On Thu, Nov 10, 2011, Avi Kivity wrote about "Re: [PATCH 01/10] nEPT: Module option": > > By "this", do you mean without the "nested_ept" option, or without the > > hypothetical "EPT on shadow page tables" feature? > > Er, both. The feature should be controlled on a per-guest basis, not > per host. >.. > It's just redundant, since we do need a per-guest control.
I agreed that per-guest control would have been nicer, but since we don't have an API for specifying that per guest since EPT is not, unfortunately, a CPUID feature, I thought that at least a host-level flag would be useful. Why would it be useful? I agree it isn't the most important option since sliced bread, but if, for example, one day we discover a bug with nested EPT, L0 can disable it for all L1 guests and basically force them to use shadow page tables on EPT. It was also useful for me to have this option for benchmarking, because I can force back the old shadow-on-EPT method with just a single option in L0 (instead of needing to give "ept=0" option in L1s). If you really don't like the existance of this option, I can easily remove it of course. -- Nadav Har'El | Thursday, Nov 10 2011, n...@math.technion.ac.il |----------------------------------------- Phone +972-523-790466, ICQ 13349191 |Guarantee: this email is 100% free of http://nadav.harel.org.il |magnetic monopoles, or your money back! -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
