On 24/05/2016 04:09, Wincy Van wrote: > The server side use kernel spin-lock frequently, NT kernel is > different with Linux, > it will raise TPR to 2 if a spin-lock acquired. We also see that the > context switch > rate on HOST is very high w/o APICv, and GUEST ping will raise up to ~2000ms, > even lost network respond. I think the frequently _tpr_below_threshold_ and > the _irq_window_ vmexits slow down the GUEST, and the interrupt of guest will > have a huge latency. > > With APICv, the guest will run normally. What actually makes a difference here is the self-IPI acceleration, not simply raising the TPR. Windows does a self-IPI when you schedule a DPC. Thanks, 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
