Re: [PATCH 2/9] vhost: move vhost worker creation to kick setup

On Tue, May 25, 2021 at 01:05:53PM -0500, Mike Christie wrote:

The next patch will add new ioctls that allows userspace to create workers
and bind them to devs and vqs after VHOST_SET_OWNER. To support older
tools, newer tools that want to go wild with worker threads, and newer
tools that want the old/default behavior this patch moves the default
worker setup to the kick setup.

After the first vq's kick/poll setup is done we could start to get works
queued, so this is the point when we must have a worker setup. If we are
using older tools or the newer tools just want the default single vhost
thread per dev behavior then it will automatically be done here. If the
tools are using the newer ioctls that have already created the workers
then we also detect that here and do nothing.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 drivers/vhost/vhost.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>