[PATCH v6 04/11] nfit/libnvdimm: add unlock of nvdimm support for Intel DIMMs

[Dave Jiang <dave.jiang@intel.com>]

Add support to allow query the security status of the Intel nvdimms and
also unlock the dimm via the kernel key management APIs. The passphrase is
expected to be pulled from userspace through keyutils. Moving the Intel
related bits to its own source file as well.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/acpi/nfit/Makefile |    1 
 drivers/acpi/nfit/core.c   |    3 +
 drivers/acpi/nfit/intel.c  |  152 ++++++++++++++++++++++++++++++++++++++++++++
 drivers/acpi/nfit/intel.h  |   15 ++++
 drivers/nvdimm/dimm.c      |    7 ++
 drivers/nvdimm/dimm_devs.c |  132 ++++++++++++++++++++++++++++++++++++++
 drivers/nvdimm/nd-core.h   |    4 +
 drivers/nvdimm/nd.h        |    2 +
 include/linux/libnvdimm.h  |   24 +++++++
 security/keys/key.c        |    1 
 10 files changed, 338 insertions(+), 3 deletions(-)
 create mode 100644 drivers/acpi/nfit/intel.c

diff --git a/drivers/acpi/nfit/Makefile b/drivers/acpi/nfit/Makefile
index a407e769f103..443c7ef4e6a6 100644
--- a/drivers/acpi/nfit/Makefile
+++ b/drivers/acpi/nfit/Makefile
@@ -1,3 +1,4 @@
 obj-$(CONFIG_ACPI_NFIT) := nfit.o
 nfit-y := core.o
+nfit-$(CONFIG_X86) += intel.o
 nfit-$(CONFIG_X86_MCE) += mce.o
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 21235d555b5f..9cb6a108ecba 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -1904,7 +1904,8 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
 		nvdimm = nvdimm_create(acpi_desc->nvdimm_bus, nfit_mem,
 				acpi_nfit_dimm_attribute_groups,
 				flags, cmd_mask, flush ? flush->hint_count : 0,
-				nfit_mem->flush_wpq, &nfit_mem->id[0]);
+				nfit_mem->flush_wpq, &nfit_mem->id[0],
+				acpi_nfit_get_security_ops(nfit_mem->family));
 		if (!nvdimm)
 			return -ENOMEM;
 
