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
35 static bool allow_unsafe_assigned_interrupts;
36 module_param_named(allow_unsafe_assigned_interrupts,
37 allow_unsafe_assigned_interrupts, bool, S_IRUGO | S_IWUSR);
38 MODULE_PARM_DESC(allow_unsafe_assigned_interrupts,
39 "Enable device assignment on platforms without interrupt remapping support.");
40
41 static int kvm_iommu_unmap_memslots(struct kvm *kvm);
42 static void kvm_iommu_put_pages(struct kvm *kvm,
43 gfn_t base_gfn, unsigned long npages);
44
kvm_pin_pages(struct kvm * kvm,struct kvm_memory_slot * slot,gfn_t gfn,unsigned long size)45 static pfn_t kvm_pin_pages(struct kvm *kvm, struct kvm_memory_slot *slot,
46 gfn_t gfn, unsigned long size)
47 {
48 gfn_t end_gfn;
49 pfn_t pfn;
50
51 pfn = gfn_to_pfn_memslot(kvm, slot, gfn);
52 end_gfn = gfn + (size >> PAGE_SHIFT);
53 gfn += 1;
54
55 if (is_error_pfn(pfn))
56 return pfn;
57
58 while (gfn < end_gfn)
59 gfn_to_pfn_memslot(kvm, slot, gfn++);
60
61 return pfn;
62 }
63
kvm_iommu_map_pages(struct kvm * kvm,struct kvm_memory_slot * slot)64 int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
65 {
66 gfn_t gfn, end_gfn;
67 pfn_t pfn;
68 int r = 0;
69 struct iommu_domain *domain = kvm->arch.iommu_domain;
70 int flags;
71
72 /* check if iommu exists and in use */
73 if (!domain)
74 return 0;
75
76 gfn = slot->base_gfn;
77 end_gfn = gfn + slot->npages;
78
79 flags = IOMMU_READ | IOMMU_WRITE;
80 if (kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY)
81 flags |= IOMMU_CACHE;
82
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 */
108 pfn = kvm_pin_pages(kvm, slot, gfn, page_size);
109 if (is_error_pfn(pfn)) {
110 gfn += 1;
111 continue;
112 }
113
114 /* Map into IO address space */
115 r = iommu_map(domain, gfn_to_gpa(gfn), pfn_to_hpa(pfn),
116 page_size, flags);
117 if (r) {
118 printk(KERN_ERR "kvm_iommu_map_address:"
119 "iommu failed to map pfn=%llx\n", pfn);
120 goto unmap_pages;
121 }
122
123 gfn += page_size >> PAGE_SHIFT;
124
125
126 }
127
128 return 0;
129
130 unmap_pages:
131 kvm_iommu_put_pages(kvm, slot->base_gfn, gfn);
132 return r;
133 }
134
kvm_iommu_map_memslots(struct kvm * kvm)135 static int kvm_iommu_map_memslots(struct kvm *kvm)
136 {
137 int idx, r = 0;
138 struct kvm_memslots *slots;
139 struct kvm_memory_slot *memslot;
140
141 idx = srcu_read_lock(&kvm->srcu);
142 slots = kvm_memslots(kvm);
143
144 kvm_for_each_memslot(memslot, slots) {
145 r = kvm_iommu_map_pages(kvm, memslot);
146 if (r)
147 break;
148 }
149 srcu_read_unlock(&kvm->srcu, idx);
150
151 return r;
152 }
153
kvm_assign_device(struct kvm * kvm,struct kvm_assigned_dev_kernel * assigned_dev)154 int kvm_assign_device(struct kvm *kvm,
155 struct kvm_assigned_dev_kernel *assigned_dev)
156 {
157 struct pci_dev *pdev = NULL;
158 struct iommu_domain *domain = kvm->arch.iommu_domain;
159 int r, last_flags;
160
161 /* check if iommu exists and in use */
162 if (!domain)
163 return 0;
164
165 pdev = assigned_dev->dev;
166 if (pdev == NULL)
167 return -ENODEV;
168
169 r = iommu_attach_device(domain, &pdev->dev);
170 if (r) {
171 printk(KERN_ERR "assign device %x:%x:%x.%x failed",
172 pci_domain_nr(pdev->bus),
173 pdev->bus->number,
174 PCI_SLOT(pdev->devfn),
175 PCI_FUNC(pdev->devfn));
176 return r;
177 }
178
179 last_flags = kvm->arch.iommu_flags;
180 if (iommu_domain_has_cap(kvm->arch.iommu_domain,
181 IOMMU_CAP_CACHE_COHERENCY))
182 kvm->arch.iommu_flags |= KVM_IOMMU_CACHE_COHERENCY;
183
184 /* Check if need to update IOMMU page table for guest memory */
185 if ((last_flags ^ kvm->arch.iommu_flags) ==
186 KVM_IOMMU_CACHE_COHERENCY) {
187 kvm_iommu_unmap_memslots(kvm);
188 r = kvm_iommu_map_memslots(kvm);
189 if (r)
190 goto out_unmap;
