned_dev)
205{
19de40a8 206 struct iommu_domain *domain = kvm->arch.iommu_domain;
0a920356
WH
207 struct pci_dev *pdev = NULL;
208
209 /* check if iommu exists and in use */
210 if (!domain)
211 return 0;
212
213 pdev = assigned_dev->dev;
214 if (pdev == NULL)
215 return -ENODEV;
216
19de40a8 217 iommu_detach_device(domain, &pdev->dev);
0a920356 218
6777829c
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219 pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
220
ab9f4ecb
ZE
221 printk(KERN_DEBUG "deassign device %x:%x:%x.%x\n",
222 assigned_dev->host_segnr,
0a920356
WH
223 assigned_dev->host_busnr,
224 PCI_SLOT(assigned_dev->host_devfn),
225 PCI_FUNC(assigned_dev->host_devfn));
226
227 return 0;
228}
229
260782bc
WH
230int kvm_iommu_map_guest(struct kvm *kvm)
231{
232 int r;
233
a1b60c1c 234 if (!iommu_present(&pci_bus_type)) {
19de40a8 235 printk(KERN_ERR "%s: iommu not found\n", __func__);
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236 return -ENODEV;
237 }
238
21a1416a
AW
239 mutex_lock(&kvm->slots_lock);
240
905d66c1 241 kvm->arch.iommu_domain = iommu_domain_alloc(&pci_bus_type);
21a1416a
AW
242 if (!kvm->arch.iommu_domain) {
243 r = -ENOMEM;
244 goto out_unlock;
245 }
62c476c7 246
3f68b031
AW
247 if (!allow_unsafe_assigned_interrupts &&
248 !iommu_domain_has_cap(kvm->arch.iommu_domain,
249 IOMMU_CAP_INTR_REMAP)) {
250 printk(KERN_WARNING "%s: No interrupt remapping support,"
251 " disallowing device assignment."
252 " Re-enble with \"allow_unsafe_assigned_interrupts=1\""
253 " module option.\n", __func__);
254 iommu_domain_free(kvm->arch.iommu_domain);
255 kvm->arch.iommu_domain = NULL;
21a1416a
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256 r = -EPERM;
257 goto out_unlock;
3f68b031
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258 }
259
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260 r = kvm_iommu_map_memslots(kvm);
261 if (r)
21a1416a 262 kvm_iommu_unmap_memslots(kvm);
62c476c7 263
21a1416a
AW
264out_unlock:
265 mutex_unlock(&kvm->slots_lock);
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266 return r;
267}
268
fcd95807
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269static void kvm_unpin_pages(struct kvm *kvm, pfn_t pfn, unsigned long npages)
270{
271 unsigned long i;
272
273 for (i = 0; i < npages; ++i)
274 kvm_release_pfn_clean(pfn + i);
275}
276
62c476c7 277static void kvm_iommu_put_pages(struct kvm *kvm,
260782bc 278 gfn_t base_gfn, unsigned long npages)
62c476c7 279{
fcd95807
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280 struct iommu_domain *domain;
281 gfn_t end_gfn, gfn;
62c476c7 282 pfn_t pfn;
260782bc
WH
283 u64 phys;
284
fcd95807
JR
285 domain = kvm->arch.iommu_domain;
286 end_gfn = base_gfn + npages;
287 gfn = base_gfn;
288
260782bc
WH
289 /* check if iommu exists and in use */
290 if (!domain)
291 return;
62c476c7 292
fcd95807
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293 while (gfn < end_gfn) {
294 unsigned long unmap_pages;
7d3002cc 295 size_t size;
fcd95807
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296
297 /* Get physical address */
19de40a8 298 phys = iommu_iova_to_phys(domain, gfn_to_gpa(gfn));
16b854c8
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299
300 if (!phys) {
301 gfn++;
302 continue;
303 }
304
fcd95807
JR
305 pfn = phys >> PAGE_SHIFT;
306
307 /* Unmap address from IO address space */
7d3002cc
OBC
308 size = iommu_unmap(domain, gfn_to_gpa(gfn), PAGE_SIZE);
309 unmap_pages = 1ULL << get_order(size);
260782bc 310
fcd95807
JR
311 /* Unpin all pages we just unmapped to not leak any memory */
312 kvm_unpin_pages(kvm, pfn, unmap_pages);
313
314 gfn += unmap_pages;
315 }
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316}
317
32f6daad
AW
318void kvm_iommu_unmap_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
319{
320 kvm_iommu_put_pages(kvm, slot->base_gfn, slot->npages);
321}
322
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323static int kvm_iommu_unmap_memslots(struct kvm *kvm)
324{
be6ba0f0 325 int idx;
46a26bf5 326 struct kvm_memslots *slots;
be6ba0f0 327 struct kvm_memory_slot *memslot;
46a26bf5 328
95c87e2b 329 idx = srcu_read_lock(&kvm->srcu);
90d83dc3 330 slots = kvm_memslots(kvm);
682edb4c 331
be6ba0f0 332 kvm_for_each_memslot(memslot, slots)
32f6daad 333 kvm_iommu_unmap_pages(kvm, memslot);
be6ba0f0 334
95c87e2b 335 srcu_read_unlock(&kvm->srcu, idx);
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336
337 return 0;
338}
339
340int kvm_iommu_unmap_guest(struct kvm *kvm)
341{
19de40a8 342 struct iommu_domain *domain = kvm->arch.iommu_domain;
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343
344 /* check if iommu exists and in use */
345 if (!domain)
346 return 0;
347
21a1416a 348 mutex_lock(&kvm->slots_lock);
62c476c7 349 kvm_iommu_unmap_memslots(kvm);
21a1416a
AW
350 kvm->arch.iommu_domain = NULL;
351 mutex_unlock(&kvm->slots_lock);
352
19de40a8 353 iommu_domain_free(domain);
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354 return 0;
355}
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