[Qemu-devel] [PATCH] check if we have space left for hotplugged memory

[Hu Tao <hutao@cn.fujitsu.com>]

If pc-dimm is specified on qemu command line, but only with
-m size (aka not -m size,maxmem,slots) then qemu will core dump.

This patch fixes the problem.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
---
 hw/i386/pc.c     | 5 +++++
 hw/mem/pc-dimm.c | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 2cf22b1..1a0d96e 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1566,6 +1566,11 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev,
         goto out;
     }
 
+    if (memory_region_size(&pcms->hotplug_memory) == 0) {
+        error_setg(&local_err, "no space left for hotplugged memory.");
+        goto out;
+    }
+
     addr = pc_dimm_get_free_addr(pcms->hotplug_memory_base,
                                  memory_region_size(&pcms->hotplug_memory),
                                  !addr ? NULL : &addr,
diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index ad176b7..59ed9c0 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -146,6 +146,11 @@ uint64_t pc_dimm_get_free_addr(uint64_t address_space_start,
     uint64_t new_addr, ret = 0;
     uint64_t address_space_end = address_space_start + address_space_size;
 
+    if (address_space_size == 0) {
+        error_setg(errp, "no space left for hotplugged memory.");
+        goto out;
+    }
+
     assert(address_space_end > address_space_size);
     object_child_foreach(qdev_get_machine(), pc_dimm_built_list, &list);
 
-- 
1.9.3