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Date: Fri, 1 Apr 2016 11:15:07 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Juergen Gross <jgross@suse.com>
Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org,
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Subject: Re: [PATCH v3 5/6] virt, sched: add cpu pinning to
 smp_call_sync_on_phys_cpu()
Message-ID: <20160401091507.GG3448@twins.programming.kicks-ass.net>
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On Fri, Apr 01, 2016 at 11:03:21AM +0200, Juergen Gross wrote:
> > Maybe just make the vpin thing an option like:
> > 
> > 	smp_call_on_cpu(int (*func)(void *), int phys_cpu);

> > Also; is something like the vpin thing possible on KVM? because if we're
> > going to expose it to generic code like this we had maybe look at wider
> > support.
> 
> It is necessary for dom0 under Xen. I don't think there is a need to do
> this on KVM as a guest has no direct access to e.g. BIOS functions of
> the real hardware and the host system needs no vcpu pinning. I'm not
> sure about VMWare.

OK, then can we WARN if .phys=1 and the platform doesn't support it?