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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 E6DD3C433B4 for ; Wed, 14 Apr 2021 21:24:48 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 0E461600D1 for ; Wed, 14 Apr 2021 21:24:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0E461600D1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4FLFqL1v4Tz3c1t for ; Thu, 15 Apr 2021 07:24:46 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=intel.com (client-ip=134.134.136.20; helo=mga02.intel.com; envelope-from=ira.weiny@intel.com; receiver=) Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4FLFpz049Fz303q for ; Thu, 15 Apr 2021 07:24:21 +1000 (AEST) IronPort-SDR: dyKYvq1Y1i/q+m10MCxumSJK7x7GwLGxQT8t4qmdn4q0jXJldaevDUf1OJyaSrATe5PFrIE4Lx YV7DbIau2Tag== X-IronPort-AV: E=McAfee;i="6200,9189,9954"; a="181863134" X-IronPort-AV: E=Sophos;i="5.82,223,1613462400"; d="scan'208";a="181863134" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2021 14:24:17 -0700 IronPort-SDR: OQisyYjSRzHMWbR1sr/zXCDxGy72+URmxBOoD1fbM+AL9NfJQcgg2I0UHNQN18pC0s0enQ9zW4 HhdrOg8+GkbQ== X-IronPort-AV: E=Sophos;i="5.82,223,1613462400"; d="scan'208";a="522128834" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2021 14:24:17 -0700 Date: Wed, 14 Apr 2021 14:24:17 -0700 From: Ira Weiny To: Vaibhav Jain Subject: Re: [PATCH] powerpc/papr_scm: Reduce error severity if nvdimm stats inaccessible Message-ID: <20210414212417.GC1904484@iweiny-DESK2.sc.intel.com> References: <20210414124026.332472-1-vaibhav@linux.ibm.com> <20210414153625.GB1904484@iweiny-DESK2.sc.intel.com> <87lf9kkfaj.fsf@vajain21.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87lf9kkfaj.fsf@vajain21.in.ibm.com> User-Agent: Mutt/1.11.1 (2018-12-01) 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: Santosh Sivaraj , linux-nvdimm@lists.01.org, "Aneesh Kumar K . V" , Dan Williams , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Wed, Apr 14, 2021 at 09:51:40PM +0530, Vaibhav Jain wrote: > Thanks for looking into this patch Ira, > > Ira Weiny writes: > > > On Wed, Apr 14, 2021 at 06:10:26PM +0530, Vaibhav Jain wrote: > >> Currently drc_pmem_qeury_stats() generates a dev_err in case > >> "Enable Performance Information Collection" feature is disabled from > >> HMC. The error is of the form below: > >> > >> papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Failed to query > >> performance stats, Err:-10 > >> > >> This error message confuses users as it implies a possible problem > >> with the nvdimm even though its due to a disabled feature. > >> > >> So we fix this by explicitly handling the H_AUTHORITY error from the > >> H_SCM_PERFORMANCE_STATS hcall and generating a warning instead of an > >> error, saying that "Performance stats in-accessible". > >> > >> Fixes: 2d02bf835e57('powerpc/papr_scm: Fetch nvdimm performance stats from PHYP') > >> Signed-off-by: Vaibhav Jain > >> --- > >> arch/powerpc/platforms/pseries/papr_scm.c | 3 +++ > >> 1 file changed, 3 insertions(+) > >> > >> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c > >> index 835163f54244..9216424f8be3 100644 > >> --- a/arch/powerpc/platforms/pseries/papr_scm.c > >> +++ b/arch/powerpc/platforms/pseries/papr_scm.c > >> @@ -277,6 +277,9 @@ static ssize_t drc_pmem_query_stats(struct papr_scm_priv *p, > >> dev_err(&p->pdev->dev, > >> "Unknown performance stats, Err:0x%016lX\n", ret[0]); > >> return -ENOENT; > >> + } else if (rc == H_AUTHORITY) { > >> + dev_warn(&p->pdev->dev, "Performance stats in-accessible"); > >> + return -EPERM; > > > > Is this because of a disabled feature or because of permissions? > > Its because of a disabled feature that revokes permission for a guest to > retrieve performance statistics. > > The feature is called "Enable Performance Information Collection" and > once disabled the hcall H_SCM_PERFORMANCE_STATS returns an error > H_AUTHORITY indicating that the guest doesn't have permission to retrieve > performance statistics. In that case would it be appropriate to have the error message indicate a permission issue? Something like 'permission denied'? Ira