[ndctl PATCH v5 0/6] Add partitioning support for CXL memdevs

[ndctl PATCH v5 0/6] Add partitioning support for CXL memdevs

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

Provisioning PMEM over CXL requires the ability to view and change
partition layouts of CXL memory devices that support partitioning.
Provide access to these capabilities as defined in the CXL 2.0
specification.

The first 4 patches add accessors for all the information needed
to formulate a new partition layout. This info is accessible via
the libcxl API and a new option in the 'cxl list' command:

Example:
    "partition_info":{
      "active_volatile_size":273535729664,
      "active_persistent_size":0,
      "next_volatile_size":0,
      "next_persistent_size":0,
      "total_size":273535729664,
      "volatile_only_size":0,
      "persistent_only_size":0,
      "partition_alignment_size":268435456
    }

Patch 5 introduces the libcxl interfaces for the CXL SET_PARTITION_INFO
mailbox command and Patch 6 adds the cxl set-partition command.

 Usage: cxl set-partition <mem0> [<mem1>..<memN>] [<options>]

    -v, --verbose         turn on debug
    -S, --serial          use serial numbers to id memdevs
    -t, --type <type>     'pmem' or 'volatile' (Default: 'pmem')
    -s, --size <size>     size in bytes (Default: all available capacity)
    -a, --align           auto-align --size per device's requirement


The cxl set-partition command does not offer the IMMEDIATE mode option
defined in the CXL 2.0 spec because the CXL kernel driver does not
support immediate mode yet. Since userspace could use the libcxl API
to send a SET_PARTITION_INFO mailbox command with immediate mode
selected, a kernel patch that rejects such requests is in review for
the CXL driver.

Changes in v5: (from Dan's review)
- Applied Dan Reviewed-by tags to all except Patch #3
- Cover letter: update the cxl list, and synopsis output.
- Cover letter: s/CXL/'cxl set-partition'/ for clarity.
- Redefine capacity_to_bytes helper to reflect that it converts
  the le64 to uint64_t.
- Add NULL checks (!cmd) in cmd_to_get_partition() and cmd_to_identify().
- replace ?: statements with if() in libcxl get_<field> helpers.
- replace ?: statements with if() in param_to_volatile_size() helper.
- Add a note in Patch 3 log about this early API behavior change.
- Use the cmd_to_identify() and cxl_capacity_to_bytes() pair for
  retrieving partition_align_size.
- Add note about role of cxl_cmd_partition_set_mode() to libcxl.txt
- Updated cxl-set-partition man page.
- command synopsis: update align description to say 'auto-align...'
- command synopsis: update size default by s/partitionable/available
- add and use an enum for param.type
- s/partitionable/available in many places when referring to size available
  to be partitioned.

Changes in v4: (from Dan's review)
- cxl set-partition command: add type (pmem | volatile),
  add defaults for type and size, and add an align option.
- Replace macros with return statements with functions.
- Add cxl_set_partition_set_mode() to the libcxl API.
- Add API documentation to Documentation/cxl/lib/libcxl.txt.
- Use log_err/info mechanism.
- Display memdev JSON info upon completion of set-partition command.
- Remove unneeded casts when accessing command payloads.
- Name changes - like drop _info suffix, use _size instead of _bytes.

Changes in v3:
- Back out the API name change to the partition align accessor.
  The API was already released in v72.
- Man page: collapse into one .txt file. 
- Man page: add to Documentation/meson.build 

Changes in v2:
- Rebase onto https://github.com/pmem/ndctl.git djbw/meson.
- Clarify that capacities are reported in bytes. (Ira)
  This led to renaming accessors like *_capacity to  *_bytes and 
  a spattering of changes in the man pages and commit messages.
- Add missing cxl_cmd_unref() when creating json objects. (Ira)
- Change the cxl list option to: -I --partition (Dan) 
- Use OPT_STRING for the --volatile_size parameter (Dan, Vishal)
- Drop extra _get_ in accessor names. (Vishal)
- Add an accessor for the SET_PARTITION_INFO mbox cmd flag.
- Display usage_with_options if size parameter is missing.
- Drop the OPT64 define patch. Use OPT_STRING instead.

Alison Schofield (6):
  libcxl: add GET_PARTITION_INFO mailbox command and accessors
  libcxl: add accessors for capacity fields of the IDENTIFY command
  libcxl: return the partition alignment field in bytes
  cxl: add memdev partition information to cxl-list
  libcxl: add interfaces for SET_PARTITION_INFO mailbox command
  cxl: add command 'cxl set-partition'

 Documentation/cxl/cxl-list.txt          |  23 +++
 Documentation/cxl/cxl-set-partition.txt |  68 ++++++++
 Documentation/cxl/lib/libcxl.txt        |  12 ++
 Documentation/cxl/meson.build           |   1 +
 cxl/builtin.h                           |   1 +
 cxl/cxl.c                               |   1 +
 cxl/filter.c                            |   2 +
 cxl/filter.h                            |   1 +
 cxl/json.c                              | 113 +++++++++++++
 cxl/lib/libcxl.c                        | 151 ++++++++++++++++-
 cxl/lib/libcxl.sym                      |  10 ++
 cxl/lib/private.h                       |  18 +++
 cxl/libcxl.h                            |  18 +++
 cxl/list.c                              |   2 +
 cxl/memdev.c                            | 206 ++++++++++++++++++++++++
 util/json.h                             |   1 +
 util/size.h                             |   1 +
 17 files changed, 621 insertions(+), 8 deletions(-)
 create mode 100644 Documentation/cxl/cxl-set-partition.txt

-- 
2.31.1

[ndctl PATCH v5 1/6] libcxl: add GET_PARTITION_INFO mailbox command and accessors

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

The CXL PMEM provisioning model depends upon the values reported
in the CXL GET_PARTITION_INFO mailbox command when changing the
partitioning between volatile and persistent capacity.

Add libcxl APIs to create a new GET_PARTITION_INFO mailbox command,
the command output data structure (privately), and accessor APIs to
return the fields in the partition info output.

