On Wed, Oct 23, 2013 at 09:29:20PM +0800, Xiao Guangrong wrote: > Currently, kvm zaps the large spte if write-protected is needed, the later > read can fault on that spte. Actually, we can make the large spte readonly > instead of making them un-present, the page fault caused by read access can > be avoided > > The idea is from Avi: > | As I mentioned before, write-protecting a large spte is a good idea, > | since it moves some work from protect-time to fault-time, so it reduces > | jitter. This removes the need for the return value. > > This version has fixed the issue reported in 6b73a9606, the reason of that > issue is that fast_page_fault() directly sets the readonly large spte to > writable but only dirty the first page into the dirty-bitmap that means > other pages are missed. Fixed it by only the normal sptes (on the > PT_PAGE_TABLE_LEVEL level) can be fast fixed > > Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx> Reviewed-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx> -- 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
