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[Xen-users] Re: Why pv-on-hvm drivers?

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-users] Re: Why pv-on-hvm drivers?
From: Markus Schuster <ml@xxxxxxxxxxxxxxxxxxxx>
Date: Mon, 06 Sep 2010 10:59:26 +0200
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Pasi Kärkkäinen wrote:
> On Sun, Sep 05, 2010 at 01:29:19AM +0200, Markus Schuster wrote:
>> Hi list,
>> I've read about recent efforts to push pv-on-hvm drivers to Linux
>> mainline and I'm curious to know the cause for this. What's the advantage
>> over using pv_ops directly and booting the kernel paravirtualized?
> The other point is performance: 32bit PV (paravirtualized) guests
> perform OK, but 64bit PV guests have a performance hit if your
> workload creates a lot of new processes in the guest.
> HVM helps there; 64bit Linux guests might be faster as HVM,
> depending on the workload.

Hi Parsi, thanks for your (as usual :)) good answer. 
That's the first time I read about a PV performance hit compared to HVM - 
maybe you (or someone else) can write a few words about what's causing that? 
Could be interesting for other people, maybe?


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