Avi Kivity wrote: > On 06/29/2010 06:16 AM, Sheng Yang wrote: >> Some guest device driver may leverage the "Non-Snoop" I/O, and explicitly >> WBINVD or CLFLUSH to a RAM space. Since migration may occur before WBINVD or >> CLFLUSH, we need to maintain data consistency either by: >> 1: flushing cache (wbinvd) when the guest is scheduled out if there is no >> wbinvd exit, or >> 2: execute wbinvd on all dirty physical CPUs when guest wbinvd exits. >> >> > > Looks good. > There is just the question remaining if we want to add some disable knob, maybe as an option in the device assignment configuration. I wonder what the performance impact of this feature is when using CPUs without wbinvd exiting. Can we afford to enable it unconditionally (in the presence of pass-through) even if the guest doesn't need it? Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 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
