Re: [PATCH 1/1] numa: check mem or memdev in numa configuration

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 16 Feb 2022 17:36:13 +0100
Li Zhang <lizhang@suse.de> wrote:

> If there is no mem or memdev in numa configuration, it always
> reports the error as the following:
> 
> total memory for NUMA nodes (0x0) should equal RAM size (0x100000000)
> 
> This error is confusing and the reason is that total memory of numa nodes
> is always 0 if there is no mem or memdev in numa configuration.
> So it's better to check mem or memdev in numa configuration.
> 
> Signed-off-by: Li Zhang <lizhang@suse.de>
> ---
>  hw/core/numa.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/hw/core/numa.c b/hw/core/numa.c
> index 1aa05dcf42..11cbec51eb 100644
> --- a/hw/core/numa.c
> +++ b/hw/core/numa.c
> @@ -132,6 +132,11 @@ static void parse_numa_node(MachineState *ms, NumaNodeOptions *node,
>  
>      have_memdevs = have_memdevs ? : node->has_memdev;
>      have_mem = have_mem ? : node->has_mem;
> +    if (!node->has_memdev && !node->has_mem) {
> +        error_setg(errp, "numa configuration should use mem= or memdev= ");
> +        return;
> +    }

Wouldn't this breaks memory less numa nodes?

I'd rather add/rephrase to original error message that memory
should be specified explicitly for desired numa nodes.
And I'd not mention 'mem=' since
  docs/about/removed-features.rst:``-numa node,mem=...`` (removed in 5.1)

> +
>      if ((node->has_mem && have_memdevs) || (node->has_memdev && have_mem)) {
>          error_setg(errp, "numa configuration should use either mem= or memdev=,"
>                     "mixing both is not allowed");