Re: [PATCH 08/11] KVM: implement multiple address spaces

From: Paolo Bonzini
Date: Wed May 20 2015 - 14:17:42 EST




On 20/05/2015 17:46, Radim KrÄmÃÅ wrote:
> I am a bit worried about the explosion that would happen if we wanted,
> for example, per-VCPU address spaces

Those would be very expensive. If we were to implement relocatable APIC
base, we would have to do it in a different way than with memslots.

> My main issue (orthogonal to layering) is that we don't allow a way to
> let userspace tell us that some slots in different name spaces are the
> same slot. We're losing information that could be useful in the future
> (I can only think of less slot queries for dirty log now).

You're right. On the other hand, I think the ship has sailed the moment
the dirty log was GPA-indexed.

> What I like about your solution is that it fits existing code really
> well, is easily modified if needs change, and that it already exists.

Yes, it does fit existing code really well.

Thanks for the discussion!

Paolo
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