jcs.org
qemu with hax to log dma reads & writes
jcs.org/2018/11/12/vfio
1/*
2 * QEMU memory mapping
3 *
4 * Copyright Fujitsu, Corp. 2011, 2012
5 *
6 * Authors:
7 * Wen Congyang <wency@cn.fujitsu.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2 or later.
10 * See the COPYING file in the top-level directory.
11 *
12 */
13
14#include "qemu/osdep.h"
15#include "qapi/error.h"
16
17#include "cpu.h"
18#include "sysemu/memory_mapping.h"
19#include "exec/memory.h"
20#include "exec/address-spaces.h"
21
22//#define DEBUG_GUEST_PHYS_REGION_ADD
23
24static void memory_mapping_list_add_mapping_sorted(MemoryMappingList *list,
25 MemoryMapping *mapping)
26{
27 MemoryMapping *p;
28
29 QTAILQ_FOREACH(p, &list->head, next) {
30 if (p->phys_addr >= mapping->phys_addr) {
31 QTAILQ_INSERT_BEFORE(p, mapping, next);
32 return;
33 }
34 }
35 QTAILQ_INSERT_TAIL(&list->head, mapping, next);
36}
37
38static void create_new_memory_mapping(MemoryMappingList *list,
39 hwaddr phys_addr,
40 hwaddr virt_addr,
41 ram_addr_t length)
42{
43 MemoryMapping *memory_mapping;
44
45 memory_mapping = g_malloc(sizeof(MemoryMapping));
46 memory_mapping->phys_addr = phys_addr;
47 memory_mapping->virt_addr = virt_addr;
48 memory_mapping->length = length;
49 list->last_mapping = memory_mapping;
50 list->num++;
51 memory_mapping_list_add_mapping_sorted(list, memory_mapping);
52}
53
54static inline bool mapping_contiguous(MemoryMapping *map,
55 hwaddr phys_addr,
56 hwaddr virt_addr)
57{
58 return phys_addr == map->phys_addr + map->length &&
59 virt_addr == map->virt_addr + map->length;
60}
61
62/*
63 * [map->phys_addr, map->phys_addr + map->length) and
64 * [phys_addr, phys_addr + length) have intersection?
65 */
66static inline bool mapping_have_same_region(MemoryMapping *map,
67 hwaddr phys_addr,
68 ram_addr_t length)
69{
70 return !(phys_addr + length < map->phys_addr ||
71 phys_addr >= map->phys_addr + map->length);
72}
73
74/*
75 * [map->phys_addr, map->phys_addr + map->length) and
76 * [phys_addr, phys_addr + length) have intersection. The virtual address in the
77 * intersection are the same?
78 */
79static inline bool mapping_conflict(MemoryMapping *map,
80 hwaddr phys_addr,
81 hwaddr virt_addr)
82{
83 return virt_addr - map->virt_addr != phys_addr - map->phys_addr;
84}
85
86/*
87 * [map->virt_addr, map->virt_addr + map->length) and
88 * [virt_addr, virt_addr + length) have intersection. And the physical address
89 * in the intersection are the same.
