On 24/11/2015 15:35, Radim Krcmár wrote: > > Thanks for your guys' review. Yes, we can introduce a module option > > for it. According to Radim's comments above, we need use the > > same policy for PI and non-PI lowest-priority interrupts, so here is the > > question: for vector hashing, it is easy to apply it for both non-PI and PI > > case, however, for Round-Robin, in non-PI case, the round robin counter > > is used and updated when the interrupt is injected to guest, but for > > PI case, the interrupt is injected to guest totally by hardware, software > > cannot control it while interrupt delivery, we can only decide the > > destination vCPU for the PI interrupt in the initial configuration > > time (guest update vMSI -> QEMU -> KVM). Do you guys have any good > > suggestion to do round robin for PI lowest-priority? Seems Round robin > > is not a good way for PI lowest-priority interrupts. Any comments > > are appreciated! > > It's meaningless to try dynamic algorithms with PI so if we allow both > lowest priority algorithms, I'd let PI handle any lowest priority only > with vector hashing. (It's an ugly compromise.) For now, I would just keep the 4.4 behavior, i.e. disable PI unless there is a single destination || vector hashing is enabled. We can flip the switch later. Paolo -- 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
