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 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 51FEFC4361B for ; Sun, 20 Dec 2020 15:47:10 +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 6C40D2312B for ; Sun, 20 Dec 2020 15:47:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6C40D2312B 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]:44008 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kr0vM-0002Sf-8q for qemu-devel@archiver.kernel.org; Sun, 20 Dec 2020 10:47:08 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:37028) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kr0u6-0001rD-5J for qemu-devel@nongnu.org; Sun, 20 Dec 2020 10:45:50 -0500 Received: from indium.canonical.com ([91.189.90.7]:56416) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kr0tx-0000w2-7X for qemu-devel@nongnu.org; Sun, 20 Dec 2020 10:45:48 -0500 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1kr0tv-0003IX-JT for ; Sun, 20 Dec 2020 15:45:39 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 8814B2E8087 for ; Sun, 20 Dec 2020 15:45:39 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Sun, 20 Dec 2020 15:40:10 -0000 From: Luqman <1908489@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=New; importance=Undecided; assignee=None; X-Launchpad-Bug: distribution=centos; sourcepackage=qemu-kvm; component=None; status=Unknown; importance=Unknown; assignee=None; X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: bonzini luqmana X-Launchpad-Bug-Reporter: Luqman (luqmana) X-Launchpad-Bug-Modifier: Luqman (luqmana) References: <160818582988.15420.16250079431178848252.malonedeb@soybean.canonical.com> Message-Id: <160847881081.3345.2714558992962751854.malone@wampee.canonical.com> Subject: [Bug 1908489] Re: qemu 4.2 bootloops with -cpu host and nested hypervisor 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="34b3ffd45c9543b7f7aa5aa313925241e9e7ca3f"; Instance="production" X-Launchpad-Hash: 6ce6dc1817f9f14e4e0d1408389ad0483848b601 Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-Spam_score_int: -66 X-Spam_score: -6.7 X-Spam_bar: ------ X-Spam_report: (-6.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, 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 1908489 <1908489@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" I haven't tried 5.9, just: - 5.4.0-58 Works - 5.8.0-33 (20.04 HWE Edge) Bootloop - 5.10.1-051001 Works If I have time later I can try narrowing down which kernel causes the issue. But is the BNDCFGS MSR issue considered a bug in qemu or what? -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1908489 Title: qemu 4.2 bootloops with -cpu host and nested hypervisor Status in QEMU: New Status in qemu-kvm package in CentOS: Unknown Bug description: I've noticed that after upgrading from Ubuntu 18.04 to 20.04 that nested virtualization isn't working anymore. I have a simple repro where I create a Windows 10 2004 guest and enable Hyper-V in it. This worked fine in 18.04 and specifically qemu <4.2 (I specifically tested Qemu 2.11-4.1 which work fine). The -cpu arg I'm passing is simply: -cpu host,l3-cache=3Don,hv_relaxed,hv_spinlocks=3D0x1fff,hv_vapic,hv_= time Using that Windows won't boot because the nested hypervisor (Hyper-V) is unable to be initialize and so it just boot loops. Using the exact same qemu command works fine with 4.1 and lower. Switching to a named CPU model like Skylake-Client-noTSX-IBRS instead of host lets the VM boot but causes some weird behaviour later trying to use nested VMs. If I had to guess I think it would probably be related to this change https://github.com/qemu/qemu/commit/20a78b02d31534ae478779c2f2816c273601e= 869 which would line up with 4.2 being the first bad version but unsure. For now I just have to keep an older build of QEMU to work around this. Let me know if there's anything else needed. I can also try out any patches. I already have at least a dozen copies of qemu lying around now. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1908489/+subscriptions