Hi, did anyone recently tried current KVM for Intel over some real-time Linux? I'm seeing more than 500 us latency peaks on the host, specifically during VM startup. This applies to both 2.6.29.6-rt23 and Xenomai/I-pipe. For -rt, I both tried the included (patched) KVM modules as well as kvm.git head with some additionally required -rt fixes. Xenomai ran over a 2.6.30 kernel with my own KVM-enabler patch. Early instrumentation actually points to the guest exit itself: I added markers right before and after the assembly part of vmx_vcpu_run, and further instrumentation reports that the next host APIC tick should go off right inside guest mode. But KVM leaves the switching part 500 us too late in that case - as if guest exit on external IRQs was disabled. Will debug this further, but I'm also curious to hear other user experiences. Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux -- 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
