Received: by 2002:a05:6a10:a0d1:0:0:0:0 with SMTP id j17csp1423610pxa; Thu, 20 Aug 2020 10:53:57 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxmwJPIRo/IVax7ulbyeRxb0W03zs/wriJVC4VwqVbB0zX16i9JSRSIcWGIGm43D390P9Ik X-Received: by 2002:a05:6402:1151:: with SMTP id g17mr4093431edw.227.1597946037706; Thu, 20 Aug 2020 10:53:57 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1597946037; cv=none; d=google.com; s=arc-20160816; b=Fgi4NwpLLC/ZIdKayrk6mMOlNorTFCueGsDXlOpEfB584UMrKSfVKRaYTzC+DeGELu n+ftaPU3eD4QXKhgv46MXKGCu9cRj3SUxwGkH1VHWoyJgu0vnbK9J3gphvf3mTs3A5yX VrRZ9rLQ1guoAb8jbbXfE1imfCwZbepzH+F1PlAtIJNLmQsxWrFC6EXur78Npj5/l1Tu qAm5flTL16X2Ro/t4chpzoOmZJfF+XoEPbFgNPDzDfVPN2uLpy3Ef+JvUod74schEaq2 82p1OV8B4o4W5YW/AOqkI7uj7HfZwhpRgdjXGZV2I1e+jtGM9TxYhJz1H144djyXgJL9 Wu0w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:dkim-signature; bh=3JhxcH5/8++wzwKu5ornAJP/O+yoAneuS16DEYWEARg=; b=K7HHE0w2mVJSjYi6cPjQFKKq4d3X4cnrMp1aYHU2U9C24li8471KFMk84PFD+CYP4g cGldWqkATVXZ8jFSu6rwcVAoIXQDu4OtmSrdd05tXTsnLkE9nmXBVy4a9wkVqiT+3pER gKoIDWtgTzNfDAxw2kaitBp/FrzkhX2TKMUTYgUdJqf1csXucVwagmnwYAO3pTf53LeT wGE2IoItP9v2+iwFUxbdbcKEaMBfBKUGv5UuzR4ehmedgZSH0aOz1zN/iBfiYTPMKvid bx1kQZGx6A2Hz08uI1fDc3h82BUh8yjSDHdUmKBB+5FeNLiD7k3D/3AciJ3TKI8xZwOq 7GFg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=Im+4gBzl; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id m22si1728287edr.374.2020.08.20.10.53.32; Thu, 20 Aug 2020 10:53:57 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=Im+4gBzl; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726815AbgHTRv1 (ORCPT + 99 others); Thu, 20 Aug 2020 13:51:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:57580 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725859AbgHTRvY (ORCPT ); Thu, 20 Aug 2020 13:51:24 -0400 Received: from mail-wm1-f51.google.com (mail-wm1-f51.google.com [209.85.128.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 41E9A22B47 for ; Thu, 20 Aug 2020 17:51:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597945883; bh=Hd7dQCZl4iX+4WliBBdnAj0CCq4bi2DQ3q+O7Ti6Nlg=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=Im+4gBzl5bMAbo5vl1UwPaLrbBNkZB3oa0hi94GLj5UtzODGxtqGempxVlLZ6SyAN DWUTs3AziuArOpNOWYiwlXGA3yelXsbpk+EPT+DZQBHhOpNrdYm/EGPU0MyeMKr3oP qIQxfSVS2YOdxm67vTzEAebMWTZQhZkNX5qFMfVE= Received: by mail-wm1-f51.google.com with SMTP id x5so2454265wmi.2 for ; Thu, 20 Aug 2020 10:51:23 -0700 (PDT) X-Gm-Message-State: AOAM530kTY5HCkb4uo5Va8aX+exGMKrdBOee18QjKMgrbR3QogLxIh7a 25ja/pyvMU72A6KUUITyEb65fql8EB88LC/QXCnccg== X-Received: by 2002:a1c:7e02:: with SMTP id z2mr4577943wmc.138.1597945881693; Thu, 20 Aug 2020 10:51:21 -0700 (PDT) MIME-Version: 1.0 References: <39d57e4d-5db4-f536-6f5e-6b0414c0dccc@amd.com> <7dedb0ab-56a6-5d96-577b-21ab1ecdad24@amd.com> In-Reply-To: From: Andy Lutomirski Date: Thu, 20 Aug 2020 10:51:10 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: FSGSBASE causing panic on 5.9-rc1 To: Paolo Bonzini Cc: Andy Lutomirski , Tom Lendacky , Joerg Roedel , "Christopherson, Sean J" , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Linux Kernel Mailing List , X86 ML , "Chang S. Bae" , Thomas Gleixner , Sasha Levin , Borislav Petkov , Peter Zijlstra , Ingo Molnar Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 20, 2020 at 6:43 AM Paolo Bonzini wrote: > > 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? load_gs_index() sets the index between a pair of swapgs's -- it writes the inactive base, too. --Andy