On Fri, Jan 31, 2014 at 04:17:16PM +1030, Rusty Russell wrote:
> "Michael S. Tsirkin" <> writes:
> > I think we can take away these points about the introduction:
> >
> > 1. they in "they are not all that different" is ambigious. One might think it means
> > virtual environments (which one might take to mean all
> > virtual devices) are like physical devices.
> > 2. from what point of view is virtio like a physical device?
> > it's very different from host POV
> > 3. "the guest" appears out of nowhere. It's the guest that runs
> > in the vm of course.
> > 4. "not all that different" means similar so there's not need to be
> > verbose
> > 5. This in "This allows" is ambigious: what allows guest to use standard drivers?
> > It's the device being like a physical one - not how this
> > document is written.
> >
> > So I think this will address this comment without making strong claims.
> >
> > diff --git a/abstract.tex b/abstract.tex
> > index b42a0b6..6684540 100644
> > --- a/abstract.tex
> > +++ b/abstract.tex
> > @@ -1,5 +1,7 @@
> > -This document describes the specifications of the “virtio” family of
> > -devices. These devices are found in virtual environments, yet by
> > -design they are not all that different from physical devices, and this
> > -document treats them as such. This allows the guest to use standard
> > -drivers and discovery mechanisms.
> > +This document describes the specifications of the “virtio” family of
> > +devices. These devices are found in virtual environments, yet by
> > +design from the point of view of the virtual machine guest
> > +virtio devices look similar to physical devices -
> > +and this document treats them as such.
> > +This similarity allows the guest to use standard
> > +drivers and discovery mechanisms.
>
> 'from the point of view of the virtual machine guest' is a bit long.
>
> Perhaps ", yet by design they look like physical devices to the guest
> within the virtual machine."?
I agree. But I prefer "similar to" rather than "like" which seems
a bit weaker to me: we don't promise that devices
are exactly like physical devices.
>
> >> 8. Standard: CHANGE TO READ: Virtio makes no assumptions about the environment in which
> >> it operates, beyond what is required in order to allow the bus to attach the host device to the driver on the guest. Virtio
> >> devices are implemented over PCI and other buses, and earlier drafts that
> >> have been implemented on other buses not included in this specification.[2]
> >>
> >> Thanks!
> >
> > It looks like "supporting the bus attaching the device" can be
> > misunderstood to mean we need to support attaching
> > the device. In reality this talks about supporting the bus.
> >
> > This should address this:
> >
> > - it operates, beyond supporting the bus attaching the device. Virtio
> > - it operates, beyond supporting the bus to which the device is attached. Virtio
>
> That works.
>
> So we add this?
>
> Cheers,
> Rusty.
>
> diff --git a/abstract.tex b/abstract.tex
> index b42a0b6..6e0fb27 100644
> --- a/abstract.tex
> +++ b/abstract.tex
> @@ -1,6 +1,7 @@
> This document describes the specifications of the “virtio” family of
> devices. These devices are found in virtual environments, yet by
> -design they are not all that different from physical devices, and this
> +design they look like physical devices to the guest
> +within the virtual machine - and this
> document treats them as such. This allows the guest to use standard
> drivers and discovery mechanisms.
Still does not clarify what "This" means in the second sentence.
document? physical devices?
That's why I wrote "This similarity".
>
> diff --git a/introduction.tex b/introduction.tex
> index 5d57f78..6c59887 100644
> --- a/introduction.tex
> +++ b/introduction.tex
> @@ -18,7 +18,7 @@ inter-guest communication) requires copying.
> lines.
>
> Standard: Virtio makes no assumptions about the environment in which
> - it operates, beyond supporting the bus attaching the device. Virtio
> + it operates, beyond supporting the bus to which the device is attached. Virtio
> devices are implemented over PCI and other buses, and earlier drafts
> been implemented on other buses not included in this spec.
> \footnote{The Linux implementation further separates the PCI virtio code
