Re: [Xen-devel] Re: Install paravirtualized drivers after booting forhigh-performance IO

[Mark Williamson <mark.williamson@xxxxxxxxxxxx>]

> What is the difference between paravirtualized and virtualized?

Paravirtualisation is providing virtual machines to operating systems that 
have been ported to run on Xen.

Full virtualisation is providing virtual machines to unmodified operating 
systems.

A compromise for when you can't properly modify an OS is to full virtualise 
the CPU using VT but install device drivers that are Xen-aware.

Cheers,
Mark

>
>
> ----- Original Message -----
> From: "Mark Williamson" <mark.williamson@xxxxxxxxxxxx>
> To: <xen-devel@xxxxxxxxxxxxxxxxxxx>
> Cc: "Arlen.D.Wang" <dengyu@xxxxxxxxxxxxxxxx>
> Sent: Tuesday, May 10, 2005 10:24 AM
> Subject: Re: [Xen-devel] Re: Install paravirtualized drivers after booting
> forhigh-performance IO
>
> > Where is get  a reference to the Windows support using Vanderpool
> > Technology ?
>
> The code in the unstable tree is the best reference (if you feel brave).
> There are the slides for a couple of talks about VT at the Xen Summit
> webpage (http://summit.xensource.com/presentations/).
>
> > Who is doing that Windows support using Vanderpool Technology ?
>
> This implementation work has been spearheaded by Intel, although I think
> there are also some people at IBM also working on Xen/VT (is that right?)
>
> > If Xen can run unmodified Linux , then Xen can run unmodified Windows
> > also , right ?
>
> Not yet: running Windows requires emulating extra 16 bit x86 stuff that
> Linux doesn't need in order to run.  There is a design for supporting this
> and it might even be under development right now.
>
> HTH,
> Mark
>
> > DengYu  Wang
> >
> > "Mark Williamson" <mark.williamson@xxxxxxxxxxxx>
> > ÐÏ:200505091257.04034.mark.williamson@xxxxxxxxxxxxxxx
> >
> > > Hi there,
> > >
> > > I expect you've seen a reference to the Windows support using
> > > Vanderpool Technology?
> > >
> > > The current VT implementation provides an emulation of real hardware
> > > devices
> > > (e.g. an NE2000 ethernet card) to the guest OS.  This has the advantage
> > > that
> > > you can boot an unmodified OS and it'll recognise the emulated devices
> > > and Just Work.  This will allow you to install the OS using its usual
> > > installer
> > > and get things up and running.
> > >
> > > However, you pay a performance price for emulating a device like this.
> > > The
> > > most straightforward way to solve this is to replace the emulated
> > > device drivers with Xen-aware drivers (like the ones used by the
> > > Xen-native Linux port).  Once you've installed the OS, you can upgrade
> > > to the Xen device drivers.
> > >
> > > This should give better bandwidth for things like disk and network IO.
> > >
> > > Does that help?
> > >
> > > Cheers,
> > > Mark
> > >
> > >>     What is "high-performance IO" ?
> > >>     What meaning for "Install paravirtualized drivers after booting
> > >> for high-performance IO"?
> > >>
> > >>     Thanks,
> >
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-devel

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel