Re: vhost question

On Sun, Mar 25, 2012 at 1:29 PM, Steve Glass [off-list ref] wrote:

On 22 March 2012 19:52, Stefan Hajnoczi [off-list ref] wrote:

quoted

Can you queue a tx->rx kick on the vhost work queue with
vhost_work_queue()?

Stefan

I've been looking at this and trying to work out how to achieve that. I can
see how I can enqueue some work on the vhost queue but the rx_handler needs
to run in the process context of the receiving VM (or else it can't access
the ring). I don't think that's true of the work queue (doesn't it run with
the qemu process context?)

The vhost worker thread has the mm of the process, see use_mm(dev->mm)
in drivers/vhost/vhost.c:vhost_worker().  It sounds like you need
vhost worker A (tx) to schedule work for vhost worker B (rx).

Stefan