From patchwork Wed Oct 17 16:52:52 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peng Hao X-Patchwork-Id: 10645029 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A383C13A4 for ; Wed, 17 Oct 2018 08:41:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 90B5C2AB54 for ; Wed, 17 Oct 2018 08:41:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8E5282AB35; Wed, 17 Oct 2018 08:41:41 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C3AF92ABB7 for ; Wed, 17 Oct 2018 08:41:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726976AbeJQQgQ (ORCPT ); Wed, 17 Oct 2018 12:36:16 -0400 Received: from out1.zte.com.cn ([202.103.147.172]:47128 "EHLO mxct.zte.com.cn" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726482AbeJQQgQ (ORCPT ); Wed, 17 Oct 2018 12:36:16 -0400 Received: from mse01.zte.com.cn (unknown [10.30.3.20]) by Forcepoint Email with ESMTPS id 16A7EF36D0422A502FAC; Wed, 17 Oct 2018 16:41:33 +0800 (CST) Received: from notes_smtp.zte.com.cn ([10.30.1.239]) by mse01.zte.com.cn with ESMTP id w9H8fRpS053988; Wed, 17 Oct 2018 16:41:27 +0800 (GMT-8) (envelope-from peng.hao2@zte.com.cn) Received: from localhost.localdomain.localdomain ([10.74.120.59]) by szsmtp06.zte.com.cn (Lotus Domino Release 8.5.3FP6) with ESMTP id 2018101716414946-5075400 ; Wed, 17 Oct 2018 16:41:49 +0800 From: Peng Hao To: pbonzini@redhat.com, rkrcmar@redhat.com, mst@redhat.com, ehabkost@redhat.com Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, Peng Hao Subject: [PATCH 0/5] target/i386: introduce coalesced pio Date: Thu, 18 Oct 2018 00:52:52 +0800 Message-Id: <1539795177-21038-1-git-send-email-peng.hao2@zte.com.cn> X-Mailer: git-send-email 1.8.3.1 X-MIMETrack: Itemize by SMTP Server on SZSMTP06/server/zte_ltd(Release 8.5.3FP6|November 21, 2013) at 2018-10-17 16:41:49, Serialize by Router on notes_smtp/zte_ltd(Release 9.0.1FP7|August 17, 2016) at 2018-10-17 16:41:18, Serialize complete at 2018-10-17 16:41:18 X-MAIL: mse01.zte.com.cn w9H8fRpS053988 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Coalesced pio is base on coalesced mmio and can be used for some port like rtc port, pci-host config port and so on. Specially in case of rtc as coalesced pio, some versions of windows guest access rtc frequently because of rtc as system tick. guest access rtc like this: write register index to 0x70, then write or read data from 0x71. writing 0x70 port is just as index and do nothing else. So we can use coalesced pio to handle this scene to reduce VM-EXIT time. When it starts and closes the virtual machine, it will access pci-host config port or virtio-pci config port frequently. So setting these port as coalesced pio can reduce startup and shutdown time. In qemu I just realize piixfx's pci-host, it is convenient for other pci-host type implementations. without my patch, get the vm-exit time of accessing rtc 0x70 and piix 0xcf8 using perf tools: (guest OS : windows 7 64bit) IO Port Access Samples Samples% Time% Min Time Max Time Avg time 0x70:POUT 86 30.99% 74.59% 9us 29us 10.75us (+- 3.41%) 0xcf8:POUT 1119 2.60% 2.12% 2.79us 56.83us 3.41us (+- 2.23%) with my patch IO Port Access Samples Samples% Time% Min Time Max Time Avg time 0x70:POUT 106 32.02% 29.47% 0us 10us 1.57us (+- 7.38%) 0xcf8:POUT 1065 1.67% 0.28% 0.41us 65.44us 0.66us (+- 10.55%) These are just qemu's patches, another patches are for kernel. Changes v4 --> v5: update kvm header, improve compatibility. Changes v3 --> v4 modify coalesced_mmio_{add|del} to coalesced_io_{add|del} delete unnecessary macro define Peng Hao (5): target-i386: add rtc 0x70 port as coalesced_pio target-i386: add i440fx 0xcf8 port as coalesced_pio target-i386: add q35 0xcf8 port as coalesced_pio target/i386: add coalesced pio support target-i386: add coalesced_pio API accel/kvm/kvm-all.c | 60 +++++++++++++++++++++++++++++++++++++++++++---- hw/pci-host/piix.c | 4 ++++ hw/pci-host/q35.c | 4 ++++ hw/timer/mc146818rtc.c | 8 +++++++ include/exec/memory.h | 4 ++-- linux-headers/linux/kvm.h | 9 ++++++- memory.c | 4 ++-- 7 files changed, 83 insertions(+), 10 deletions(-)