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
19 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
20 *
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>
28 #include <linux/module.h>
29 #include <linux/pci.h>
30 #include <linux/stat.h>
31 #include <linux/dmar.h>
32 #include <linux/iommu.h>
33 #include <linux/intel-iommu.h>
34 #include "assigned-dev.h"
35
36 static bool allow_unsafe_assigned_interrupts;
37 module_param_named(allow_unsafe_assigned_interrupts,
38 allow_unsafe_assigned_interrupts, bool, S_IRUGO | S_IWUSR);
39 MODULE_PARM_DESC(allow_unsafe_assigned_interrupts,
40 "Enable device assignment on platforms without interrupt remapping support.");
41
42 static int kvm_iommu_unmap_memslots(struct kvm *kvm);
43 static void kvm_iommu_put_pages(struct kvm *kvm,
44 gfn_t base_gfn, unsigned long npages);
45
kvm_pin_pages(struct kvm_memory_slot * slot,gfn_t gfn,unsigned long npages)46 static pfn_t kvm_pin_pages(struct kvm_memory_slot *slot, gfn_t gfn,
47 unsigned long npages)
48 {
49 gfn_t end_gfn;
50 pfn_t pfn;
51
52 pfn = gfn_to_pfn_memslot(slot, gfn);
53 end_gfn = gfn + npages;
54 gfn += 1;
55
56 if (is_error_noslot_pfn(pfn))
57 return pfn;
58
59 while (gfn < end_gfn)
60 gfn_to_pfn_memslot(slot, gfn++);
61
62 return pfn;
63 }
64
kvm_unpin_pages(struct kvm * kvm,pfn_t pfn,unsigned long npages)65 static void kvm_unpin_pages(struct kvm *kvm, pfn_t pfn, unsigned long npages)
66 {
67 unsigned long i;
68
69 for (i = 0; i < npages; ++i)
70 kvm_release_pfn_clean(pfn + i);
71 }
72
kvm_iommu_map_pages(struct kvm * kvm,struct kvm_memory_slot * slot)73 int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
74 {
75 gfn_t gfn, end_gfn;
76 pfn_t pfn;
77 int r = 0;
78 struct iommu_domain *domain = kvm->arch.iommu_domain;
79 int flags;
80
81 /* check if iommu exists and in use */
82 if (!domain)
83 return 0;
84
85 gfn = slot->base_gfn;
86 end_gfn = gfn + slot->npages;
87
88 flags = IOMMU_READ;
89 if (!(slot->flags & KVM_MEM_READONLY))
90 flags |= IOMMU_WRITE;
91 if (!kvm->arch.iommu_noncoherent)
92 flags |= IOMMU_CACHE;
93
94
95 while (gfn < end_gfn) {
96 unsigned long page_size;
97
98 /* Check if already mapped */
99 if (iommu_iova_to_phys(domain, gfn_to_gpa(gfn))) {
100 gfn += 1;
101 continue;
102 }
103
104 /* Get the page size we could use to map */
105 page_size = kvm_host_page_size(kvm, gfn);
106
107 /* Make sure the page_size does not exceed the memslot */
108 while ((gfn + (page_size >> PAGE_SHIFT)) > end_gfn)
109 page_size >>= 1;
110
111 /* Make sure gfn is aligned to the page size we want to map */
112 while ((gfn << PAGE_SHIFT) & (page_size - 1))
113 page_size >>= 1;
114
115 /* Make sure hva is aligned to the page size we want to map */
116 while (__gfn_to_hva_memslot(slot, gfn) & (page_size - 1))
117 page_size >>= 1;
118
119 /*
120 * Pin all pages we are about to map in memory. This is
121 * important because we unmap and unpin in 4kb steps later.
