Re: [PATCH 1/2] hw/mips/jazz: Use generic I/O bus via get_system_io()

[Peter Xu <peterx@redhat.com>]

On Wed, Mar 10, 2021 at 09:11:40PM +0100, Philippe Mathieu-Daudé wrote:
> >>      /* ISA bus: IO space at 0x90000000, mem space at 0x91000000 */
> >> -    memory_region_init(isa_io, NULL, "isa-io", 0x00010000);
> >>      memory_region_init(isa_mem, NULL, "isa-mem", 0x01000000);
> >> -    memory_region_add_subregion(address_space, 0x90000000, isa_io);
> >> +    memory_region_add_subregion(address_space, 0x90000000, get_system_io());
> > 
> > The old code has an alias created just for adding subregion into address_space:
> > 
> > -    /* ISA IO space at 0x90000000 */
> > -    memory_region_init_alias(isa, NULL, "isa_mmio",
> > -                             get_system_io(), 0, 0x01000000);
> > -    memory_region_add_subregion(address_space, 0x90000000, isa);
> > -    isa_mem_base = 0x11000000;
> > 
> > While you didn't revert that part.  Maybe that's the issue?
> 
> Hmm I'll have a look. This is not the series I'm working on, which
> is much bigger and not ready for posting yet. I simply looked for
> something similar (a bus mapped into sysbus) and remembered the
> ISA bus from Jazz machines. I'll see if I can find a better PoC.

Yeah no worry - it's just that I feel one memory_region_init_alias() call is
probably missing in your huge series somewhere, so that you'll take that alias
MR as subregion rather than the real MR (which is the root of one AS).

-- 
Peter Xu