On 23/12/2014 01:37, Zhang, Yang Z wrote: > I don't quite understand it. If user set an interrupt's affinity to a > CPU, but he still see the interrupt delivers to other CPUs in host. > Do you think it is a right behavior? No, the interrupt is not delivered at all in the host. Normally you'd have: - interrupt delivered to CPU from host affinity - VFIO interrupt handler writes to irqfd - interrupt delivered to vCPU from guest affinity Here, you just skip the first two steps. The interrupt is delivered to the thread that is running the vCPU directly, so the host affinity is bypassed entirely. ... unless you are considering the case where the vCPU is blocked and the host is processing the posted interrupt wakeup vector. In that case yes, it would be better to set NDST to a CPU matching the host affinity. But it would be handled in patch 24. We also have the same problem with lowest-priority interrupts; likely the host has configured the interrupt affinity for any CPU. So we can do it later when we add vector hashing support. In the meanwhile, Feng, please add a FIXME comment. Does this make sense? 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
