xref: /openbmc/qemu/hw/mem/memory-device.c (revision 53d28455)
1 /*
2  * Memory Device Interface
3  *
4  * Copyright ProfitBricks GmbH 2012
5  * Copyright (C) 2014 Red Hat Inc
6  * Copyright (c) 2018 Red Hat Inc
7  *
8  * This work is licensed under the terms of the GNU GPL, version 2 or later.
9  * See the COPYING file in the top-level directory.
10  */
11 
12 #include "qemu/osdep.h"
13 #include "hw/mem/memory-device.h"
14 #include "hw/qdev.h"
15 #include "qapi/error.h"
16 #include "hw/boards.h"
17 #include "qemu/range.h"
18 #include "hw/virtio/vhost.h"
19 #include "sysemu/kvm.h"
20 #include "trace.h"
21 
22 static gint memory_device_addr_sort(gconstpointer a, gconstpointer b)
23 {
24     const MemoryDeviceState *md_a = MEMORY_DEVICE(a);
25     const MemoryDeviceState *md_b = MEMORY_DEVICE(b);
26     const MemoryDeviceClass *mdc_a = MEMORY_DEVICE_GET_CLASS(a);
27     const MemoryDeviceClass *mdc_b = MEMORY_DEVICE_GET_CLASS(b);
28     const uint64_t addr_a = mdc_a->get_addr(md_a);
29     const uint64_t addr_b = mdc_b->get_addr(md_b);
30 
31     if (addr_a > addr_b) {
32         return 1;
33     } else if (addr_a < addr_b) {
34         return -1;
35     }
36     return 0;
37 }
38 
39 static int memory_device_build_list(Object *obj, void *opaque)
40 {
41     GSList **list = opaque;
42 
43     if (object_dynamic_cast(obj, TYPE_MEMORY_DEVICE)) {
44         DeviceState *dev = DEVICE(obj);
45         if (dev->realized) { /* only realized memory devices matter */
46             *list = g_slist_insert_sorted(*list, dev, memory_device_addr_sort);
47         }
48     }
49 
50     object_child_foreach(obj, memory_device_build_list, opaque);
51     return 0;
52 }
53 
54 static int memory_device_used_region_size(Object *obj, void *opaque)
55 {
56     uint64_t *size = opaque;
57 
58     if (object_dynamic_cast(obj, TYPE_MEMORY_DEVICE)) {
59         const DeviceState *dev = DEVICE(obj);
60         const MemoryDeviceState *md = MEMORY_DEVICE(obj);
61 
62         if (dev->realized) {
63             *size += memory_device_get_region_size(md, &error_abort);
64         }
65     }
66 
67     object_child_foreach(obj, memory_device_used_region_size, opaque);
68     return 0;
69 }
70 
71 static void memory_device_check_addable(MachineState *ms, uint64_t size,
72                                         Error **errp)
73 {
74     uint64_t used_region_size = 0;
75 
76     /* we will need a new memory slot for kvm and vhost */
77     if (kvm_enabled() && !kvm_has_free_slot(ms)) {
78         error_setg(errp, "hypervisor has no free memory slots left");
79         return;
80     }
81     if (!vhost_has_free_slot()) {
82         error_setg(errp, "a used vhost backend has no free memory slots left");
83         return;
84     }
85 
86     /* will we exceed the total amount of memory specified */
87     memory_device_used_region_size(OBJECT(ms), &used_region_size);
88     if (used_region_size + size > ms->maxram_size - ms->ram_size) {
89         error_setg(errp, "not enough space, currently 0x%" PRIx64
90                    " in use of total space for memory devices 0x" RAM_ADDR_FMT,
91                    used_region_size, ms->maxram_size - ms->ram_size);
92         return;
93     }
94 
95 }
96 
97 static uint64_t memory_device_get_free_addr(MachineState *ms,
98                                             const uint64_t *hint,
99                                             uint64_t align, uint64_t size,
100                                             Error **errp)
101 {
102     uint64_t address_space_start, address_space_end;
103     GSList *list = NULL, *item;
104     uint64_t new_addr = 0;
105 
106     if (!ms->device_memory) {
107         error_setg(errp, "memory devices (e.g. for memory hotplug) are not "
108                          "supported by the machine");
109         return 0;
110     }
111 
112     if (!memory_region_size(&ms->device_memory->mr)) {
113         error_setg(errp, "memory devices (e.g. for memory hotplug) are not "
114                          "enabled, please specify the maxmem option");
