diff mbox series

[RFC,06/15] cxl/pmem: Add Disable Passphrase security command support

Message ID 165791934720.2491387.11236603584810515256.stgit@djiang5-desk3.ch.intel.com (mailing list archive)
State Superseded
Headers show
Series Introduce security commands for CXL pmem device | expand

Commit Message

Dave Jiang July 15, 2022, 9:09 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.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/cxl/cxlmem.h   |    8 ++++++++
 drivers/cxl/security.c |   30 ++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

Comments

Jonathan Cameron Aug. 3, 2022, 5:21 p.m. UTC | #1
On Fri, 15 Jul 2022 14:09:07 -0700
Dave Jiang <dave.jiang@intel.com> 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
nvdimm...
> function will only support user passphrase.
> 
> See CXL 2.0 spec section 8.2.9.5.6.3 for reference.
> 
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Trivial comment inline otherwise lgtm

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  drivers/cxl/cxlmem.h   |    8 ++++++++
>  drivers/cxl/security.c |   30 ++++++++++++++++++++++++++++++
>  2 files changed, 38 insertions(+)
> 
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index 1e76d22f4fd2..70a1eb7720d3 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -252,6 +252,7 @@ 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
>  };
>  
> @@ -359,6 +360,13 @@ 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 76ec5087f966..4aec8e41e167 100644
> --- a/drivers/cxl/security.c
> +++ b/drivers/cxl/security.c
> @@ -76,9 +76,39 @@ 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;
> +
> +	dis_pass = kzalloc(sizeof(*dis_pass), GFP_KERNEL);

Another fairly small structure. Maybe just put it on the stack...

> +	if (!dis_pass)
> +		return -ENOMEM;
> +
> +	/*
> +	 * While the CXL spec defines the ability to erase the master passphrase,
> +	 * the original nvdimm security ops does not provide that capability.
> +	 * In order to preserve backward compatibility, this callback will
> +	 * only support disable of user passphrase. The disable master passphrase
> +	 * ability will need to be added as a new callback.

Curious. Why is that callback set in stone? If this is exposed directly to userspace
perhaps call that out here.


> +	 */
> +	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);
> +	kfree(dis_pass);
> +	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 mbox series

Patch

diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 1e76d22f4fd2..70a1eb7720d3 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -252,6 +252,7 @@  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
 };
 
@@ -359,6 +360,13 @@  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 76ec5087f966..4aec8e41e167 100644
--- a/drivers/cxl/security.c
+++ b/drivers/cxl/security.c
@@ -76,9 +76,39 @@  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;
+
+	dis_pass = kzalloc(sizeof(*dis_pass), GFP_KERNEL);
+	if (!dis_pass)
+		return -ENOMEM;
+
+	/*
+	 * While the CXL spec defines the ability to erase the master passphrase,
+	 * the original nvdimm security ops does not provide that capability.
+	 * In order to preserve backward compatibility, 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);
+	kfree(dis_pass);
+	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;