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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 87163C433C1 for ; Mon, 22 Mar 2021 19:47:13 +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 B83056198E for ; Mon, 22 Mar 2021 19:47:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B83056198E 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]:40406 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lOQW7-0006GI-P0 for qemu-devel@archiver.kernel.org; Mon, 22 Mar 2021 15:47:11 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50534) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lOQP8-00011s-6k for qemu-devel@nongnu.org; Mon, 22 Mar 2021 15:39:58 -0400 Received: from indium.canonical.com ([91.189.90.7]:44110) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lOQP6-00058o-8P for qemu-devel@nongnu.org; Mon, 22 Mar 2021 15:39:57 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1lOQP4-0006qV-35 for ; Mon, 22 Mar 2021 19:39:54 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 0710F2E8165 for ; Mon, 22 Mar 2021 19:39:54 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Mon, 22 Mar 2021 19:22:40 -0000 From: Peter Maydell <1407808@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=Fix Committed; 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 pmaydell th-huth X-Launchpad-Bug-Reporter: Nadav Har'El (nyh) X-Launchpad-Bug-Modifier: Peter Maydell (pmaydell) References: <20150105215424.22410.18753.malonedeb@gac.canonical.com> Message-Id: <161644096067.28371.10292134086588423661.malone@gac.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="4446feb642ca86be4f6eceb855b408397dad6a50"; Instance="production" X-Launchpad-Hash: 2eb249569c95ffb574d301d7e5c8be5adbfb60c4 Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-Spam_score_int: -65 X-Spam_score: -6.6 X-Spam_bar: ------ X-Spam_report: (-6.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, 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" This should be fixed in head-of-git by commit 8eb13bbbac08a, which will be in QEMU 6.0. (The underlying bug is that when the GTK front-end tries to send sequences of more than one byte to a UART, it didn't account for UARTs which don't have a FIFO capable of holding the whole sequence at once.) ** Changed in: qemu Status: Triaged =3D> Fix Committed -- = 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: Fix Committed 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). 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