As expected, this is taking longer than expected, so I'm releasing something
less complete than I'd have liked. Not even all of the PC machine is
converted, but the difficult parts are (cirrus). It appears to work well.
The major change compared to v1 is the introduction of
memory_region_init_alias(), which defines a memory region in terms of another.
With the current API, the ability to alias is provided by address arithmetic
on ram_addr_t:
ram_addr = qemu_ram_alloc(...);
cpu_register_physical_memory(..., ram_addr, size, ...);
/* alias: */
cpu_register_physical_memory(..., ram_addr + offset, another_size, ...);
With the new API, you have to create an alias:
memory_region_init_ram(&mem, ...);
memory_region_register_subregion(...,&mem);
/* alias: */
memory_region_init_alias(&alias, ...,&mem, offset, another_size);
memory_region_register_subregion(...,&alias);