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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 21B10C28CBC for ; Sat, 9 May 2020 17:06:13 +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 EBDB12184D for ; Sat, 9 May 2020 17:06:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EBDB12184D 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]:48312 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jXSvU-0004N9-44 for qemu-devel@archiver.kernel.org; Sat, 09 May 2020 13:06:12 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58174) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jXSut-0003gi-Kc for qemu-devel@nongnu.org; Sat, 09 May 2020 13:05:35 -0400 Received: from indium.canonical.com ([91.189.90.7]:57292) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jXSus-0007qO-Fi for qemu-devel@nongnu.org; Sat, 09 May 2020 13:05:35 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1jXSuq-0002ev-PM for ; Sat, 09 May 2020 17:05:32 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id BBF932E80E7 for ; Sat, 9 May 2020 17:05:32 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Sat, 09 May 2020 16:56:05 -0000 From: Christian Schoenebeck <1877688@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=In Progress; importance=Undecided; assignee=qemu_oss@crudebyte.com; X-Launchpad-Bug-Tags: 9p virtfs X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: c3bacd17 schoenebeck X-Launchpad-Bug-Reporter: A A (c3bacd17) X-Launchpad-Bug-Modifier: Christian Schoenebeck (schoenebeck) References: <158898272347.4759.14841085044555564691.malonedeb@chaenomeles.canonical.com> Message-Id: <158904336517.13032.6540918277423307470.malone@gac.canonical.com> Subject: [Bug 1877688] Re: 9p virtfs device reports error when opening certain files 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="fbdff7602bd10fb883bf7e2ddcc7fd5a16f60398"; Instance="production-secrets-lazr.conf" X-Launchpad-Hash: 6e38bd436ec4c06e185d2d139757609184c21c3c 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 = 2020/05/09 13:05:33 X-ACL-Warn: Detected OS = Linux 3.11 and newer 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, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN 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 1877688 <1877688@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The following patch should fix this bug for the kvm backend (not for the XEN backend yet). Please let me know if it fixes this bug for you. ** Patch added: "bug1877688_kvm_fix.patch" https://bugs.launchpad.net/qemu/+bug/1877688/+attachment/5369130/+files/= bug1877688_kvm_fix.patch ** Changed in: qemu Status: New =3D> In Progress ** Changed in: qemu Assignee: (unassigned) =3D> Christian Schoenebeck (schoenebeck) -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1877688 Title: 9p virtfs device reports error when opening certain files Status in QEMU: In Progress Bug description: Reading certain files on a 9p mounted FS produces this error message: qemu-system-x86_64: VirtFS reply type 117 needs 12 bytes, buffer has 12, less than minimum After this error message is generated, further accesses to the 9p FS hangs whatever tries to access it. The Arch Linux guest system is otherwise usable. This happens with QEMU 5.0.0 and guest kernel version 5.6.11, hosted on an Arch Linux distro. I use the following command to launch QEMU: exec qemu-system-x86_64 -enable-kvm -display gtk -vga virtio -cpu host -m 4G -netdev tap,ifname=3Dvmtap0,id=3Dvn0,script=3Dno,downscript=3Dno -d= evice virtio-net-pci,netdev=3Dvn0 -kernel kernel.img -drive file=3Dfile.img,format=3Draw,if=3Dvirtio -virtfs local,path=3Dmnt,mount_tag=3Dhost0,security_model=3Dpassthrough,id=3Dhost0 -append "console=3DttyS0 root=3D/dev/vda rw" There's nothing relevant in the guest kernel logs as far as I'm aware of with loglevel set to 7. I tracked down the issue to readv() with a small buffer(<=3D12 bytes) and then a large buffer(>=3D 1024 bytes). A C program is provided to trigger this behavior. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1877688/+subscriptions