From patchwork Thu Aug 30 16:17:21 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peng Hao X-Patchwork-Id: 10581307 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 BE135174A for ; Thu, 30 Aug 2018 08:03:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B1FA72B7B4 for ; Thu, 30 Aug 2018 08:03:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A54C32B7BF; Thu, 30 Aug 2018 08:03:27 +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=-4.9 required=2.0 tests=BAYES_00,DATE_IN_FUTURE_03_06, 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 46ADC2B7B4 for ; Thu, 30 Aug 2018 08:03:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727982AbeH3MEN (ORCPT ); Thu, 30 Aug 2018 08:04:13 -0400 Received: from out1.zte.com.cn ([202.103.147.172]:59520 "EHLO mxct.zte.com.cn" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727870AbeH3MEM (ORCPT ); Thu, 30 Aug 2018 08:04:12 -0400 Received: from mse01.zte.com.cn (unknown [10.30.3.20]) by Forcepoint Email with ESMTPS id 493C41B4C99F76CC7CC5; Thu, 30 Aug 2018 16:03:16 +0800 (CST) Received: from notes_smtp.zte.com.cn ([10.30.1.239]) by mse01.zte.com.cn with ESMTP id w7U839rO016073; Thu, 30 Aug 2018 16:03:09 +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 2018083016031650-6560001 ; Thu, 30 Aug 2018 16:03:16 +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 V4 2/2] kvm/x86 : add document for coalesced pio Date: Fri, 31 Aug 2018 00:17:21 +0800 Message-Id: <1535645841-111837-3-git-send-email-peng.hao2@zte.com.cn> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1535645841-111837-1-git-send-email-peng.hao2@zte.com.cn> References: <1535645841-111837-1-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 2018-08-30 16:03:16, Serialize by Router on notes_smtp/zte_ltd(Release 9.0.1FP7|August 17, 2016) at 2018-08-30 16:02:57, Serialize complete at 2018-08-30 16:02:57 X-MAIL: mse01.zte.com.cn w7U839rO016073 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Signed-off-by: Peng Hao --- Documentation/virtual/kvm/00-INDEX | 2 ++ Documentation/virtual/kvm/coalesced-pio.txt | 15 +++++++++++++++ 2 files changed, 17 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..4b7a37b 100644 --- a/Documentation/virtual/kvm/00-INDEX +++ b/Documentation/virtual/kvm/00-INDEX @@ -9,6 +9,8 @@ arm - internal ABI between the kernel and HYP (for arm/arm64) cpuid.txt - KVM-specific cpuid leaves (x86). +coalesced-pio.txt + - KVM_CAP_COALESCED_PIO devices/ - KVM_CAP_DEVICE_CTRL userspace API. halt-polling.txt diff --git a/Documentation/virtual/kvm/coalesced-pio.txt b/Documentation/virtual/kvm/coalesced-pio.txt new file mode 100644 index 0000000..38dac11 --- /dev/null +++ b/Documentation/virtual/kvm/coalesced-pio.txt @@ -0,0 +1,15 @@ +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.