Re: [virtio] [PATCH v12] VIRTIO_F_NOTIFICATION_DATA: extra data to devices

[Cornelia Huck <cohuck@redhat.com>]

On Thu, 29 Mar 2018 15:52:34 +0300
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> On Thu, Mar 29, 2018 at 11:05:55AM +0200, Cornelia Huck wrote:
> > On Wed, 28 Mar 2018 20:21:47 +0300
> > "Michael S. Tsirkin" <mst@redhat.com> wrote:
> >   
> > > On Wed, Mar 28, 2018 at 06:56:13PM +0200, Halil Pasic wrote:  

> > > > The notifications *sent by the device to the driver (virtqueue or
> > > > configuration change)* are often referred to as *interrupts* but occasionally
> > > > also as notifications (e.g. 'host->guest notification').  
> > 
> > I think 'notifications' is a better term for these. I'm thinking of a
> > driver polling for outstanding notifications from the device, no
> > interrupts involved.  
> 
> In this context when polling there are no notifications - rememeber we are
> talking about notification suppression.

OK, that's my s390 background again. We can easily make notification
status available (setting indicators, making a subchannel status
pending), but not deliver an interrupt because the guest has not
enabled interrupts and polls instead. (In fact, such an operation mode
is not uncommon for the traditional s390 OSs.)

But we can also just keep this as-is, it's probably not confusing for
most people anyway.