From patchwork Thu Aug 30 15:50:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peng Hao X-Patchwork-Id: 10581261 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 DAE7213AC for ; Thu, 30 Aug 2018 07:37:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CAE522B549 for ; Thu, 30 Aug 2018 07:37:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BEC502B576; Thu, 30 Aug 2018 07:37:35 +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=-6.0 required=2.0 tests=BAYES_00,DATE_IN_FUTURE_06_12, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 749FC2B549 for ; Thu, 30 Aug 2018 07:37:35 +0000 (UTC) Received: from localhost ([::1]:47470 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fvHWI-0007kf-5y for patchwork-qemu-devel@patchwork.kernel.org; Thu, 30 Aug 2018 03:37:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57747) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fvHV4-0005wD-A5 for qemu-devel@nongnu.org; Thu, 30 Aug 2018 03:36:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fvHV1-0007TW-2H for qemu-devel@nongnu.org; Thu, 30 Aug 2018 03:36:18 -0400 Received: from mxhk.zte.com.cn ([63.217.80.70]:54518) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fvHV0-0007Lc-Li for qemu-devel@nongnu.org; Thu, 30 Aug 2018 03:36:14 -0400 Received: from mse01.zte.com.cn (unknown [10.30.3.20]) by Forcepoint Email with ESMTPS id 9E10A8330CCC063FF6F1; Thu, 30 Aug 2018 15:36:06 +0800 (CST) Received: from notes_smtp.zte.com.cn ([10.30.1.239]) by mse01.zte.com.cn with ESMTP id w7U7Zvmr073719; Thu, 30 Aug 2018 15:35:57 +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 2018083015360503-6553118 ; Thu, 30 Aug 2018 15:36:05 +0800 From: Peng Hao To: pbonzini@redhat.com, rkrcmar@redhat.com, mst@redhat.com, ehabkost@redhat.com Date: Thu, 30 Aug 2018 23:50:12 +0800 Message-Id: <1535644216-111422-1-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 2018-08-30 15:36:05, Serialize by Router on notes_smtp/zte_ltd(Release 9.0.1FP7|August 17, 2016) at 2018-08-30 15:35:46, Serialize complete at 2018-08-30 15:35:46 X-MAIL: mse01.zte.com.cn w7U7Zvmr073719 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 63.217.80.70 Subject: [Qemu-devel] [PATCH V5 0/4] introduce coalesced pio support X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peng Hao , zhong.weidong@zte.com.cn, qemu-devel@nongnu.org, kvm@vger.kernel.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" 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, virtio-pci 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 (4): target-i386: introduce coalesced_pio kvm header update target-i386: add coalesced_pio API target-i386: add rtc 0x70 port as coalesced_pio target-i386: add i440fx 0xcf8 port as coalesced_pio accel/kvm/kvm-all.c | 61 ++++++++++++++++++++++++++++++++++++++++++----- hw/pci-host/piix.c | 4 ++++ hw/timer/mc146818rtc.c | 8 +++++++ include/exec/memory.h | 4 ++-- linux-headers/linux/kvm.h | 11 +++++++-- memory.c | 4 ++-- 6 files changed, 80 insertions(+), 12 deletions(-)