On Friday 10 October 2008 14:49:13 Avi Kivity wrote: > Sheng Yang wrote: > > Yeah, I think the condition I mentioned is a example of yours. But in > > fact it's difficult to get a optimize value... I think it's possible that > > qemu may access all memory it owned, if so, no guest mtrr would affect. > > But how can we tell qemu would access which region of memory? We know it > > for vram, but any other cases? Seems it's indeed a big potential > > problem... If we want to do this, maybe we can hack something into host > > cache consistent check, though it's pretty dirty and got limit usage... > > qemu will access all of memory, for example during live migration. > > So we need to distinguish between RAM and mmio somehow.
Yes... But it's easy to do with assigned devices' mmio, but what if guest specific some non-mmio memory's memory type? E.g. we have met one issue in Xen, that a assigned-device's XP driver specific one memory region as buffer, and modify the memory type then do DMA. Only map MMIO space can be first step, but I guess we can modify assigned memory region memory type follow guest's? -- regards Yang, Sheng -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
