Messages in this thread | | | Subject | Re: [PATCH 00/11] KVM: x86: track guest page access | From | Paolo Bonzini <> | Date | Tue, 1 Dec 2015 16:08:28 +0100 |
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On 01/12/2015 16:02, Andrea Arcangeli wrote: > > Applying your technique to non-leaf shadow pages actually makes this > > series quite interesting. :) Shadow paging is still in use for nested > > EPT, so it's always a good idea to speed it up. > > I don't have the full picture of how userfaultfd write tracking could > also fit in the leaf/non-leaf shadow pagetable write tracking yet but > it's good to think about it.
It's unrelated.
Xiao wrote this series for KVM-GT. I'm suggesting that he uses userfaultfd write tracking (or similar techniques---but anyway implemented out of KVM) for KVM-GT. The benefit is that KVM-GT is then unrelated to KVM, similar to legacy KVM device assignment vs. VFIO.
However, he also applied this new API to shadow pagetable write tracking. He gets measurable (~2%) performance improvement. We can look separately at how to get a similar performance improvement, even if KVM-GT will not use the new page tracking API.
Paolo
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