On Tue, May 19, 2009 at 04:56:48PM +0300, Avi Kivity wrote: > Marcelo Tosatti wrote: >>> I think that for ASID!=0 you can actually do nothing. The guest >>> entry is a cr3 switch, so we'll both get a tlb flush and a resync on >>> any modified ptes. >>> >>> For ASID==0 you can do the invlpg thing. >>> >>> Marcelo? >>> >> >> kvm_mmu_invlpg is cheap, better just invalidate the entry. If hyper-v >> uses invlpga to invalidate TLB entries which it has updated pte's in >> memory for, and you skip the invalidation now and somehow later use an >> unsync spte, you're toast. >> > > But won't the guest entry cause a resync? If its a cr3/cr4 exit, yes. > Doing nothing is even cheaper. My brain is nested. -- 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
