On 11/02/2012 10:00 AM, Jan Kiszka wrote: > > > >> As I understand the series, as->lock == NULL means that we will never > >> take any lock during dispatch as the caller is not yet ready for > >> fine-grained locking. This prevents the problem - for PIO at least. But > >> this series should break TCG as it calls into MMIO dispatch from the > >> VCPU while holding the BQL. > >> > > What about add another condition "dispatch_type == DISPATCH_MMIO" to > > tell this situation. > > An alternative pattern that we will also use for core services is to > provide an additional entry point, one that indicates that the caller > doesn't hold the BQL. Then we will gradually move things over until the > existing entry point is obsolete. >
I like it (or rather, least dislike it). So we'd have address_space_rw() and address_space_rw_unlocked() (or maybe, address_space_rw() and address_space_rw_locked(), to indicate the preferred way of doing things). -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.
