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Re: Balloon driver.

On 7 July 2010 17:07, Thor Lancelot Simon <> wrote:
> On Wed, Jul 07, 2010 at 01:57:30PM +0530, Cherry G. Mathew wrote:
>> >
>> > How would you stop the domU being able to increase its memory size (e.g. on
>> > a hosted service, you wouldn't want the client taking more resources than
>> > they've paid for)?
>> >
>> There are no such limits by design at the moment. However at the
>> moment a de-facto limit exists (ie; the amount specified in the domU
>> config file), because we don't add more pages than we had to begin
>> with. Fixing this will need looking at uvm(9).)
> This is pretty bogus -- it seems like it allows a single domU to
> effectively take over the entire virtualization environment.  I think

First off, as I pointed out in an earlier mail, I doubt that the
hypervisor allows this.

> there really needs to be a hard cap enforced by the dom0 --

The dom0 does not arbitrate memory allocation. DomU's talk directly to
the hypervisor to ask/relinquish memory within prescribed limits. What
the dom0 can do is to tell the hypervisor what these limits are.


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