From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DATE_IN_FUTURE_03_06, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD494C4321D for ; Fri, 24 Aug 2018 03:06:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 69A6121571 for ; Fri, 24 Aug 2018 03:06:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 69A6121571 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zte.com.cn Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727501AbeHXGim (ORCPT ); Fri, 24 Aug 2018 02:38:42 -0400 Received: from out1.zte.com.cn ([202.103.147.172]:38252 "EHLO mxct.zte.com.cn" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726287AbeHXGil (ORCPT ); Fri, 24 Aug 2018 02:38:41 -0400 Received: from mse01.zte.com.cn (unknown [10.30.3.20]) by Forcepoint Email with ESMTPS id 84B2BB2A474EFA4E3352; Fri, 24 Aug 2018 11:06:02 +0800 (CST) Received: from notes_smtp.zte.com.cn ([10.30.1.239]) by mse01.zte.com.cn with ESMTP id w7O35tQi036824; Fri, 24 Aug 2018 11:05:55 +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 2018082411060379-5963665 ; Fri, 24 Aug 2018 11:06:03 +0800 From: Peng Hao To: pbonzini@redhat.com, rkrcmar@redhat.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, zhong.weidong@zte.com.cn, wanpeng.li@hotmail.com, Peng Hao Subject: [PATCH V3 2/2] kvm/x86 : add document for coalesced pio Date: Fri, 24 Aug 2018 19:20:32 +0800 Message-Id: <1535109632-59745-3-git-send-email-peng.hao2@zte.com.cn> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1535109632-59745-1-git-send-email-peng.hao2@zte.com.cn> References: <1535109632-59745-1-git-send-email-peng.hao2@zte.com.cn> X-MIMETrack: Itemize by SMTP Server on SZSMTP06/server/zte_ltd(Release 8.5.3FP6|November 21, 2013) at 2018-08-24 11:06:03, Serialize by Router on notes_smtp/zte_ltd(Release 9.0.1FP7|August 17, 2016) at 2018-08-24 11:05:40, Serialize complete at 2018-08-24 11:05:40 X-MAIL: mse01.zte.com.cn w7O35tQi036824 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Signed-off-by: Peng Hao --- Documentation/virtual/kvm/00-INDEX | 2 ++ Documentation/virtual/kvm/coalesced-pio.txt | 14 ++++++++++++++ 2 files changed, 16 insertions(+) create mode 100644 Documentation/virtual/kvm/coalesced-pio.txt diff --git a/Documentation/virtual/kvm/00-INDEX b/Documentation/virtual/kvm/00-INDEX index 3492458..3d68164 100644 --- a/Documentation/virtual/kvm/00-INDEX +++ b/Documentation/virtual/kvm/00-INDEX @@ -11,6 +11,8 @@ cpuid.txt - KVM-specific cpuid leaves (x86). devices/ - KVM_CAP_DEVICE_CTRL userspace API. +coalesced-pio.txt + - KVM_CAP_COALESCED_PIO halt-polling.txt - notes on halt-polling hypercalls.txt diff --git a/Documentation/virtual/kvm/coalesced-pio.txt b/Documentation/virtual/kvm/coalesced-pio.txt new file mode 100644 index 0000000..932d5cd --- /dev/null +++ b/Documentation/virtual/kvm/coalesced-pio.txt @@ -0,0 +1,14 @@ +Linux KVM Coalesced PIO: +======================== +Coalesced pio is base on coalesced mmio. When the write access to a port +of a device does a simple work (just like setting a register ID or address +index), then we can use coalesced pio. + +Setting a port as coalesced pio, the write access to the port don't need to +exit to userspace, and just record the value in shared coalesced ring in kernel. +Then following access to another port of the same device which relys on the first +port's setting or a read access to the first port will set the previous write +value of the first port firstly in usersapce according to the shared coalesced ring. + +Coalesced pio can be used for rtc 0x70 port, pci-host config port, virtio-pci config +port and so on. -- 1.8.3.1