From: Will Deacon <will.deacon@arm.com>
To: Sasha Levin <sasha.levin@oracle.com>
Cc: andre.przywara@arm.com, josh@joshtriplett.org,
penberg@kernel.org, asias.hejun@gmail.com, kvm@vger.kernel.org
Subject: Re: [PATCH 2/2] kvmtool: assume dead vcpus are paused too
Date: Thu, 5 Nov 2015 14:41:16 +0000 [thread overview]
Message-ID: <20151105144116.GE26684@arm.com> (raw)
In-Reply-To: <563A99F0.10100@oracle.com>
On Wed, Nov 04, 2015 at 06:51:12PM -0500, Sasha Levin wrote:
> On 11/04/2015 06:51 AM, Will Deacon wrote:
> > + mutex_lock(&pause_lock);
> > +
> > + /* The kvm->cpus array contains a null pointer in the last location */
> > + for (i = 0; ; i++) {
> > + if (kvm->cpus[i])
> > + pthread_kill(kvm->cpus[i]->thread, SIGKVMEXIT);
> > + else
> > + break;
> > + }
> > +
> > + kvm__continue(kvm);
>
> In this scenario: if we grabbed pause_lock, signaled vcpu0 to exit, and it did
> before we called kvm__continue(), we won't end up releasing pause_lock, which
> might cause a lockup later, no?
Hmm, yeah, maybe that should be an explicit mutex_unlock rather than a
call to kvm__continue.
Will
next prev parent reply other threads:[~2015-11-05 14:41 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1445265650-25616-1-git-send-email-sasha.levin@oracle.com>
[not found] ` <1445265650-25616-2-git-send-email-sasha.levin@oracle.com>
[not found] ` <20151027160802.GD20208@arm.com>
[not found] ` <56302E2C.2010207@oracle.com>
[not found] ` <20151028122745.GC29512@arm.com>
[not found] ` <5630C6D7.2020608@oracle.com>
[not found] ` <20151028133425.GB18966@arm.com>
2015-11-04 11:51 ` [PATCH 2/2] kvmtool: assume dead vcpus are paused too Will Deacon
2015-11-04 23:51 ` Sasha Levin
2015-11-05 14:41 ` Will Deacon [this message]
2015-11-05 16:02 ` Sasha Levin
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