xref: /freebsd/sys/amd64/vmm/io/iommu.c (revision e796cc77c586c2955b2f3940dbf4991b31e8d289)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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  * $FreeBSD$
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/types.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/sysctl.h>
39 
40 #include <dev/pci/pcivar.h>
41 #include <dev/pci/pcireg.h>
42 
43 #include <machine/cpu.h>
44 #include <machine/md_var.h>
45 
46 #include "vmm_util.h"
47 #include "vmm_mem.h"
48 #include "iommu.h"
49 
50 SYSCTL_DECL(_hw_vmm);
51 SYSCTL_NODE(_hw_vmm, OID_AUTO, iommu, CTLFLAG_RW, 0, "bhyve iommu parameters");
52 
53 static int iommu_avail;
54 SYSCTL_INT(_hw_vmm_iommu, OID_AUTO, initialized, CTLFLAG_RD, &iommu_avail,
55     0, "bhyve iommu initialized?");
56 
57 static int iommu_enable = 1;
58 SYSCTL_INT(_hw_vmm_iommu, OID_AUTO, enable, CTLFLAG_RDTUN, &iommu_enable, 0,
59     "Enable use of I/O MMU (required for PCI passthrough).");
60 
61 static struct iommu_ops *ops;
62 static void *host_domain;
63 static eventhandler_tag add_tag, delete_tag;
64 
65 static __inline int
66 IOMMU_INIT(void)
67 {
68 	if (ops != NULL)
69 		return ((*ops->init)());
70 	else
71 		return (ENXIO);
72 }
73 
74 static __inline void
75 IOMMU_CLEANUP(void)
76 {
77 	if (ops != NULL && iommu_avail)
78 		(*ops->cleanup)();
79 }
80 
81 static __inline void *
82 IOMMU_CREATE_DOMAIN(vm_paddr_t maxaddr)
83 {
84 
85 	if (ops != NULL && iommu_avail)
86 		return ((*ops->create_domain)(maxaddr));
87 	else
88 		return (NULL);
89 }
90 
91 static __inline void
92 IOMMU_DESTROY_DOMAIN(void *dom)
93 {
94 
95 	if (ops != NULL && iommu_avail)
96 		(*ops->destroy_domain)(dom);
97 }
98 
99 static __inline uint64_t
100 IOMMU_CREATE_MAPPING(void *domain, vm_paddr_t gpa, vm_paddr_t hpa, uint64_t len)
101 {
102 
103 	if (ops != NULL && iommu_avail)
104 		return ((*ops->create_mapping)(domain, gpa, hpa, len));
105 	else
106 		return (len);		/* XXX */
107 }
108 
109 static __inline uint64_t
110 IOMMU_REMOVE_MAPPING(void *domain, vm_paddr_t gpa, uint64_t len)
111 {
112 
113 	if (ops != NULL && iommu_avail)
114 		return ((*ops->remove_mapping)(domain, gpa, len));
115 	else
116 		return (len);		/* XXX */
117 }
118 
119 static __inline void
120 IOMMU_ADD_DEVICE(void *domain, uint16_t rid)
121 {
122 
123 	if (ops != NULL && iommu_avail)
124 		(*ops->add_device)(domain, rid);
125 }
126 
127 static __inline void
128 IOMMU_REMOVE_DEVICE(void *domain, uint16_t rid)
129 {
130 
131 	if (ops != NULL && iommu_avail)
132 		(*ops->remove_device)(domain, rid);
133 }
134 
135 static __inline void
136 IOMMU_INVALIDATE_TLB(void *domain)
137 {
138 
139 	if (ops != NULL && iommu_avail)
140 		(*ops->invalidate_tlb)(domain);
141 }
142 
143 static __inline void
144 IOMMU_ENABLE(void)
145 {
146 
147 	if (ops != NULL && iommu_avail)
148 		(*ops->enable)();
149 }
150 
151 static __inline void
152 IOMMU_DISABLE(void)
153 {
154 
155 	if (ops != NULL && iommu_avail)
156 		(*ops->disable)();
157 }
158 
159 static void
160 iommu_pci_add(void *arg, device_t dev)
161 {
162 
163 	/* Add new devices to the host domain. */
164 	iommu_add_device(host_domain, pci_get_rid(dev));
165 }
166 
167 static void
168 iommu_pci_delete(void *arg, device_t dev)
169 {
170 
171 	iommu_remove_device(host_domain, pci_get_rid(dev));
172 }
173 
174 static void
175 iommu_init(void)
176 {
177 	int error, bus, slot, func;
178 	vm_paddr_t maxaddr;
179 	devclass_t dc;
180 	device_t dev;
181 
182 	if (!iommu_enable)
