Re: [PATCH] KVM: avoid using rcu_dereference_protected

From: Radim KrÄmÃÅ
Date: Wed Aug 02 2017 - 16:16:46 EST

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@xxxxxxxxxx>
> ---

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