xref: /freebsd/sys/amd64/vmm/io/iommu.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2011 NetApp, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/param.h>
30 #include <sys/bus.h>
31 #include <sys/eventhandler.h>
32 #include <sys/sysctl.h>
33 #include <sys/systm.h>
34 
35 #include <dev/pci/pcivar.h>
36 #include <dev/pci/pcireg.h>
37 
38 #include <machine/cpu.h>
39 #include <machine/md_var.h>
40 
41 #include "vmm_util.h"
42 #include "vmm_mem.h"
43 #include "iommu.h"
44 
45 SYSCTL_DECL(_hw_vmm);
46 SYSCTL_NODE(_hw_vmm, OID_AUTO, iommu, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
47     "bhyve iommu parameters");
48 
49 static int iommu_avail;
50 SYSCTL_INT(_hw_vmm_iommu, OID_AUTO, initialized, CTLFLAG_RD, &iommu_avail,
51     0, "bhyve iommu initialized?");
52 
53 static int iommu_enable = 1;
54 SYSCTL_INT(_hw_vmm_iommu, OID_AUTO, enable, CTLFLAG_RDTUN, &iommu_enable, 0,
55     "Enable use of I/O MMU (required for PCI passthrough).");
56 
57 static const struct iommu_ops *ops;
58 static void *host_domain;
59 static eventhandler_tag add_tag, delete_tag;
60 
61 static __inline int
62 IOMMU_INIT(void)
63 {
64 	if (ops != NULL)
65 		return ((*ops->init)());
66 	else
67 		return (ENXIO);
68 }
69 
70 static __inline void
71 IOMMU_CLEANUP(void)
72 {
73 	if (ops != NULL && iommu_avail)
74 		(*ops->cleanup)();
75 }
76 
77 static __inline void *
78 IOMMU_CREATE_DOMAIN(vm_paddr_t maxaddr)
79 {
80 
81 	if (ops != NULL && iommu_avail)
82 		return ((*ops->create_domain)(maxaddr));
83 	else
84 		return (NULL);
85 }
86 
87 static __inline void
88 IOMMU_DESTROY_DOMAIN(void *dom)
89 {
90 
91 	if (ops != NULL && iommu_avail)
92 		(*ops->destroy_domain)(dom);
93 }
94 
95 static __inline uint64_t
96 IOMMU_CREATE_MAPPING(void *domain, vm_paddr_t gpa, vm_paddr_t hpa, uint64_t len)
97 {
98 
99 	if (ops != NULL && iommu_avail)
100 		return ((*ops->create_mapping)(domain, gpa, hpa, len));
101 	else
102 		return (len);		/* XXX */
103 }
104 
105 static __inline uint64_t
106 IOMMU_REMOVE_MAPPING(void *domain, vm_paddr_t gpa, uint64_t len)
107 {
108 
109 	if (ops != NULL && iommu_avail)
110 		return ((*ops->remove_mapping)(domain, gpa, len));
111 	else
112 		return (len);		/* XXX */
113 }
114 
115 static __inline void
116 IOMMU_ADD_DEVICE(void *domain, uint16_t rid)
117 {
118 
119 	if (ops != NULL && iommu_avail)
120 		(*ops->add_device)(domain, rid);
121 }
122 
123 static __inline void
124 IOMMU_REMOVE_DEVICE(void *domain, uint16_t rid)
125 {
126 
127 	if (ops != NULL && iommu_avail)
128 		(*ops->remove_device)(domain, rid);
129 }
130 
131 static __inline void
132 IOMMU_INVALIDATE_TLB(void *domain)
133 {
134 
135 	if (ops != NULL && iommu_avail)
136 		(*ops->invalidate_tlb)(domain);
137 }
138 
139 static __inline void
140 IOMMU_ENABLE(void)
141 {
142 
143 	if (ops != NULL && iommu_avail)
144 		(*ops->enable)();
145 }
146 
147 static __inline void
148 IOMMU_DISABLE(void)
149 {
150 
151 	if (ops != NULL && iommu_avail)
152 		(*ops->disable)();
153 }
154 
155 static void
156 iommu_pci_add(void *arg, device_t dev)
157 {
158 
159 	/* Add new devices to the host domain. */
160 	iommu_add_device(host_domain, pci_get_rid(dev));
161 }
162 
163 static void
164 iommu_pci_delete(void *arg, device_t dev)
165 {
166 
167 	iommu_remove_device(host_domain, pci_get_rid(dev));
168 }
169 
170 static void
171 iommu_init(void)
172 {
173 	int error, bus, slot, func;
174 	vm_paddr_t maxaddr;
175 	devclass_t dc;
176 	device_t dev;
177 
178 	if (!iommu_enable)
179 		return;
180 
