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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 E70D6C433DB for ; Tue, 16 Feb 2021 15:50:10 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (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 5181A64DE0 for ; Tue, 16 Feb 2021 15:50:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5181A64DE0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=Huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id C8D99100EB33C; Tue, 16 Feb 2021 07:50:09 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=185.176.79.56; helo=frasgout.his.huawei.com; envelope-from=jonathan.cameron@huawei.com; receiver= Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 237B4100EBBC3 for ; Tue, 16 Feb 2021 07:50:07 -0800 (PST) Received: from fraeml744-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Dg4xW0tBwz67pRK; Tue, 16 Feb 2021 23:43:11 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml744-chm.china.huawei.com (10.206.15.225) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Tue, 16 Feb 2021 16:50:05 +0100 Received: from localhost (10.47.75.223) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Tue, 16 Feb 2021 15:50:03 +0000 Date: Tue, 16 Feb 2021 15:48:57 +0000 From: Jonathan Cameron To: Ben Widawsky Subject: Re: [PATCH v4 9/9] cxl/mem: Add payload dumping for debug Message-ID: <20210216154857.0000261d@Huawei.com> In-Reply-To: <20210216014538.268106-10-ben.widawsky@intel.com> References: <20210216014538.268106-1-ben.widawsky@intel.com> <20210216014538.268106-10-ben.widawsky@intel.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; i686-w64-mingw32) MIME-Version: 1.0 X-Originating-IP: [10.47.75.223] X-ClientProxiedBy: lhreml717-chm.china.huawei.com (10.201.108.68) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Message-ID-Hash: EBJBWQZ2VDOQAK7QH655FD6C2IHLGZJ3 X-Message-ID-Hash: EBJBWQZ2VDOQAK7QH655FD6C2IHLGZJ3 X-MailFrom: jonathan.cameron@huawei.com X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: linux-cxl@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-pci@vger.kernel.org, Bjorn Helgaas , "Chris Browy , Christoph Hellwig , Dan Williams , David Hildenbrand , David Rientjes" , "Jon Masters , Rafael Wysocki , Randy Dunlap" , "John Groves (jgroves)" , "Kelley, Sean V" X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Mon, 15 Feb 2021 17:45:38 -0800 Ben Widawsky wrote: > It's often useful in debug scenarios to see what the hardware has dumped > out. As it stands today, any device error will result in the payload not > being copied out, so there is no way to triage commands which weren't > expected to fail (and sometimes the payload may have that information). > > The functionality is protected by normal kernel security mechanisms as > well as a CONFIG option in the CXL driver. > > This was extracted from the original version of the CXL enabling patch > series. > > Signed-off-by: Ben Widawsky My gut feeling here is use a tracepoint rather than spamming the kernel log. Alternatively just don't bother merging this patch - it's on the list now anyway so trivial for anyone doing such debug to pick it up. Jonathan > --- > drivers/cxl/Kconfig | 13 +++++++++++++ > drivers/cxl/mem.c | 8 ++++++++ > 2 files changed, 21 insertions(+) > > diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig > index 97dc4d751651..3eec9276e586 100644 > --- a/drivers/cxl/Kconfig > +++ b/drivers/cxl/Kconfig > @@ -50,4 +50,17 @@ config CXL_MEM_RAW_COMMANDS > potential impact to memory currently in use by the kernel. > > If developing CXL hardware or the driver say Y, otherwise say N. > + > +config CXL_MEM_INSECURE_DEBUG > + bool "CXL.mem debugging" > + depends on CXL_MEM > + help > + Enable debug of all CXL command payloads. > + > + Some CXL devices and controllers support encryption and other > + security features. The payloads for the commands that enable > + those features may contain sensitive clear-text security > + material. Disable debug of those command payloads by default. > + If you are a kernel developer actively working on CXL > + security enabling say Y, otherwise say N. > endif > diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c > index dc608bb20a31..237b956f0be0 100644 > --- a/drivers/cxl/mem.c > +++ b/drivers/cxl/mem.c > @@ -342,6 +342,14 @@ static int __cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm, > > /* #5 */ > rc = cxl_mem_wait_for_doorbell(cxlm); > + > + if (!cxl_is_security_command(mbox_cmd->opcode) || > + IS_ENABLED(CONFIG_CXL_MEM_INSECURE_DEBUG)) { > + print_hex_dump_debug("Payload ", DUMP_PREFIX_OFFSET, 16, 1, > + mbox_cmd->payload_in, mbox_cmd->size_in, > + true); > + } > + > if (rc == -ETIMEDOUT) { > cxl_mem_mbox_timeout(cxlm, mbox_cmd); > return rc; _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org