On Wed, Dec 01, 2010 at 02:15:29AM +0800, Xiao Guangrong wrote: > On 12/01/2010 01:50 AM, Gleb Natapov wrote: > > On Wed, Dec 01, 2010 at 12:52:22AM +0800, Xiao Guangrong wrote: > >> On 11/30/2010 09:29 PM, Gleb Natapov wrote: > >> > >>>> + if (!shadow_accessed_mask) > >>>> + return; > >>>> + > >>> I don't get this. As far as I can see VMX inits shadow_accessed_mask to > >>> be zero if ept is enabled. This line here means that we never prefault with ept > >>> enabled. It is opposite from what it should be. > >>> > >> > >> Since it's no accessed bit on EPT, it's no way to distinguish between actually > >> accessed translations and prefault. > > Why is this a problem? We do what this page to not be evicted again > > since we expect it to be accessed. > > > > It can't avoid the page to be evicted again since the page is marked accessed only > when spte is droped or updated. I still do not understand why are you disabling prefault for ept. Why do you want to distinguish between actually accessed translations and prefauls? What problem are you trying to fix? -- Gleb. -- 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