xref: /openbmc/qemu/hw/mem/memory-device.c (revision b7d89466)
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 < used_region_size ||
89         used_region_size + size > ms->maxram_size - ms->ram_size) {
90         error_setg(errp, "not enough space, currently 0x%" PRIx64
91                    " in use of total space for memory devices 0x" RAM_ADDR_FMT,
92                    used_region_size, ms->maxram_size - ms->ram_size);
93         return;
94     }
95 
96 }
97 
98 static uint64_t memory_device_get_free_addr(MachineState *ms,
99                                             const uint64_t *hint,
100                                             uint64_t align, uint64_t size,
101                                             Error **errp)
102 {
103     uint64_t address_space_start, address_space_end;
104     GSList *list = NULL, *item;
105     uint64_t new_addr = 0;
106 
107     if (!ms->device_memory) {
108         error_setg(errp, "memory devices (e.g. for memory hotplug) are not "
109                          "supported by the machine");
110         return 0;
111     }
112 
113     if (!memory_region_size(&ms->device_memory->mr)) {
114         error_setg(errp, "memory devices (e.g. for memory hotplug) are not "
115                          "enabled, please specify the maxmem option");
116         return 0;
117     }
118     address_space_start = ms->device_memory->base;
119     address_space_end = address_space_start +
120                         memory_region_size(&ms->device_memory->mr);
121     g_assert(address_space_end >= address_space_start);
122 
123     /* address_space_start indicates the maximum alignment we expect */
124     if (!QEMU_IS_ALIGNED(address_space_start, align)) {
125         error_setg(errp, "the alignment (0x%" PRIx64 ") is not supported",
126                    align);
127         return 0;
128     }
129 
130     memory_device_check_addable(ms, size, errp);
131     if (*errp) {
132         return 0;
133     }
134 
135     if (hint && !QEMU_IS_ALIGNED(*hint, align)) {
136         error_setg(errp, "address must be aligned to 0x%" PRIx64 " bytes",
137                    align);
138         return 0;
139     }
140 
141     if (!QEMU_IS_ALIGNED(size, align)) {
142         error_setg(errp, "backend memory size must be multiple of 0x%"
143                    PRIx64, align);
144         return 0;
145     }
146 
147     if (hint) {
148         new_addr = *hint;
149         if (new_addr < address_space_start) {
150             error_setg(errp, "can't add memory device [0x%" PRIx64 ":0x%" PRIx64
151                        "] before 0x%" PRIx64, new_addr, size,
152                        address_space_start);
153             return 0;
154         } else if ((new_addr + size) > address_space_end) {
155             error_setg(errp, "can't add memory device [0x%" PRIx64 ":0x%" PRIx64
156                        "] beyond 0x%" PRIx64, new_addr, size,
157                        address_space_end);
158             return 0;
159         }
160     } else {
161         new_addr = address_space_start;
162     }
163 
164     /* find address range that will fit new memory device */
165     object_child_foreach(OBJECT(ms), memory_device_build_list, &list);
166     for (item = list; item; item = g_slist_next(item)) {
167         const MemoryDeviceState *md = item->data;
168         const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(OBJECT(md));
169         uint64_t md_size, md_addr;
170 
171         md_addr = mdc->get_addr(md);
172         md_size = memory_device_get_region_size(md, &error_abort);
173 
174         if (ranges_overlap(md_addr, md_size, new_addr, size)) {
175             if (hint) {
176                 const DeviceState *d = DEVICE(md);
177                 error_setg(errp, "address range conflicts with memory device"
178                            " id='%s'", d->id ? d->id : "(unnamed)");
179                 goto out;
180             }
181             new_addr = QEMU_ALIGN_UP(md_addr + md_size, align);
182         }
183     }
184 
185     if (new_addr + size > address_space_end) {
186         error_setg(errp, "could not find position in guest address space for "
187                    "memory device - memory fragmented due to alignments");
188         goto out;
189     }
190 out:
191     g_slist_free(list);
192     return new_addr;
193 }
194 
195 MemoryDeviceInfoList *qmp_memory_device_list(void)
196 {
197     GSList *devices = NULL, *item;
198     MemoryDeviceInfoList *list = NULL, *prev = NULL;
199 
200     object_child_foreach(qdev_get_machine(), memory_device_build_list,
201                          &devices);
202 
