From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrea Arcangeli Subject: Re: swapping with MMU Notifiers V2 Date: Tue, 29 Jan 2008 19:34:51 +0100 Message-ID: <20080129183451.GT7233@v2.random> References: <20080129145021.GJ7233@v2.random> <479F50D6.4020005@de.ibm.com> <479F532C.1020503@qumranet.com> <479F55D6.1090807@de.ibm.com> <20080129175420.GR7233@v2.random> <479F6AE0.3080702@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: carsteno-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org, kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Avi Kivity Return-path: Content-Disposition: inline In-Reply-To: <479F6AE0.3080702-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org On Tue, Jan 29, 2008 at 08:05:20PM +0200, Avi Kivity wrote: > If a hypervisor mandates (host virtual) == (guest physical), it would work. > x86 still misses the dual-tagged tlb, so mmu notifiers are needed > regardless. With s390, they have an additional offset parameter, so (host Yep. NPT is certainly better given two levels are bad enough. The mmu notifiers aren't really a performance problem unlike the three levels would be (the bigger cost is likely the ipi for the tlb flushes on a smp guest on smp host, and they cost nothing on up guest). > virtual) == (guest physical) + offset, so qemu can coexist with the guest, > and dual tagged tlb so that a host invalidate also evicts guest tlb > entries. Thanks! ------------------------------------------------------------------------- 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/