Per the CXL 2.0 specification, devices report partition capacities
as multiples of 256MB. Define and use a capacity multiplier to
convert the raw data into bytes for user consumption. Use byte
format as the norm for all capacity values produced or consumed
using CXL Mailbox commands.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
---
 Documentation/cxl/lib/libcxl.txt |  1 +
 cxl/lib/libcxl.c                 | 66 ++++++++++++++++++++++++++++++++
 cxl/lib/libcxl.sym               |  5 +++
 cxl/lib/private.h                | 10 +++++
 cxl/libcxl.h                     |  5 +++
 util/size.h                      |  1 +
 6 files changed, 88 insertions(+)

diff --git a/Documentation/cxl/lib/libcxl.txt b/Documentation/cxl/lib/libcxl.txt
index 4392b47..a6986ab 100644
--- a/Documentation/cxl/lib/libcxl.txt
+++ b/Documentation/cxl/lib/libcxl.txt
@@ -131,6 +131,7 @@ int cxl_memdev_read_label(struct cxl_memdev *memdev, void *buf, size_t length,
 			  size_t offset);
 int cxl_memdev_write_label(struct cxl_memdev *memdev, void *buf, size_t length,
 			   size_t offset);
+struct cxl_cmd *cxl_cmd_new_get_partition(struct cxl_memdev *memdev);
 
 ----
 
diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
index e0b443f..4557a71 100644
--- a/cxl/lib/libcxl.c
+++ b/cxl/lib/libcxl.c
@@ -1985,6 +1985,11 @@ static int cxl_cmd_validate_status(struct cxl_cmd *cmd, u32 id)
 	return 0;
 }
 
+static uint64_t cxl_capacity_to_bytes(leint64_t size)
+{
+	return le64_to_cpu(size) * CXL_CAPACITY_MULTIPLIER;
+}
+
 /* Helpers for health_info fields (no endian conversion) */
 #define cmd_get_field_u8(cmd, n, N, field)				\
 do {									\
@@ -2371,6 +2376,67 @@ CXL_EXPORT ssize_t cxl_cmd_read_label_get_payload(struct cxl_cmd *cmd,
 	return length;
 }
 
+CXL_EXPORT struct cxl_cmd *cxl_cmd_new_get_partition(struct cxl_memdev *memdev)
+{
+	return cxl_cmd_new_generic(memdev,
+				   CXL_MEM_COMMAND_ID_GET_PARTITION_INFO);
+}
+
+static struct cxl_cmd_get_partition *
+cmd_to_get_partition(struct cxl_cmd *cmd)
+{
+	if (cxl_cmd_validate_status(cmd, CXL_MEM_COMMAND_ID_GET_PARTITION_INFO))
+		return NULL;
+
+	if (!cmd)
+		return NULL;
+	return cmd->output_payload;
+}
+
+CXL_EXPORT unsigned long long
+cxl_cmd_partition_get_active_volatile_size(struct cxl_cmd *cmd)
+{
+	struct cxl_cmd_get_partition *c;
+
+	c = cmd_to_get_partition(cmd);
+	if (!c)
+		return ULLONG_MAX;
+	return cxl_capacity_to_bytes(c->active_volatile);
+}
+
+CXL_EXPORT unsigned long long
+cxl_cmd_partition_get_active_persistent_size(struct cxl_cmd *cmd)
+{
+	struct cxl_cmd_get_partition *c;
+
+	c = cmd_to_get_partition(cmd);
+	if (!c)
+		return ULLONG_MAX;
+	return cxl_capacity_to_bytes(c->active_persistent);
+}
+
+CXL_EXPORT unsigned long long
+cxl_cmd_partition_get_next_volatile_size(struct cxl_cmd *cmd)
+{
+	struct cxl_cmd_get_partition *c;
+
+	c = cmd_to_get_partition(cmd);
+	if (!c)
+		return ULLONG_MAX;
+	return cxl_capacity_to_bytes(c->next_volatile);
+}
+
+CXL_EXPORT unsigned long long
+cxl_cmd_partition_get_next_persistent_size(struct cxl_cmd *cmd)
+{
+	struct cxl_cmd_get_partition *c;
+
+	c = cmd_to_get_partition(cmd);
+	if (!c)
+		return ULLONG_MAX;
+	return cxl_capacity_to_bytes(c->next_persistent);
+}
+
 CXL_EXPORT int cxl_cmd_submit(struct cxl_cmd *cmd)
 {
 	struct cxl_memdev *memdev = cmd->memdev;
diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym
index e56a2bf..509e62d 100644
--- a/cxl/lib/libcxl.sym
+++ b/cxl/lib/libcxl.sym
@@ -155,4 +155,9 @@ global:
 	cxl_dport_get_port;
 	cxl_port_get_dport_by_memdev;
 	cxl_dport_maps_memdev;
+	cxl_cmd_new_get_partition;
+	cxl_cmd_partition_get_active_volatile_size;
+	cxl_cmd_partition_get_active_persistent_size;
+	cxl_cmd_partition_get_next_volatile_size;
+	cxl_cmd_partition_get_next_persistent_size;
 } LIBCXL_1;
diff --git a/cxl/lib/private.h b/cxl/lib/private.h
index f483c30..7f3a562 100644
--- a/cxl/lib/private.h
+++ b/cxl/lib/private.h
@@ -7,6 +7,7 @@
 #include <cxl/cxl_mem.h>
 #include <ccan/endian/endian.h>
 #include <ccan/short_types/short_types.h>
+#include <util/size.h>
 
 #define CXL_EXPORT __attribute__ ((visibility("default")))
 
@@ -185,6 +186,15 @@ struct cxl_cmd_get_health_info {
 	le32 pmem_errors;
 } __attribute__((packed));
 
+struct cxl_cmd_get_partition {
+	le64 active_volatile;
+	le64 active_persistent;
+	le64 next_volatile;
+	le64 next_persistent;
+} __attribute__((packed));
+
+#define CXL_CAPACITY_MULTIPLIER		SZ_256M
+
 /* CXL 2.0 8.2.9.5.3 Byte 0 Health Status */
 #define CXL_CMD_HEALTH_INFO_STATUS_MAINTENANCE_NEEDED_MASK		BIT(0)
 #define CXL_CMD_HEALTH_INFO_STATUS_PERFORMANCE_DEGRADED_MASK		BIT(1)
diff --git a/cxl/libcxl.h b/cxl/libcxl.h
index 3b2293b..2c0a8d1 100644
--- a/cxl/libcxl.h
+++ b/cxl/libcxl.h
@@ -242,6 +242,11 @@ ssize_t cxl_cmd_read_label_get_payload(struct cxl_cmd *cmd, void *buf,
 		unsigned int length);
 struct cxl_cmd *cxl_cmd_new_write_label(struct cxl_memdev *memdev,
 		void *buf, unsigned int offset, unsigned int length);
+struct cxl_cmd *cxl_cmd_new_get_partition(struct cxl_memdev *memdev);
+unsigned long long cxl_cmd_partition_get_active_volatile_size(struct cxl_cmd *cmd);
+unsigned long long cxl_cmd_partition_get_active_persistent_size(struct cxl_cmd *cmd);
+unsigned long long cxl_cmd_partition_get_next_volatile_size(struct cxl_cmd *cmd);
+unsigned long long cxl_cmd_partition_get_next_persistent_size(struct cxl_cmd *cmd);
 
