Qemu CXL

Must enable linux CONFIG_CXL_REGION_INVALIDATION_TEST if Qemu, see https://lore.kernel.org/all/CAGEDW0dVEk-QXuL=DPVvSP4t5cafz6N-r_SrCxgFnBfFOsixSA@mail.gmail.com/.

• QEMU CCIX patches

• Q35

┌─────────────────────────────────────────┐
│             Q35 Host bridge             │
│                 (0:0.0)                 │
│                                         │
│     ┌───────────┐     ┌───────────┐     │
│     │ Root Port │     │ Root Port │     │
│     │  (0:7.0)  │     │ (0:1c.0)  │     │
└─────┴──────┬────┴─────┴─────┬─────┴─────┘
     ┌───────┘                │
     ▼                        ▼
┌────────┐          ┌─────┬────────┬────┐
│Endpoint│          │     │upstream│    │
│(10:0.0)│          │     └────────┘    │
└────────┘          │┌────┐      ┌────┐ │
                    ││down│      │down│ │
                    └┴──┬─┴──────┴──┬─┴─┘
                     ┌──┘           └─┐
                     ▼                ▼
                 ┌────────┐       ┌────────┐
                 │Endpoint│       │Endpoint│
                 │(20:0.0)│       │(30:0.0)│
                 └────────┘       └────────┘

Links

• https://www.qemu.org/docs/master/system/devices/cxl.html

• https://github.com/pmem/run_qemu