docs/devel/memory.rst

25 These represent memory as seen from the CPU or a device's viewpoint.
37   memory_region_init_ram_from_file(), or memory_region_init_ram_ptr().
40   each read or write causes a callback to be called on the host.
65   can overlay a subregion of RAM with MMIO or ROM, or a PCI controller
73   of RAM addressed, or a memory controller that splits main memory to
79   but an alias may not point back to itself, directly or indirectly.
89 (that is, to an MMIO, RAM or ROM region). This means that the region
92 container itself (ie by its MMIO callbacks or RAM backing). However
146 attached to an object, which acts as its owner or parent.  QEMU ensures
148 the guest, or as long as the region is in use by a virtual CPU or another
152 After creation, a region can be added to an address space or a
159 or never.
170 device or CPU.  In order to do this, as a general rule do not create or
189 object_unparent at any time for an alias or a container region.  It is
190 therefore also okay to create or destroy alias and container regions
196 or containers, and the above situation then cannot happen.  Exploiting
203 on regions that have no owner, unless they are aliases or containers.
220 If the higher priority region in an overlap is a container or alias, then
223 (This applies recursively -- if the subregions are themselves containers or
251 D or E, and the result would be::
258 a bus or a memory controller) can use them to manage the interaction of
275   - if the subregion is a leaf (RAM or MMIO), the search terminates, returning
281   - if a recursive search within a container or alias subregion does not
283     address range), then if this is a container with its own MMIO or RAM
347 based on the attributes used for the memory transaction, or need
357   have device and bus specific behaviour (ignored, or machine check)
360   appropriate bus or CPU specific behaviour.