Should not be a problem right now, but it could theoretically happen
in the future.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 hw/mem/memory-device.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c
index 996ad1490f..8be63c8032 100644
--- a/hw/mem/memory-device.c
+++ b/hw/mem/memory-device.c
@@ -85,7 +85,8 @@ static void memory_device_check_addable(MachineState *ms, uint64_t size,
 
     /* will we exceed the total amount of memory specified */
     memory_device_used_region_size(OBJECT(ms), &used_region_size);
-    if (used_region_size + size > ms->maxram_size - ms->ram_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
                    " in use of total space for memory devices 0x" RAM_ADDR_FMT,
                    used_region_size, ms->maxram_size - ms->ram_size);
-- 
2.17.1

On Tue, Oct 23, 2018 at 05:23:05PM +0200, David Hildenbrand wrote:
> Should not be a problem right now, but it could theoretically happen
> in the future.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  hw/mem/memory-device.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c
> index 996ad1490f..8be63c8032 100644
> --- a/hw/mem/memory-device.c
> +++ b/hw/mem/memory-device.c
> @@ -85,7 +85,8 @@ static void memory_device_check_addable(MachineState *ms, uint64_t size,
>  
>      /* will we exceed the total amount of memory specified */
>      memory_device_used_region_size(OBJECT(ms), &used_region_size);
> -    if (used_region_size + size > ms->maxram_size - ms->ram_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
>                     " in use of total space for memory devices 0x" RAM_ADDR_FMT,
>                     used_region_size, ms->maxram_size - ms->ram_size);

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

On Tue, 23 Oct 2018 17:23:05 +0200
David Hildenbrand <david@redhat.com> wrote:

> Should not be a problem right now, but it could theoretically happen
> in the future.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  hw/mem/memory-device.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c
> index 996ad1490f..8be63c8032 100644
> --- a/hw/mem/memory-device.c
> +++ b/hw/mem/memory-device.c
> @@ -85,7 +85,8 @@ static void memory_device_check_addable(MachineState *ms, uint64_t size,
>  
>      /* will we exceed the total amount of memory specified */
>      memory_device_used_region_size(OBJECT(ms), &used_region_size);
> -    if (used_region_size + size > ms->maxram_size - ms->ram_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
>                     " in use of total space for memory devices 0x" RAM_ADDR_FMT,
>                     used_region_size, ms->maxram_size - ms->ram_size);