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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 29E09C19F2D for ; Tue, 9 Aug 2022 22:31:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229506AbiHIWbz (ORCPT ); Tue, 9 Aug 2022 18:31:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229445AbiHIWby (ORCPT ); Tue, 9 Aug 2022 18:31:54 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD48365645 for ; Tue, 9 Aug 2022 15:31:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1660084313; x=1691620313; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=uJ0j7F5UQuGiNMvMsZgXUX6HBQS4EnY3+TDCK4xF7aM=; b=W01qYeLmqXsP6qdn5EhdWOfack7/sOCjtd3uRcsauoGVUhfmNcKbHneF m3+Lzbf8x9AzigriATYGUiWA+GcUtHmcqQyOcJw0Jfa6an3ei6RYhuMFs piKC/R4VYhngI/1caGFsqE0HfdP49ieOzzcTy6NNHxDz4GuQQlv9CprtN XIcwwjTL4zwkpKVXLOakyh3ax7PGemPEubLaVTYJ6c9THPE7Ya3alH5iO 7trsNqvB/HYWzguh3hilVRe2mWZ3qDpo9/Kge/YLSzXz0iNBKKIRXynY6 57/W264eXjm4wc5JgV0gvu2XnaX6W4RZMoSEv1dsuBWQYmiZqduiXXyt8 Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10434"; a="377239266" X-IronPort-AV: E=Sophos;i="5.93,225,1654585200"; d="scan'208";a="377239266" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Aug 2022 15:31:36 -0700 X-IronPort-AV: E=Sophos;i="5.93,225,1654585200"; d="scan'208";a="664623936" Received: from djiang5-mobl1.amr.corp.intel.com (HELO [10.212.24.249]) ([10.212.24.249]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Aug 2022 15:31:35 -0700 Message-ID: <14d33af5-e8c7-c30d-7cd9-08f55a270992@intel.com> Date: Tue, 9 Aug 2022 15:31:35 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Firefox/91.0 Thunderbird/91.12.0 Subject: Re: [PATCH RFC 11/15] cxl/pmem: Add "Unlock" security command support Content-Language: en-US To: Jonathan Cameron Cc: linux-cxl@vger.kernel.org, nvdimm@lists.linux.dev, dan.j.williams@intel.com, bwidawsk@kernel.org, ira.weiny@intel.com, vishal.l.verma@intel.com, alison.schofield@intel.com, dave@stgolabs.net References: <165791918718.2491387.4203738301057301285.stgit@djiang5-desk3.ch.intel.com> <165791937639.2491387.6281906434880014077.stgit@djiang5-desk3.ch.intel.com> <20220804141901.00005a2a@huawei.com> From: Dave Jiang In-Reply-To: <20220804141901.00005a2a@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On 8/4/2022 6:19 AM, Jonathan Cameron wrote: > On Fri, 15 Jul 2022 14:09:36 -0700 > Dave Jiang wrote: > >> Create callback function to support the nvdimm_security_ops() ->unlock() >> callback. Translate the operation to send "Unlock" security command for CXL >> mem device. >> >> When the mem device is unlocked, arch_invalidate_nvdimm_cache() is called >> in order to invalidate all CPU caches before attempting to access the mem >> device. >> >> See CXL 2.0 spec section 8.2.9.5.6.4 for reference. >> >> Signed-off-by: Dave Jiang > Hi Dave, > > One trivial thing inline. > > Thanks, > > Jonathan > >> --- >> drivers/cxl/cxlmem.h | 1 + >> drivers/cxl/security.c | 21 +++++++++++++++++++++ >> 2 files changed, 22 insertions(+) >> >> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h >> index ced85be291f3..ae8ccd484491 100644 >> --- a/drivers/cxl/cxlmem.h >> +++ b/drivers/cxl/cxlmem.h >> @@ -253,6 +253,7 @@ enum cxl_opcode { >> CXL_MBOX_OP_GET_SECURITY_STATE = 0x4500, >> CXL_MBOX_OP_SET_PASSPHRASE = 0x4501, >> CXL_MBOX_OP_DISABLE_PASSPHRASE = 0x4502, >> + CXL_MBOX_OP_UNLOCK = 0x4503, >> CXL_MBOX_OP_FREEZE_SECURITY = 0x4504, >> CXL_MBOX_OP_MAX = 0x10000 >> }; >> diff --git a/drivers/cxl/security.c b/drivers/cxl/security.c >> index 6399266a5908..d15520f280f0 100644 >> --- a/drivers/cxl/security.c >> +++ b/drivers/cxl/security.c >> @@ -114,11 +114,32 @@ static int cxl_pmem_security_freeze(struct nvdimm *nvdimm) >> return cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_FREEZE_SECURITY, NULL, 0, NULL, 0); >> } >> >> +static int cxl_pmem_security_unlock(struct nvdimm *nvdimm, >> + const struct nvdimm_key_data *key_data) >> +{ >> + struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm); >> + struct cxl_memdev *cxlmd = cxl_nvd->cxlmd; >> + struct cxl_dev_state *cxlds = cxlmd->cxlds; >> + u8 pass[NVDIMM_PASSPHRASE_LEN]; >> + int rc; >> + >> + memcpy(pass, key_data->data, NVDIMM_PASSPHRASE_LEN); > Why do we need a local copy? I'd have thought we could just > pass keydata->data in as the payload for cxl_mbox_send_cmd() > There might be some value in making it easier to check by > having a structure defined for this payload (obviously trivial) > but given we are using an array of length defined by a non CXL > define, I'm not sure there is any point in the copy. We end up hitting a compile warning if we just directly pass in because key_data->data has const qualifier. tools/testing/cxl/../../../drivers/cxl/security.c: In function ‘cxl_pmem_security_unlock’: tools/testing/cxl/../../../drivers/cxl/security.c:116:40: warning: passing argument 3 of ‘cxl_mbox_send_cmd’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers] 116 | key_data->data, NVDIMM_PASSPHRASE_LEN, NULL, 0); | ~~~~~~~~^~~~~~ In file included from tools/testing/cxl/../../../drivers/cxl/security.c:8: tools/testing/cxl/../../../drivers/cxl/cxlmem.h:408:70: note: expected ‘void *’ but argument is of type ‘const u8 *’ {aka ‘const unsigned char *’} 408 | int cxl_mbox_send_cmd(struct cxl_dev_state *cxlds, u16 opcode, void *in, | ~~~~~~^~ > >> + rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_UNLOCK, >> + pass, NVDIMM_PASSPHRASE_LEN, NULL, 0); >> + if (rc < 0) >> + return rc; >> + >> + /* DIMM unlocked, invalidate all CPU caches before we read it */ >> + arch_invalidate_nvdimm_cache(); >> + return 0; >> +} >> + >> static const struct nvdimm_security_ops __cxl_security_ops = { >> .get_flags = cxl_pmem_get_security_flags, >> .change_key = cxl_pmem_security_change_key, >> .disable = cxl_pmem_security_disable, >> .freeze = cxl_pmem_security_freeze, >> + .unlock = cxl_pmem_security_unlock, >> }; >> >> const struct nvdimm_security_ops *cxl_security_ops = &__cxl_security_ops; >> >>