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=-6.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,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 62C07C433E3 for ; Thu, 20 Aug 2020 13:47:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2773F208DB for ; Thu, 20 Aug 2020 13:47:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cL1q1AuL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729503AbgHTNri (ORCPT ); Thu, 20 Aug 2020 09:47:38 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:24223 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729762AbgHTNn2 (ORCPT ); Thu, 20 Aug 2020 09:43:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597931005; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=fUj6yx5X7ltWZxH/b96euv3aQubH9i85achpimDWoYg=; b=cL1q1AuLDPLpG2AGCod7/hSccPe6qmDMrn+dYt1OFsDCec4jzy9RIfohEYScJcf3at3hH9 wmcPRl7y+zlCFCHlFM19ebW2bJNj1eindiqlCj+acicYnKT6euUiFsfvTS8HWvyHGRpq4A uSggMoJRzReN4UEhpJbdr26dwtvdnY0= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-363-Dzfst2oTM1a4u5Y44wfmlw-1; Thu, 20 Aug 2020 09:43:21 -0400 X-MC-Unique: Dzfst2oTM1a4u5Y44wfmlw-1 Received: by mail-wr1-f70.google.com with SMTP id k11so676344wrv.1 for ; Thu, 20 Aug 2020 06:43:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=fUj6yx5X7ltWZxH/b96euv3aQubH9i85achpimDWoYg=; b=EOy+RdSUHK5yhb7s43CNktaJIdBJ4AgH7CSd8jc9CQuNrazi5oJfuXRU4jBcVp70uo xmKQzTS1lR3Bvcum46VAX3sk/Dg8hq+FFRUb0AuKQlRr/c/xVCYH+4K0dC+n3NCnRhau YtIyRmJGzwEwYjTNIqTvCBhdKf18MNwRbEk6r8Jyfl3FSEWc9lG3Q0oRqPiXjjE1sAJg WdNBY8ZYtutL/O6SLXtbLdyZl+wOWr2IKS0tn0G3vUqDH0S1kzN3bg3pWLwbtPhaqiZH uzXUekU996RBP7B3rjIyQbz5ZvzBk1UhkN8GnEn/sfHGCWpxpvVFOU950T3pHn0dtACD jipw== X-Gm-Message-State: AOAM530PT7wr+pUHw8t642SnpKrrJsCAiDotZk+xOcGMXEN64Z8e+YQU qAlczZ64j720AftrA+7YA6tzb6js9aYjNh6GduWoRf9M30I8/13lTHxnv/cHSFs4kUOEI2N1D2t dMaOmPDHOadzenJ9txE6YnsP0 X-Received: by 2002:adf:9501:: with SMTP id 1mr3285837wrs.413.1597930999853; Thu, 20 Aug 2020 06:43:19 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxk4AYhMdLAx9L3X17nzshI8k7fQJaU0SM+fw+yWM5KCtAXxh9slvySYS9RNfo3aInUv8N2Cw== X-Received: by 2002:adf:9501:: with SMTP id 1mr3285752wrs.413.1597930998734; Thu, 20 Aug 2020 06:43:18 -0700 (PDT) Received: from [192.168.10.150] ([93.56.170.5]) by smtp.gmail.com with ESMTPSA id d14sm4210136wre.44.2020.08.20.06.43.17 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 20 Aug 2020 06:43:18 -0700 (PDT) Subject: Re: FSGSBASE causing panic on 5.9-rc1 To: Andy Lutomirski , Tom Lendacky , Joerg Roedel , "Christopherson, Sean J" , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson Cc: Linux Kernel Mailing List , X86 ML , "Chang S. Bae" , Thomas Gleixner , Sasha Levin , Borislav Petkov , Peter Zijlstra , Ingo Molnar References: <39d57e4d-5db4-f536-6f5e-6b0414c0dccc@amd.com> <7dedb0ab-56a6-5d96-577b-21ab1ecdad24@amd.com> From: Paolo Bonzini Message-ID: Date: Thu, 20 Aug 2020 15:43:16 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/08/20 23:25, Andy Lutomirski wrote: > wrmsrl(MSR_KERNEL_GS_BASE, current->thread.gsbase); > load_gs_index(svm->host.gs); > > Surely that should do load_gs_index() *before* wrmsrl(). But that's > not the problem at hand. The wrmsrl is writing the inactive GS base so the ordering between load_gs_index and wrmsrl(MSR_KERNEL_GS_BASE) should be irrelevant? Paolo