122 */
123 pfn = kvm_pin_pages(slot, gfn, page_size >> PAGE_SHIFT);
124 if (is_error_noslot_pfn(pfn)) {
125 gfn += 1;
126 continue;
127 }
128
129 /* Map into IO address space */
130 r = iommu_map(domain, gfn_to_gpa(gfn), pfn_to_hpa(pfn),
131 page_size, flags);
132 if (r) {
133 printk(KERN_ERR "kvm_iommu_map_address:"
134 "iommu failed to map pfn=%llx\n", pfn);
135 kvm_unpin_pages(kvm, pfn, page_size >> PAGE_SHIFT);
136 goto unmap_pages;
137 }
138
139 gfn += page_size >> PAGE_SHIFT;
140
141 cond_resched();
142 }
143
144 return 0;
145
146 unmap_pages:
147 kvm_iommu_put_pages(kvm, slot->base_gfn, gfn - slot->base_gfn);
148 return r;
149 }
150
kvm_iommu_map_memslots(struct kvm * kvm)151 static int kvm_iommu_map_memslots(struct kvm *kvm)
152 {
153 int idx, r = 0;
154 struct kvm_memslots *slots;
155 struct kvm_memory_slot *memslot;
156
157 if (kvm->arch.iommu_noncoherent)
158 kvm_arch_register_noncoherent_dma(kvm);
159
160 idx = srcu_read_lock(&kvm->srcu);
161 slots = kvm_memslots(kvm);
162
163 kvm_for_each_memslot(memslot, slots) {
164 r = kvm_iommu_map_pages(kvm, memslot);
165 if (r)
166 break;
167 }
168 srcu_read_unlock(&kvm->srcu, idx);
169
170 return r;
171 }
172
kvm_assign_device(struct kvm * kvm,struct pci_dev * pdev)173 int kvm_assign_device(struct kvm *kvm, struct pci_dev *pdev)
174 {
175 struct iommu_domain *domain = kvm->arch.iommu_domain;
176 int r;
177 bool noncoherent;
178
179 /* check if iommu exists and in use */
180 if (!domain)
181 return 0;
182
183 if (pdev == NULL)
184 return -ENODEV;
185
186 r = iommu_attach_device(domain, &pdev->dev);
187 if (r) {
188 dev_err(&pdev->dev, "kvm assign device failed ret %d", r);
189 return r;
190 }
191
192 noncoherent = !iommu_capable(&pci_bus_type, IOMMU_CAP_CACHE_COHERENCY);
193
194 /* Check if need to update IOMMU page table for guest memory */
195 if (noncoherent != kvm->arch.iommu_noncoherent) {
196 kvm_iommu_unmap_memslots(kvm);
197 kvm->arch.iommu_noncoherent = noncoherent;
198 r = kvm_iommu_map_memslots(kvm);
199 if (r)
200 goto out_unmap;
201 }
202
203 pci_set_dev_assigned(pdev);
204
205 dev_info(&pdev->dev, "kvm assign device\n");
206
207 return 0;
208 out_unmap:
209 kvm_iommu_unmap_memslots(kvm);
210 return r;
211 }
212
kvm_deassign_device(struct kvm * kvm,struct pci_dev * pdev)213 int kvm_deassign_device(struct kvm *kvm, struct pci_dev *pdev)
214 {
215 struct iommu_domain *domain = kvm->arch.iommu_domain;
216
217 /* check if iommu exists and in use */
218 if (!domain)
219 return 0;
220
221 if (pdev == NULL)
222 return -ENODEV;
223
224 iommu_detach_device(domain, &pdev->dev);
225
226 pci_clear_dev_assigned(pdev);
227
228 dev_info(&pdev->dev, "kvm deassign device\n");
229
230 return 0;
231 }
232
kvm_iommu_map_guest(struct kvm * kvm)233 int kvm_iommu_map_guest(struct kvm *kvm)
234 {
235 int r;
236
237 if (!iommu_present(&pci_bus_type)) {
238 printk(KERN_ERR "%s: iommu not found\n", __func__);
239 return -ENODEV;
240 }
241
242 mutex_lock(&kvm->slots_lock);
243
244 kvm->arch.iommu_domain = iommu_domain_alloc(&pci_bus_type);
245 if (!kvm->arch.iommu_domain) {
246 r = -ENOMEM;
247 goto out_unlock;
248 }
249
250 if (!allow_unsafe_assigned_interrupts &&
251 !iommu_capable(&pci_bus_type, IOMMU_CAP_INTR_REMAP)) {
252 printk(KERN_WARNING "%s: No interrupt remapping support,"
253 " disallowing device assignment."