 #ifdef __cplusplus
 } /* extern "C" */
diff --git a/util/size.h b/util/size.h
index a0f3593..e72467f 100644
--- a/util/size.h
+++ b/util/size.h
@@ -15,6 +15,7 @@
 #define SZ_4M     0x00400000
 #define SZ_16M    0x01000000
 #define SZ_64M    0x04000000
+#define SZ_256M	  0x10000000
 #define SZ_1G     0x40000000
 #define SZ_1T 0x10000000000ULL
 
-- 
2.31.1

[ndctl PATCH v5 2/6] libcxl: add accessors for capacity fields of the IDENTIFY command

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

The CXL PMEM provisioning model depends upon the values reported
in the CXL IDENTIFY mailbox command when changing the partitioning
between volatile and persistent capacity.

Add accessors to the libcxl API to retrieve the total, volatile only,
and persistent only capacities from the IDENTIFY command.

The fields are specified in multiples of 256MB per the CXL 2.0 spec.
Use the capacity multiplier to convert the raw data into bytes for user
consumption.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
---
 cxl/lib/libcxl.c   | 44 ++++++++++++++++++++++++++++++++++++++++++++
 cxl/lib/libcxl.sym |  3 +++
 cxl/libcxl.h       |  3 +++
 3 files changed, 50 insertions(+)

diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
index 4557a71..9413384 100644
--- a/cxl/lib/libcxl.c
+++ b/cxl/lib/libcxl.c
@@ -2277,6 +2277,17 @@ CXL_EXPORT struct cxl_cmd *cxl_cmd_new_identify(struct cxl_memdev *memdev)
 	return cxl_cmd_new_generic(memdev, CXL_MEM_COMMAND_ID_IDENTIFY);
 }
 
+static struct cxl_cmd_identify *
+cmd_to_identify(struct cxl_cmd *cmd)
+{
+	if (cxl_cmd_validate_status(cmd, CXL_MEM_COMMAND_ID_IDENTIFY))
+		return NULL;
+
+	if (!cmd)
+		return NULL;
+	return cmd->output_payload;
+}
+
 CXL_EXPORT int cxl_cmd_identify_get_fw_rev(struct cxl_cmd *cmd, char *fw_rev,
 		int fw_len)
 {
@@ -2321,6 +2332,39 @@ CXL_EXPORT unsigned int cxl_cmd_identify_get_label_size(struct cxl_cmd *cmd)
 	return le32_to_cpu(id->lsa_size);
 }
 
+CXL_EXPORT unsigned long long
+cxl_cmd_identify_get_total_size(struct cxl_cmd *cmd)
+{
+	struct cxl_cmd_identify *c;
+
+	c = cmd_to_identify(cmd);
+	if (!c)
+		return ULLONG_MAX;
+	return cxl_capacity_to_bytes(c->total_capacity);
+}
+
+CXL_EXPORT unsigned long long
+cxl_cmd_identify_get_volatile_only_size(struct cxl_cmd *cmd)
+{
+	struct cxl_cmd_identify *c;
+
+	c = cmd_to_identify(cmd);
+	if (!c)
+		return ULLONG_MAX;
+	return cxl_capacity_to_bytes(c->volatile_capacity);
+}
+
+CXL_EXPORT unsigned long long
+cxl_cmd_identify_get_persistent_only_size(struct cxl_cmd *cmd)
+{
+	struct cxl_cmd_identify *c;
+
+	c = cmd_to_identify(cmd);
+	if (!c)
+		return ULLONG_MAX;
+	return cxl_capacity_to_bytes(c->persistent_capacity);
+}
+
 CXL_EXPORT struct cxl_cmd *cxl_cmd_new_raw(struct cxl_memdev *memdev,
 		int opcode)
 {
diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym
index 509e62d..5ac6e9b 100644
--- a/cxl/lib/libcxl.sym
+++ b/cxl/lib/libcxl.sym
@@ -160,4 +160,7 @@ global:
 	cxl_cmd_partition_get_active_persistent_size;
 	cxl_cmd_partition_get_next_volatile_size;
 	cxl_cmd_partition_get_next_persistent_size;
+	cxl_cmd_identify_get_total_size;
+	cxl_cmd_identify_get_volatile_only_size;
+	cxl_cmd_identify_get_persistent_only_size;
 } LIBCXL_1;
diff --git a/cxl/libcxl.h b/cxl/libcxl.h
index 2c0a8d1..6e18e84 100644
--- a/cxl/libcxl.h
+++ b/cxl/libcxl.h
@@ -201,6 +201,9 @@ int cxl_cmd_get_mbox_status(struct cxl_cmd *cmd);
 int cxl_cmd_get_out_size(struct cxl_cmd *cmd);
 struct cxl_cmd *cxl_cmd_new_identify(struct cxl_memdev *memdev);
 int cxl_cmd_identify_get_fw_rev(struct cxl_cmd *cmd, char *fw_rev, int fw_len);
+unsigned long long cxl_cmd_identify_get_total_size(struct cxl_cmd *cmd);
+unsigned long long cxl_cmd_identify_get_volatile_only_size(struct cxl_cmd *cmd);
+unsigned long long cxl_cmd_identify_get_persistent_only_size(struct cxl_cmd *cmd);
 unsigned long long cxl_cmd_identify_get_partition_align(struct cxl_cmd *cmd);
 unsigned int cxl_cmd_identify_get_label_size(struct cxl_cmd *cmd);
 struct cxl_cmd *cxl_cmd_new_get_health_info(struct cxl_memdev *memdev);
-- 
2.31.1

[ndctl PATCH v5 3/6] libcxl: return the partition alignment field in bytes

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

Per the CXL specification, the partition alignment field reports
the alignment value in multiples of 256MB. In the libcxl API, values
for all capacity fields are defined to return bytes.

Update the partition alignment accessor to return bytes so that it
is in sync with other capacity related fields. Use the helpers
cmd_to_identify() and cxl_capacity_to_bytes() to accomplish.

