Re: [PATCH v3 7/8] KVM: x86/mmu: Protect rmaps independently with SRCU

[Paolo Bonzini]

On 11/05/21 18:22, Ben Gardon wrote:
> > Yes, and I'm arguing that annotating the rmaps as __rcu is wrong because they
> > themselves are not protected by SRCU.  The memslot that contains the rmaps is
> > protected by SRCU, and because of that asserting SRCU is held for read will hold
> > true.  But, if the memslot code were changed to use a different protection scheme,
> > e.g. a rwlock for argument's sake, then the SRCU assertion would fail even though
> > the rmap logic itself didn't change.
>
> I'm inclined to agree with Sean that the extra RCU annotations are
> probably unnecessary since we're already doing the srcu dereference
> for all the slots. I'll move all these RCU annotations to their own
> patch and put it at the end of the series when I send v4.

Fair enough, you can even remove them then.

Paolo