Re: [Qemu-devel] [PATCH 00/12] virtio: cleanup ioeventfd start/stop

[Paolo Bonzini <pbonzini@redhat.com>]

----- Original Message -----
> From: "Cornelia Huck" <cornelia.huck@de.ibm.com>
> To: "Paolo Bonzini" <pbonzini@redhat.com>
> Cc: qemu-devel@nongnu.org, stefanha@redhat.com, borntraeger@de.ibm.com, famz@redhat.com, mst@redhat.com
> Sent: Tuesday, October 18, 2016 7:24:45 PM
> Subject: Re: [PATCH 00/12] virtio: cleanup ioeventfd start/stop
> 
> On Mon, 10 Oct 2016 13:53:28 +0200
> Paolo Bonzini <pbonzini@redhat.com> wrote:
> 
> > This series started as an attempt to always use the dataplane path
> > for virtio-blk and virtio-scsi when ioeventfd is active.  The aim
> > was three-fold:
> > 
> > 1) to add more coverage for dataplane
> > 
> > 2) to remove virtio_add_queue_aio
> > 
> > 3) to simplify the dataplane start/stop code
> > 
> > It achieves the first two objectives, and while it doesn't quite
> > achieve the third it does cleanup the generic ioeventfd code in
> > virtio-bus more than I expected.  In particular, it reduces the set
> > of callbacks that transports must implement, and it removes the ugly
> > case where ioeventfd is started with generic callbacks and then moved
> > to the dataplane callbacks.  It also enables some simplification of the
> > functions that deal with host notifiers, and detects some configuration
> > errors better.
> > 
> > I've tested it with virtio-blk, virtio-scsi and vhost-net.
> 
> Do you have a branch somewhere?

ioeventfd-virtio at git://github.com/bonzini/qemu.git

Paolo

> > 
> > Patch 1 is a bugfix that I found while testing the TCG+dataplane combo.
> > 
> > Patches 2 and 3 are simplifications that are too nice to leave
> > them for later in the series.
> > 
> > Patch 4 moves some of the ioeventfd code from virtio-bus.c to
> > virtio.c.  At this point the transition is a bit half-assed, but
> > this changes as soon as we remove the generic->dataplane
> > handler transition.
> > 
> > Patches 5 to 7 do exactly that, and then the spring cleaning
> > begins, lasting for the whole second half of the series.
> 
> I'll continue to look at the patches from 4 on tomorrow.
> 
>