v2: - Missing colon and tags (Fan) - Simpler handling block size parameters. The spec constrains these to be power of 2 so the v1 code of BITUL((int)log2(x) is equivalent of just using x directly. (Michael) - Check for power of 2 (Fan + Anisa)
Hi Michael, I consider these ready for upstream. They are only lightly tweaked from Anisa's last posting to drop some long lines and change a few patch titles + drag them to be directly based on upstream rather than on top of some stuff on my gitlab tree (trivial fuzz + context stuff only in the rebase). There is one long line checkpatch warns about but I couldn't come up with a remotely elegant alternative so it seemed resonable to ignore that. The fix from Fan has been on list for a while and is a necessary precursor of the FMAPI part. You may already have that queued. Anisa's cover letter for v4 follows which gives a lot more detail on what we have here. 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 USB. Test Configuration: - Kernel: To perform end-to-end tests, both MCTP and DCD support are needed for the kernel. The kernel version used is Ira's latest DCD branch which is based on 6.15-rc2, which includes the upstreamed support for MCTP over USB: https://github.com/weiny2/linux-kernel/tree/dcd-v6-2025-04-13 - QEMU: To enable MCTP over USB in QEMU, Jonathan's RFC patches are applied on ToT master branch (https://lore.kernel.org/linux-cxl/20250609163334.922346-1-jonathan.came...@huawei.com/T/#m21b9e0dfc689cb1890bb4d961710c23379e04902) 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: '-device usb-ehci,id=ehci \ -object memory-backend-file,id=cxl-mem1,mem-path=/tmp/t3_cxl1.raw,size=4G \ -object memory-backend-file,id=cxl-lsa1,mem-path=/tmp/t3_lsa1.raw,size=1M \ -device pxb-cxl,bus_nr=12,bus=pcie.0,id=cxl.1,hdm_for_passthrough=true \ -device cxl-rp,port=0,bus=cxl.1,id=cxl_rp_port0,chassis=0,slot=2 \ -device cxl-upstream,port=2,sn=1234,bus=cxl_rp_port0,id=us0,addr=0.0,multifunction=on, \ -device cxl-switch-mailbox-cci,bus=cxl_rp_port0,addr=0.1,target=us0 \ -device cxl-downstream,port=0,bus=us0,id=swport0,chassis=0,slot=4 \ -device cxl-type3,bus=swport0,volatile-dc-memdev=cxl-mem1,id=cxl-dcd0,lsa=cxl-lsa1,num-dc-regions=2,sn=99 \ -device usb-cxl-mctp,bus=ehci.0,id=usb0,target=us0 \ -device usb-cxl-mctp,bus=ehci.0,id=usb1,target=cxl-dcd0\ -machine cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=4G,cxl-fmw.0.interleave-granularity=1k' 2. Load the CXL related drivers in the VM & configure MCTP endpoints: 3. Create a DC region for the DCD device attached: cxl create-region -m mem0 -d decoder0.0 -s 1G -t dynamic_ram_a 4. Add/release DC extents by sending 0x5604 and 0x5605 respectively through the following libcxlmi test program: https://github.com/computexpresslink/libcxlmi/blob/main/examples/fmapi-mctp.c 5. Check and verify the extents by retrieving the extents list through command 0x5603 in the test program. 6. Create a DAX Device from the extents added: daxctl create-device -r region0 daxctl reconfigure-device dax0.1 -m system-ram The remaining 3 commands in this series (0x5606-0x5608) are related to tags and sharing, thus have not been implemented. Anisa Su (10): hw/cxl: mailbox-utils: 0x5600 - FMAPI Get DCD Info hw/mem: cxl_type3: Add dsmas_flags to CXLDCRegion struct hw/cxl: mailbox-utils: 0x5601 - FMAPI Get Host Region Config hw/cxl: Move definition for dynamic_capacity_uuid and enum for DC event types to header hw/mem: cxl_type3: Add DC Region bitmap lock hw/cxl: mailbox-utils: 0x5602 - FMAPI Set DC Region Config hw/cxl: mailbox-utils: 0x5603 - FMAPI Get DC Region Extent Lists hw/cxl: Create helper function to create DC Event Records from extents hw/cxl: mailbox-utils: 0x5604 - FMAPI Initiate DC Add hw/cxl: mailbox-utils: 0x5605 - FMAPI Initiate DC Release Fan Ni (1): hw/cxl: fix DC extent capacity tracking include/hw/cxl/cxl.h | 1 + include/hw/cxl/cxl_device.h | 31 +- include/hw/cxl/cxl_events.h | 15 + include/hw/cxl/cxl_mailbox.h | 6 + hw/cxl/cxl-events.c | 38 +++ hw/cxl/cxl-mailbox-utils.c | 552 ++++++++++++++++++++++++++++++++++- hw/mem/cxl_type3.c | 83 ++---- 7 files changed, 657 insertions(+), 69 deletions(-) -- 2.48.1
