Message-ID: <555CCFB9.8090300@redhat.com>
Date: Wed, 20 May 2015 20:17:29 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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CC: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        Xiao Guangrong <guangrong.xiao@linux.intel.com>, bdas@redhat.com
Subject: Re: [PATCH 08/11] KVM: implement multiple address spaces
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On 20/05/2015 17:46, Radim Krčmář 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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