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=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_PASS autolearn=ham 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 1AFA0C43381 for ; Tue, 5 Mar 2019 06:59:43 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7F3412082C for ; Tue, 5 Mar 2019 06:59:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7F3412082C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 44D7700HVyzDqGm for ; Tue, 5 Mar 2019 17:59:40 +1100 (AEDT) Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 44D74t1NhbzDqDr for ; Tue, 5 Mar 2019 17:57:50 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 44D74s6270z9s6w; Tue, 5 Mar 2019 17:57:49 +1100 (AEDT) From: Michael Ellerman To: linuxppc-dev@lists.ozlabs.org Subject: Printing of machine check severity Date: Tue, 05 Mar 2019 17:57:47 +1100 Message-ID: <87pnr5vmdw.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mahesh J Salgaonkar , satheera@in.ibm.com, Nicholas Piggin Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Hi all, RE: https://github.com/linuxppc/issues/issues/230 > Host dmesg throws lot of below SLB [Multihit] HMI's > > [295216.837358] Severe Machine check interrupt [Recovered] > [295216.837365] Harmless Hypervisor Maintenance interrupt [Recovered] > [295216.837374] Guest NIP: c00000000024a7dc > [295216.837378] Error detail: Processor Recovery done > [295216.837381] HMER: 2040000000000000 > [295216.837388] Initiator: CPU > [295216.837406] Error type: SLB [Multihit] > [295216.837415] Effective address: d00000000316c400 Paul points out that these aren't severe errors from the hosts point of view, and possibly not even for the guest. I think the key problem here is that we print "Severe" for most types of MCEs, even though some really aren't. That comes from the severity being set to `MCE_SEV_ERROR_SYNC` in the i/derror table. All the enum values are `MCE_SEV` so the value is actually `ERROR_SYNC`, which I think means "synchronous error". That is correct. But I don't think it's correct that all synchronous errors are "severe". We also have some errors in `mce_ierror_table` that are marked `MCE_SEV_FATAL` and then have a comment saying `/* ASYNC is fatal */`. So I feel like we have severity and sync/async conflated in the severity value, ie. we should split out sync/async and then have a separate severity field. We need to be careful because a few places check for `MCE_SEV_ERROR_SYNC`, it's not *only* used for the severity string. We could then mark eg. SLB multi-hits as warning rather than severe. Additionally we probably want to use the `in_guest` flag to modulate the severity or the message, or both. cheers