From mboxrd@z Thu Jan  1 00:00:00 1970
From: Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>
Subject: Re: [PATCH] KVM: avoid using rcu_dereference_protected
Date: Wed, 2 Aug 2017 22:16:33 +0200
Message-ID: <20170802201633.GA32403@flask>
References: <1501689354-18699-1-git-send-email-pbonzini@redhat.com>
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Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        borntraeger@de.ibm.com
To: Paolo Bonzini <pbonzini@redhat.com>
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2017-08-02 17:55+0200, Paolo Bonzini:
> During teardown, accesses to memslots and buses are using
> rcu_dereference_protected with an always-true condition because
> these accesses are done outside the usual mutexes.  This
> is because the last reference is gone and there cannot be any
> concurrent modifications, but rcu_dereference_protected is
> ugly and unobvious.
> 
> Instead, check the refcount in kvm_get_bus and __kvm_memslots.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---

Probably looks nicer than temporarily taking the slots_lock.
Queued for 4.13,

thanks.