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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 B70AEC433E0 for ; Tue, 23 Mar 2021 16:33:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9377F619C3 for ; Tue, 23 Mar 2021 16:33:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233228AbhCWQdY (ORCPT ); Tue, 23 Mar 2021 12:33:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47678 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233116AbhCWQdC (ORCPT ); Tue, 23 Mar 2021 12:33:02 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 09FF6C061574; Tue, 23 Mar 2021 09:33:02 -0700 (PDT) Received: from zn.tnic (p200300ec2f0be1003a038ae7f2775171.dip0.t-ipconnect.de [IPv6:2003:ec:2f0b:e100:3a03:8ae7:f277:5171]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 60A651EC0473; Tue, 23 Mar 2021 17:32:59 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1616517179; 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:in-reply-to:in-reply-to: references:references; bh=ynniguAvocBA5TaZX6yhXh7I9tFvwuCf45CIvRLvQto=; b=dQ6yDPlDogaJF5WR37hi11J48ABmzpxWpsxDOBjR6ykFHO5C1U9GUuoMBGp/ee8gAzeaId M7zxsdU0/pDQCEnZHFApJX/SjXrC3+37Px8xw6VogO4ST7T3ToDK3aKlqfYQ1avrcLpi9i nJ0tnH5zH69UfjbEhv3sk4AAoSeM5PY= Date: Tue, 23 Mar 2021 17:32:58 +0100 From: Borislav Petkov To: Sean Christopherson Cc: Kai Huang , kvm@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org, jarkko@kernel.org, luto@kernel.org, dave.hansen@intel.com, rick.p.edgecombe@intel.com, haitao.huang@intel.com, pbonzini@redhat.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Subject: Re: [PATCH v3 03/25] x86/sgx: Wipe out EREMOVE from sgx_free_epc_page() Message-ID: <20210323163258.GC4729@zn.tnic> References: <20210322191540.GH6481@zn.tnic> <20210322210645.GI6481@zn.tnic> <20210323110643.f29e214ebe8ec7a4a3d0bc2e@intel.com> <20210322223726.GJ6481@zn.tnic> <20210323121643.e06403a1bc7819bab7c15d95@intel.com> <20210323160604.GB4729@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 23, 2021 at 04:21:47PM +0000, Sean Christopherson wrote: > I like the idea of pointing at the documentation. The documentation should > probably emphasize that something is very, very wrong. Yap, because no matter how we formulate the error message, it still ain't enough and needs a longer explanation. > E.g. if a kernel bug triggers EREMOVE failure and isn't detected until > the kernel is widely deployed in a fleet, then the folks deploying the > kernel probably _should_ be in all out panic. For this variety of bug > to escape that far, it means there are huge holes in test coverage, in > both the kernel itself and in the infrasturcture of whoever is rolling > out their new kernel. You sound just like someone who works at a company with a big fleet, oh wait... :-) And yap, you big fleeted guys will more likely catch it but we do have all these other customers who have a handful of servers only so they probably won't be able to do such a wide coverage. So I hope they'll appreciate this longer explanation about what to do when they hit it. And normally I wouldn't even care but we almost never tell people to reboot their boxes to fix sh*t - that's the other OS. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette