On Thu, Nov 18, 2010 at 03:12:56PM +0800, Xiao Guangrong wrote: > On 11/17/2010 11:57 PM, Avi Kivity wrote: > > >>> set_pte: > >>> update_spte(sptep, spte); > >>> + /* > >>> + * If we overwrite a writable spte with a read-only one we > >>> + * should flush remote TLBs. Otherwise rmap_write_protect > >>> + * will find a read-only spte, even though the writable spte > >>> + * might be cached on a CPU's TLB. > >>> + */ > >>> + if (is_writable_pte(entry)&& !is_writable_pte(*sptep)) > >>> + kvm_flush_remote_tlbs(vcpu->kvm); > >> There is no need to flush on sync_page path since the guest is > >> responsible for it. > >> > > > > If we don't, the next rmap_write_protect() will incorrectly decide that > > there's no need to flush tlbs. > > > > Maybe it's not a problem if guest can flush all tlbs after overwrite it? > Marcelo, what's your comment about this? It can, but there is no guarantee. Your patch is correct. -- 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