diff --git a/drivers/acpi/nfit/intel.c b/drivers/acpi/nfit/intel.c
new file mode 100644
index 000000000000..4bfc1c1da339
--- /dev/null
+++ b/drivers/acpi/nfit/intel.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2018 Intel Corporation. All rights reserved. */
+/*
+ * Intel specific NFIT ops
+ */
+#include <linux/libnvdimm.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/ndctl.h>
+#include <linux/sysfs.h>
+#include <linux/delay.h>
+#include <linux/acpi.h>
+#include <linux/io.h>
+#include <linux/nd.h>
+#include <asm/cacheflush.h>
+#include <asm/smp.h>
+#include <acpi/nfit.h>
+#include "intel.h"
+#include "nfit.h"
+
+static int intel_dimm_security_unlock(struct nvdimm_bus *nvdimm_bus,
+		struct nvdimm *nvdimm, const struct nvdimm_key_data *nkey)
+{
+	struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
+	int cmd_rc, rc = 0;
+	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
+	struct {
+		struct nd_cmd_pkg pkg;
+		struct nd_intel_unlock_unit cmd;
+	} nd_cmd = {
+		.pkg = {
+			.nd_command = NVDIMM_INTEL_UNLOCK_UNIT,
+			.nd_family = NVDIMM_FAMILY_INTEL,
+			.nd_size_in = ND_INTEL_PASSPHRASE_SIZE,
+			.nd_size_out = ND_INTEL_STATUS_SIZE,
+			.nd_fw_size = ND_INTEL_STATUS_SIZE,
+		},
+		.cmd = {
+			.status = 0,
+		},
+	};
+
+	if (!test_bit(NVDIMM_INTEL_UNLOCK_UNIT, &nfit_mem->dsm_mask))
+		return -ENOTTY;
+
+	memcpy(nd_cmd.cmd.passphrase, nkey->data,
+			sizeof(nd_cmd.cmd.passphrase));
+	rc = nd_desc->ndctl(nd_desc, nvdimm, ND_CMD_CALL, &nd_cmd,
+			sizeof(nd_cmd), &cmd_rc);
+	if (rc < 0)
+		goto out;
+	if (cmd_rc < 0) {
+		rc = cmd_rc;
+		goto out;
+	}
+
+	switch (nd_cmd.cmd.status) {
+	case 0:
+		break;
+	case ND_INTEL_STATUS_INVALID_PASS:
+		rc = -EINVAL;
+		goto out;
+	case ND_INTEL_STATUS_INVALID_STATE:
+	default:
+		rc = -ENXIO;
+		goto out;
+	}
+
+	/*
+	 * TODO: define a cross arch wbinvd when/if NVDIMM_FAMILY_INTEL
+	 * support arrives on another arch.
+	 */
+	/* DIMM unlocked, invalidate all CPU caches before we read it */
+	wbinvd_on_all_cpus();
+
+ out:
+	return rc;
+}
+
+static int intel_dimm_security_state(struct nvdimm_bus *nvdimm_bus,
+		struct nvdimm *nvdimm, enum nvdimm_security_state *state)
+{
+	struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
+	int cmd_rc, rc = 0;
+	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
+	struct {
+		struct nd_cmd_pkg pkg;
+		struct nd_intel_get_security_state cmd;
+	} nd_cmd = {
+		.pkg = {
+			.nd_command = NVDIMM_INTEL_GET_SECURITY_STATE,
+			.nd_family = NVDIMM_FAMILY_INTEL,
+			.nd_size_in = 0,
+			.nd_size_out =
+				sizeof(struct nd_intel_get_security_state),
+			.nd_fw_size =
+				sizeof(struct nd_intel_get_security_state),
+		},
+		.cmd = {
+			.status = 0,
+			.state = 0,
+		},
+	};
+
+	if (!test_bit(NVDIMM_INTEL_GET_SECURITY_STATE, &nfit_mem->dsm_mask)) {
+		*state = NVDIMM_SECURITY_UNSUPPORTED;
+		return 0;
+	}
+
+	*state = NVDIMM_SECURITY_DISABLED;
+	rc = nd_desc->ndctl(nd_desc, nvdimm, ND_CMD_CALL, &nd_cmd,
+			sizeof(nd_cmd), &cmd_rc);
+	if (rc < 0)
+		goto out;
+	if (cmd_rc < 0) {
+		rc = cmd_rc;
+		goto out;
+	}
+
+	switch (nd_cmd.cmd.status) {
+	case 0:
+		break;
+	case ND_INTEL_STATUS_RETRY:
+		rc = -EAGAIN;
+		goto out;
+	case ND_INTEL_STATUS_NOT_READY:
+	default:
+		rc = -ENXIO;
+		goto out;
+	}
+
+	/* check and see if security is enabled and locked */
+	if (nd_cmd.cmd.state & ND_INTEL_SEC_STATE_UNSUPPORTED)
+		*state = NVDIMM_SECURITY_UNSUPPORTED;
+	else if (nd_cmd.cmd.state & ND_INTEL_SEC_STATE_ENABLED) {
+		if (nd_cmd.cmd.state & ND_INTEL_SEC_STATE_LOCKED)
+			*state = NVDIMM_SECURITY_LOCKED;
+		else
+			*state = NVDIMM_SECURITY_UNLOCKED;
+	} else
+		*state = NVDIMM_SECURITY_DISABLED;
+
+ out:
+	if (rc < 0)
+		*state = NVDIMM_SECURITY_INVALID;
+	return rc;
+}
+
+const struct nvdimm_security_ops intel_security_ops = {
+	.state = intel_dimm_security_state,
+	.unlock = intel_dimm_security_unlock,
+};
diff --git a/drivers/acpi/nfit/intel.h b/drivers/acpi/nfit/intel.h
index a6f8f4bc8ebb..f9ac718776ca 100644
--- a/drivers/acpi/nfit/intel.h
+++ b/drivers/acpi/nfit/intel.h
@@ -8,6 +8,8 @@
 
 #ifdef CONFIG_X86
 
+extern const struct nvdimm_security_ops intel_security_ops;
+
 #define ND_INTEL_STATUS_SIZE		4
 #define ND_INTEL_PASSPHRASE_SIZE	32
 
@@ -64,4 +66,17 @@ struct nd_intel_query_overwrite {
 } __packed;
 #endif /* CONFIG_X86 */
 
+static inline const struct nvdimm_security_ops *
+acpi_nfit_get_security_ops(int family)
+{
+	switch (family) {
+#ifdef CONFIG_X86
+	case NVDIMM_FAMILY_INTEL:
+		return &intel_security_ops;
+#endif
+	default:
+		return NULL;
+	}
+}
+
 #endif
diff --git a/drivers/nvdimm/dimm.c b/drivers/nvdimm/dimm.c
index 6c8fb7590838..b6381ddbd6c1 100644
--- a/drivers/nvdimm/dimm.c
+++ b/drivers/nvdimm/dimm.c
@@ -51,6 +51,13 @@ static int nvdimm_probe(struct device *dev)
 	get_device(dev);
 	kref_init(&ndd->kref);
 
