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* [PATCH v3 00/25] DCD: Add support for Dynamic Capacity Devices (DCD)
@ 2024-08-16 14:44 Ira Weiny
  2024-08-16 14:44 ` [PATCH v3 01/25] range: Add range_overlaps() Ira Weiny
                   ` (24 more replies)
  0 siblings, 25 replies; 120+ messages in thread
From: Ira Weiny @ 2024-08-16 14:44 UTC (permalink / raw)
  To: Dave Jiang, Fan Ni, Jonathan Cameron, Navneet Singh, Chris Mason,
	Josef Bacik, David Sterba, Petr Mladek, Steven Rostedt,
	Andy Shevchenko, Rasmus Villemoes, Sergey Senozhatsky,
	Jonathan Corbet, Andrew Morton
  Cc: Dan Williams, Davidlohr Bueso, Alison Schofield, Vishal Verma,
	Ira Weiny, linux-btrfs, linux-cxl, linux-kernel, linux-doc,
	nvdimm, Johannes Thumshirn, Li, Ming, Jonathan Cameron

A git tree of this series can be found here:

	https://github.com/weiny2/linux-kernel/tree/dcd-v4-2024-08-16

This series requires the CXL memory notifier lock change:

	https://lore.kernel.org/all/20240814-fix-notifiers-v2-1-6bab38192c7c@intel.com/

Background
==========

A Dynamic Capacity Device (DCD) (CXL 3.1 sec 9.13.3) is a CXL memory
device that allows memory capacity within a region to change
dynamically without the need for resetting the device, reconfiguring
HDM decoders, or reconfiguring software DAX regions.

One of the biggest use cases for Dynamic Capacity is to allow hosts to
share memory dynamically within a data center without increasing the
per-host attached memory.

The general flow for the addition or removal of memory is to have an
orchestrator coordinate the use of the memory.  Generally there are 5
actors in such a system, the Orchestrator, Fabric Manager, the Logical
device, the Host Kernel, and a Host User.

Typical work flows are shown below.

Orchestrator      FM         Device       Host Kernel    Host User

    |             |           |            |              |
    |-------------- Create region ----------------------->|
    |             |           |            |              |
    |             |           |            |<-- Create ---|
    |             |           |            |    Region    |
    |<------------- Signal done --------------------------|
    |             |           |            |              |
    |-- Add ----->|-- Add --->|--- Add --->|              |
    |  Capacity   |  Extent   |   Extent   |              |
    |             |           |            |              |
    |             |<- Accept -|<- Accept  -|              |
    |             |   Extent  |   Extent   |              |
    |             |           |            |<- Create --->|
    |             |           |            |   DAX dev    |-- Use memory
    |             |           |            |              |   |
    |             |           |            |              |   |
    |             |           |            |<- Release ---| <-+
    |             |           |            |   DAX dev    |
    |             |           |            |              |
    |<------------- Signal done --------------------------|
    |             |           |            |              |
    |-- Remove -->|- Release->|- Release ->|              |
    |  Capacity   |  Extent   |   Extent   |              |
    |             |           |            |              |
    |             |<- Release-|<- Release -|              |
    |             |   Extent  |   Extent   |              |
    |             |           |            |              |
    |-- Add ----->|-- Add --->|--- Add --->|              |
    |  Capacity   |  Extent   |   Extent   |              |
    |             |           |            |              |
    |             |<- Accept -|<- Accept  -|              |
    |             |   Extent  |   Extent   |              |
    |             |           |            |<- Create ----|
    |             |           |            |   DAX dev    |-- Use memory
    |             |           |            |              |   |
    |             |           |            |<- Release ---| <-+
    |             |           |            |   DAX dev    |
    |<------------- Signal done --------------------------|
    |             |           |            |              |
    |-- Remove -->|- Release->|- Release ->|              |
    |  Capacity   |  Extent   |   Extent   |              |
    |             |           |            |              |
    |             |<- Release-|<- Release -|              |
    |             |   Extent  |   Extent   |              |
    |             |           |            |              |
    |-- Add ----->|-- Add --->|--- Add --->|              |
    |  Capacity   |  Extent   |   Extent   |              |
    |             |           |            |<- Create ----|
    |             |           |            |   DAX dev    |-- Use memory
    |             |           |            |              |   |
    |-- Remove -->|- Release->|- Release ->|              |   |
    |  Capacity   |  Extent   |   Extent   |              |   |
    |             |           |            |              |   |
    |             |           |     (Release Ignored)     |   |
    |             |           |            |              |   |
    |             |           |            |<- Release ---| <-+
    |             |           |            |   DAX dev    |
    |<------------- Signal done --------------------------|
    |             |           |            |              |
    |             |- Release->|- Release ->|              |
    |             |  Extent   |   Extent   |              |
    |             |           |            |              |
    |             |<- Release-|<- Release -|              |
    |             |   Extent  |   Extent   |              |
    |             |           |            |<- Destroy ---|
    |             |           |            |   Region     |
    |             |           |            |              |

