Re: [Qemu-devel] Storing code caching

[Antony T Curtis]

On Thu, 2004-07-08 at 18:05, John R. Hogerhuis wrote:
> On Thu, 2004-07-08 at 05:26, Martin Williams wrote:
> > Has anyone thought about trying to store the code caching on disk?
> 
> Are you talking about "save machine state" essentially "suspend/resume?"
> That is certainly possible and I believe it has been discussed on the
> list.

<snip>

I think a more interesting idea is to 'virtualize' the memory.... That
is, we provide a means for a guest to request more physical memory and
to be able to release that memory back to the host... Perhaps also some
method in which the host can warn the guest of low memory situations so
that the guest can be more aggressive on memory reclaiming.

Of course, this optimization would require changes to the guest OS to
take advantage of it but it would mean that the guest would no longer
have to worry about swap pressures and that the host can perform the
swapping on behalf of the guest - this would be much faster as the
guest's virtual hardware will be much slower to swap to than the hosts'
real hardware.

This communication mechinism has to be well defined and audited as it
could potentially allow the guest the ability to 'break out' of it's
box. I would suggest that the best way would be to make the
communication channel look like some piece of hardware - but there are
other options available - such as magic opcodes...

-- 
Antony T Curtis <address@hidden>