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 84462C433ED for ; Wed, 14 Apr 2021 13:11:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4FBD2611AD for ; Wed, 14 Apr 2021 13:11:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351122AbhDNNLf (ORCPT ); Wed, 14 Apr 2021 09:11:35 -0400 Received: from mail.skyhub.de ([5.9.137.197]:48700 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351180AbhDNNKj (ORCPT ); Wed, 14 Apr 2021 09:10:39 -0400 Received: from zn.tnic (p200300ec2f0e8f0048923c048b418a85.dip0.t-ipconnect.de [IPv6:2003:ec:2f0e:8f00:4892:3c04:8b41:8a85]) (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 445FE1EC0258; Wed, 14 Apr 2021 15:10:16 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1618405816; 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=ub16e8IgsqCsaQskNeYCBWNu+OwjL3P+PDajfBScz2g=; b=eOUVItvGPZmx64t3BeuBZnhqA0RvaTr46W3ZuhcgzHBQSeGW31lRrhGfLCuaPi38qj78qm HnO90lsvBhSyQcqZxmLQ7btlvp47NL3Cp1gNaNCl9f14oplZ7BRp6xcu5k7DbIWCRe2Uic lfJXsfATPXGHVO7tKxFvCezuRt6Jpxo= Date: Wed, 14 Apr 2021 15:10:18 +0200 From: Borislav Petkov To: Jue Wang Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, luto@kernel.org, naoya.horiguchi@nec.com, tony.luck@intel.com, x86@kernel.org, yaoaili@kingsoft.com Subject: Re: [PATCH 3/4] mce/copyin: fix to not SIGBUS when copying from user hits poison Message-ID: <20210414131018.GG10709@zn.tnic> References: 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, Apr 13, 2021 at 10:47:21PM -0700, Jue Wang wrote: > This path is when EPT #PF finds accesses to a hwpoisoned page and > sends SIGBUS to user space (KVM exits into user space) with the same > semantic as if regular #PF found access to a hwpoisoned page. > > The KVM_X86_SET_MCE ioctl actually injects a machine check into the guest. > > We are in process to launch a product with MCE recovery capability in > a KVM based virtualization product and plan to expand the scope of the > application of it in the near future. Any pointers to code or is this all non-public? Any text on what that product does with the MCEs? > The in-memory database and analytical domain are definitely using it. > A couple examples: > SAP HANA - as we've tested and planned to launch as a strategic > enterprise use case with MCE recovery capability in our product > SQL server - https://support.microsoft.com/en-us/help/2967651/inf-sql-server-may-display-memory-corruption-and-recovery-errors Aha, so they register callbacks for the processes to exec on a memory error. Good to know, thanks for those. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette