On Mon, 2011-07-18 at 12:50 +0300, Avi Kivity wrote: > 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. > Where is that happening? All the coalesced zones are stored under the coalesced "device" in a simple array. When adding and removing zones, kvm->slots_lock is taken - I don't see anything which prevents a range check during zone removal unless slots_lock prevents IO. -- Sasha. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
