diff mbox series

[v2,06/19] cxl/pmem: Add Disable Passphrase security command support

Message ID 166377432466.430546.6473491783703443307.stgit@djiang5-desk3.ch.intel.com
State Superseded
Headers show
Series Introduce security commands for CXL pmem device | expand

Commit Message

Dave Jiang Sept. 21, 2022, 3:32 p.m. UTC 
Create callback function to support the nvdimm_security_ops ->disable()
callback. Translate the operation to send "Disable Passphrase" security
command for CXL memory device. The operation supports disabling a
passphrase for the CXL persistent memory device. In the original
implementation of nvdimm_security_ops, this operation only supports
disabling of the user passphrase. This is due to the NFIT version of
disable passphrase only supported disabling of user passphrase. The CXL
spec allows disabling of the master passphrase as well which
nvidmm_security_ops does not support yet. In this commit, the callback
function will only support user passphrase.

See CXL 2.0 spec section 8.2.9.5.6.3 for reference.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/cxl/core/mbox.c      |    1 +
 drivers/cxl/cxlmem.h         |    8 ++++++++
 drivers/cxl/security.c       |   26 ++++++++++++++++++++++++++
 include/uapi/linux/cxl_mem.h |    1 +
 4 files changed, 36 insertions(+)

Comments

Davidlohr Bueso Sept. 21, 2022, 8:09 p.m. UTC | #1 
On Wed, 21 Sep 2022, Dave Jiang wrote:

>Create callback function to support the nvdimm_security_ops ->disable()
>callback. Translate the operation to send "Disable Passphrase" security
>command for CXL memory device. The operation supports disabling a
>passphrase for the CXL persistent memory device. In the original
>implementation of nvdimm_security_ops, this operation only supports
>disabling of the user passphrase. This is due to the NFIT version of
>disable passphrase only supported disabling of user passphrase. The CXL
>spec allows disabling of the master passphrase as well which
>nvidmm_security_ops does not support yet. In this commit, the callback
>function will only support user passphrase.
>
>See CXL 2.0 spec section 8.2.9.5.6.3 for reference.
>
>Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>Signed-off-by: Dave Jiang <dave.jiang@intel.com>

Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
diff mbox series

Patch

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index cc08383499e6..2563325db0f6 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -67,6 +67,7 @@  static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
 	CXL_CMD(GET_SCAN_MEDIA, 0, CXL_VARIABLE_PAYLOAD, 0),
 	CXL_CMD(GET_SECURITY_STATE, 0, 0x4, 0),
 	CXL_CMD(SET_PASSPHRASE, 0x60, 0, 0),
+	CXL_CMD(DISABLE_PASSPHRASE, 0x40, 0, 0),
 };
 
 /*
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 725b08148524..9ad92f975b78 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -275,6 +275,7 @@  enum cxl_opcode {
 	CXL_MBOX_OP_GET_SCAN_MEDIA	= 0x4305,
 	CXL_MBOX_OP_GET_SECURITY_STATE	= 0x4500,
 	CXL_MBOX_OP_SET_PASSPHRASE	= 0x4501,
+	CXL_MBOX_OP_DISABLE_PASSPHRASE	= 0x4502,
 	CXL_MBOX_OP_MAX			= 0x10000
 };
 
@@ -390,6 +391,13 @@  struct cxl_set_pass {
 	u8 new_pass[NVDIMM_PASSPHRASE_LEN];
 } __packed;
 
+/* disable passphrase input payload */
+struct cxl_disable_pass {
+	u8 type;
+	u8 reserved[31];
+	u8 pass[NVDIMM_PASSPHRASE_LEN];
+} __packed;
+
 enum {
 	CXL_PMEM_SEC_PASS_MASTER = 0,
 	CXL_PMEM_SEC_PASS_USER,
diff --git a/drivers/cxl/security.c b/drivers/cxl/security.c
index 5365646230c3..85b4c1f86881 100644
--- a/drivers/cxl/security.c
+++ b/drivers/cxl/security.c
@@ -70,9 +70,35 @@  static int cxl_pmem_security_change_key(struct nvdimm *nvdimm,
 	return rc;
 }
 
+static int cxl_pmem_security_disable(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;
+	struct cxl_disable_pass dis_pass;
+	int rc;
+
+	/*
+	 * While the CXL spec defines the ability to erase the master passphrase,
+	 * the original nvdimm security ops does not provide that capability.
+	 * The sysfs attribute exposed to user space assumes disable is for user
+	 * passphrase only. In order to preserve the user interface, this callback
+	 * will only support disable of user passphrase. The disable master passphrase
+	 * ability will need to be added as a new callback.
+	 */
+	dis_pass.type = CXL_PMEM_SEC_PASS_USER;
+	memcpy(dis_pass.pass, key_data->data, NVDIMM_PASSPHRASE_LEN);
+
+	rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_DISABLE_PASSPHRASE,
+			       &dis_pass, sizeof(dis_pass), NULL, 0);
+	return rc;
+}
+
 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,
 };
 
 const struct nvdimm_security_ops *cxl_security_ops = &__cxl_security_ops;
diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h
index 9da047e9b038..f6d383a80f22 100644
--- a/include/uapi/linux/cxl_mem.h
+++ b/include/uapi/linux/cxl_mem.h
@@ -43,6 +43,7 @@ 
 	___C(GET_SCAN_MEDIA, "Get Scan Media Results"),                   \
 	___C(GET_SECURITY_STATE, "Get Security State"),			  \
 	___C(SET_PASSPHRASE, "Set Passphrase"),				  \
+	___C(DISABLE_PASSPHRASE, "Disable Passphrase"),			  \
 	___C(MAX, "invalid / last command")
 
 #define ___C(a, b) CXL_MEM_COMMAND_ID_##a