+	nvdimm_security_get_state(dev);
+
+	/* unlock DIMM here before touch label */
+	rc = nvdimm_security_unlock_dimm(dev);
+	if (rc < 0)
+		dev_warn(dev, "failed to unlock dimm %s\n", dev_name(dev));
+
 	/*
 	 * EACCES failures reading the namespace label-area-properties
 	 * are interpreted as the DIMM capacity being locked but the
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index e753b2095402..5b247f94807a 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -20,6 +20,7 @@
 #include <linux/mm.h>
 #include <linux/key.h>
 #include <linux/init_task.h>
+#include <keys/user-type.h>
 #include "nd-core.h"
 #include "label.h"
 #include "pmem.h"
@@ -28,6 +29,133 @@
 static DEFINE_IDA(dimm_ida);
 static struct key *nvdimm_keyring;
 
+/*
+ * Find key in kernel keyring
+ */
+static struct key *nvdimm_search_key(struct device *dev)
+{
+	struct nvdimm *nvdimm = to_nvdimm(dev);
+	struct key *key;
+
+	if (!nvdimm->security_ops)
+		return NULL;
+
+	key = key_lookup(nvdimm->key_id);
+	if (IS_ERR(key))
+		key = NULL;
+	else
+		key_get(key);
+
+	dev_dbg(dev, "%s: key found: %d\n", __func__, key_serial(key));
+	return key;
+}
+
+#define NVDIMM_UPDATE_PREFIX   "nvdimm.update:"
+#define NVDIMM_PREFIX          "nvdimm:"
+
+/*
+ * Retrieve kernel key for DIMM and request from user space if necessary.
+ */
+static struct key *nvdimm_request_key(struct device *dev, bool update)
+{
+	struct nvdimm *nvdimm = to_nvdimm(dev);
+	struct key *key = NULL;
+	char desc[NVDIMM_KEY_DESC_LEN + strlen(NVDIMM_UPDATE_PREFIX)];
+
+	if (!nvdimm->security_ops)
+		return NULL;
+
+	sprintf(desc, "%s%s", update ? NVDIMM_UPDATE_PREFIX : NVDIMM_PREFIX,
+			nvdimm->dimm_id);
+	key = request_key(&key_type_logon, desc, desc);
+	if (IS_ERR(key))
+		key = NULL;
+
+	return key;
+}
+
+static int nvdimm_check_key_len(unsigned short len, bool update)
+{
+	if (len == (NVDIMM_PASSPHRASE_LEN * 2) && update)
+		return 0;
+
+	if (len == NVDIMM_PASSPHRASE_LEN)
+		return 0;
+
+	return -EINVAL;
+}
+
+int nvdimm_security_get_state(struct device *dev)
+{
+	struct nvdimm *nvdimm = to_nvdimm(dev);
+	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
+
+	if (!nvdimm->security_ops)
+		return 0;
+
+	return nvdimm->security_ops->state(nvdimm_bus, nvdimm,
+			&nvdimm->state);
+}
+
+int nvdimm_security_unlock_dimm(struct device *dev)
+{
+	struct nvdimm *nvdimm = to_nvdimm(dev);
+	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
+	struct key *key;
+	struct user_key_payload *payload;
+	int rc;
+	bool cached_key = false;
+
+	if (!nvdimm->security_ops)
+		return 0;
+
+	if (nvdimm->state == NVDIMM_SECURITY_UNLOCKED ||
+			nvdimm->state == NVDIMM_SECURITY_UNSUPPORTED ||
+			nvdimm->state == NVDIMM_SECURITY_DISABLED)
+		return 0;
+
+	key = nvdimm_search_key(dev);
+	if (!key)
+		key = nvdimm_request_key(dev, false);
+	else
+		cached_key = true;
+	if (!key)
+		return -ENXIO;
+
+	if (!cached_key) {
+		rc = nvdimm_check_key_len(key->datalen, false);
+		if (rc < 0) {
+			key_invalidate(key);
+			key_put(key);
+			return rc;
+		}
+	}
+
+	dev_dbg(dev, "%s: key: %#x\n", __func__, key_serial(key));
+	down_read(&key->sem);
+	payload = key->payload.data[0];
+	rc = nvdimm->security_ops->unlock(nvdimm_bus, nvdimm,
+			(void *)payload->data);
+	up_read(&key->sem);
+
+	if (rc == 0) {
+		if (!cached_key) {
+			key_link(nvdimm_keyring, key);
+			nvdimm->key_id = key_serial(key);
+		}
+		nvdimm->state = NVDIMM_SECURITY_UNLOCKED;
+		dev_info(dev, "DIMM %s unlocked\n", dev_name(dev));
+	} else {
+		key_unlink(nvdimm_keyring, key);
+		key_invalidate(key);
+		dev_warn(dev, "Failed to unlock dimm: %s\n", dev_name(dev));
+	}
+
+	key_put(key);
+	nvdimm_security_get_state(dev);
+	return rc;
+}
+
 /*
  * Retrieve bus and dimm handle and return if this bus supports
  * get_config_data commands
@@ -401,7 +529,8 @@ EXPORT_SYMBOL_GPL(nvdimm_attribute_group);
 struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data,
 		const struct attribute_group **groups, unsigned long flags,
 		unsigned long cmd_mask, int num_flush,
-		struct resource *flush_wpq, const char *dimm_id)
+		struct resource *flush_wpq, const char *dimm_id,
+		const struct nvdimm_security_ops *sec_ops)
 {
 	struct nvdimm *nvdimm = kzalloc(sizeof(*nvdimm), GFP_KERNEL);
 	struct device *dev;
@@ -416,6 +545,7 @@ struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data,
 	}
 