Previous versions of this series[0] resulted in architectural comments
as well as confusion on the architecture based on the organization of
patch series itself.

This version has reordered the patches to clarify the architecture.
It also streamlines extent handling more.

The series still requires the creation of regions and DAX devices to be
synchronized with the Orchestrator and Fabric Manager.  The host kernel
will reject an add extent event if the region is not created yet.  It
will also ignore a release if the DAX device is created and referencing
an extent.

These synchronizations are not anticipated to be an issue with real
applications.

In order to allow for capacity to be added and removed a new concept of
a sparse DAX region is introduced.  A sparse DAX region may have 0 or
more bytes of available space.  The total space depends on the number
and size of the extents which have been added.

Initially it is anticipated that users of the memory will carefully
coordinate the surfacing of additional capacity with the creation of DAX
devices which use that capacity.  Therefore, the allocation of the
memory to DAX devices does not allow for specific associations between
DAX device and extent.  This keeps allocations very similar to existing
DAX region behavior.

Great care was taken to keep the extent tracking simple.  Some xarray's
needed to be added but extra software objects were kept to a minimum.

Region extents continue to be tracked as sub-devices of the DAX region.
This ensures that region destruction cleans up all extent allocations
properly.

Due to these major changes all reviews were removed from the larger
patches.  A few of the straight forward patches have kept the tags.

In summary the major functionality of this series includes:

- Getting the dynamic capacity (DC) configuration information from cxl
  devices

- Configuring the DC partitions reported by hardware

- Enhancing the CXL and DAX regions for dynamic capacity support
	a. Maintain a logical separation between hardware extents and
	   software managed region extents.  This provides an
	   abstraction between the layers and should allow for
	   interleaving in the future

- Get hardware extent lists for endpoint decoders upon
  region creation.

- Adjust extent/region memory available on the following events.
        a. Add capacity Events
	b. Release capacity events

- Host response for add capacity
	a. do not accept the extent if:
		If the region does not exist
		or an error occurs realizing the extent
	b. If the region does exist
		realize a DAX region extent with 1:1 mapping (no
		interleave yet)
	c. Support the more bit by processing a list of extents marked
	   with the more bit together before setting up a response.

- Host response for remove capacity
	a. If no DAX device references the extent; release the extent
	b. If a reference does exist, ignore the request.
	   (Require FM to issue release again.)

- Modify DAX device creation/resize to account for extents within a
  sparse DAX region

- Trace Dynamic Capacity events for debugging

- Add cxl-test infrastructure to allow for faster unit testing
  (See new ndctl branch for cxl-dcd.sh test[1])

Fan Ni's upstream of Qemu DCD was used for testing.

Remaining work:

	1) Integrate the QoS work from Dave Jiang
	2) Interleave support

Possible additional work depending on requirements:

	1) Allow mapping to specific extents (perhaps based on
	   label/tag)
	2) Release extents when DAX devices are released if a release
	   was previously seen from the device
	3) Accept a new extent which extends (but overlaps) an existing
	   extent(s)
	4) Rework DAX device interfaces, memfd has been explored a bit

[0] v1: https://lore.kernel.org/all/20240324-dcd-type2-upstream-v1-0-b7b00d623625@intel.com/
[1] https://github.com/weiny2/ndctl/tree/dcd-region2-2024-08-15

