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=-9.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS 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 91168C433DF for ; Wed, 12 Aug 2020 06:40:28 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 6013C20658 for ; Wed, 12 Aug 2020 06:40:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6013C20658 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bugs.launchpad.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:42854 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k5kR1-00051s-EE for qemu-devel@archiver.kernel.org; Wed, 12 Aug 2020 02:40:27 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58702) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k5kQK-0004ZV-GI for qemu-devel@nongnu.org; Wed, 12 Aug 2020 02:39:44 -0400 Received: from indium.canonical.com ([91.189.90.7]:47860) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1k5kQI-00025d-Eq for qemu-devel@nongnu.org; Wed, 12 Aug 2020 02:39:44 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1k5kQG-00033w-8h for ; Wed, 12 Aug 2020 06:39:40 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 39BF02E8074 for ; Wed, 12 Aug 2020 06:39:40 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Wed, 12 Aug 2020 06:29:12 -0000 From: Thomas Huth <1407808@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=Triaged; importance=Undecided; assignee=None; X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: nyh th-huth X-Launchpad-Bug-Reporter: Nadav Har'El (nyh) X-Launchpad-Bug-Modifier: Thomas Huth (th-huth) References: <20150105215424.22410.18753.malonedeb@gac.canonical.com> Message-Id: <159721375321.5687.8416093096758256384.launchpad@soybean.canonical.com> Subject: [Bug 1407808] Re: virtual console gives strange response to ANSI DSR X-Launchpad-Message-Rationale: Subscriber (QEMU) @qemu-devel-ml X-Launchpad-Message-For: qemu-devel-ml Precedence: bulk X-Generated-By: Launchpad (canonical.com); Revision="6a138c03da9cc3e2e03f6dd3bbb4a615b0be6ec2"; Instance="production-secrets-lazr.conf" X-Launchpad-Hash: 18b8fd692405e07d9732fb45c0e0d9e4955d7a15 Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/12 02:20:55 X-ACL-Warn: Detected OS = Linux 3.11 and newer [fuzzy] X-Spam_score_int: -58 X-Spam_score: -5.9 X-Spam_bar: ----- X-Spam_report: (-5.9 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=1, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Bug 1407808 <1407808@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" ** Changed in: qemu Status: Incomplete =3D> Triaged -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1407808 Title: virtual console gives strange response to ANSI DSR Status in QEMU: Triaged Bug description: With "-serial vc" (which is the default), qemu make strange responses to the ANSI DSR escape sequence (\033[6n) which can confuse guests. Terminal emulators supporting the ANSI escape sequences usually support the "Device Status Report" escape sequence, \033[6n, to which as a response the terminal injects as input the response \033[n;mR, containing the current cursor position. An application running in the guest can use this escape sequence to, for example, figure out the size of the terminal it is running under, which can be useful as the guest has no other standard way to figure out a "size" for the serial port. Unfortunately, it seems that qemu when run with "-serial vc" (which appears to be the default), when qemu gets the \033[6n escape sequence on the serial port, it just responds with a single \033, and that's it! This can confuse an application, could concievably assume that a terminal either supports this escape sequence and injects the correct response (\033[n;mR), or doesn't support it and injects absolutely nothing as input - but not something in between. This caused a problem on one shell implementation on OSv that tried to figure out the terminal's size, and had to work around this unexpected behavior (see https://github.com/cloudius- systems/osv/commit/b79223584be40459861d1c12e1cb67e3e49e2a12). To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1407808/+subscriptions