Since this is early in the development cycle, the expectation is that
no third party consumers of this library have come to depend on the
encoded capacity field. If that is not the case, the original format
can be restored, and a new _bytes version introduced.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---

 cxl/lib/libcxl.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
index 9413384..c05c13c 100644
--- a/cxl/lib/libcxl.c
+++ b/cxl/lib/libcxl.c
@@ -2308,15 +2308,12 @@ CXL_EXPORT int cxl_cmd_identify_get_fw_rev(struct cxl_cmd *cmd, char *fw_rev,
 CXL_EXPORT unsigned long long cxl_cmd_identify_get_partition_align(
 		struct cxl_cmd *cmd)
 {
-	struct cxl_cmd_identify *id =
-			(struct cxl_cmd_identify *)cmd->send_cmd->out.payload;
+	struct cxl_cmd_identify *c;
 
-	if (cmd->send_cmd->id != CXL_MEM_COMMAND_ID_IDENTIFY)
-		return -EINVAL;
-	if (cmd->status < 0)
-		return cmd->status;
-
-	return le64_to_cpu(id->partition_align);
+	c = cmd_to_identify(cmd);
+	if (!c)
+		return ULLONG_MAX;
+	return cxl_capacity_to_bytes(c->partition_align);
 }
 
 CXL_EXPORT unsigned int cxl_cmd_identify_get_label_size(struct cxl_cmd *cmd)
-- 
2.31.1

Re: [ndctl PATCH v5 3/6] libcxl: return the partition alignment field in bytes

[Dan Williams]

On Wed, Feb 9, 2022 at 6:01 PM <alison.schofield@intel.com> wrote:
>
> From: Alison Schofield <alison.schofield@intel.com>
>
> Per the CXL specification, the partition alignment field reports
> the alignment value in multiples of 256MB. In the libcxl API, values
> for all capacity fields are defined to return bytes.
>
> Update the partition alignment accessor to return bytes so that it
> is in sync with other capacity related fields. Use the helpers
> cmd_to_identify() and cxl_capacity_to_bytes() to accomplish.
>
> Since this is early in the development cycle, the expectation is that
> no third party consumers of this library have come to depend on the
> encoded capacity field. If that is not the case, the original format
> can be restored, and a new _bytes version introduced.
>
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>

Looks good,

Reviewed-by: Dan Williams <dan.j.williams@intel.com>

[ndctl PATCH v5 4/6] cxl: add memdev partition information to cxl-list

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

The CXL PMEM provisioning model depends upon the values reported in
both the CXL IDENTIFY and GET_PARTITION_INFO mailbox commands when
changing the partitioning between volatile and persistent capacity.

Add an option to the 'cxl list' command to display partition information.
Include all of the fields from GET_PARTITION_INFO and the partitioning
related fields from the IDENTIFY mailbox command.

Example:
    "partition_info":{
      "active_volatile_size":273535729664,
      "active_persistent_size":0,
      "next_volatile_size":0,
      "next_persistent_size":0,
      "total_size":273535729664,
      "volatile_only_size":0,
      "persistent_only_size":0,
      "partition_alignment_size":268435456
    }

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
---
 Documentation/cxl/cxl-list.txt |  23 +++++++
 cxl/filter.c                   |   2 +
 cxl/filter.h                   |   1 +
 cxl/json.c                     | 113 +++++++++++++++++++++++++++++++++
 cxl/list.c                     |   2 +
 util/json.h                    |   1 +
 6 files changed, 142 insertions(+)

diff --git a/Documentation/cxl/cxl-list.txt b/Documentation/cxl/cxl-list.txt
index 90e6d9f..86fc4e7 100644
--- a/Documentation/cxl/cxl-list.txt
+++ b/Documentation/cxl/cxl-list.txt
@@ -196,6 +196,29 @@ OPTIONS
   }
 ]
 ----
+-I::
+--partition::
+	Include partition information in the memdev listing. Example listing:
+----
+# cxl list -m mem0 -I
+[
+  {
+    "memdev":"mem0",
+    "pmem_size":0,
+    "ram_size":273535729664,
+    "partition_info":{
+      "active_volatile_size":273535729664,
+      "active_persistent_size":0,
+      "next_volatile_size":0,
+      "next_persistent_size":0,
+      "total_size":273535729664,
+      "volatile_only_size":0,
+      "persistent_only_size":0,
+      "partition_alignment_size":268435456
+    }
+  }
+]
+----
 
 -B::
 --buses::
diff --git a/cxl/filter.c b/cxl/filter.c
index 925bf3a..b339642 100644
--- a/cxl/filter.c
+++ b/cxl/filter.c
@@ -581,6 +581,8 @@ static unsigned long params_to_flags(struct cxl_filter_params *param)
 		flags |= UTIL_JSON_HEALTH;
 	if (param->targets)
 		flags |= UTIL_JSON_TARGETS;
+	if (param->partition)
+		flags |= UTIL_JSON_PARTITION;
 	return flags;
 }
 
diff --git a/cxl/filter.h b/cxl/filter.h
index 5deabb3..697b777 100644
--- a/cxl/filter.h
+++ b/cxl/filter.h
@@ -23,6 +23,7 @@ struct cxl_filter_params {
 	bool idle;
 	bool human;
 	bool health;
+	bool partition;
 	struct log_ctx ctx;
 };
 
diff --git a/cxl/json.c b/cxl/json.c
index f3b536e..69671b3 100644
--- a/cxl/json.c
+++ b/cxl/json.c
@@ -185,6 +185,114 @@ err_jobj:
 	return NULL;
 }
 
