[pve-devel] [PATCH qemu-server 1/2] Disable memory hotplugging for custom NUMA topologies

[Alwin Antreich]

On Wed, Mar 18, 2020 at 04:18:44PM +0100, Stefan Reiter wrote:
> This cannot work, since we adjust the 'memory' property of the VM config
> on hotplugging, but then the user-defined NUMA topology won't match for
> the next start attempt.
> 
> Check needs to happen here, since it otherwise fails early with "total
> memory for NUMA nodes must be equal to vm static memory".
> 
> With this change the error message reflects what is actually happening
> and doesn't allow VMs with exactly 1GB of RAM either.
> 
> Signed-off-by: Stefan Reiter <s.reiter at proxmox.com>
> ---
Tested-by: Alwin Antreich <a.antreich at proxmox.com>

> 
> Came up after investigating:
> https://forum.proxmox.com/threads/task-error-total-memory-for-numa-nodes-must-be-equal-to-vm-static-memory.67251/
> 
> Spent way too much time 'fixing' it before realizing that it can never work
> like this anyway...
> 
>  PVE/QemuServer/Memory.pm | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/PVE/QemuServer/Memory.pm b/PVE/QemuServer/Memory.pm
> index d500b3b..ae9598b 100644
> --- a/PVE/QemuServer/Memory.pm
> +++ b/PVE/QemuServer/Memory.pm
> @@ -225,6 +225,12 @@ sub config {
>      if ($hotplug_features->{memory}) {
>  	die "NUMA needs to be enabled for memory hotplug\n" if !$conf->{numa};
>  	die "Total memory is bigger than ${MAX_MEM}MB\n" if $memory > $MAX_MEM;
> +
> +	for (my $i = 0; $i < $MAX_NUMA; $i++) {
> +	    die "cannot enable memory hotplugging with custom NUMA topology\n"
s/hotplugging/hotplug/ or s/hotplugging/hot plugging/
The word hotplugging doesn't seem to exist in the dictionaries.

> +		if $conf->{"numa$i"};
> +	}
> +
>  	my $sockets = 1;
>  	$sockets = $conf->{sockets} if $conf->{sockets};
>  
> -- 
> 2.25.1
>