Re: [PATCH V9 5/6] virtio: introduce a mdev based transport

[Jason Wang]

On 2019/11/6 äå7:00, Cornelia Huck wrote:
> On Wed,  6 Nov 2019 15:05:47 +0800
> Jason Wang <jasowang@xxxxxxxxxx> wrote:
>
> > This patch introduces a new mdev transport for virtio. This is used to
> > use kernel virtio driver to drive the mediated device that is capable
> > of populating virtqueue directly.
> >
> > A new virtio-mdev driver will be registered to the mdev bus, when a
> > new virtio-mdev device is probed, it will register the device with
> > mdev based config ops. This means it is a software transport between
> > mdev driver and mdev device. The transport was implemented through
> > device specific ops which is a part of mdev_parent_ops now.
> >
> > Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> > ---
> >   drivers/virtio/Kconfig       |  13 ++
> >   drivers/virtio/Makefile      |   1 +
> >   drivers/virtio/virtio_mdev.c | 406 +++++++++++++++++++++++++++++++++++
> >   3 files changed, 420 insertions(+)
> >   create mode 100644 drivers/virtio/virtio_mdev.c
> >
> > diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> > index 078615cf2afc..558ac607d107 100644
> > --- a/drivers/virtio/Kconfig
> > +++ b/drivers/virtio/Kconfig
> > @@ -43,6 +43,19 @@ config VIRTIO_PCI_LEGACY
> >   
> >   	  If unsure, say Y.
> >   
> > +config VIRTIO_MDEV
> > +	tristate "MDEV driver for virtio devices"
> > +	depends on VFIO_MDEV && VIRTIO
> > +	default n
> > +	help
> > +	  This driver provides support for virtio based paravirtual
> > +	  device driver over MDEV bus. This requires your environemnt
> > +	  has appropriate virtio mdev device implementation which may
> > +	  operate on the physical device that the datapath of virtio
> > +	  could be offloaded to hardware.
> That sentence is a bit confusing to me... what about
>
> "For this to be useful, you need an appropriate virtio mdev device
> implementation that operates on a physical device to allow the datapath
> of virtio to be offloaded to hardware."
>
> ?
>
> > +
> > +	  If unsure, say M
> Building this as a module should not hurt (but please add a trailing
> '.' here :)
>
> > +
> >   config VIRTIO_PMEM
> >   	tristate "Support for virtio pmem driver"
> >   	depends on VIRTIO
> With the changes above,
>
> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>

Will post V10.

Thanks