181 	if (vmm_is_intel())
182 		ops = &iommu_ops_intel;
183 	else if (vmm_is_svm())
184 		ops = &iommu_ops_amd;
185 	else
186 		ops = NULL;
187 
188 	error = IOMMU_INIT();
189 	if (error)
190 		return;
191 
192 	iommu_avail = 1;
193 
194 	/*
195 	 * Create a domain for the devices owned by the host
196 	 */
197 	maxaddr = vmm_mem_maxaddr();
198 	host_domain = IOMMU_CREATE_DOMAIN(maxaddr);
199 	if (host_domain == NULL) {
200 		printf("iommu_init: unable to create a host domain");
201 		IOMMU_CLEANUP();
202 		ops = NULL;
203 		iommu_avail = 0;
204 		return;
205 	}
206 
207 	/*
208 	 * Create 1:1 mappings from '0' to 'maxaddr' for devices assigned to
209 	 * the host
210 	 */
211 	iommu_create_mapping(host_domain, 0, 0, maxaddr);
212 
213 	add_tag = EVENTHANDLER_REGISTER(pci_add_device, iommu_pci_add, NULL, 0);
214 	delete_tag = EVENTHANDLER_REGISTER(pci_delete_device, iommu_pci_delete,
215 	    NULL, 0);
216 	dc = devclass_find("ppt");
217 	for (bus = 0; bus <= PCI_BUSMAX; bus++) {
218 		for (slot = 0; slot <= PCI_SLOTMAX; slot++) {
219 			for (func = 0; func <= PCI_FUNCMAX; func++) {
220 				dev = pci_find_dbsf(0, bus, slot, func);
221 				if (dev == NULL)
222 					continue;
223 
224 				/* Skip passthrough devices. */
225 				if (dc != NULL &&
226 				    device_get_devclass(dev) == dc)
227 					continue;
228 
229 				/*
230 				 * Everything else belongs to the host
231 				 * domain.
232 				 */
233 				iommu_add_device(host_domain,
234 				    pci_get_rid(dev));
235 			}
236 		}
237 	}
238 	IOMMU_ENABLE();
239 
240 }
241 
242 void
243 iommu_cleanup(void)
244 {
245 
246 	if (add_tag != NULL) {
247 		EVENTHANDLER_DEREGISTER(pci_add_device, add_tag);
248 		add_tag = NULL;
249 	}
250 	if (delete_tag != NULL) {
251 		EVENTHANDLER_DEREGISTER(pci_delete_device, delete_tag);
252 		delete_tag = NULL;
253 	}
254 	IOMMU_DISABLE();
255 	IOMMU_DESTROY_DOMAIN(host_domain);
256 	host_domain = NULL;
257 	IOMMU_CLEANUP();
258 }
259 
260 void *
261 iommu_create_domain(vm_paddr_t maxaddr)
262 {
263 	static volatile int iommu_initted;
264 
265 	if (iommu_initted < 2) {
266 		if (atomic_cmpset_int(&iommu_initted, 0, 1)) {
267 			iommu_init();
268 			atomic_store_rel_int(&iommu_initted, 2);
269 		} else
270 			while (iommu_initted == 1)
271 				cpu_spinwait();
272 	}
273 	return (IOMMU_CREATE_DOMAIN(maxaddr));
274 }
275 
276 void
277 iommu_destroy_domain(void *dom)
278 {
279 
280 	IOMMU_DESTROY_DOMAIN(dom);
281 }
282 
283 void
284 iommu_create_mapping(void *dom, vm_paddr_t gpa, vm_paddr_t hpa, size_t len)
285 {
286 	uint64_t mapped, remaining;
287 
288 	remaining = len;
289 
290 	while (remaining > 0) {
291 		mapped = IOMMU_CREATE_MAPPING(dom, gpa, hpa, remaining);
292 		gpa += mapped;
293 		hpa += mapped;
294 		remaining -= mapped;
295 	}
296 }
297 
298 void
299 iommu_remove_mapping(void *dom, vm_paddr_t gpa, size_t len)
300 {
301 	uint64_t unmapped, remaining;
302 
303 	remaining = len;
304 
305 	while (remaining > 0) {
306 		unmapped = IOMMU_REMOVE_MAPPING(dom, gpa, remaining);
307 		gpa += unmapped;
308 		remaining -= unmapped;
309 	}
310 }
311 
312 void *
313 iommu_host_domain(void)
314 {
315 
316 	return (host_domain);
317 }
318 
319 void
320 iommu_add_device(void *dom, uint16_t rid)
321 {
322 
323 	IOMMU_ADD_DEVICE(dom, rid);
324 }
325 
326 void
327 iommu_remove_device(void *dom, uint16_t rid)
328 {
329 
330 	IOMMU_REMOVE_DEVICE(dom, rid);
331 }
332 
333 void
334 iommu_invalidate_tlb(void *domain)
335 {
336 
337 	IOMMU_INVALIDATE_TLB(domain);
338 }
339