The RAM container is exposed as an AddressSpace.
AddressSpaces root MemoryRegion must not be mapped into other
MemoryRegion, therefore map the RAM container using an alias.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/arm/aspeed.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/hw/arm/aspeed.c b/hw/arm/aspeed.c
index a17b75f4940..daeef5b32a2 100644
--- a/hw/arm/aspeed.c
+++ b/hw/arm/aspeed.c
@@ -40,6 +40,7 @@ struct AspeedMachineState {
 
     AspeedSoCState soc;
     MemoryRegion ram_container;
+    MemoryRegion ram_container_alias;
     MemoryRegion max_ram;
     bool mmio_exec;
     char *fmc_model;
@@ -339,9 +340,12 @@ static void aspeed_machine_init(MachineState *machine)
     }
     qdev_realize(DEVICE(&bmc->soc), NULL, &error_abort);
 
+    memory_region_init_alias(&bmc->ram_container_alias, NULL,
+                             "ram-container-alias", &bmc->ram_container, 0,
+                             memory_region_size(&bmc->ram_container));
     memory_region_add_subregion(get_system_memory(),
                                 sc->memmap[ASPEED_DEV_SDRAM],
-                                &bmc->ram_container);
+                                &bmc->ram_container_alias);
 
     max_ram_size = object_property_get_uint(OBJECT(&bmc->soc), "max-ram-size",
                                             &error_abort);
-- 
2.26.2

On 3/12/21 7:28 PM, Philippe Mathieu-Daudé wrote:
> The RAM container is exposed as an AddressSpace.
> AddressSpaces root MemoryRegion must not be mapped into other
> MemoryRegion, therefore map the RAM container using an alias.
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  hw/arm/aspeed.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/arm/aspeed.c b/hw/arm/aspeed.c
> index a17b75f4940..daeef5b32a2 100644
> --- a/hw/arm/aspeed.c
> +++ b/hw/arm/aspeed.c
> @@ -40,6 +40,7 @@ struct AspeedMachineState {
>  
>      AspeedSoCState soc;
>      MemoryRegion ram_container;
> +    MemoryRegion ram_container_alias;
>      MemoryRegion max_ram;
>      bool mmio_exec;
>      char *fmc_model;
> @@ -339,9 +340,12 @@ static void aspeed_machine_init(MachineState *machine)
>      }
>      qdev_realize(DEVICE(&bmc->soc), NULL, &error_abort);
>  
> +    memory_region_init_alias(&bmc->ram_container_alias, NULL,
> +                             "ram-container-alias", &bmc->ram_container, 0,
> +                             memory_region_size(&bmc->ram_container));
>      memory_region_add_subregion(get_system_memory(),
>                                  sc->memmap[ASPEED_DEV_SDRAM],
> -                                &bmc->ram_container);
> +                                &bmc->ram_container_alias);
>  
>      max_ram_size = object_property_get_uint(OBJECT(&bmc->soc), "max-ram-size",
>                                              &error_abort);
> 

RAM is now initialized before the SoC. So we should be able to use 
machine->ram instead of the bmc->ram_container MR and simplify the
Aspeed SMC model below the SoC.

Thanks,

C.