[Qemu-devel] [PATCH v2] numa: check for busy memory backend

[Qemu-devel] [PATCH v2] numa: check for busy memory backend

[Hu Tao]

Specifying the same memory backend twice leads to an assert:

./x86_64-softmmu/qemu-system-x86_64 -m 512M -enable-kvm -object
memory-backend-ram,size=256M,id=ram0 -numa node,nodeid=0,memdev=ram0
-numa node,nodeid=1,memdev=ram0
qemu-system-x86_64: /scm/qemu/memory.c:1506:
memory_region_add_subregion_common: Assertion `!subregion->container'
failed.
Aborted (core dumped)

Detect and exit with an error message instead.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
---
 numa.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/numa.c b/numa.c
index 2fde740..7bf7834 100644
--- a/numa.c
+++ b/numa.c
@@ -301,6 +301,14 @@ void memory_region_allocate_system_memory(MemoryRegion *mr, Object *owner,
             exit(1);
         }
 
+        if (memory_region_is_mapped(seg)) {
+            char *path = object_get_canonical_path_component(OBJECT(backend));
+            error_report("memory backend %s is used multiple times. Each "
+                         "-numa option must use a different memdev value.",
+                         path);
+            exit(1);
+        }
+
         memory_region_add_subregion(mr, addr, seg);
         vmstate_register_ram_global(seg);
         addr += size;
-- 
1.9.3

Re: [Qemu-devel] [PATCH v2] numa: check for busy memory backend

[Michael S. Tsirkin]

On Mon, Jun 30, 2014 at 06:28:15PM +0800, Hu Tao wrote:
> Specifying the same memory backend twice leads to an assert:
> 
> ./x86_64-softmmu/qemu-system-x86_64 -m 512M -enable-kvm -object
> memory-backend-ram,size=256M,id=ram0 -numa node,nodeid=0,memdev=ram0
> -numa node,nodeid=1,memdev=ram0
> qemu-system-x86_64: /scm/qemu/memory.c:1506:
> memory_region_add_subregion_common: Assertion `!subregion->container'
> failed.
> Aborted (core dumped)
> 
> Detect and exit with an error message instead.
> 
> Reviewed-by: Igor Mammedov <imammedo@redhat.com>
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>

Applied, thanks.

> ---
>  numa.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/numa.c b/numa.c
> index 2fde740..7bf7834 100644
> --- a/numa.c
> +++ b/numa.c
> @@ -301,6 +301,14 @@ void memory_region_allocate_system_memory(MemoryRegion *mr, Object *owner,
>              exit(1);
>          }
>  
> +        if (memory_region_is_mapped(seg)) {
> +            char *path = object_get_canonical_path_component(OBJECT(backend));
> +            error_report("memory backend %s is used multiple times. Each "
> +                         "-numa option must use a different memdev value.",
> +                         path);
> +            exit(1);
> +        }
> +
>          memory_region_add_subregion(mr, addr, seg);
>          vmstate_register_ram_global(seg);
>          addr += size;
> -- 
> 1.9.3