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13#include "qemu/osdep.h"
14
15#include "exec/address-spaces.h"
16#include "hw/qdev-properties.h"
17#include "hw/sysbus.h"
18#include "qapi/error.h"
19#include "qemu/units.h"
20#include "sysemu/qtest.h"
21#include "hw/mem/sparse-mem.h"
22
23#define SPARSE_MEM(obj) OBJECT_CHECK(SparseMemState, (obj), TYPE_SPARSE_MEM)
24#define SPARSE_BLOCK_SIZE 0x1000
25
26typedef struct SparseMemState {
27 SysBusDevice parent_obj;
28 MemoryRegion mmio;
29 uint64_t baseaddr;
30 uint64_t length;
31 uint64_t size_used;
32 uint64_t maxsize;
33 GHashTable *mapped;
34} SparseMemState;
35
36typedef struct sparse_mem_block {
37 uint8_t data[SPARSE_BLOCK_SIZE];
38} sparse_mem_block;
39
40static uint64_t sparse_mem_read(void *opaque, hwaddr addr, unsigned int size)
41{
42 SparseMemState *s = opaque;
43 uint64_t ret = 0;
44 size_t pfn = addr / SPARSE_BLOCK_SIZE;
45 size_t offset = addr % SPARSE_BLOCK_SIZE;
46 sparse_mem_block *block;
47
48 block = g_hash_table_lookup(s->mapped, (void *)pfn);
49 if (block) {
50 assert(offset + size <= sizeof(block->data));
51 memcpy(&ret, block->data + offset, size);
52 }
53 return ret;
54}
55
56static void sparse_mem_write(void *opaque, hwaddr addr, uint64_t v,
57 unsigned int size)
58{
59 SparseMemState *s = opaque;
60 size_t pfn = addr / SPARSE_BLOCK_SIZE;
61 size_t offset = addr % SPARSE_BLOCK_SIZE;
62 sparse_mem_block *block;
63
64 if (!g_hash_table_lookup(s->mapped, (void *)pfn) &&
65 s->size_used + SPARSE_BLOCK_SIZE < s->maxsize && v) {
66 g_hash_table_insert(s->mapped, (void *)pfn,
67 g_new0(sparse_mem_block, 1));
68 s->size_used += sizeof(block->data);
69 }
70 block = g_hash_table_lookup(s->mapped, (void *)pfn);
71 if (!block) {
72 return;
73 }
74
75 assert(offset + size <= sizeof(block->data));
76
77 memcpy(block->data + offset, &v, size);
78
79}
80
81static const MemoryRegionOps sparse_mem_ops = {
82 .read = sparse_mem_read,
83 .write = sparse_mem_write,
84 .endianness = DEVICE_LITTLE_ENDIAN,
85 .valid = {
86 .min_access_size = 1,
87 .max_access_size = 8,
88 .unaligned = false,
89 },
90};
91
92static Property sparse_mem_properties[] = {
93
94 DEFINE_PROP_UINT64("baseaddr", SparseMemState, baseaddr, 0x0),
95
96 DEFINE_PROP_UINT64("length", SparseMemState, length, UINT64_MAX),
97
98 DEFINE_PROP_UINT64("maxsize", SparseMemState, maxsize, 10 * MiB),
99 DEFINE_PROP_END_OF_LIST(),
100};
101
102MemoryRegion *sparse_mem_init(uint64_t addr, uint64_t length)
103{
104 DeviceState *dev;
105
106 dev = qdev_new(TYPE_SPARSE_MEM);
107 qdev_prop_set_uint64(dev, "baseaddr", addr);
108 qdev_prop_set_uint64(dev, "length", length);
109 sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
110 sysbus_mmio_map_overlap(SYS_BUS_DEVICE(dev), 0, addr, -10000);
111 return &SPARSE_MEM(dev)->mmio;
112}
113
114static void sparse_mem_realize(DeviceState *dev, Error **errp)
115{
116 SparseMemState *s = SPARSE_MEM(dev);
117 SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
118
119 if (!qtest_enabled()) {
120 error_setg(errp, "sparse_mem device should only be used "
121 "for testing with QTest");
122 return;
123 }
124
125 assert(s->baseaddr + s->length > s->baseaddr);
126
127 s->mapped = g_hash_table_new(NULL, NULL);
128 memory_region_init_io(&s->mmio, OBJECT(s), &sparse_mem_ops, s,
129 "sparse-mem", s->length);
130 sysbus_init_mmio(sbd, &s->mmio);
131}
132
133static void sparse_mem_class_init(ObjectClass *klass, void *data)
134{
135 DeviceClass *dc = DEVICE_CLASS(klass);
136
137 device_class_set_props(dc, sparse_mem_properties);
138
139 dc->desc = "Sparse Memory Device";
140 dc->realize = sparse_mem_realize;
141}
142
143static const TypeInfo sparse_mem_types[] = {
144 {
145 .name = TYPE_SPARSE_MEM,
146 .parent = TYPE_SYS_BUS_DEVICE,
147 .instance_size = sizeof(SparseMemState),
148 .class_init = sparse_mem_class_init,
149 },
150};
151DEFINE_TYPES(sparse_mem_types);
152