From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754703AbdEIQDb (ORCPT ); Tue, 9 May 2017 12:03:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59456 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754342AbdEIQD3 (ORCPT ); Tue, 9 May 2017 12:03:29 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com E876872658 Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=bsd@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com E876872658 From: Bandan Das To: Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 0/3] nVMX: Emulated Page Modification Logging for Nested Virtualization References: <20170505192515.27833-1-bsd@redhat.com> Date: Tue, 09 May 2017 12:03:27 -0400 In-Reply-To: (Paolo Bonzini's message of "Tue, 9 May 2017 17:22:22 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Tue, 09 May 2017 16:03:29 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paolo Bonzini writes: > On 05/05/2017 21:25, Bandan Das wrote: >> v2: >> 2/3: Clear out all bits except bit 12 >> 3/3: Slightly modify an existing comment, honor L0's >> PML setting when clearing it for L1 >> >> v1: >> http://www.spinics.net/lists/kvm/msg149247.html >> >> These patches implement PML on top of EPT A/D emulation >> (ae1e2d1082ae). >> >> When dirty bit is being set, we write the gpa to the >> buffer provided by L1. If the index overflows, we just >> change the exit reason before running L1. > > I tested this with api/dirty-log-perf, and nested PML is more than 3 > times faster than pml=0. I want to do a few more tests because I don't > see any PML full exits in the L1 trace, but it seems to be a nice > improvement! Thanks for testing! Regarding the PML full exits, I did notice their absence. I induced it artifically in my testing with a lower index and it seemed to work fine. > Paolo > >> Bandan Das (3): >> kvm: x86: Add a hook for arch specific dirty logging emulation >> nVMX: Implement emulated Page Modification Logging >> nVMX: Advertise PML to L1 hypervisor >> >> arch/x86/include/asm/kvm_host.h | 2 + >> arch/x86/kvm/mmu.c | 15 +++++++ >> arch/x86/kvm/mmu.h | 1 + >> arch/x86/kvm/paging_tmpl.h | 4 ++ >> arch/x86/kvm/vmx.c | 97 ++++++++++++++++++++++++++++++++++++++--- >> 5 files changed, 112 insertions(+), 7 deletions(-) >>