[PATCH v2] bus/vmbus: add device argument to configure if NUMA information on the device should be ignored

[Stephen Hemminger]

On Mon, 18 Aug 2025 17:24:26 -0700
longli at linuxonhyperv.com wrote:

> From: Long Li <longli at microsoft.com>
> 
> In most cases, netvsc is used with a VF device. The application generally
> runs with better performance when all the device memory is allocated on
> VF's NUMA node, as the VF device carries most of the data packets.
> 
> But sometimes netvsc may run on a different NUMA node than that of the VF.
> This patch adds a device argument "numa" to allow the application to
> configure if this vmbus device (netvsc) should be NUMA aware. The default
> behavior is NUMA aware. Setting "numa=0" specifies this vmbus device is
> not NUMA aware.
> 
> The device argument is parsed at the time of vmbus device probe to ensure
> all the following memory allocations are done on the configured NUMA node.
> 
> Signed-off-by: Long Li <longli at microsoft.com>

Putting all the args in vmbus seems confusing, and not what I meant.
Was more thing that ethdev and queues should be on same NUMA node.

If NUMA is better why wouldn't it always be on?
Since netvsc is really a virtual device not sure.
I suspect 99% of users will be using with VF, that should be the default.