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> > > + struct hvm_gsi_eoi_callback *cb; > > > + > > > + read_lock(&hvm_irq->gsi_callbacks_lock); > > > + list_for_each_entry ( cb, &hvm_irq->gsi_callbacks[gsi], list ) > > > + cb->callback(gsi, cb->data); > > > + read_unlock(&hvm_irq->gsi_callbacks_lock); > > > +} > > > > Just as an observation (for now at least) - holding the lock here > > means the callbacks cannot re-register themselves. > > Well, re-registering would be weird, as the callback is not > unregistered after execution. What is likely more relevant is that the > callback cannot unregister itself. I haven't found a need for this so > far, so I think it's fine. I'm afraid I was wrong here - rtc_pf_callback could attempt to unregister the timer, and thus end up calling hvm_gsi_unregister_callback inside of a callback. I need to figure a way to solve this. We already run the RTC in no ack mode (which is correct because of the flag we expose in the WAET ACPI table), and hence I wonder if we still need to keep the code for the strict_mode around, since it's not used at all. Would you be OK with me removing the mode_strict related code? Thanks, Roger.