From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Tian, Kevin" <kevin.tian@intel.com>
Subject: RE: [PATCH 08/31] nVMX: Fix local_vcpus_link handling
Date: Tue, 24 May 2011 19:30:46 +0800
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Cc: Nadav Har'El <nyh@math.technion.ac.il>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"gleb@redhat.com" <gleb@redhat.com>,
	"Roedel, Joerg" <Joerg.Roedel@amd.com>
To: Avi Kivity <avi@redhat.com>
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> From: Avi Kivity [mailto:avi@redhat.com]
> Sent: Tuesday, May 24, 2011 7:27 PM
> 
> On 05/24/2011 02:20 PM, Tian, Kevin wrote:
> > >  I don't think it's possible.  Both calls are done with interrupts disabled.
> >
> > If that's the case then there's another potential issue. Deadlock may happen
> > when calling smp_call_function_single with interrupt disabled.
> 
> We don't do that.  vcpu migration calls vcpu_clear() with interrupts
> enabled, which then calls smp_call_function_single(), which calls
> __vcpu_clear() with interrupts disabled.  vmclear_local_vcpus() is
> called from interrupts disabled (and calls __vcpu_clear() directly).
> 

OK, that's clear to me now. 

Thanks
Kevin