From patchwork Tue Feb 16 01:45:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12089381 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=-16.8 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_GIT 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 87C46C433E0 for ; Tue, 16 Feb 2021 01:48:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56EFB64DAF for ; Tue, 16 Feb 2021 01:48:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229754AbhBPBsZ (ORCPT ); Mon, 15 Feb 2021 20:48:25 -0500 Received: from mga07.intel.com ([134.134.136.100]:3274 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229981AbhBPBsJ (ORCPT ); Mon, 15 Feb 2021 20:48:09 -0500 IronPort-SDR: YKTTbh2c2zqb1lUNM6Yjf8LKWv+dLovs2XZ22zk43zZultCz/gzlOAhKHqQ3g5GfPc18Fh0f/T SmsymvQulNiQ== X-IronPort-AV: E=McAfee;i="6000,8403,9896"; a="246852891" X-IronPort-AV: E=Sophos;i="5.81,182,1610438400"; d="scan'208";a="246852891" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Feb 2021 17:45:58 -0800 IronPort-SDR: CM/kNTgy5+2NNwreOrPZn2YmO4CweyPi7LXOc+kc7bo1KigCQoNjlvS1Fykquoy6Z22EtmaAUB BG4hFJktC/rg== X-IronPort-AV: E=Sophos;i="5.81,182,1610438400"; d="scan'208";a="399296125" Received: from dlbingha-mobl1.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.134.31]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Feb 2021 17:45:59 -0800 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , 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 , Ira Weiny , Jon Masters , Jonathan Cameron , Rafael Wysocki , Randy Dunlap , Vishal Verma , "John Groves (jgroves)" , "Kelley, Sean V" Subject: [PATCH v4 9/9] cxl/mem: Add payload dumping for debug Date: Mon, 15 Feb 2021 17:45:38 -0800 Message-Id: <20210216014538.268106-10-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210216014538.268106-1-ben.widawsky@intel.com> References: <20210216014538.268106-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org 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 --- 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;