From: Anisa Su <anisa...@samsung.com> This patchset adds support for 6 FM API DCD Management commands (0x5600-0x5605) according to the CXL r3.2 Spec.
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. v1: https://lore.kernel.org/linux-cxl/20250317164204.2299371-1-anisa.su...@gmail.com/ v2: https://lore.kernel.org/linux-cxl/ad3jkrbhmbdc9...@deb-101020-bm01.eng.stellus.in/T/#t Changes v2 --> v3 ================================================================================ 1. Rebased on ToT master branch + applied Fan's patch fixing DC extent tracking (https://lore.kernel.org/linux-cxl/20250529163925.2916725-1-nifan....@gmail.com/) 2. Picked up Fan's review tag on several patches. Still need review tag for the following: - cxl-mailbox-utils: 0x5602 - FMAPI Set DC Region Config - cxl-mailbox-utils: 0x5604 - FMAPI Initiate DC Add - cxl-mailbox-utils: 0x5605 - FMAPI Initiate DC Release 3. Changes: - 0x5602: Deleted redundant function cxl_mbox_dc_event_create_record_hdr() and replaced calls to it with existing function cxl_assign_event_header(). This is done in the below patches as well, which also add records to the event log. - 0x5604: Deleted redundant function cxl_mbox_dc_prescriptive_sanity_check() and replaced calls to it with existing function cxl_detect_malformed_extent_list(), which was originally added by Fan for the DCD Add/Release Response commands (0x4802 and 0x4803), which needs to check for similar errors. Deleted helper functions to count # of pending/accepted extents because Fan's fix for dc.total_extent_count to correctly track pending and accepted extents means we don't need to add them up separately. - 0x5605: Similar to above, uses cxl_detect_malformed_extent_list() and additionally, reuses existing function cxl_dc_extent_release_dry_run() to detect additional errors that can occur in the case of releasing extents, which are: - extent to release is not actually block backed - releasing extents would cause the device to exceed max. extents supported Because these patches have been rebased on upstream QEMU which is missing I2C MCTP support, I have retested them in a manner similar to what is described above but hacked to add the FM commands to the general T3 mailbox (initialized by the cxl_initialize_mailbox_t3() function). Then libcxlmi is used to send the FMAPI commands via ioctl instead of MCTP and the output is verified. Anisa Su (9): 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 hw/cxl_type3: Add DC Region bitmap lock 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 | 538 +++++++++++++++++++++++++++++++++++ hw/mem/cxl_type3.c | 45 ++- include/hw/cxl/cxl_device.h | 24 ++ include/hw/cxl/cxl_events.h | 15 + include/hw/cxl/cxl_mailbox.h | 6 + 5 files changed, 605 insertions(+), 23 deletions(-) -- 2.47.2
