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>
> 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.)
--
Eduardo