+/*
+ * Present complete view of memdev partition by presenting fields from
+ * both GET_PARTITION_INFO and IDENTIFY mailbox commands.
+ */
+static struct json_object *util_cxl_memdev_partition_to_json(struct cxl_memdev *memdev,
+		unsigned long flags)
+{
+	struct json_object *jobj = NULL;
+	struct json_object *jpart;
+	unsigned long long cap;
+	struct cxl_cmd *cmd;
+	int rc;
+
+	jpart = json_object_new_object();
+	if (!jpart)
+		return NULL;
+	if (!memdev)
+		goto err_jobj;
+
+	/* Retrieve partition info in GET_PARTITION_INFO mbox cmd */
+	cmd = cxl_cmd_new_get_partition(memdev);
+	if (!cmd)
+		goto err_jobj;
+
+	rc = cxl_cmd_submit(cmd);
+	if (rc < 0)
+		goto err_cmd;
+	rc = cxl_cmd_get_mbox_status(cmd);
+	if (rc != 0)
+		goto err_cmd;
+
+	cap = cxl_cmd_partition_get_active_volatile_size(cmd);
+	if (cap != ULLONG_MAX) {
+		jobj = util_json_object_size(cap, flags);
+		if (jobj)
+			json_object_object_add(jpart,
+					"active_volatile_size", jobj);
+	}
+	cap = cxl_cmd_partition_get_active_persistent_size(cmd);
+	if (cap != ULLONG_MAX) {
+		jobj = util_json_object_size(cap, flags);
+		if (jobj)
+			json_object_object_add(jpart,
+					"active_persistent_size", jobj);
+	}
+	cap = cxl_cmd_partition_get_next_volatile_size(cmd);
+	if (cap != ULLONG_MAX) {
+		jobj = util_json_object_size(cap, flags);
+		if (jobj)
+			json_object_object_add(jpart,
+					"next_volatile_size", jobj);
+	}
+	cap = cxl_cmd_partition_get_next_persistent_size(cmd);
+	if (cap != ULLONG_MAX) {
+		jobj = util_json_object_size(cap, flags);
+		if (jobj)
+			json_object_object_add(jpart,
+					"next_persistent_size", jobj);
+	}
+	cxl_cmd_unref(cmd);
+
+	/* Retrieve partition info in the IDENTIFY mbox cmd */
+	cmd = cxl_cmd_new_identify(memdev);
+	if (!cmd)
+		goto err_jobj;
+
+	rc = cxl_cmd_submit(cmd);
+	if (rc < 0)
+		goto err_cmd;
+	rc = cxl_cmd_get_mbox_status(cmd);
+	if (rc != 0)
+		goto err_cmd;
+
+	cap = cxl_cmd_identify_get_total_size(cmd);
+	if (cap != ULLONG_MAX) {
+		jobj = util_json_object_size(cap, flags);
+		if (jobj)
+			json_object_object_add(jpart, "total_size", jobj);
+	}
+	cap = cxl_cmd_identify_get_volatile_only_size(cmd);
+	if (cap != ULLONG_MAX) {
+		jobj = util_json_object_size(cap, flags);
+		if (jobj)
+			json_object_object_add(jpart,
+					"volatile_only_size", jobj);
+	}
+	cap = cxl_cmd_identify_get_persistent_only_size(cmd);
+	if (cap != ULLONG_MAX) {
+		jobj = util_json_object_size(cap, flags);
+		if (jobj)
+			json_object_object_add(jpart,
+					"persistent_only_size", jobj);
+	}
+	cap = cxl_cmd_identify_get_partition_align(cmd);
+	jobj = util_json_object_size(cap, flags);
+	if (jobj)
+		json_object_object_add(jpart, "partition_alignment_size", jobj);
+
+	cxl_cmd_unref(cmd);
+	return jpart;
+
+err_cmd:
+	cxl_cmd_unref(cmd);
+err_jobj:
+	json_object_put(jpart);
+	return NULL;
+}
+
 struct json_object *util_cxl_memdev_to_json(struct cxl_memdev *memdev,
 		unsigned long flags)
 {
@@ -239,6 +347,11 @@ struct json_object *util_cxl_memdev_to_json(struct cxl_memdev *memdev,
 			json_object_object_add(jdev, "state", jobj);
 	}
 
+	if (flags & UTIL_JSON_PARTITION) {
+		jobj = util_cxl_memdev_partition_to_json(memdev, flags);
+		if (jobj)
+			json_object_object_add(jdev, "partition_info", jobj);
+	}
 	return jdev;
 }
 
diff --git a/cxl/list.c b/cxl/list.c
index de96ff9..1e9d441 100644
--- a/cxl/list.c
+++ b/cxl/list.c
@@ -48,6 +48,8 @@ static const struct option options[] = {
 		    "use human friendly number formats "),
 	OPT_BOOLEAN('H', "health", &param.health,
 		    "include memory device health information "),
+	OPT_BOOLEAN('I', "partition", &param.partition,
+		    "include memory device partition information "),
 #ifdef ENABLE_DEBUG
 	OPT_BOOLEAN(0, "debug", &debug, "debug list walk"),
 #endif
diff --git a/util/json.h b/util/json.h
index e026df1..73bb9f0 100644
--- a/util/json.h
+++ b/util/json.h
@@ -19,6 +19,7 @@ enum util_json_flags {
 	UTIL_JSON_DAX_MAPPINGS	= (1 << 9),
 	UTIL_JSON_HEALTH	= (1 << 10),
 	UTIL_JSON_TARGETS	= (1 << 11),
+	UTIL_JSON_PARTITION	= (1 << 12),
 };
 
 void util_display_json_array(FILE *f_out, struct json_object *jarray,
-- 
2.31.1

[ndctl PATCH v5 5/6] libcxl: add interfaces for SET_PARTITION_INFO mailbox command

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

The CXL PMEM provisioning model depends upon the CXL mailbox command
SET_PARTITION_INFO to change a device's partitioning between volatile
and persistent capacity.

Add interfaces to libcxl to allocate and send a SET_PARTITION_INFO
mailbox command as defined in the CXL 2.0 specification.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
---
 Documentation/cxl/lib/libcxl.txt | 11 +++++++++++
 cxl/lib/libcxl.c                 | 28 ++++++++++++++++++++++++++++
 cxl/lib/libcxl.sym               |  2 ++
 cxl/lib/private.h                |  8 ++++++++
 cxl/libcxl.h                     | 10 ++++++++++
 5 files changed, 59 insertions(+)

diff --git a/Documentation/cxl/lib/libcxl.txt b/Documentation/cxl/lib/libcxl.txt
index a6986ab..7b223cb 100644
--- a/Documentation/cxl/lib/libcxl.txt
+++ b/Documentation/cxl/lib/libcxl.txt
@@ -132,6 +132,8 @@ int cxl_memdev_read_label(struct cxl_memdev *memdev, void *buf, size_t length,
 int cxl_memdev_write_label(struct cxl_memdev *memdev, void *buf, size_t length,
 			   size_t offset);
 struct cxl_cmd *cxl_cmd_new_get_partition(struct cxl_memdev *memdev);
+struct cxl_cmd *cxl_cmd_new_set_partition(struct cxl_memdev *memdev,
+					  unsigned long long volatile_size);
 
 ----
 
@@ -148,6 +150,8 @@ this sub-class of interfaces, there are:
    a CXL standard opcode. See the potential command ids in
    /usr/include/linux/cxl_mem.h.
 
