mem.c revision 268976 
1/*-
2 * Copyright (c) 2012 NetApp, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: stable/10/usr.sbin/bhyve/mem.c 268976 2014-07-22 04:39:16Z jhb $
27 */
28
29/*
30 * Memory ranges are represented with an RB tree. On insertion, the range
31 * is checked for overlaps. On lookup, the key has the same base and limit
32 * so it can be searched within the range.
33 */
34
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD: stable/10/usr.sbin/bhyve/mem.c 268976 2014-07-22 04:39:16Z jhb $");
37
38#include <sys/types.h>
39#include <sys/tree.h>
40#include <sys/errno.h>
41#include <machine/vmm.h>
42#include <machine/vmm_instruction_emul.h>
43
44#include <stdio.h>
45#include <stdlib.h>
46#include <assert.h>
47#include <pthread.h>
48
49#include "mem.h"
50
51struct mmio_rb_range {
52	RB_ENTRY(mmio_rb_range)	mr_link;	/* RB tree links */
53	struct mem_range	mr_param;
54	uint64_t                mr_base;
55	uint64_t                mr_end;
56};
57
58struct mmio_rb_tree;
59RB_PROTOTYPE(mmio_rb_tree, mmio_rb_range, mr_link, mmio_rb_range_compare);
60
61RB_HEAD(mmio_rb_tree, mmio_rb_range) mmio_rb_root, mmio_rb_fallback;
62
63/*
64 * Per-vCPU cache. Since most accesses from a vCPU will be to
65 * consecutive addresses in a range, it makes sense to cache the
66 * result of a lookup.
67 */
68static struct mmio_rb_range	*mmio_hint[VM_MAXCPU];
69
70static pthread_rwlock_t mmio_rwlock;
71
72static int
73mmio_rb_range_compare(struct mmio_rb_range *a, struct mmio_rb_range *b)
74{
75	if (a->mr_end < b->mr_base)
76		return (-1);
77	else if (a->mr_base > b->mr_end)
78		return (1);
79	return (0);
80}
81
82static int
83mmio_rb_lookup(struct mmio_rb_tree *rbt, uint64_t addr,
84    struct mmio_rb_range **entry)
85{
86	struct mmio_rb_range find, *res;
87
88	find.mr_base = find.mr_end = addr;
89
90	res = RB_FIND(mmio_rb_tree, rbt, &find);
91
92	if (res != NULL) {
93		*entry = res;
94		return (0);
95	}
96
97	return (ENOENT);
98}
99
100static int
101mmio_rb_add(struct mmio_rb_tree *rbt, struct mmio_rb_range *new)
102{
103	struct mmio_rb_range *overlap;
104
105	overlap = RB_INSERT(mmio_rb_tree, rbt, new);
106
107	if (overlap != NULL) {
108#ifdef RB_DEBUG
109		printf("overlap detected: new %lx:%lx, tree %lx:%lx\n",
110		       new->mr_base, new->mr_end,
111		       overlap->mr_base, overlap->mr_end);
112#endif
113
114		return (EEXIST);
115	}
116
117	return (0);
118}
119
120#if 0
121static void
122mmio_rb_dump(struct mmio_rb_tree *rbt)
123{
124	struct mmio_rb_range *np;
125
126	pthread_rwlock_rdlock(&mmio_rwlock);
127	RB_FOREACH(np, mmio_rb_tree, rbt) {
128		printf(" %lx:%lx, %s\n", np->mr_base, np->mr_end,
129		       np->mr_param.name);
130	}
131	pthread_rwlock_unlock(&mmio_rwlock);
132}
133#endif
134
135RB_GENERATE(mmio_rb_tree, mmio_rb_range, mr_link, mmio_rb_range_compare);
136
137static int
138mem_read(void *ctx, int vcpu, uint64_t gpa, uint64_t *rval, int size, void *arg)
139{
140	int error;
141	struct mem_range *mr = arg;
142
143	error = (*mr->handler)(ctx, vcpu, MEM_F_READ, gpa, size,
