On Wed, Oct 03, 2018 at 09:48:09AM +0200, Paolo Bonzini wrote: >On 03/10/2018 03:40, Wei Yang wrote: >> * guest/host writable >> * A/D bit is clear, when A/D enabled >> >> If either one is true, a page fault will be triggered when spte changes. >> This means someone else would modify this spte simultaneously. > >Hi, > >page faults happen under mmu_lock, with the exception of "fast page >fault" that change the accessed and dirty bits. Therefore, neither a >concurent present<->nonpresent switch nor a change of >spte_has_volatile_bits(old_spte) can happen during >mmu_spte_clear_track_bits. > Thanks for your explanation. :-) Let me prepare v2. >Paolo -- Wei Yang Help you, Help me
