Re: [PATCH v3] KVM: MMU: lazily drop large spte

2013-02-06 Thread Marcelo Tosatti
On Tue, Feb 05, 2013 at 03:11:09PM +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 > b

Re: [PATCH v3] KVM: MMU: lazily drop large spte

2013-02-05 Thread Gleb Natapov
On Tue, Feb 05, 2013 at 03:11:09PM +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 > b

[PATCH v3] KVM: MMU: lazily drop large spte

2013-02-04 Thread Xiao Guangrong
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 avoid The idea is from Avi: | As I mentioned before, write-protecting