Re: [Qemu-devel] [PATCH for-2.3] arm: memory: Replace memory_region_init_ram with memory_region_allocate_system_memory

[Dirk Müller]

Hi Paolo,

> You cannot call memory_region_allocate_system_memory twice.  For cases
> like this one, the right thing to do is to create a region with
> memory_region_allocate_system_memory, and then replace
> memory_region_init_ram with memory_region_init_alias.  This "slices" the
> region created by memory_region_allocate_system_memory.

Thanks for the review and the explanation. Like this?

--- a/hw/arm/exynos4210.c
+++ b/hw/arm/exynos4210.c
@@ -144,6 +144,7 @@ Exynos4210State *exynos4210_init(MemoryRegion *system_mem,
     DeviceState *dev;
     SysBusDevice *busdev;
     ObjectClass *cpu_oc;
+    MemoryRegion *ram_all = g_new(MemoryRegion, 1);

     cpu_oc = cpu_class_by_name(TYPE_ARM_CPU, "cortex-a9");
     assert(cpu_oc);
@@ -281,18 +282,22 @@ Exynos4210State *exynos4210_init(MemoryRegion *system_mem,
                                 &s->iram_mem);

     /* DRAM */
+    memory_region_allocate_system_memory(ram_all, NULL, "exynos4210.ram",
+                                         ram_size);
+
     mem_size = ram_size;
     if (mem_size > EXYNOS4210_DRAM_MAX_SIZE) {
-        memory_region_init_ram(&s->dram1_mem, NULL, "exynos4210.dram1",
-                mem_size - EXYNOS4210_DRAM_MAX_SIZE, &error_abort);
-        vmstate_register_ram_global(&s->dram1_mem);
+        memory_region_init_alias(&s->dram1_mem, NULL, "exynos4210.dram1",
+                                 ram_all,
+                                 EXYNOS4210_DRAM1_BASE_ADDR,
+                                 mem_size - EXYNOS4210_DRAM_MAX_SIZE);
         memory_region_add_subregion(system_mem, EXYNOS4210_DRAM1_BASE_ADDR,
                 &s->dram1_mem);
         mem_size = EXYNOS4210_DRAM_MAX_SIZE;
     }
-    memory_region_init_ram(&s->dram0_mem, NULL, "exynos4210.dram0", mem_size,
-                           &error_abort);
-    vmstate_register_ram_global(&s->dram0_mem);
+    memory_region_init_alias(&s->dram1_mem, NULL, "exynos4210.dram0",
+                                ram_all,
+                                EXYNOS4210_DRAM0_BASE_ADDR, mem_size);
     memory_region_add_subregion(system_mem, EXYNOS4210_DRAM0_BASE_ADDR,
             &s->dram0_mem);