183 		return;
184 
185 	if (vmm_is_intel())
186 		ops = &iommu_ops_intel;
187 	else if (vmm_is_amd())
188 		ops = &iommu_ops_amd;
189 	else
190 		ops = NULL;
191 
192 	error = IOMMU_INIT();
193 	if (error)
194 		return;
195 
196 	iommu_avail = 1;
197 
198 	/*
199 	 * Create a domain for the devices owned by the host
200 	 */
201 	maxaddr = vmm_mem_maxaddr();
202 	host_domain = IOMMU_CREATE_DOMAIN(maxaddr);
203 	if (host_domain == NULL) {
204 		printf("iommu_init: unable to create a host domain");
205 		IOMMU_CLEANUP();
206 		ops = NULL;
207 		iommu_avail = 0;
208 		return;
209 	}
210 
211 	/*
212 	 * Create 1:1 mappings from '0' to 'maxaddr' for devices assigned to
213 	 * the host
214 	 */
215 	iommu_create_mapping(host_domain, 0, 0, maxaddr);
216 
217 	add_tag = EVENTHANDLER_REGISTER(pci_add_device, iommu_pci_add, NULL, 0);
218 	delete_tag = EVENTHANDLER_REGISTER(pci_delete_device, iommu_pci_delete,
219 	    NULL, 0);
220 	dc = devclass_find("ppt");
221 	for (bus = 0; bus <= PCI_BUSMAX; bus++) {
222 		for (slot = 0; slot <= PCI_SLOTMAX; slot++) {
223 			for (func = 0; func <= PCI_FUNCMAX; func++) {
224 				dev = pci_find_dbsf(0, bus, slot, func);
225 				if (dev == NULL)
226 					continue;
227 
228 				/* Skip passthrough devices. */
229 				if (dc != NULL &&
230 				    device_get_devclass(dev) == dc)
231 					continue;
232 
233 				/*
234 				 * Everything else belongs to the host
235 				 * domain.
236 				 */
237 				iommu_add_device(host_domain,
238 				    pci_get_rid(dev));
239 			}
240 		}
241 	}
242 	IOMMU_ENABLE();
243 
244 }
245 
246 void
247 iommu_cleanup(void)
248 {
249 
250 	if (add_tag != NULL) {
251 		EVENTHANDLER_DEREGISTER(pci_add_device, add_tag);
252 		add_tag = NULL;
253 	}
254 	if (delete_tag != NULL) {
255 		EVENTHANDLER_DEREGISTER(pci_delete_device, delete_tag);
256 		delete_tag = NULL;
257 	}
258 	IOMMU_DISABLE();
259 	IOMMU_DESTROY_DOMAIN(host_domain);
260 	IOMMU_CLEANUP();
261 }
262 
263 void *
264 iommu_create_domain(vm_paddr_t maxaddr)
265 {
266 	static volatile int iommu_initted;
267 
268 	if (iommu_initted < 2) {
269 		if (atomic_cmpset_int(&iommu_initted, 0, 1)) {
270 			iommu_init();
271 			atomic_store_rel_int(&iommu_initted, 2);
272 		} else
273 			while (iommu_initted == 1)
274 				cpu_spinwait();
275 	}
276 	return (IOMMU_CREATE_DOMAIN(maxaddr));
277 }
278 
279 void
280 iommu_destroy_domain(void *dom)
281 {
282 
283 	IOMMU_DESTROY_DOMAIN(dom);
284 }
285 
286 void
287 iommu_create_mapping(void *dom, vm_paddr_t gpa, vm_paddr_t hpa, size_t len)
288 {
289 	uint64_t mapped, remaining;
290 
291 	remaining = len;
292 
293 	while (remaining > 0) {
294 		mapped = IOMMU_CREATE_MAPPING(dom, gpa, hpa, remaining);
295 		gpa += mapped;
296 		hpa += mapped;
297 		remaining -= mapped;
298 	}
299 }
300 
301 void
302 iommu_remove_mapping(void *dom, vm_paddr_t gpa, size_t len)
303 {
304 	uint64_t unmapped, remaining;
305 
306 	remaining = len;
307 
308 	while (remaining > 0) {
309 		unmapped = IOMMU_REMOVE_MAPPING(dom, gpa, remaining);
310 		gpa += unmapped;
311 		remaining -= unmapped;
312 	}
313 }
314 
315 void *
316 iommu_host_domain(void)
317 {
318 
319 	return (host_domain);
320 }
321 
322 void
323 iommu_add_device(void *dom, uint16_t rid)
324 {
325 
326 	IOMMU_ADD_DEVICE(dom, rid);
327 }
328 
329 void
330 iommu_remove_device(void *dom, uint16_t rid)
331 {
332 
333 	IOMMU_REMOVE_DEVICE(dom, rid);
334 }
335 
336 void
337 iommu_invalidate_tlb(void *domain)
338 {
339 
340 	IOMMU_INVALIDATE_TLB(domain);
341 }
342