Re: [QUERY] lguest64

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Wed, Jul 31, 2013 at 05:17:35AM -0700, H. Peter Anvin wrote:
> On 07/31/2013 02:39 AM, Mike Rapoport wrote:
> > 
> > The use case I had in mind is to use lguest as a nested hypervisor in
> > public clouds. As of today, major public clouds do not support nested
> > virtualization and it's not clear at all if they will expose this
> > ability in their deployments. Addition of 64-bit support for lguest
> > won't require changes to pvops and, as far as I can tell, won't change
> > the number of pvops users...
> > 
> 
> "We can add a pvops user and that won't change the number of pvops
> users" What?!
> 
> >> Yes, the subset of x86-64 machines for which there isn't hardware
> >> virtualization support is pretty uninteresting.
> > 
> > There are plenty virtual machines in EC2, Rackspace, HP and other
> > clouds that do not have hardware virtualization. I believe that
> > running a hypervisor on them may be pretty interesting.
> 
> The big problem with pvops is that they are a permanent tax on future
> development -- a classic case of "the hooks problem."  As such it is
> important that there be a real, significant, use case with enough users
> to make the pain worthwhile.  With Xen looking at sunsetting PV support
> with a long horizon, it might currently be possible to remove pvops some

PV MMU parts specifically.

> time in the early 2020s or so timeframe.  Introducing and promoting a
> new user now would definitely make that impossible.
> 
> So it matters that the use case be real.
> 
> 	-hpa
> 
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