+ * 'cxl_cmd_<name>_set_<field>' interfaces that set specific fields in a cxl_cmd
+
  * 'cxl_cmd_submit' which submits the command via ioctl()
 
  * 'cxl_cmd_<name>_get_<field>' interfaces that get specific fields out of the
@@ -167,6 +171,13 @@ cxl_memdev{read,write,zero}_label() are helpers for marshaling multiple
 label access commands over an arbitrary extent of the device's label
 area.
 
+cxl_cmd_partition_set_mode() supports selecting NEXTBOOT or IMMEDIATE
+mode. When CXL_SETPART_IMMEDIATE mode is set, it is the caller’s
+responsibility to avoid immediate changes to partitioning when the
+device is in use. When CXL_SETPART_NEXTBOOT mode is set, the change
+in partitioning shall become the “next” configuration, to become
+active on the next device reset.
+
 BUSES
 -----
 The CXL Memory space is CPU and Device coherent. The address ranges that
diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
index c05c13c..daa2bbc 100644
--- a/cxl/lib/libcxl.c
+++ b/cxl/lib/libcxl.c
@@ -2478,6 +2478,34 @@ cxl_cmd_partition_get_next_persistent_size(struct cxl_cmd *cmd)
 	return cxl_capacity_to_bytes(c->next_persistent);
 }
 
+CXL_EXPORT int cxl_cmd_partition_set_mode(struct cxl_cmd *cmd,
+		enum cxl_setpartition_mode mode)
+{
+	struct cxl_cmd_set_partition *setpart = cmd->input_payload;
+
+	if (mode == CXL_SETPART_IMMEDIATE)
+		setpart->flags = CXL_CMD_SET_PARTITION_FLAG_IMMEDIATE;
+	else
+		setpart->flags = !CXL_CMD_SET_PARTITION_FLAG_IMMEDIATE;
+
+	return 0;
+}
+
+CXL_EXPORT struct cxl_cmd *cxl_cmd_new_set_partition(struct cxl_memdev *memdev,
+		unsigned long long volatile_size)
+{
+	struct cxl_cmd_set_partition *setpart;
+	struct cxl_cmd *cmd;
+
+	cmd = cxl_cmd_new_generic(memdev,
+			CXL_MEM_COMMAND_ID_SET_PARTITION_INFO);
+
+	setpart = cmd->input_payload;
+	setpart->volatile_size = cpu_to_le64(volatile_size)
+					/ CXL_CAPACITY_MULTIPLIER;
+	return cmd;
+}
+
 CXL_EXPORT int cxl_cmd_submit(struct cxl_cmd *cmd)
 {
 	struct cxl_memdev *memdev = cmd->memdev;
diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym
index 5ac6e9b..aab1112 100644
--- a/cxl/lib/libcxl.sym
+++ b/cxl/lib/libcxl.sym
@@ -163,4 +163,6 @@ global:
 	cxl_cmd_identify_get_total_size;
 	cxl_cmd_identify_get_volatile_only_size;
 	cxl_cmd_identify_get_persistent_only_size;
+	cxl_cmd_new_set_partition;
+	cxl_cmd_partition_set_mode;
 } LIBCXL_1;
diff --git a/cxl/lib/private.h b/cxl/lib/private.h
index 7f3a562..c6d88f7 100644
--- a/cxl/lib/private.h
+++ b/cxl/lib/private.h
@@ -195,6 +195,14 @@ struct cxl_cmd_get_partition {
 
 #define CXL_CAPACITY_MULTIPLIER		SZ_256M
 
+struct cxl_cmd_set_partition {
+	le64 volatile_size;
+	u8 flags;
+} __attribute__((packed));
+
+/* CXL 2.0 8.2.9.5.2 Set Partition Info */
+#define CXL_CMD_SET_PARTITION_FLAG_IMMEDIATE				BIT(0)
+
 /* CXL 2.0 8.2.9.5.3 Byte 0 Health Status */
 #define CXL_CMD_HEALTH_INFO_STATUS_MAINTENANCE_NEEDED_MASK		BIT(0)
 #define CXL_CMD_HEALTH_INFO_STATUS_PERFORMANCE_DEGRADED_MASK		BIT(1)
diff --git a/cxl/libcxl.h b/cxl/libcxl.h
index 6e18e84..0063d31 100644
--- a/cxl/libcxl.h
+++ b/cxl/libcxl.h
@@ -250,6 +250,16 @@ unsigned long long cxl_cmd_partition_get_active_volatile_size(struct cxl_cmd *cm
 unsigned long long cxl_cmd_partition_get_active_persistent_size(struct cxl_cmd *cmd);
 unsigned long long cxl_cmd_partition_get_next_volatile_size(struct cxl_cmd *cmd);
 unsigned long long cxl_cmd_partition_get_next_persistent_size(struct cxl_cmd *cmd);
+struct cxl_cmd *cxl_cmd_new_set_partition(struct cxl_memdev *memdev,
+		unsigned long long volatile_size);
+
+enum cxl_setpartition_mode {
+	CXL_SETPART_NEXTBOOT,
+	CXL_SETPART_IMMEDIATE,
+};
+
+int cxl_cmd_partition_set_mode(struct cxl_cmd *cmd,
+		enum cxl_setpartition_mode mode);
 
 #ifdef __cplusplus
 } /* extern "C" */
-- 
2.31.1

[ndctl PATCH v5 6/6] cxl: add command 'cxl set-partition'

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

CXL devices may support both volatile and persistent memory capacity.
The amount of device capacity set aside for each type is typically
established at the factory, but some devices also allow for dynamic
re-partitioning. Add a command for this purpose.

 usage: cxl set-partition <mem0> [<mem1>..<memN>] [<options>]

    -v, --verbose         turn on debug
    -S, --serial          use serial numbers to id memdevs
    -t, --type <type>     'pmem' or 'volatile' (Default: 'pmem')
    -s, --size <size>     size in bytes (Default: all available capacity)
    -a, --align           auto-align --size per device's requirement

