hw/mem/memory-device.h

2  * Memory Device Interface
10  * See the COPYING file in the top-level directory.
16 #include "hw/qdev-core.h"
17 #include "qapi/qapi-types-machine.h"
20 #define TYPE_MEMORY_DEVICE "memory-device"
33  * All memory devices need to implement TYPE_MEMORY_DEVICE as an interface.
35  * A memory device is a device that owns a memory region which is
37  * address in guest physical memory can either be specified explicitly
40  * Some memory device might not own a memory region in certain device
42  * empty memory devices are mostly ignored by the memory device code.
44  * Conceptually, memory devices only span one memory region. If multiple
45  * successive memory regions are used, a covering memory region has to
46  * be provided. Scattered memory regions are not supported for single
49  * The device memory region returned via @get_memory_region may either be a
50  * single RAM memory region or a memory region container with subregions
51  * that are RAM memory regions or aliases to RAM memory regions. Other
52  * memory regions or subregions are not supported.
54  * If the device memory region returned via @get_memory_region is a
55  * memory region container, it's supported to dynamically (un)map subregions
57  * be exceeded and as long as all memory regions are of the same kind (e.g.,
65      * Return the address of the memory device in guest physical memory.
67      * Called when (un)plugging a memory device or when iterating over
68      * all memory devices mapped into guest physical address space.
71      * no address has been assigned to this memory device yet.
76      * Set the address of the memory device in guest physical memory.
78      * Called when plugging the memory device to configure the determined
79      * address in guest physical memory.
84      * Return the amount of memory provided by the memory device currently
88      * VM (e.g. to report memory stats to the user).
91      * memory accessible by the guest via the reserved memory region. For
92      * most devices, this corresponds to the size of the memory region.
97      * Return the memory region of the memory device. If the device is
100      * Called when (un)plugging the memory device, to (un)map the
101      * memory region in guest physical memory, but also to detect the
103      * memory region is required.
108      * Optional: Instruct the memory device to decide how many memory slots
111      * Called exactly once when pre-plugging the memory device, before
117      * Optional for memory devices that require only a single memslot,
118      * required for all other memory devices: Return the number of memslots
119      * (distinct RAM memory regions in the device memory region) that are
124      * Called when (un)plugging the memory device, to check if the requirements
132      * alignment and the alignment requirements of the memory region.
134      * Called when plugging the memory device to detect the required alignment
140      * Translate the memory device into #MemoryDeviceInfo.
148  * 253 memslots were "reserved" for boot memory and other devices (such
153  * the soft-limit of memslots used by memory devices to the traditional
156  * If we have less than 509 memslots, we will instruct memory devices that