On 2 August 2011 19:05, Avi Kivity <a...@redhat.com> wrote: > On 08/02/2011 08:21 PM, Peter Maydell wrote: >> So I think we just need a sysbus_mmio_get_memoryregion() >> (and convert the devices I need to attach to use memory >> regions, and live with not being able to attach unconverted >> devices). > > I don't follow - why do we need get_memoryregion? who would call it?
The machine model would call it. So you do something like DeviceState *dev = qdev_create(NULL, "whatever"); /* Note the parallel here to the existing * sysbus_mmio_map(sysbus_from_qdev(dev), mmio_idx, addr); */ MemoryRegion *mr = sysbus_mmio_get_memoryregion(sysbus_from_qdev(dev), mmio_idx); omap_gpmc_attach(gpmc, 7, mr); ie the machine model is where we wire up the subdevices to the gpmc, and at the machine model level what you have is a pointer to an entire device, so you need to be able to convert the (sysbus*, mmio_index) tuple to a MemoryRegion*. >> [That is, the only reason I'm passing SysBus objects around >> is that at the moment that is the only useful abstraction we >> have for saying "I'm an arbitrary device object and I provide >> some GPIO pins and some memory mappable regions". MemoryRegion* >> allows me to pass around a memory mappable region in a more >> direct way than having to pass a (SysBus*, mmio_index) tuple.] > > I think I see. Perhaps you're describing qdev/MemoryRegion integration. I think qdev devices need to be able to expose MemoryRegions as first class named 'properties' or 'plugs' or 'sockets' or whatever we want to call them, yes. (Ditto gpio/irq, which at the moment we can kind of expose but not by name.) -- PMM