 	nvdimm->dimm_id = dimm_id;
+	nvdimm->security_ops = sec_ops;
 	nvdimm->provider_data = provider_data;
 	nvdimm->flags = flags;
 	nvdimm->cmd_mask = cmd_mask;
diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index ed650f1607d8..ff8919f9b67a 100644
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -18,6 +18,7 @@
 #include <linux/sizes.h>
 #include <linux/mutex.h>
 #include <linux/nd.h>
+#include <linux/key.h>
 
 extern struct list_head nvdimm_bus_list;
 extern struct mutex nvdimm_bus_list_mutex;
@@ -43,6 +44,9 @@ struct nvdimm {
 	int id, num_flush;
 	struct resource *flush_wpq;
 	const char *dimm_id;
+	const struct nvdimm_security_ops *security_ops;
+	enum nvdimm_security_state state;
+	key_serial_t key_id;
 };
 
 /**
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 9d17abd9f8d0..9c80e0f8c327 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -424,4 +424,6 @@ static inline bool is_bad_pmem(struct badblocks *bb, sector_t sector,
 resource_size_t nd_namespace_blk_validate(struct nd_namespace_blk *nsblk);
 const u8 *nd_dev_to_uuid(struct device *dev);
 bool pmem_should_map_pages(struct device *dev);
+int nvdimm_security_unlock_dimm(struct device *dev);
+int nvdimm_security_get_state(struct device *dev);
 #endif /* __ND_H__ */
diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 3c1f18fdf76f..257ff2637ce1 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -155,9 +155,30 @@ static inline struct nd_blk_region_desc *to_blk_region_desc(
 
 }
 
+enum nvdimm_security_state {
+	NVDIMM_SECURITY_INVALID = 0,
+	NVDIMM_SECURITY_DISABLED,
+	NVDIMM_SECURITY_UNLOCKED,
+	NVDIMM_SECURITY_LOCKED,
+	NVDIMM_SECURITY_UNSUPPORTED,
+};
+
 #define NVDIMM_PASSPHRASE_LEN		32
 #define NVDIMM_KEY_DESC_LEN		22
 
+struct nvdimm_key_data {
+	u8 data[NVDIMM_PASSPHRASE_LEN];
+};
+
+struct nvdimm_security_ops {
+	int (*state)(struct nvdimm_bus *nvdimm_bus,
+			struct nvdimm *nvdimm,
+			enum nvdimm_security_state *state);
+	int (*unlock)(struct nvdimm_bus *nvdimm_bus,
+			struct nvdimm *nvdimm,
+			const struct nvdimm_key_data *nkey);
+};
+
 void badrange_init(struct badrange *badrange);
 int badrange_add(struct badrange *badrange, u64 addr, u64 length);
 void badrange_forget(struct badrange *badrange, phys_addr_t start,
@@ -181,7 +202,8 @@ void *nvdimm_provider_data(struct nvdimm *nvdimm);
 struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data,
 		const struct attribute_group **groups, unsigned long flags,
 		unsigned long cmd_mask, int num_flush,
-		struct resource *flush_wpq, const char *dimm_id);
+		struct resource *flush_wpq, const char *dimm_id,
+		const struct nvdimm_security_ops *sec_ops);
 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd);
 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd);
 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
diff --git a/security/keys/key.c b/security/keys/key.c
index d97c9394b5dd..5aa367b2fd24 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -679,6 +679,7 @@ struct key *key_lookup(key_serial_t id)
 	spin_unlock(&key_serial_lock);
 	return key;
 }
+EXPORT_SYMBOL(key_lookup);
 
 /*
  * Find and lock the specified key type against removal.

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