From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [patch 2/5] KVM: hypercall based pte updates and TLB flushes Date: Sun, 17 Feb 2008 10:28:07 +0200 Message-ID: <47B7F017.10902@qumranet.com> References: <20080216220924.733723618@redhat.com>> <20080216221220.843135254@redhat.com>> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel@lists.sourceforge.net To: Marcelo Tosatti Return-path: In-Reply-To: <20080216221220.843135254@redhat.com>> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org Marcelo Tosatti wrote: > Hypercall based pte updates are faster than faults, and also allow use > of the lazy MMU mode to batch operations. > > Don't report the feature if two dimensional paging is enabled. > > Signed-off-by: Marcelo Tosatti > +/* > + * We only need to hook operations that are MMU writes. We hook these so that > + * we can use lazy MMU mode to batch these operations. We could probably > + * improve the performance of the host code if we used some of the information > + * here to simplify processing of batched writes. > + */ > One option is, if the guest promises never to write to a page table directly, is to avoid write protecting guest page tables. I think the shadow code can handle it (since the gfn/spte relationship is maintained by shadow code, and doesn't require reading the guest page tables), but am not sure. -- Any sufficiently difficult bug is indistinguishable from a feature. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/