90 */
91static inline void mapping_merge(MemoryMapping *map,
92 hwaddr virt_addr,
93 ram_addr_t length)
94{
95 if (virt_addr < map->virt_addr) {
96 map->length += map->virt_addr - virt_addr;
97 map->virt_addr = virt_addr;
98 }
99
100 if ((virt_addr + length) >
101 (map->virt_addr + map->length)) {
102 map->length = virt_addr + length - map->virt_addr;
103 }
104}
105
106void memory_mapping_list_add_merge_sorted(MemoryMappingList *list,
107 hwaddr phys_addr,
108 hwaddr virt_addr,
109 ram_addr_t length)
110{
111 MemoryMapping *memory_mapping, *last_mapping;
112
113 if (QTAILQ_EMPTY(&list->head)) {
114 create_new_memory_mapping(list, phys_addr, virt_addr, length);
115 return;
116 }
117
118 last_mapping = list->last_mapping;
119 if (last_mapping) {
120 if (mapping_contiguous(last_mapping, phys_addr, virt_addr)) {
121 last_mapping->length += length;
122 return;
123 }
124 }
125
126 QTAILQ_FOREACH(memory_mapping, &list->head, next) {
127 if (mapping_contiguous(memory_mapping, phys_addr, virt_addr)) {
128 memory_mapping->length += length;
129 list->last_mapping = memory_mapping;
130 return;
131 }
132
133 if (phys_addr + length < memory_mapping->phys_addr) {
134 /* create a new region before memory_mapping */
135 break;
136 }
137
138 if (mapping_have_same_region(memory_mapping, phys_addr, length)) {
139 if (mapping_conflict(memory_mapping, phys_addr, virt_addr)) {
140 continue;
141 }
142
143 /* merge this region into memory_mapping */
144 mapping_merge(memory_mapping, virt_addr, length);
145 list->last_mapping = memory_mapping;
146 return;
147 }
148 }
149
150 /* this region can not be merged into any existed memory mapping. */
151 create_new_memory_mapping(list, phys_addr, virt_addr, length);
152}
153
154void memory_mapping_list_free(MemoryMappingList *list)
155{
156 MemoryMapping *p, *q;
157
158 QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {
159 QTAILQ_REMOVE(&list->head, p, next);
160 g_free(p);
161 }
162
163 list->num = 0;
164 list->last_mapping = NULL;
165}
166
167void memory_mapping_list_init(MemoryMappingList *list)
168{
169 list->num = 0;
170 list->last_mapping = NULL;
171 QTAILQ_INIT(&list->head);
172}
173
174void guest_phys_blocks_free(GuestPhysBlockList *list)
175{
176 GuestPhysBlock *p, *q;
177
178 QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {
179 QTAILQ_REMOVE(&list->head, p, next);
180 memory_region_unref(p->mr);
181 g_free(p);
182 }
183 list->num = 0;
184}
185
186void guest_phys_blocks_init(GuestPhysBlockList *list)
187{
188 list->num = 0;
189 QTAILQ_INIT(&list->head);
190}
191
192typedef struct GuestPhysListener {
193 GuestPhysBlockList *list;
194 MemoryListener listener;
195} GuestPhysListener;
196
197static void guest_phys_blocks_region_add(MemoryListener *listener,
198 MemoryRegionSection *section)
199{
200 GuestPhysListener *g;
201 uint64_t section_size;
202 hwaddr target_start, target_end;
203 uint8_t *host_addr;
204 GuestPhysBlock *predecessor;
205
206 /* we only care about RAM */
207 if (!memory_region_is_ram(section->mr) ||
208 memory_region_is_ram_device(section->mr) ||
209 memory_region_is_nonvolatile(section->mr)) {
210 return;
211 }
212
213 g = container_of(listener, GuestPhysListener, listener);
214 section_size = int128_get64(section->size);
215 target_start = section->offset_within_address_space;
216 target_end = target_start + section_size;
217 host_addr = memory_region_get_ram_ptr(section->mr) +
218 section->offset_within_region;
219 predecessor = NULL;
220
221 /* find continuity in guest physical address space */
222 if (!QTAILQ_EMPTY(&g->list->head)) {
223 hwaddr predecessor_size;
224
225 predecessor = QTAILQ_LAST(&g->list->head);
226 predecessor_size = predecessor->target_end - predecessor->target_start;