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
---
 Documentation/cxl/cxl-set-partition.txt |  68 ++++++++
 Documentation/cxl/meson.build           |   1 +
 cxl/builtin.h                           |   1 +
 cxl/cxl.c                               |   1 +
 cxl/memdev.c                            | 206 ++++++++++++++++++++++++
 5 files changed, 277 insertions(+)
 create mode 100644 Documentation/cxl/cxl-set-partition.txt

diff --git a/Documentation/cxl/cxl-set-partition.txt b/Documentation/cxl/cxl-set-partition.txt
new file mode 100644
index 0000000..1e548af
--- /dev/null
+++ b/Documentation/cxl/cxl-set-partition.txt
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+
+cxl-set-partition(1)
+====================
+
+NAME
+----
+cxl-set-partition - set the partitioning between volatile and persistent capacity on a CXL memdev
+
+SYNOPSIS
+--------
+[verse]
+'cxl set-partition <mem0> [ [<mem1>..<memN>] [<options>]'
+
+DESCRIPTION
+-----------
+CXL devices may support both volatile and persistent memory capacity.
+The amount of device capacity set aside for each type is typically
+established at the factory, but some devices also allow for dynamic
+re-partitioning.
+
+Use this command to partition a device into volatile and persistent
+capacity. The change in partitioning becomes the “next” configuration,
+to become active on the next device reset.
+
+Use "cxl list -m <memdev> -I" to examine the partitioning capabilities
+of a device. A partition_alignment_size value of zero means there is
+no available capacity and therefore the partitions cannot be changed.
+
+Using this command to change the size of the persistent capacity shall
+result in the loss of data stored.
+
+OPTIONS
+-------
+<memory device(s)>::
+include::memdev-option.txt[]
+
+-t::
+--type=::
+	Type of partition, 'pmem' or 'volatile', to modify.
+	Default: 'pmem'
+
+-s::
+--size=::
+	Size of the <type> partition in bytes. Size must align to the
+	devices alignment requirement. Use 'cxl list -m <memdev> -I'
+	to find 'partition_alignment_size', or, use the --align option.
+	Default: All available capacity is assigned to <type>.
+
+-a::
+--align::
+	Select this option to allow the automatic alignment of --size
+	to meet device alignment requirements. When using this option,
+	specify the minimum --size of the --type partition needed. When
+	this option is omitted, the command fails if --size is not
+	properly aligned. Use 'cxl list -m <memdev> -I' to examine the
+	partition_alignment_size.
+
+-v::
+        Turn on verbose debug messages in the library (if libcxl was built with
+        logging and debug enabled).
+
+include::../copyright.txt[]
+
+SEE ALSO
+--------
+linkcxl:cxl-list[1],
+CXL-2.0 8.2.9.5.2
diff --git a/Documentation/cxl/meson.build b/Documentation/cxl/meson.build
index 96f4666..e927644 100644
--- a/Documentation/cxl/meson.build
+++ b/Documentation/cxl/meson.build
@@ -34,6 +34,7 @@ cxl_manpages = [
   'cxl-disable-memdev.txt',
   'cxl-enable-port.txt',
   'cxl-disable-port.txt',
+  'cxl-set-partition.txt',
 ]
 
 foreach man : cxl_manpages
diff --git a/cxl/builtin.h b/cxl/builtin.h
index 3123d5e..7bbad98 100644
--- a/cxl/builtin.h
+++ b/cxl/builtin.h
@@ -14,4 +14,5 @@ int cmd_disable_memdev(int argc, const char **argv, struct cxl_ctx *ctx);
 int cmd_enable_memdev(int argc, const char **argv, struct cxl_ctx *ctx);
 int cmd_disable_port(int argc, const char **argv, struct cxl_ctx *ctx);
 int cmd_enable_port(int argc, const char **argv, struct cxl_ctx *ctx);
+int cmd_set_partition(int argc, const char **argv, struct cxl_ctx *ctx);
 #endif /* _CXL_BUILTIN_H_ */
diff --git a/cxl/cxl.c b/cxl/cxl.c
index c20c569..ab4bbec 100644
--- a/cxl/cxl.c
+++ b/cxl/cxl.c
@@ -68,6 +68,7 @@ static struct cmd_struct commands[] = {
 	{ "enable-memdev", .c_fn = cmd_enable_memdev },
 	{ "disable-port", .c_fn = cmd_disable_port },
 	{ "enable-port", .c_fn = cmd_enable_port },
+	{ "set-partition", .c_fn = cmd_set_partition },
 };
 
 int main(int argc, const char **argv)
diff --git a/cxl/memdev.c b/cxl/memdev.c
index 90b33e1..91d914d 100644
--- a/cxl/memdev.c
+++ b/cxl/memdev.c
@@ -6,11 +6,14 @@
 #include <unistd.h>
 #include <limits.h>
 #include <util/log.h>
+#include <util/json.h>
+#include <util/size.h>
 #include <cxl/libcxl.h>
 #include <util/parse-options.h>
 #include <ccan/minmax/minmax.h>
 #include <ccan/array_size/array_size.h>
 
+#include "json.h"
 #include "filter.h"
 
 struct action_context {
@@ -26,10 +29,18 @@ static struct parameters {
 	bool verbose;
 	bool serial;
 	bool force;
+	bool align;
+	const char *type;
+	const char *size;
 } param;
 
 static struct log_ctx ml;
 
+enum cxl_setpart_type {
+	CXL_SETPART_PMEM,
+	CXL_SETPART_VOLATILE,
+};
+
 #define BASE_OPTIONS() \
 OPT_BOOLEAN('v',"verbose", &param.verbose, "turn on debug"), \
 OPT_BOOLEAN('S', "serial", &param.serial, "use serial numbers to id memdevs")
@@ -51,6 +62,14 @@ OPT_UINTEGER('O', "offset", &param.offset, \
 OPT_BOOLEAN('f', "force", &param.force,                                \
 	    "DANGEROUS: override active memdev safety checks")
 
+#define SET_PARTITION_OPTIONS() \
+OPT_STRING('t', "type",  &param.type, "type",			\
+	"'pmem' or 'volatile' (Default: 'pmem')"),		\
+OPT_STRING('s', "size",  &param.size, "size",			\
+	"size in bytes (Default: all available capacity)"),	\
+OPT_BOOLEAN('a', "align",  &param.align,			\
+	"auto-align --size per device's requirement")
+
 static const struct option read_options[] = {
 	BASE_OPTIONS(),
 	LABEL_OPTIONS(),
@@ -82,6 +101,12 @@ static const struct option enable_options[] = {
 	OPT_END(),
 };
 
+static const struct option set_partition_options[] = {
+	BASE_OPTIONS(),
+	SET_PARTITION_OPTIONS(),
+	OPT_END(),
+};
+
 static int action_disable(struct cxl_memdev *memdev, struct action_context *actx)
 {
 	if (!cxl_memdev_is_enabled(memdev))
@@ -209,6 +234,176 @@ out:
 	return rc;
 }
 