144			       rval, mr->arg1, mr->arg2);
145	return (error);
146}
147
148static int
149mem_write(void *ctx, int vcpu, uint64_t gpa, uint64_t wval, int size, void *arg)
150{
151	int error;
152	struct mem_range *mr = arg;
153
154	error = (*mr->handler)(ctx, vcpu, MEM_F_WRITE, gpa, size,
155			       &wval, mr->arg1, mr->arg2);
156	return (error);
157}
158
159int
160emulate_mem(struct vmctx *ctx, int vcpu, uint64_t paddr, struct vie *vie)
161{
162	struct mmio_rb_range *entry;
163	int err;
164
165	pthread_rwlock_rdlock(&mmio_rwlock);
166	/*
167	 * First check the per-vCPU cache
168	 */
169	if (mmio_hint[vcpu] &&
170	    paddr >= mmio_hint[vcpu]->mr_base &&
171	    paddr <= mmio_hint[vcpu]->mr_end) {
172		entry = mmio_hint[vcpu];
173	} else
174		entry = NULL;
175
176	if (entry == NULL) {
177		if (mmio_rb_lookup(&mmio_rb_root, paddr, &entry) == 0) {
178			/* Update the per-vCPU cache */
179			mmio_hint[vcpu] = entry;
180		} else if (mmio_rb_lookup(&mmio_rb_fallback, paddr, &entry)) {
181			pthread_rwlock_unlock(&mmio_rwlock);
182			return (ESRCH);
183		}
184	}
185
186	assert(entry != NULL);
187	err = vmm_emulate_instruction(ctx, vcpu, paddr, vie,
188				      mem_read, mem_write, &entry->mr_param);
189	pthread_rwlock_unlock(&mmio_rwlock);
190
191	return (err);
192}
193
194static int
195register_mem_int(struct mmio_rb_tree *rbt, struct mem_range *memp)
196{
197	struct mmio_rb_range *entry, *mrp;
198	int		err;
199
200	err = 0;
201
202	mrp = malloc(sizeof(struct mmio_rb_range));
203
204	if (mrp != NULL) {
205		mrp->mr_param = *memp;
206		mrp->mr_base = memp->base;
207		mrp->mr_end = memp->base + memp->size - 1;
208		pthread_rwlock_wrlock(&mmio_rwlock);
209		if (mmio_rb_lookup(rbt, memp->base, &entry) != 0)
210			err = mmio_rb_add(rbt, mrp);
211		pthread_rwlock_unlock(&mmio_rwlock);
212		if (err)
213			free(mrp);
214	} else
215		err = ENOMEM;
216
217	return (err);
218}
219
220int
221register_mem(struct mem_range *memp)
222{
223
224	return (register_mem_int(&mmio_rb_root, memp));
225}
226
227int
228register_mem_fallback(struct mem_range *memp)
229{
230
231	return (register_mem_int(&mmio_rb_fallback, memp));
232}
233
234int
235unregister_mem(struct mem_range *memp)
236{
237	struct mem_range *mr;
238	struct mmio_rb_range *entry = NULL;
239	int err, i;
240
241	pthread_rwlock_wrlock(&mmio_rwlock);
242	err = mmio_rb_lookup(&mmio_rb_root, memp->base, &entry);
243	if (err == 0) {
244		mr = &entry->mr_param;
245		assert(mr->name == memp->name);
246		assert(mr->base == memp->base && mr->size == memp->size);
247		RB_REMOVE(mmio_rb_tree, &mmio_rb_root, entry);
248
249		/* flush Per-vCPU cache */
250		for (i=0; i < VM_MAXCPU; i++) {
251			if (mmio_hint[i] == entry)
252				mmio_hint[i] = NULL;
253		}
254	}
255	pthread_rwlock_unlock(&mmio_rwlock);
256
257	if (entry)
258		free(entry);
259
260	return (err);
261}
262
263void
264init_mem(void)
265{
266
267	RB_INIT(&mmio_rb_root);
268	RB_INIT(&mmio_rb_fallback);
269	pthread_rwlock_init(&mmio_rwlock, NULL);
270}
271