---
Major changes:
- Jonathan: support the more bit
- djbw: Allow more than 1 region per DC partition
- All: Address the many comments on the series.
- iweiny: rebase
- iweiny: Rework the series to make it easier to review and understand
          the flow
- Link to v1: https://lore.kernel.org/r/20240324-dcd-type2-upstream-v1-0-b7b00d623625@intel.com
- Link to v2: https://lore.kernel.org/all/20240816-dcd-type2-upstream-v2-0-20189a10ad7d@intel.com/

---
Ira Weiny (11):
      range: Add range_overlaps()
      printk: Add print format (%par) for struct range
      dax: Document dax dev range tuple
      cxl/pci: Delay event buffer allocation
      cxl/region: Refactor common create region code
      cxl/events: Split event msgnum configuration from irq setup
      cxl/pci: Factor out interrupt policy check
      cxl/core: Return endpoint decoder information from region search
      dax/bus: Factor out dev dax resize logic
      tools/testing/cxl: Make event logs dynamic
      tools/testing/cxl: Add DC Regions to mock mem data

Navneet Singh (14):
      cxl/mbox: Flag support for Dynamic Capacity Devices (DCD)
      cxl/mem: Read dynamic capacity configuration from the device
      cxl/core: Separate region mode from decoder mode
      cxl/region: Add dynamic capacity decoder and region modes
      cxl/hdm: Add dynamic capacity size support to endpoint decoders
      cxl/port: Add endpoint decoder DC mode support to sysfs
      cxl/mem: Expose DCD partition capabilities in sysfs
      cxl/region: Add sparse DAX region support
      cxl/mem: Configure dynamic capacity interrupts
      cxl/extent: Process DCD events and realize region extents
      cxl/region/extent: Expose region extent information in sysfs
      dax/region: Create resources on sparse DAX regions
      cxl/region: Read existing extents on region creation
      cxl/mem: Trace Dynamic capacity Event Record

 Documentation/ABI/testing/sysfs-bus-cxl   |  68 ++-
 Documentation/core-api/printk-formats.rst |  14 +
 drivers/cxl/core/Makefile                 |   2 +-
 drivers/cxl/core/core.h                   |  33 +-
 drivers/cxl/core/extent.c                 | 467 ++++++++++++++
 drivers/cxl/core/hdm.c                    | 206 ++++++-
 drivers/cxl/core/mbox.c                   | 578 +++++++++++++++++-
 drivers/cxl/core/memdev.c                 | 101 ++-
 drivers/cxl/core/port.c                   |  13 +-
 drivers/cxl/core/region.c                 | 173 ++++--
 drivers/cxl/core/trace.h                  |  65 ++
 drivers/cxl/cxl.h                         | 122 +++-
 drivers/cxl/cxlmem.h                      | 128 +++-
 drivers/cxl/pci.c                         | 123 +++-
 drivers/dax/bus.c                         | 352 +++++++++--
 drivers/dax/bus.h                         |   4 +-
 drivers/dax/cxl.c                         |  73 ++-
 drivers/dax/dax-private.h                 |  39 +-
 drivers/dax/hmem/hmem.c                   |   2 +-
 drivers/dax/pmem.c                        |   2 +-
 fs/btrfs/ordered-data.c                   |  10 +-
 include/linux/cxl-event.h                 |  32 +
 include/linux/range.h                     |   7 +
 lib/vsprintf.c                            |  37 ++
 tools/testing/cxl/Kbuild                  |   3 +-
 tools/testing/cxl/test/mem.c              | 981 ++++++++++++++++++++++++++----
 26 files changed, 3327 insertions(+), 308 deletions(-)
---
base-commit: 3cef9316df4cda21b5bf25e4230221b02050dfa1
change-id: 20230604-dcd-type2-upstream-0cd15f6216fd

Best regards,
-- 
Ira Weiny <ira.weiny@intel.com>


^ permalink raw reply	[flat|nested] 120+ messages in thread

end of thread, other threads:[~2024-09-09 14:08 UTC | newest]

