Re: [PATCH/RFC 7/9] Virtual network guest device driver

Christoph Hellwig
2007-05-22T12:56:55Z

On Tue, May 22, 2007 at 07:49:51AM -0500, Eric Van Hensbergen wrote:
> > In the general case, you can't pass a command line argument to Linux
> > either. kvm doesn't boot Linux; it boots the bios, which boots the boot
> > sector, which boots grub, which boots Linux. Relying on the user to
> > edit the command line in grub is wrong.
> >
>
> I didn't think we were talking about the general case, I thought we
> were discussing the PV case. In the PV case, having bios/bootloader
> is unnecessary overhead. To that same end, I don't see Windows in the
> PV case unless they magically want to to coordinate PV standards with
> us, in which case we certainly can negotiate a more sane discovery
> mechanism.

In case of KVM no one is speaking of pure PV. What people have been
working on is PV accelaration of a vullvirt host, similar to how
s390 is working for decaded. The host emulates the full architecture,
but there are some escape for speedups. Typical escapes would be drivers
for storage or networking because those can no be virtualized very well
on x86-style hardware.