Re: [libvirt] [Qemu-devel] [PATCH V17 02/11] NUMA: check if the total numa memory size is equal to ram_size

On Tue, Dec 10, 2013 at 07:03:50PM +0100, Paolo Bonzini wrote: > Il 10/12/2013 14:15, Eduardo Habkost ha scritto: > >> > If the total number of the assigned numa nodes memory is not > >> > equal to the assigned ram size, it will write the wrong data > >> > to ACPI talb, then the guest will ignore the wrong ACPI table > >> > and recognize all memory to one node. It's buggy, we should > >> > check it to ensure that we write the right data to ACPI table. > >> > > >> > Signed-off-by: Wanlong Gao <gaowanlong(a)cn.fujitsu.com&gt; > > This will make configurations that could be running for years (except > > that the guest OS was ignoring the NUMA data) suddenly stop running. I > > just want to confirm: we really want that, right? > > > > Does libvirt allow this kind of broken configuration to be generated, or > > it already ensures the total NUMA node sizes match RAM size? > > It allows this. It just converts the <numa> XML to "-numa node". In that case, if we apply this patch we may want to make libvirt validate the NUMA configuration instead of getting a cryptic "QEMU aborted" error message with the actual problem buried in a log file. (Well, even if we do not apply this patch, I believe it is a good idea to make libvirt validate the NUMA configuration.)