Thread overview: 120+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-08-16 14:44 [PATCH v3 00/25] DCD: Add support for Dynamic Capacity Devices (DCD) Ira Weiny
2024-08-16 14:44 ` [PATCH v3 01/25] range: Add range_overlaps() Ira Weiny
2024-08-16 14:44 ` [PATCH v3 02/25] printk: Add print format (%par) for struct range Ira Weiny
2024-08-20 14:08   ` Petr Mladek
2024-08-22 17:53     ` Ira Weiny
2024-08-22 18:10       ` Andy Shevchenko
2024-08-26 13:23         ` Petr Mladek
2024-08-26 17:23           ` Andy Shevchenko
2024-08-26 21:17             ` Ira Weiny
2024-08-27  7:43               ` Petr Mladek
2024-08-27 13:21                 ` Andy Shevchenko
2024-08-27 21:44                 ` Ira Weiny
2024-08-27 13:17               ` Andy Shevchenko
2024-08-28  4:12                 ` Ira Weiny
2024-08-28 13:50                   ` Andy Shevchenko
2024-08-26 13:17       ` Petr Mladek
2024-08-26 13:24         ` Andy Shevchenko
2024-08-16 14:44 ` [PATCH v3 03/25] dax: Document dax dev range tuple Ira Weiny
2024-08-16 20:58   ` Dave Jiang
2024-08-23 15:29   ` Jonathan Cameron
2024-08-16 14:44 ` [PATCH v3 04/25] cxl/pci: Delay event buffer allocation Ira Weiny
2024-09-03  6:49   ` Li, Ming4
2024-09-05 19:44   ` Fan Ni
2024-08-16 14:44 ` [PATCH v3 05/25] cxl/mbox: Flag support for Dynamic Capacity Devices (DCD) ira.weiny
2024-09-03  6:50   ` Li, Ming4
2024-08-16 14:44 ` [PATCH v3 06/25] cxl/mem: Read dynamic capacity configuration from the device ira.weiny
2024-08-16 21:45   ` Dave Jiang
2024-08-20 17:01     ` Fan Ni
2024-08-23  2:01       ` Ira Weiny
2024-08-23  2:02       ` Ira Weiny
2024-08-23 15:45   ` Jonathan Cameron
2024-08-16 14:44 ` [PATCH v3 07/25] cxl/core: Separate region mode from decoder mode ira.weiny
2024-08-16 22:11   ` Dave Jiang
2024-08-23 15:47   ` Jonathan Cameron
2024-09-03  6:56   ` Li, Ming4
2024-08-16 14:44 ` [PATCH v3 08/25] cxl/region: Add dynamic capacity decoder and region modes ira.weiny
2024-08-16 22:14   ` Dave Jiang
2024-09-03  6:57   ` Li, Ming4
2024-08-16 14:44 ` [PATCH v3 09/25] cxl/hdm: Add dynamic capacity size support to endpoint decoders ira.weiny
2024-08-16 23:08   ` Dave Jiang
2024-08-23  2:26     ` Ira Weiny
2024-08-23 16:09   ` Jonathan Cameron
2024-08-16 14:44 ` [PATCH v3 10/25] cxl/port: Add endpoint decoder DC mode support to sysfs ira.weiny
2024-08-16 23:17   ` Dave Jiang
2024-08-23 16:12   ` Jonathan Cameron
2024-08-16 14:44 ` [PATCH v3 11/25] cxl/mem: Expose DCD partition capabilities in sysfs ira.weiny
2024-08-16 23:42   ` Dave Jiang
2024-08-23  2:28     ` Ira Weiny
2024-08-23 14:58       ` Dave Jiang
2024-08-23 16:14       ` Jonathan Cameron
2024-08-16 14:44 ` [PATCH v3 12/25] cxl/region: Refactor common create region code Ira Weiny
2024-08-16 23:43   ` Dave Jiang
2024-08-22 18:51   ` Fan Ni
2024-08-23 16:17   ` Jonathan Cameron
2024-09-03  7:04   ` Li, Ming4
2024-08-16 14:44 ` [PATCH v3 13/25] cxl/region: Add sparse DAX region support ira.weiny
