Il 09/09/2013 11:45, Sunil ha scritto: > Hello List, > > (1) What is the correct way of tracking reads on given gfn ? > > Looks like functions rmap_write_protect(kvm, gfn) and > kvm_mmu_rmap_write_protect(kvm, gfn, slot) removes the write > permission for the given page, by flipping write bit using > PT_WRITABLE_MASK. Thus trapping writes. > > For trapping reads, are there similar routines ? If not, I see > equivalent flag PM_PRESENT_MASK. Thus one way probably is writing > wrapper routines similar to above to flip both read(present) and write > bits. Or would it be just enough to drop the spte instead using > function drop_spte() ? If you are using EPT and your processor has the accessed and dirty bits for EPT page tables (cat /sys/module/kvm_intel/parameters/eptad), you could use the accessed bit to track reads. They wouldn't trap, but you would be able to poll the EPT page tables. Paolo > (2) Is kvm_flush_remote_tlbs() required after either of above approaches ? > Is kvm_flush_remote_tlbs() correct function to flush tlbs ? > > -- > -- > 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 > -- 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