254 " Re-enble with \"allow_unsafe_assigned_interrupts=1\""
255 " module option.\n", __func__);
256 iommu_domain_free(kvm->arch.iommu_domain);
257 kvm->arch.iommu_domain = NULL;
258 r = -EPERM;
259 goto out_unlock;
260 }
261
262 r = kvm_iommu_map_memslots(kvm);
263 if (r)
264 kvm_iommu_unmap_memslots(kvm);
265
266 out_unlock:
267 mutex_unlock(&kvm->slots_lock);
268 return r;
269 }
270
kvm_iommu_put_pages(struct kvm * kvm,gfn_t base_gfn,unsigned long npages)271 static void kvm_iommu_put_pages(struct kvm *kvm,
272 gfn_t base_gfn, unsigned long npages)
273 {
274 struct iommu_domain *domain;
275 gfn_t end_gfn, gfn;
276 pfn_t pfn;
277 u64 phys;
278
279 domain = kvm->arch.iommu_domain;
280 end_gfn = base_gfn + npages;
281 gfn = base_gfn;
282
283 /* check if iommu exists and in use */
284 if (!domain)
285 return;
286
287 while (gfn < end_gfn) {
288 unsigned long unmap_pages;
289 size_t size;
290
291 /* Get physical address */
292 phys = iommu_iova_to_phys(domain, gfn_to_gpa(gfn));
293
294 if (!phys) {
295 gfn++;
296 continue;
297 }
298
299 pfn = phys >> PAGE_SHIFT;
300
301 /* Unmap address from IO address space */
302 size = iommu_unmap(domain, gfn_to_gpa(gfn), PAGE_SIZE);
303 unmap_pages = 1ULL << get_order(size);
304
305 /* Unpin all pages we just unmapped to not leak any memory */
306 kvm_unpin_pages(kvm, pfn, unmap_pages);
307
308 gfn += unmap_pages;
309
310 cond_resched();
311 }
312 }
313
kvm_iommu_unmap_pages(struct kvm * kvm,struct kvm_memory_slot * slot)314 void kvm_iommu_unmap_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
315 {
316 kvm_iommu_put_pages(kvm, slot->base_gfn, slot->npages);
317 }
318
kvm_iommu_unmap_memslots(struct kvm * kvm)319 static int kvm_iommu_unmap_memslots(struct kvm *kvm)
320 {
321 int idx;
322 struct kvm_memslots *slots;
323 struct kvm_memory_slot *memslot;
324
325 idx = srcu_read_lock(&kvm->srcu);
326 slots = kvm_memslots(kvm);
327
328 kvm_for_each_memslot(memslot, slots)
329 kvm_iommu_unmap_pages(kvm, memslot);
330
331 srcu_read_unlock(&kvm->srcu, idx);
332
333 if (kvm->arch.iommu_noncoherent)
334 kvm_arch_unregister_noncoherent_dma(kvm);
335
336 return 0;
337 }
338
kvm_iommu_unmap_guest(struct kvm * kvm)339 int kvm_iommu_unmap_guest(struct kvm *kvm)
340 {
341 struct iommu_domain *domain = kvm->arch.iommu_domain;
342
343 /* check if iommu exists and in use */
344 if (!domain)
345 return 0;
346
347 mutex_lock(&kvm->slots_lock);
348 kvm_iommu_unmap_memslots(kvm);
349 kvm->arch.iommu_domain = NULL;
350 kvm->arch.iommu_noncoherent = false;
351 mutex_unlock(&kvm->slots_lock);
352
353 iommu_domain_free(domain);
354 return 0;
355 }
356