203     for (item = devices; item; item = g_slist_next(item)) {
204         const MemoryDeviceState *md = MEMORY_DEVICE(item->data);
205         const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(item->data);
206         MemoryDeviceInfoList *elem = g_new0(MemoryDeviceInfoList, 1);
207         MemoryDeviceInfo *info = g_new0(MemoryDeviceInfo, 1);
208 
209         mdc->fill_device_info(md, info);
210 
211         elem->value = info;
212         elem->next = NULL;
213         if (prev) {
214             prev->next = elem;
215         } else {
216             list = elem;
217         }
218         prev = elem;
219     }
220 
221     g_slist_free(devices);
222 
223     return list;
224 }
225 
226 static int memory_device_plugged_size(Object *obj, void *opaque)
227 {
228     uint64_t *size = opaque;
229 
230     if (object_dynamic_cast(obj, TYPE_MEMORY_DEVICE)) {
231         const DeviceState *dev = DEVICE(obj);
232         const MemoryDeviceState *md = MEMORY_DEVICE(obj);
233         const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(obj);
234 
235         if (dev->realized) {
236             *size += mdc->get_plugged_size(md, &error_abort);
237         }
238     }
239 
240     object_child_foreach(obj, memory_device_plugged_size, opaque);
241     return 0;
242 }
243 
244 uint64_t get_plugged_memory_size(void)
245 {
246     uint64_t size = 0;
247 
248     memory_device_plugged_size(qdev_get_machine(), &size);
249 
250     return size;
251 }
252 
253 void memory_device_pre_plug(MemoryDeviceState *md, MachineState *ms,
254                             const uint64_t *legacy_align, Error **errp)
255 {
256     const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(md);
257     Error *local_err = NULL;
258     uint64_t addr, align;
259     MemoryRegion *mr;
260 
261     mr = mdc->get_memory_region(md, &local_err);
262     if (local_err) {
263         goto out;
264     }
265 
266     align = legacy_align ? *legacy_align : memory_region_get_alignment(mr);
267     addr = mdc->get_addr(md);
268     addr = memory_device_get_free_addr(ms, !addr ? NULL : &addr, align,
269                                        memory_region_size(mr), &local_err);
270     if (local_err) {
271         goto out;
272     }
273     mdc->set_addr(md, addr, &local_err);
274     if (!local_err) {
275         trace_memory_device_pre_plug(DEVICE(md)->id ? DEVICE(md)->id : "",
276                                      addr);
277     }
278 out:
279     error_propagate(errp, local_err);
280 }
281 
282 void memory_device_plug(MemoryDeviceState *md, MachineState *ms)
283 {
284     const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(md);
285     const uint64_t addr = mdc->get_addr(md);
286     MemoryRegion *mr;
287 
288     /*
289      * We expect that a previous call to memory_device_pre_plug() succeeded, so
290      * it can't fail at this point.
291      */
292     mr = mdc->get_memory_region(md, &error_abort);
293     g_assert(ms->device_memory);
294 
295     memory_region_add_subregion(&ms->device_memory->mr,
296                                 addr - ms->device_memory->base, mr);
297     trace_memory_device_plug(DEVICE(md)->id ? DEVICE(md)->id : "", addr);
298 }
299 
300 void memory_device_unplug(MemoryDeviceState *md, MachineState *ms)
301 {
302     const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(md);
303     MemoryRegion *mr;
304 
305     /*
306      * We expect that a previous call to memory_device_pre_plug() succeeded, so
307      * it can't fail at this point.
308      */
309     mr = mdc->get_memory_region(md, &error_abort);
310     g_assert(ms->device_memory);
311 
312     memory_region_del_subregion(&ms->device_memory->mr, mr);
313     trace_memory_device_unplug(DEVICE(md)->id ? DEVICE(md)->id : "",
314                                mdc->get_addr(md));
315 }
316 
317 uint64_t memory_device_get_region_size(const MemoryDeviceState *md,
318                                        Error **errp)
319 {
320     const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(md);
321     MemoryRegion *mr;
322 
323     /* dropping const here is fine as we don't touch the memory region */
324     mr = mdc->get_memory_region((MemoryDeviceState *)md, errp);
325     if (!mr) {
326         return 0;
327     }
328 
329     return memory_region_size(mr);
330 }
331 
332 static const TypeInfo memory_device_info = {
333     .name          = TYPE_MEMORY_DEVICE,
334     .parent        = TYPE_INTERFACE,
335     .class_size = sizeof(MemoryDeviceClass),
336 };
337 
338 static void memory_device_register_types(void)
339 {
340     type_register_static(&memory_device_info);
341 }
342 
343 type_init(memory_device_register_types)
344