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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 1DA3EECE59D for ; Wed, 16 Oct 2019 04:49:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E47A42168B for ; Wed, 16 Oct 2019 04:49:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731923AbfJPEtx (ORCPT ); Wed, 16 Oct 2019 00:49:53 -0400 Received: from new-01-2.privateemail.com ([198.54.127.55]:16013 "EHLO NEW-01-2.privateemail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726502AbfJPEtx (ORCPT ); Wed, 16 Oct 2019 00:49:53 -0400 Received: from MTA-05-1.privateemail.com (unknown [10.20.147.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by NEW-01.privateemail.com (Postfix) with ESMTPS id C0F8460756 for ; Wed, 16 Oct 2019 04:49:52 +0000 (UTC) Received: from MTA-05.privateemail.com (localhost [127.0.0.1]) by MTA-05.privateemail.com (Postfix) with ESMTP id A1DBB6004E for ; Wed, 16 Oct 2019 00:49:52 -0400 (EDT) Received: from zetta.local (unknown [10.20.151.227]) by MTA-05.privateemail.com (Postfix) with ESMTPA id 69CF36004C for ; Wed, 16 Oct 2019 04:49:52 +0000 (UTC) From: Derek Yerger Subject: PROBLEM: Regression of MMU causing guest VM application errors To: kvm@vger.kernel.org Message-ID: <1e525b08-6204-3238-5d56-513f82f1d7fb@djy.llc> Date: Wed, 16 Oct 2019 00:49:51 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Virus-Scanned: ClamAV using ClamSMTP Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org In at least Linux 5.2.7 via Fedora, up to 5.2.18, guest OS applications repeatedly crash with segfaults. The problem does not occur on 5.1.16. System is running Fedora 29 with kernel 5.2.18. Guest OS is Windows 10 with an AMD Radeon 540 GPU passthrough. When on 5.2.7 or 5.2.18, specific windows applications frequently and repeatedly crash, throwing exceptions in random libraries. Going back to 5.1.16, the issue does not occur. The host system is unaffected by the regression. Keywords: kvm mmu pci passthrough vfio vfio-pci amdgpu Possibly related: Unmerged [PATCH] KVM: x86/MMU: Zap all when removing memslot if VM has assigned device Workaround: Use 5.1.16 kernel. | | -- Derek Yerger