227
228 /* the memory API guarantees monotonically increasing traversal */
229 g_assert(predecessor->target_end <= target_start);
230
231 /* we want continuity in both guest-physical and host-virtual memory */
232 if (predecessor->target_end < target_start ||
233 predecessor->host_addr + predecessor_size != host_addr) {
234 predecessor = NULL;
235 }
236 }
237
238 if (predecessor == NULL) {
239 /* isolated mapping, allocate it and add it to the list */
240 GuestPhysBlock *block = g_malloc0(sizeof *block);
241
242 block->target_start = target_start;
243 block->target_end = target_end;
244 block->host_addr = host_addr;
245 block->mr = section->mr;
246 memory_region_ref(section->mr);
247
248 QTAILQ_INSERT_TAIL(&g->list->head, block, next);
249 ++g->list->num;
250 } else {
251 /* expand predecessor until @target_end; predecessor's start doesn't
252 * change
253 */
254 predecessor->target_end = target_end;
255 }
256
257#ifdef DEBUG_GUEST_PHYS_REGION_ADD
258 fprintf(stderr, "%s: target_start=" TARGET_FMT_plx " target_end="
259 TARGET_FMT_plx ": %s (count: %u)\n", __func__, target_start,
260 target_end, predecessor ? "joined" : "added", g->list->num);
261#endif
262}
263
264void guest_phys_blocks_append(GuestPhysBlockList *list)
265{
266 GuestPhysListener g = { 0 };
267
268 g.list = list;
269 g.listener.region_add = &guest_phys_blocks_region_add;
270 memory_listener_register(&g.listener, &address_space_memory);
271 memory_listener_unregister(&g.listener);
272}
273
274static CPUState *find_paging_enabled_cpu(CPUState *start_cpu)
275{
276 CPUState *cpu;
277
278 CPU_FOREACH(cpu) {
279 if (cpu_paging_enabled(cpu)) {
280 return cpu;
281 }
282 }
283
284 return NULL;
285}
286
287void qemu_get_guest_memory_mapping(MemoryMappingList *list,
288 const GuestPhysBlockList *guest_phys_blocks,
289 Error **errp)
290{
291 CPUState *cpu, *first_paging_enabled_cpu;
292 GuestPhysBlock *block;
293 ram_addr_t offset, length;
294
295 first_paging_enabled_cpu = find_paging_enabled_cpu(first_cpu);
296 if (first_paging_enabled_cpu) {
297 for (cpu = first_paging_enabled_cpu; cpu != NULL;
298 cpu = CPU_NEXT(cpu)) {
299 Error *err = NULL;
300 cpu_get_memory_mapping(cpu, list, &err);
301 if (err) {
302 error_propagate(errp, err);
303 return;
304 }
305 }
306 return;
307 }
308
309 /*
310 * If the guest doesn't use paging, the virtual address is equal to physical
311 * address.
312 */
313 QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
314 offset = block->target_start;
315 length = block->target_end - block->target_start;
316 create_new_memory_mapping(list, offset, offset, length);
317 }
318}
319
320void qemu_get_guest_simple_memory_mapping(MemoryMappingList *list,
321 const GuestPhysBlockList *guest_phys_blocks)
322{
323 GuestPhysBlock *block;
324
325 QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
326 create_new_memory_mapping(list, block->target_start, 0,
327 block->target_end - block->target_start);
328 }
329}
330
331void memory_mapping_filter(MemoryMappingList *list, int64_t begin,
332 int64_t length)
333{
334 MemoryMapping *cur, *next;
335
336 QTAILQ_FOREACH_SAFE(cur, &list->head, next, next) {
337 if (cur->phys_addr >= begin + length ||
338 cur->phys_addr + cur->length <= begin) {
339 QTAILQ_REMOVE(&list->head, cur, next);
340 g_free(cur);
341 list->num--;
342 continue;
343 }
344
345 if (cur->phys_addr < begin) {
346 cur->length -= begin - cur->phys_addr;
347 if (cur->virt_addr) {
348 cur->virt_addr += begin - cur->phys_addr;
349 }
350 cur->phys_addr = begin;
351 }
352
353 if (cur->phys_addr + cur->length > begin + length) {
354 cur->length -= cur->phys_addr + cur->length - begin - length;
355 }
356 }
357}