[0/9] CXL: FMAPI DCD Management Commands 0x5600-0x5605

Message

[e-mail] March 17, 2025, 4:31 p.m. UTC

From: Anisa Su <[e-mail]>

This patchset adds support for 6 FM API DCD Management commands (0x5600-0x5605)
according to the CXL r3.2 Spec. It is based on the following branch:
https://gitlab.com/jic23/qemu/-/tree/cxl-2025-02-20.

The code was tested with libcxlmi, which runs in the QEMU VM and sends 56xxh
commands to the device (QEMU emulated) through MCTP messages over I2C
bus. To perform end-to-end tests, both MCTP and DCD support are needed
for the kernel, so the needed MCTP patches are applied on top of Ira's DCD
branch https://github.com/weiny2/linux-kernel/tree/dcd-v4-2024-12-11.

For the tests of commands 0x5600 (Get DCD Info), 0x5601 (Get Host DC Region
Config), and 0x5603 (Get DC Region Extent Lists), DCD kernel code is not involved.
The libcxlmi test program is used to send the command to the device and results
are collected and verified.

For command 0x5602 (Set DC Region Config): device creates an event record with type
DC_EVENT_REGION_CONFIG_UPDATED and triggers an interrupt to the host
if the configuration changes as a result of the command. Currently, the kernel
version used to test this only supports Add/Release type events. Thus, this
request essentially gets ignored but did not cause problems besides the host
not knowing about the configuration change when tested.

For the command 0x5604 (Initiate DC Add) and 0x5605 (Initiate DC Release), the
tests involve libcxlmi test program (acting as the FM), kernel DCD
code (host) and QEMU device. The test workflow follows that in cxl r3.2 section
7.6.7.6.5 and 7.6.7.6.6. More specifically, the tests involve following
steps,
1. Start a VM with CXL topology: https://github.com/moking/cxl-test-tool/blob/main/utils/cxl.py#L54.
2. Load the CXL related drivers in the VM;
3. Create a DC region for the DCD device attached.
4. add/release DC extents by sending 0x5604 and 0x5605 respectively through
the out-of-tree libcxlmi test program
(https://github.com/anisa-su993/libcxlmi/blob/dcd_management_cmds/tests/test-fmapi.c).
5. Check and verify the extents by retrieving the extents list through
command 0x5603 in the test program.

The remaining 3 commands in this series (0x5606-0x5608) are related to tags
and sharing, thus have not been implemented.

Anisa Su (9):
  cxl/type3: Add supported block sizes bitmask to CXLDCRegion struct
  cxl-mailbox-utils: 0x5600 - FMAPI Get DCD Info
  cxl/type3: Add dsmas_flags to CXLDCRegion struct
  cxl-mailbox-utils: 0x5601 - FMAPI Get Host Region Config
  cxl_events.h: move definition for dynamic_capacity_uuid and enum for
    DC event types
  cxl-mailbox-utils: 0x5602 - FMAPI Set DC Region Config
  cxl-mailbox-utils: 0x5603 - FMAPI Get DC Region Extent Lists
  cxl-mailbox-utils: 0x5604 -  FMAPI Initiate DC Add
  cxl-mailbox-utils: 0x5605 - FMAPI Initiate DC Release

 hw/cxl/cxl-mailbox-utils.c   | 615 +++++++++++++++++++++++++++++++++++
 hw/cxl/i2c_mctp_cxl.c        |   6 +-
 hw/mem/cxl_type3.c           |  30 +-
 include/hw/cxl/cxl_device.h  |   9 +
 include/hw/cxl/cxl_events.h  |  15 +
 include/hw/cxl/cxl_mailbox.h |   6 +
 6 files changed, 660 insertions(+), 21 deletions(-)