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=-3.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 63023C41604 for ; Tue, 6 Oct 2020 08:13:55 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E0763206F7 for ; Tue, 6 Oct 2020 08:13:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="BGWdDV2L" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E0763206F7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.3129.9037 (Exim 4.92) (envelope-from ) id 1kPi6J-0004Bd-9B; Tue, 06 Oct 2020 08:13:35 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 3129.9037; Tue, 06 Oct 2020 08:13:35 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kPi6J-0004BW-5m; Tue, 06 Oct 2020 08:13:35 +0000 Received: by outflank-mailman (input) for mailman id 3129; Tue, 06 Oct 2020 08:13:34 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kPi6H-0004BR-W3 for xen-devel@lists.xen.org; Tue, 06 Oct 2020 08:13:34 +0000 Received: from mail-ej1-x641.google.com (unknown [2a00:1450:4864:20::641]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id f5145476-7603-4130-bd30-e1eb5714aab8; Tue, 06 Oct 2020 08:13:33 +0000 (UTC) Received: by mail-ej1-x641.google.com with SMTP id p15so16309656ejm.7 for ; Tue, 06 Oct 2020 01:13:33 -0700 (PDT) Received: from CBGR90WXYV0 (54-240-197-238.amazon.com. [54.240.197.238]) by smtp.gmail.com with ESMTPSA id o9sm1765320eds.5.2020.10.06.01.13.30 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 06 Oct 2020 01:13:31 -0700 (PDT) Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kPi6H-0004BR-W3 for xen-devel@lists.xen.org; Tue, 06 Oct 2020 08:13:34 +0000 X-Inumbo-ID: f5145476-7603-4130-bd30-e1eb5714aab8 Received: from mail-ej1-x641.google.com (unknown [2a00:1450:4864:20::641]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id f5145476-7603-4130-bd30-e1eb5714aab8; Tue, 06 Oct 2020 08:13:33 +0000 (UTC) Received: by mail-ej1-x641.google.com with SMTP id p15so16309656ejm.7 for ; Tue, 06 Oct 2020 01:13:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:reply-to:to:cc:references:in-reply-to:subject:date:message-id :mime-version:content-transfer-encoding:content-language :thread-index; bh=HR56wJereoyhBJKXAri+fewH/8JdbbDXN6I88FBg51M=; b=BGWdDV2L20bs5zTZev8MACb1x5mxhk/dBnNElUsvJHEPO3oI9dbf0u5SgNc7VVJgqB aSoCEms3yykCTtOBS16hfMc8CjNRul2GFIO7ACkO82ZPkXjdEgfZrg1tV3GDE6x4V1Ys oyj7iW+a0m1z+CV8Ud17rgOq0kLpvse6gsazZwH0Q1/8XkFL3oZrsEgHh6/BJVmHrfK9 3VaX7I2i/aLxyuRiKSnzZqahQQEu64n1MzwlnffeFMbP6LTWcFGw4mnhX95ssPgbSfiG YzKrtLRysK2Qf3J54NJDrCtPz1+zIe001QxzQNKiK2Ng24RLN4U9CXIM//GrkDuttEC3 u6sw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:reply-to:to:cc:references:in-reply-to :subject:date:message-id:mime-version:content-transfer-encoding :content-language:thread-index; bh=HR56wJereoyhBJKXAri+fewH/8JdbbDXN6I88FBg51M=; b=QU847Dd22JueiDkQyFPEQdxhEzcpooMxa10X7IKAkcnESzcgeWM0BIeIvfFOSQdv1U RTQx6U/U0iApZdZoQ54/z4bX+DSG/tYapssr1cP7YUFUQc8yzRItwMQcEe3r/hR1CTig ZTih78IAqx7fouaQFvDqyA1bJgcpdaxy7+TluGfkHO1XV/X9TVKnspGYtrW5ypOJ2qjV ks3hP2JQ96z9SaM6yXTfVHWXgJc0Zhofcw7X2R03gE3gRXcKsH/x4A8GCR+he5WUqPoi 68HMatX939RAi+TxD7YknW6bHjlE6Mrk+yyLWPfUvrZ6ZXI6QZbuh4LGHZV9Rw4/i5v9 wwNQ== X-Gm-Message-State: AOAM533F+ibkYQUq36ArdpHLMiePS2mALt5IvN6sa0x1KVnE760ypnWd PbAEK5le5S/WxHvrVl+++uE= X-Google-Smtp-Source: ABdhPJyA8I1Q/+tUvyuIXDyjYz8pEVzJJon+Pyfj0lBbLmQRT9sSWNHdG7Cq1Vz0bQf+Ih0me0RUyA== X-Received: by 2002:a17:906:c191:: with SMTP id g17mr4053148ejz.117.1601972012225; Tue, 06 Oct 2020 01:13:32 -0700 (PDT) Received: from CBGR90WXYV0 (54-240-197-238.amazon.com. [54.240.197.238]) by smtp.gmail.com with ESMTPSA id o9sm1765320eds.5.2020.10.06.01.13.30 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 06 Oct 2020 01:13:31 -0700 (PDT) From: Paul Durrant X-Google-Original-From: "Paul Durrant" Reply-To: To: "'Jan Beulich'" , "'Don Slutz'" Cc: , "'Boris Ostrovsky'" , "'Ian Jackson'" , "'Jun Nakajima'" , "'Kevin Tian'" , "'Stefano Stabellini'" , "'Tim Deegan'" , "'Andrew Cooper'" , "'Konrad Rzeszutek Wilk'" , "'George Dunlap'" References: In-Reply-To: Subject: RE: [XEN PATCH v14 7/8] Add IOREQ_TYPE_VMWARE_PORT Date: Tue, 6 Oct 2020 09:13:29 +0100 Message-ID: <000901d69bb8$941489b0$bc3d9d10$@xen.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Mailer: Microsoft Outlook 16.0 Content-Language: en-gb Thread-Index: AQE3EbIOCgkLUtOBXNlfcF4M3GLQwwHXOsu5AXIpxzqqrv4WAA== > -----Original Message----- > From: Jan Beulich > Sent: 01 October 2020 15:42 > To: Don Slutz > Cc: xen-devel@lists.xen.org; Boris Ostrovsky = ; Ian Jackson > ; Jun Nakajima ; Kevin = Tian ; > Stefano Stabellini ; Tim Deegan ; = Andrew Cooper > ; Konrad Rzeszutek Wilk = ; George Dunlap > ; Paul Durrant > Subject: Re: [XEN PATCH v14 7/8] Add IOREQ_TYPE_VMWARE_PORT >=20 > On 19.08.2020 18:52, Don Slutz wrote: > > This adds synchronization of the 6 vcpu registers (only 32bits of > > them) that QEMU's vmport.c and vmmouse.c needs between Xen and QEMU. > > This is how VMware defined the use of these registers. > > > > This is to avoid a 2nd and 3rd exchange between QEMU and Xen to > > fetch and put these 6 vcpu registers used by the code in QEMU's > > vmport.c and vmmouse.c >=20 > I'm unconvinced this warrants a new ioreq type, and all the overhead > associated with it. I'd be curious to know what Paul or the qemu > folks think here. >=20 The current shared ioreq_t does appear have enough space to accommodate = 6 32-bit registers (in the addr, data, count and size) fields co = couldn't the new IOREQ_TYPE_VMWARE_PORT type be dealt with by simply = unioning the regs with these fields? That avoids the need for a whole = new shared page. Paul