115         return 0;
116     }
117     address_space_start = ms->device_memory->base;
118     address_space_end = address_space_start +
119                         memory_region_size(&ms->device_memory->mr);
120     g_assert(address_space_end >= address_space_start);
121 
122     /* address_space_start indicates the maximum alignment we expect */
123     if (QEMU_ALIGN_UP(address_space_start, align) != address_space_start) {
124         error_setg(errp, "the alignment (0x%" PRIx64 ") is not supported",
125                    align);
126         return 0;
127     }
128 
129     memory_device_check_addable(ms, size, errp);
130     if (*errp) {
131         return 0;
132     }
133 
134     if (hint && QEMU_ALIGN_UP(*hint, align) != *hint) {
135         error_setg(errp, "address must be aligned to 0x%" PRIx64 " bytes",
136                    align);
137         return 0;
138     }
139 
140     if (QEMU_ALIGN_UP(size, align) != size) {
141         error_setg(errp, "backend memory size must be multiple of 0x%"
142                    PRIx64, align);
143         return 0;
144     }
145 
146     if (hint) {
147         new_addr = *hint;
148         if (new_addr < address_space_start) {
149             error_setg(errp, "can't add memory device [0x%" PRIx64 ":0x%" PRIx64
150                        "] before 0x%" PRIx64, new_addr, size,
151                        address_space_start);
152             return 0;
153         } else if ((new_addr + size) > address_space_end) {
154             error_setg(errp, "can't add memory device [0x%" PRIx64 ":0x%" PRIx64
155                        "] beyond 0x%" PRIx64, new_addr, size,
156                        address_space_end);
157             return 0;
158         }
159     } else {
160         new_addr = address_space_start;
161     }
162 
163     /* find address range that will fit new memory device */
164     object_child_foreach(OBJECT(ms), memory_device_build_list, &list);
165     for (item = list; item; item = g_slist_next(item)) {
166         const MemoryDeviceState *md = item->data;
167         const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(OBJECT(md));
168         uint64_t md_size, md_addr;
169 
170         md_addr = mdc->get_addr(md);
171         md_size = memory_device_get_region_size(md, &error_abort);
172 
173         if (ranges_overlap(md_addr, md_size, new_addr, size)) {
174             if (hint) {
175                 const DeviceState *d = DEVICE(md);
176                 error_setg(errp, "address range conflicts with memory device"
177                            " id='%s'", d->id ? d->id : "(unnamed)");
178                 goto out;
179             }
180             new_addr = QEMU_ALIGN_UP(md_addr + md_size, align);
181         }
182     }
183 
184     if (new_addr + size > address_space_end) {
185         error_setg(errp, "could not find position in guest address space for "
186                    "memory device - memory fragmented due to alignments");
187         goto out;
188     }
189 out:
190     g_slist_free(list);
191     return new_addr;
192 }
193 
194 MemoryDeviceInfoList *qmp_memory_device_list(void)
195 {
196     GSList *devices = NULL, *item;
197     MemoryDeviceInfoList *list = NULL, *prev = NULL;
198 
199     object_child_foreach(qdev_get_machine(), memory_device_build_list,
200                          &devices);
201 
202     for (item = devices; item; item = g_slist_next(item)) {
203         const MemoryDeviceState *md = MEMORY_DEVICE(item->data);
204         const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(item->data);
205         MemoryDeviceInfoList *elem = g_new0(MemoryDeviceInfoList, 1);
206         MemoryDeviceInfo *info = g_new0(MemoryDeviceInfo, 1);
207 
208         mdc->fill_device_info(md, info);
209 
210         elem->value = info;
211         elem->next = NULL;
212         if (prev) {
213             prev->next = elem;
214         } else {
215             list = elem;
216         }
217         prev = elem;
218     }
219 
220     g_slist_free(devices);
