From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [PATCH 15/15] KVM: Fix racy in kvm_free_assigned_irq
Date: Sat, 27 Dec 2008 18:15:46 -0200
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References: <20081225115609.GA10087@syang10-desktop> <1230258607-15208-1-git-send-email-sheng@linux.intel.com> <20081227200626.GA4095@amt.cnet>
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Cc: Avi Kivity <avi@redhat.com>, kvm@vger.kernel.org
To: Sheng Yang <sheng@linux.intel.com>
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On Sat, Dec 27, 2008 at 06:06:26PM -0200, Marcelo Tosatti wrote:
> On Fri, Dec 26, 2008 at 10:30:07AM +0800, Sheng Yang wrote:
> > Thanks to Marcelo's observation, The following code have potential issue:
> > 
> > if (cancel_work_sync(&assigned_dev->interrupt_work))
> > 	kvm_put_kvm(kvm);
> > 
> > In fact, cancel_work_sync() would return true either work struct is only
> > scheduled or the callback of work struct is executed. This code only
> > consider the former situation.
> 
> Why not simply drop the reference inc / dec from irq handler/work
> function?
> 
> Just make sure that there is no queued/executing work left behind on
> vm shutdown. Don't think an additional reference is necessary. Or am I
> missing something?

And maybe drop this issue from the patchset and fix it separately, since
it is a bugfix.