Re: [PATCH v2 1/2] KVM: MMIO: Lock coalesced device when checking for available entry

Avi Kivity
2011-07-18T09:50:42Z

On 07/18/2011 12:29 PM, Sasha Levin wrote:
> > Hmm. This means we take the lock for every I/O, whether it hits
> > coalesced mmio or not.
> >
> > We need to do the range check before taking the lock and the space check
> > after taking the lock.
> >
>
> I'll fix that.
>
> Shouldn't the range check be also locked somehow? Currently it is
> possible that a coalesced region was removed while we are checking the
> ranges, and we won't issue a mmio exit as the host expects

It's "locked" using rcu.

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