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 3EF0FC77B73 for ; Wed, 31 May 2023 16:41:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229849AbjEaQle (ORCPT ); Wed, 31 May 2023 12:41:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229520AbjEaQlc (ORCPT ); Wed, 31 May 2023 12:41:32 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E062098 for ; Wed, 31 May 2023 09:41:30 -0700 (PDT) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4QWZjN3MKmz67xpB; Thu, 1 Jun 2023 00:39:20 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Wed, 31 May 2023 17:41:28 +0100 Date: Wed, 31 May 2023 17:41:27 +0100 From: Jonathan Cameron To: Davidlohr Bueso CC: , , , , , Subject: Re: [PATCH 5/6] cxl/mem: Support Secure Erase Message-ID: <20230531174127.000004a3@Huawei.com> In-Reply-To: <20230526033344.17167-6-dave@stgolabs.net> References: <20230526033344.17167-1-dave@stgolabs.net> <20230526033344.17167-6-dave@stgolabs.net> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml100003.china.huawei.com (7.191.160.210) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On Thu, 25 May 2023 20:33:43 -0700 Davidlohr Bueso wrote: > Implement support for the non-pmem exclusive secure erase, per > CXL specs. Create a write-only 'security/erase' sysfs file to > perform the requested operation. > > As with the sanitation this requires the device being offline > and thus no active HPA-DPA decoding. > > The expectation is that userspace can use it such as: > > cxl disable-memdev memX > echo 1 > /sys/bus/cxl/devices/memX/security/erase > cxl enable-memdev memX > > Signed-off-by: Davidlohr Bueso Trivial comment inline. Reviewed-by: Jonathan Cameron > --- > Documentation/ABI/testing/sysfs-bus-cxl | 10 +++++++++ > drivers/cxl/core/mbox.c | 6 +++++- > drivers/cxl/core/memdev.c | 28 +++++++++++++++++++++++++ > drivers/cxl/cxlmem.h | 1 + > 4 files changed, 44 insertions(+), 1 deletion(-) > > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl > index 5753cba98692..f224c1215f22 100644 > --- a/Documentation/ABI/testing/sysfs-bus-cxl > +++ b/Documentation/ABI/testing/sysfs-bus-cxl > @@ -85,6 +85,16 @@ Description: > the device to be not be actively decoding any HPA ranges. > > > +What /sys/bus/cxl/devices/memX/security/erase > +Date: June, 2023 > +KernelVersion: v6.5 > +Contact: linux-cxl@vger.kernel.org > +Description: > + (WO) Write a boolean 'true' string value to this attribute to > + secure erase user data by changing the media encryption keys for > + all user data areas of the device. > + > + > What: /sys/bus/cxl/devices/*/devtype > Date: June, 2021 > KernelVersion: v5.14 > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c > index 51c64829f20a..6622eac66bf1 100644 > --- a/drivers/cxl/core/mbox.c > +++ b/drivers/cxl/core/mbox.c > @@ -1102,7 +1102,7 @@ int cxl_mem_sanitize(struct cxl_dev_state *cxlds, u16 cmd) > }; > struct cxl_mbox_cmd mbox_cmd = { .opcode = cmd }; > > - if (cmd != CXL_MBOX_OP_SANITIZE) > + if (cmd != CXL_MBOX_OP_SANITIZE && cmd != CXL_MBOX_OP_SECURE_ERASE) Maybe just use a switch + default for the inevitable growth of this list and attempting to avoid churn? > return -EINVAL; > > rc = cxl_internal_send_cmd(cxlds, &sec_cmd); > @@ -1120,6 +1120,10 @@ int cxl_mem_sanitize(struct cxl_dev_state *cxlds, u16 cmd) > if (sec_out & CXL_PMEM_SEC_STATE_USER_PASS_SET) > return -EINVAL; > > + if (cmd == CXL_MBOX_OP_SECURE_ERASE && > + sec_out & CXL_PMEM_SEC_STATE_LOCKED) > + return -EINVAL; > + > rc = cxl_internal_send_cmd(cxlds, &mbox_cmd); > if (rc < 0) { > dev_err(cxlds->dev, "Failed to sanitize device : %d", rc); > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > index 90f23e53d483..d06c8539e82c 100644 > --- a/drivers/cxl/core/memdev.c > +++ b/drivers/cxl/core/memdev.c > @@ -163,6 +163,33 @@ static ssize_t security_sanitize_store(struct device *dev, > static struct device_attribute dev_attr_security_sanitize = > __ATTR(sanitize, 0200, NULL, security_sanitize_store); > > +static ssize_t security_erase_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t len) > +{ > + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); > + struct cxl_dev_state *cxlds = cxlmd->cxlds; > + struct cxl_port *port = dev_get_drvdata(&cxlmd->dev); > + ssize_t rc; > + bool erase; > + > + if (kstrtobool(buf, &erase) || !erase) > + return -EINVAL; > + > + if (!port || !is_cxl_endpoint(port)) > + return -EINVAL; > + > + /* ensure no regions are mapped to this memdev */ > + if (port->commit_end != -1) > + return -EBUSY; > + > + rc = cxl_mem_sanitize(cxlds, CXL_MBOX_OP_SECURE_ERASE); > + > + return rc ? rc : len; > +} > +static struct device_attribute dev_attr_security_erase = > + __ATTR(erase, 0200, NULL, security_erase_store); > + > static int cxl_get_poison_by_memdev(struct cxl_memdev *cxlmd) > { > struct cxl_dev_state *cxlds = cxlmd->cxlds; > @@ -411,6 +438,7 @@ static struct attribute *cxl_memdev_ram_attributes[] = { > static struct attribute *cxl_memdev_security_attributes[] = { > &dev_attr_security_state.attr, > &dev_attr_security_sanitize.attr, > + &dev_attr_security_erase.attr, > NULL, > }; > > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h > index 408ec33c8480..758fea7b9dbf 100644 > --- a/drivers/cxl/cxlmem.h > +++ b/drivers/cxl/cxlmem.h > @@ -392,6 +392,7 @@ enum cxl_opcode { > CXL_MBOX_OP_SCAN_MEDIA = 0x4304, > CXL_MBOX_OP_GET_SCAN_MEDIA = 0x4305, > CXL_MBOX_OP_SANITIZE = 0x4400, > + CXL_MBOX_OP_SECURE_ERASE = 0x4401, > CXL_MBOX_OP_GET_SECURITY_STATE = 0x4500, > CXL_MBOX_OP_SET_PASSPHRASE = 0x4501, > CXL_MBOX_OP_DISABLE_PASSPHRASE = 0x4502,