191 }
192
193 pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
194
195 printk(KERN_DEBUG "assign device %x:%x:%x.%x\n",
196 assigned_dev->host_segnr,
197 assigned_dev->host_busnr,
198 PCI_SLOT(assigned_dev->host_devfn),
199 PCI_FUNC(assigned_dev->host_devfn));
200
201 return 0;
202 out_unmap:
203 kvm_iommu_unmap_memslots(kvm);
204 return r;
205 }
206
kvm_deassign_device(struct kvm * kvm,struct kvm_assigned_dev_kernel * assigned_dev)207 int kvm_deassign_device(struct kvm *kvm,
208 struct kvm_assigned_dev_kernel *assigned_dev)
209 {
210 struct iommu_domain *domain = kvm->arch.iommu_domain;
211 struct pci_dev *pdev = NULL;
212
213 /* check if iommu exists and in use */
214 if (!domain)
215 return 0;
216
217 pdev = assigned_dev->dev;
218 if (pdev == NULL)
219 return -ENODEV;
220
221 iommu_detach_device(domain, &pdev->dev);
222
223 pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
224
225 printk(KERN_DEBUG "deassign device %x:%x:%x.%x\n",
226 assigned_dev->host_segnr,
227 assigned_dev->host_busnr,
228 PCI_SLOT(assigned_dev->host_devfn),
229 PCI_FUNC(assigned_dev->host_devfn));
230
231 return 0;
232 }
233
kvm_iommu_map_guest(struct kvm * kvm)234 int kvm_iommu_map_guest(struct kvm *kvm)
235 {
236 int r;
237
238 if (!iommu_present(&pci_bus_type)) {
239 printk(KERN_ERR "%s: iommu not found\n", __func__);
240 return -ENODEV;
241 }
242
243 kvm->arch.iommu_domain = iommu_domain_alloc(&pci_bus_type);
244 if (!kvm->arch.iommu_domain)
245 return -ENOMEM;
246
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;
256 return -EPERM;
257 }
258
259 r = kvm_iommu_map_memslots(kvm);
260 if (r)
261 goto out_unmap;
262
263 return 0;
264
265 out_unmap:
266 kvm_iommu_unmap_memslots(kvm);
267 return r;
268 }
269
kvm_unpin_pages(struct kvm * kvm,pfn_t pfn,unsigned long npages)270 static void kvm_unpin_pages(struct kvm *kvm, pfn_t pfn, unsigned long npages)
271 {
272 unsigned long i;
273
274 for (i = 0; i < npages; ++i)
275 kvm_release_pfn_clean(pfn + i);
276 }
277
kvm_iommu_put_pages(struct kvm * kvm,gfn_t base_gfn,unsigned long npages)278 static void kvm_iommu_put_pages(struct kvm *kvm,
279 gfn_t base_gfn, unsigned long npages)
280 {
281 struct iommu_domain *domain;
282 gfn_t end_gfn, gfn;
283 pfn_t pfn;
284 u64 phys;
285
286 domain = kvm->arch.iommu_domain;
287 end_gfn = base_gfn + npages;
288 gfn = base_gfn;
289
290 /* check if iommu exists and in use */
291 if (!domain)
292 return;
293
294 while (gfn < end_gfn) {
295 unsigned long unmap_pages;
296 size_t size;
297
298 /* Get physical address */
299 phys = iommu_iova_to_phys(domain, gfn_to_gpa(gfn));
300 pfn = phys >> PAGE_SHIFT;
301
302 /* Unmap address from IO address space */
303 size = iommu_unmap(domain, gfn_to_gpa(gfn), PAGE_SIZE);
304 unmap_pages = 1ULL << get_order(size);
305
306 /* Unpin all pages we just unmapped to not leak any memory */
307 kvm_unpin_pages(kvm, pfn, unmap_pages);
308
309 gfn += unmap_pages;
310 }
311 }
312
kvm_iommu_unmap_memslots(struct kvm * kvm)313 static int kvm_iommu_unmap_memslots(struct kvm *kvm)
314 {
315 int idx;
316 struct kvm_memslots *slots;
317 struct kvm_memory_slot *memslot;
318
319 idx = srcu_read_lock(&kvm->srcu);
320 slots = kvm_memslots(kvm);
321
322 kvm_for_each_memslot(memslot, slots)
323 kvm_iommu_put_pages(kvm, memslot->base_gfn, memslot->npages);
324
325 srcu_read_unlock(&kvm->srcu, idx);
326
327 return 0;
328 }
329
kvm_iommu_unmap_guest(struct kvm * kvm)330 int kvm_iommu_unmap_guest(struct kvm *kvm)
331 {
332 struct iommu_domain *domain = kvm->arch.iommu_domain;
333
334 /* check if iommu exists and in use */
335 if (!domain)
336 return 0;
337
338 kvm_iommu_unmap_memslots(kvm);
339 iommu_domain_free(domain);
340 return 0;
341 }
342