Re: [PATCH 3/3] system/physmem: Assign global system I/O Memory to machine

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

(+Markus I forgot to Cc)

On 9/2/24 17:06, Peter Maydell wrote:
> On Fri, 9 Feb 2024 at 15:01, Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>>
>> So far there is only one system I/O and one system
>> memory per machine.
>>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>> ---
>>   system/physmem.c | 7 ++++---
>>   1 file changed, 4 insertions(+), 3 deletions(-)
>>
>> diff --git a/system/physmem.c b/system/physmem.c
>> index 5e66d9ae36..50947a374e 100644
>> --- a/system/physmem.c
>> +++ b/system/physmem.c
>> @@ -2554,12 +2554,13 @@ static void memory_map_init(void)
>>   {
>>       system_memory = g_malloc(sizeof(*system_memory));
>>
>> -    memory_region_init(system_memory, NULL, "system", UINT64_MAX);
>> +    memory_region_init(system_memory, OBJECT(current_machine),
>> +                       "system", UINT64_MAX);
>>       address_space_init(&address_space_memory, system_memory, "memory");
>>
>>       system_io = g_malloc(sizeof(*system_io));
>> -    memory_region_init_io(system_io, NULL, &unassigned_io_ops, NULL, "io",
>> -                          65536);
>> +    memory_region_init_io(system_io, OBJECT(current_machine),
>> +                          &unassigned_io_ops, NULL, "io", 65535);
>>       address_space_init(&address_space_io, system_io, "I/O");
>>   }
> 
> What's the intention in doing this? What does it change?

We want to remove access to pre-QOM and possibly hotplug QOM paths
from external API (CLI & QMP so far).

When the parent object is obvious and missing we simply have to
explicit it.

> It seems to be OK to pass a non-Device owner in for
> memory_region_init() (whereas it is *not* OK to do that
> for memory_region_init_ram()), but this seems to be
> getting a bit tricky.

Yes, memory_region_init_ram() is problematic; I'm hardly trying
to ignore it at this point.