memory-device: Track used region size in DeviceMemoryState

Let's avoid iterating over all devices and simply track it in the
DeviceMemoryState.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20230623124553.400585-11-david@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

1 files changed, 3 insertions, 19 deletions

diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c
index 00c7755..667d56b 100644
--- a/hw/mem/memory-device.c
+++ b/hw/mem/memory-device.c
@@ -52,28 +52,11 @@ static int memory_device_build_list(Object *obj, void *opaque)
     return 0;
 }
 
-static int memory_device_used_region_size(Object *obj, void *opaque)
-{
-    uint64_t *size = opaque;
-
-    if (object_dynamic_cast(obj, TYPE_MEMORY_DEVICE)) {
-        const DeviceState *dev = DEVICE(obj);
-        const MemoryDeviceState *md = MEMORY_DEVICE(obj);
-
-        if (dev->realized) {
-            *size += memory_device_get_region_size(md, &error_abort);
-        }
-    }
-
-    object_child_foreach(obj, memory_device_used_region_size, opaque);
-    return 0;
-}
-
 static void memory_device_check_addable(MachineState *ms, MemoryRegion *mr,
                                         Error **errp)
 {
+    const uint64_t used_region_size = ms->device_memory->used_region_size;
     const uint64_t size = memory_region_size(mr);
-    uint64_t used_region_size = 0;
 
     /* we will need a new memory slot for kvm and vhost */
     if (kvm_enabled() && !kvm_has_free_slot(ms)) {
@@ -86,7 +69,6 @@ static void memory_device_check_addable(MachineState *ms, MemoryRegion *mr,
     }
 
     /* will we exceed the total amount of memory specified */
-    memory_device_used_region_size(OBJECT(ms), &used_region_size);
     if (used_region_size + size < used_region_size ||
         used_region_size + size > ms->maxram_size - ms->ram_size) {
         error_setg(errp, "not enough space, currently 0x%" PRIx64
@@ -292,6 +274,7 @@ void memory_device_plug(MemoryDeviceState *md, MachineState *ms)
     mr = mdc->get_memory_region(md, &error_abort);
     g_assert(ms->device_memory);
 
+    ms->device_memory->used_region_size += memory_region_size(mr);
     memory_region_add_subregion(&ms->device_memory->mr,
                                 addr - ms->device_memory->base, mr);
     trace_memory_device_plug(DEVICE(md)->id ? DEVICE(md)->id : "", addr);
@@ -310,6 +293,7 @@ void memory_device_unplug(MemoryDeviceState *md, MachineState *ms)
     g_assert(ms->device_memory);
 
     memory_region_del_subregion(&ms->device_memory->mr, mr);
+    ms->device_memory->used_region_size -= memory_region_size(mr);
     trace_memory_device_unplug(DEVICE(md)->id ? DEVICE(md)->id : "",
                                mdc->get_addr(md));
 }