2024-08-16 23:51   ` Dave Jiang
2024-08-22 18:50   ` Fan Ni
2024-08-23 16:59   ` Jonathan Cameron
2024-09-03  2:15   ` Li, Ming4
2024-08-16 14:44 ` [PATCH v3 14/25] cxl/events: Split event msgnum configuration from irq setup Ira Weiny
2024-08-16 23:57   ` Dave Jiang
2024-08-22 21:39   ` Fan Ni
2024-08-23 17:01   ` Jonathan Cameron
2024-09-03  7:06   ` Li, Ming4
2024-08-16 14:44 ` [PATCH v3 15/25] cxl/pci: Factor out interrupt policy check Ira Weiny
2024-08-22 21:41   ` Fan Ni
2024-09-03  7:07   ` Li, Ming4
2024-08-16 14:44 ` [PATCH v3 16/25] cxl/mem: Configure dynamic capacity interrupts ira.weiny
2024-08-17  0:02   ` Dave Jiang
2024-08-23 17:08   ` Jonathan Cameron
2024-09-03  7:09   ` Li, Ming4
2024-08-16 14:44 ` [PATCH v3 17/25] cxl/core: Return endpoint decoder information from region search Ira Weiny
2024-08-19 16:35   ` Dave Jiang
2024-08-23 17:12   ` Jonathan Cameron
2024-09-03  7:10   ` Li, Ming4
2024-08-16 14:44 ` [PATCH v3 18/25] cxl/extent: Process DCD events and realize region extents ira.weiny
2024-08-19 18:51   ` Dave Jiang
2024-08-23  2:53     ` Ira Weiny
2024-08-23 21:32   ` Fan Ni
2024-08-27 12:08     ` Jonathan Cameron
2024-08-27 16:02       ` Fan Ni
2024-08-27 13:18   ` Jonathan Cameron
2024-08-29 21:16     ` Ira Weiny
2024-08-30  9:21       ` Jonathan Cameron
2024-09-03  6:37   ` Li, Ming4
2024-09-05 19:30   ` Fan Ni
2024-08-16 14:44 ` [PATCH v3 19/25] cxl/region/extent: Expose region extent information in sysfs ira.weiny
2024-08-19 19:05   ` Dave Jiang
2024-08-23  2:58     ` Ira Weiny
2024-08-23 17:17       ` Jonathan Cameron
2024-08-23 17:19   ` Jonathan Cameron
2024-08-28 17:44   ` Fan Ni
2024-08-16 14:44 ` [PATCH v3 20/25] dax/bus: Factor out dev dax resize logic Ira Weiny
2024-08-19 22:35   ` Dave Jiang
2024-08-27 13:26   ` Jonathan Cameron
2024-08-29 21:36     ` Ira Weiny
2024-08-16 14:44 ` [PATCH v3 21/25] dax/region: Create resources on sparse DAX regions ira.weiny
2024-08-18 11:38   ` Markus Elfring
2024-08-19 23:30   ` Dave Jiang
2024-08-23 14:28     ` Ira Weiny
2024-08-27 14:12   ` Jonathan Cameron
2024-08-29 21:54     ` Ira Weiny
2024-08-16 14:44 ` [PATCH v3 22/25] cxl/region: Read existing extents on region creation ira.weiny
2024-08-20  0:06   ` Dave Jiang
2024-08-23 21:31     ` Ira Weiny
2024-08-27 14:19   ` Jonathan Cameron
2024-09-05 19:35   ` Fan Ni
2024-08-16 14:44 ` [PATCH v3 23/25] cxl/mem: Trace Dynamic capacity Event Record ira.weiny
2024-08-20 22:54   ` Dave Jiang
2024-08-26 18:02     ` Ira Weiny
2024-08-27 14:20   ` Jonathan Cameron
2024-09-05 19:38   ` Fan Ni
2024-08-16 14:44 ` [PATCH v3 24/25] tools/testing/cxl: Make event logs dynamic Ira Weiny
2024-08-20 23:30   ` Dave Jiang
2024-08-27 14:32   ` Jonathan Cameron
2024-09-09 13:57     ` Ira Weiny
2024-08-16 14:44 ` [PATCH v3 25/25] tools/testing/cxl: Add DC Regions to mock mem data Ira Weiny
2024-08-27 14:39   ` Jonathan Cameron
2024-09-09 14:08     ` Ira Weiny

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