221 
222     return list;
223 }
224 
225 static int memory_device_plugged_size(Object *obj, void *opaque)
226 {
227     uint64_t *size = opaque;
228 
229     if (object_dynamic_cast(obj, TYPE_MEMORY_DEVICE)) {
230         const DeviceState *dev = DEVICE(obj);
231         const MemoryDeviceState *md = MEMORY_DEVICE(obj);
232         const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(obj);
233 
234         if (dev->realized) {
235             *size += mdc->get_plugged_size(md, &error_abort);
236         }
237     }
238 
239     object_child_foreach(obj, memory_device_plugged_size, opaque);
240     return 0;
241 }
242 
243 uint64_t get_plugged_memory_size(void)
244 {
245     uint64_t size = 0;
246 
247     memory_device_plugged_size(qdev_get_machine(), &size);
248 
249     return size;
250 }
251 
252 void memory_device_pre_plug(MemoryDeviceState *md, MachineState *ms,
253                             const uint64_t *legacy_align, Error **errp)
254 {
255     const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(md);
256     Error *local_err = NULL;
257     uint64_t addr, align;
258     MemoryRegion *mr;
259 
260     mr = mdc->get_memory_region(md, &local_err);
261     if (local_err) {
262         goto out;
263     }
264 
265     align = legacy_align ? *legacy_align : memory_region_get_alignment(mr);
266     addr = mdc->get_addr(md);
267     addr = memory_device_get_free_addr(ms, !addr ? NULL : &addr, align,
268                                        memory_region_size(mr), &local_err);
269     if (local_err) {
270         goto out;
271     }
272     mdc->set_addr(md, addr, &local_err);
273     if (!local_err) {
274         trace_memory_device_pre_plug(DEVICE(md)->id ? DEVICE(md)->id : "",
275                                      addr);
276     }
277 out:
278     error_propagate(errp, local_err);
279 }
280 
281 void memory_device_plug(MemoryDeviceState *md, MachineState *ms)
282 {
283     const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(md);
284     const uint64_t addr = mdc->get_addr(md);
285     MemoryRegion *mr;
286 
287     /*
288      * We expect that a previous call to memory_device_pre_plug() succeeded, so
289      * it can't fail at this point.
290      */
291     mr = mdc->get_memory_region(md, &error_abort);
292     g_assert(ms->device_memory);
293 
294     memory_region_add_subregion(&ms->device_memory->mr,
295                                 addr - ms->device_memory->base, mr);
296     trace_memory_device_plug(DEVICE(md)->id ? DEVICE(md)->id : "", addr);
297 }
298 
299 void memory_device_unplug(MemoryDeviceState *md, MachineState *ms)
300 {
301     const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(md);
302     MemoryRegion *mr;
303 
304     /*
305      * We expect that a previous call to memory_device_pre_plug() succeeded, so
306      * it can't fail at this point.
307      */
308     mr = mdc->get_memory_region(md, &error_abort);
309     g_assert(ms->device_memory);
310 
311     memory_region_del_subregion(&ms->device_memory->mr, mr);
312     trace_memory_device_unplug(DEVICE(md)->id ? DEVICE(md)->id : "",
313                                mdc->get_addr(md));
314 }
315 
316 uint64_t memory_device_get_region_size(const MemoryDeviceState *md,
317                                        Error **errp)
318 {
319     const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(md);
320     MemoryRegion *mr;
321 
322     /* dropping const here is fine as we don't touch the memory region */
323     mr = mdc->get_memory_region((MemoryDeviceState *)md, errp);
324     if (!mr) {
325         return 0;
326     }
327 
328     return memory_region_size(mr);
329 }
330 
331 static const TypeInfo memory_device_info = {
332     .name          = TYPE_MEMORY_DEVICE,
333     .parent        = TYPE_INTERFACE,
334     .class_size = sizeof(MemoryDeviceClass),
335 };
336 
337 static void memory_device_register_types(void)
338 {
339     type_register_static(&memory_device_info);
340 }
341 
342 type_init(memory_device_register_types)
343