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Date: Wed, 10 Dec 2014 17:39:46 -0500
Message-ID: <CAFMmRNx18L829FhexZmrgmJ7kj-hi+Xy556KPV7Nyb4qgo2A3g@mail.gmail.com>
Subject: Re: KVM Clock
From: Ryan Stone <rysto32@gmail.com>
To: Julian Stecklina <jsteckli@os.inf.tu-dresden.de>
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On Mon, Jan 20, 2014 at 7:41 PM, Julian Stecklina
<jsteckli@os.inf.tu-dresden.de> wrote:
> Ah. Thanks. This will do. Something like access_once would be perfect, though.
>
> I'll post an updated patch that does not duplicate code that is in xen/ soonish. Didn't get around to testing it the last days.
>
> Julian

I'm interesting in helping to get this into the tree.  I see that
you've address all of the comments in this thread here:

https://github.com/blitz/freebsd/commit/e130f4ba550eb905c7f56a6a26243660b4df834b

I have one final question.  Don't we need to run rdtsc() in the loop
in pvclock_fetch_vcpu_tinfo()?  If we don't, isn't there a chance that
after we leave the loop, the hypervisor could migrate the guest to a
different CPU where the value returned by rdtsc() will not match the
parameters in the pvclock_time_info structure?