+static unsigned long long
+partition_align(const char *devname, enum cxl_setpart_type type,
+		unsigned long long volatile_size, unsigned long long alignment,
+		unsigned long long available)
+{
+	if (IS_ALIGNED(volatile_size, alignment))
+		return volatile_size;
+
+	if (!param.align) {
+		log_err(&ml, "%s: size %lld is not partition aligned %lld\n",
+			devname, volatile_size, alignment);
+		return ULLONG_MAX;
+	}
+
+	/* Align based on partition type to fulfill users size request */
+	if (type == CXL_SETPART_PMEM)
+		volatile_size = ALIGN_DOWN(volatile_size, alignment);
+	else
+		volatile_size = ALIGN(volatile_size, alignment);
+
+	/* Fail if the align pushes size over the available limit. */
+	if (volatile_size > available) {
+		log_err(&ml, "%s: aligned partition size %lld exceeds available size %lld\n",
+			devname, volatile_size, available);
+		volatile_size = ULLONG_MAX;
+	}
+
+	return volatile_size;
+}
+
+static unsigned long long
+param_size_to_volatile_size(const char *devname, enum cxl_setpart_type type,
+		unsigned long long size, unsigned long long available)
+{
+	/* User omits size option. Apply all available capacity to type. */
+	if (size == ULLONG_MAX) {
+		if (type == CXL_SETPART_PMEM)
+			return 0;
+		return available;
+	}
+
+	/* User includes a size option. Apply it to type */
+	if (size > available) {
+		log_err(&ml, "%s: %lld exceeds available capacity %lld\n",
+			devname, size, available);
+			return ULLONG_MAX;
+	}
+	if (type == CXL_SETPART_PMEM)
+		return available - size;
+	return size;
+}
+
+/*
+ * Return the volatile_size to use in the CXL set paritition
+ * command, or ULLONG_MAX if unable to validate the partition
+ * request.
+ */
+static unsigned long long
+validate_partition(struct cxl_memdev *memdev, enum cxl_setpart_type type,
+		unsigned long long size)
+{
+	unsigned long long total_cap, volatile_only, persistent_only;
+	const char *devname = cxl_memdev_get_devname(memdev);
+	unsigned long long volatile_size = ULLONG_MAX;
+	unsigned long long available, alignment;
+	struct cxl_cmd *cmd;
+	int rc;
+
+	cmd = cxl_cmd_new_identify(memdev);
+	if (!cmd)
+		return ULLONG_MAX;
+	rc = cxl_cmd_submit(cmd);
+	if (rc < 0)
+		goto out;
+	rc = cxl_cmd_get_mbox_status(cmd);
+	if (rc != 0)
+		goto out;
+
+	alignment = cxl_cmd_identify_get_partition_align(cmd);
+	if (alignment == 0) {
+		log_err(&ml, "%s: no available capacity\n", devname);
+		goto out;
+	}
+
+	/* Calculate the actual available capacity */
+	total_cap = cxl_cmd_identify_get_total_size(cmd);
+	volatile_only = cxl_cmd_identify_get_volatile_only_size(cmd);
+	persistent_only = cxl_cmd_identify_get_persistent_only_size(cmd);
+	available = total_cap - volatile_only - persistent_only;
+
+	/* Translate the users size request into an aligned volatile_size */
+	volatile_size = param_size_to_volatile_size(devname, type, size,
+				available);
+	if (volatile_size == ULLONG_MAX)
+		goto out;
+
+	volatile_size = partition_align(devname, type, volatile_size, alignment,
+				available);
+
+out:
+	cxl_cmd_unref(cmd);
+	return volatile_size;
+}
+
+static int action_setpartition(struct cxl_memdev *memdev,
+		struct action_context *actx)
+{
+	const char *devname = cxl_memdev_get_devname(memdev);
+	enum cxl_setpart_type type = CXL_SETPART_PMEM;
+	unsigned long long size = ULLONG_MAX;
+	struct json_object *jmemdev;
+	struct cxl_cmd *cmd;
+	int rc;
+
+	if (param.type) {
+		if (strcmp(param.type, "pmem") == 0)
+			/* default */;
+		else if (strcmp(param.type, "volatile") == 0)
+			type = CXL_SETPART_VOLATILE;
+		else {
+			log_err(&ml, "invalid type '%s'\n", param.type);
+			return -EINVAL;
+		}
+	}
+
+	if (param.size) {
+		size = parse_size64(param.size);
+		if (size == ULLONG_MAX) {
+			log_err(&ml, "%s: failed to parse size option '%s'\n",
+			devname, param.size);
+			return -EINVAL;
+		}
+	}
+
+	size = validate_partition(memdev, type, size);
+	if (size == ULLONG_MAX)
+		return -EINVAL;
+
+	cmd = cxl_cmd_new_set_partition(memdev, size);
+	if (!cmd) {
+		rc = -ENXIO;
+		goto out_err;
+	}
+
+	rc = cxl_cmd_submit(cmd);
+	if (rc < 0) {
+		log_err(&ml, "cmd submission failed: %s\n", strerror(-rc));
+		goto out_cmd;
+	}
+
+	rc = cxl_cmd_get_mbox_status(cmd);
+	if (rc != 0) {
+		log_err(&ml, "%s: mbox status: %d\n", __func__, rc);
+		rc = -ENXIO;
+	}
+
+out_cmd:
+	cxl_cmd_unref(cmd);
+out_err:
+	if (rc)
+		log_err(&ml, "%s error: %s\n", devname, strerror(-rc));
+
+	jmemdev = util_cxl_memdev_to_json(memdev, UTIL_JSON_PARTITION);
+	if (jmemdev)
+		printf("%s\n", json_object_to_json_string_ext(jmemdev,
+		       JSON_C_TO_STRING_PRETTY));
+
+	return rc;
+}
+
 static int memdev_action(int argc, const char **argv, struct cxl_ctx *ctx,
 			 int (*action)(struct cxl_memdev *memdev,
 				       struct action_context *actx),
@@ -398,3 +593,14 @@ int cmd_enable_memdev(int argc, const char **argv, struct cxl_ctx *ctx)
 		 count > 1 ? "s" : "");
 	return count >= 0 ? 0 : EXIT_FAILURE;
 }
+
+int cmd_set_partition(int argc, const char **argv, struct cxl_ctx *ctx)
+{
+	int count = memdev_action(argc, argv, ctx, action_setpartition,
+			set_partition_options,
+			"cxl set-partition <mem0> [<mem1>..<memN>] [<options>]");
+	log_info(&ml, "set_partition %d mem%s\n", count >= 0 ? count : 0,
+		 count > 1 ? "s" : "");
+
+	return count >= 0 ? 0 : EXIT_FAILURE;
+}
-- 
2.31.1