On 05/01/2012 05:15 PM, Anthony Liguori wrote: >>> I think a nice fix would be to make it_shift as memory region mutator >>> and allow it to be set after initialization. >> >> Indeed I wanted to make it_shift as part of the memory core. But a >> mutator? It doesn't change in real hardware, so this looks artificial. >> So far all mutators really change at runtime. > > > QOM has a concept of initialization and realize. You can change > properties after initialization but not before realize. > > So as long as it_shift can be set after initialization but before > realize (which I think is roughly memory_region_add_subregion) it > doesn't need to be a mutator.
Ok, good. > >> What is the problem with delaying region initialization until realize? > > We need to initialize the MemoryRegion in order to expose it as a > property. We want to do that during initialize. Here's an example: > > qom-create isa-i8259 foo > qom-set /peripheral/foo/io it_shift 1 > qom-set /peripheral/foo/realize true > > For this to work, it_shift needs to be a QOM property of the "io" > MemoryRegion. The MemoryRegion needs to be created in instance_init. So it looks like we need two phase initialization for memory regions as well? Not so pretty. > >>> b) There's some duplication in MemoryRegions with respect to QOM. >>> Memory regions want to have a name but with QOM they'll be addressable >>> via a path. I go back and forth about how aggressively we want to >>> refactor MemoryRegions. >> >> These days region names are purely for debugging. The ABI bit was moved >> to a separate function. > > Fair enough. > > BTW, in the branch I've posted, I've got a number of memory API > conversions or removal of legacy interfaces. Nice. But you use get_system_io(), which is bad. -- error compiling committee.c: too many arguments to function
