Issues with CXL emulation invocation in QEMU 7.1.0

[Stephen Bates]

Hi All

I am trying to emulate CXL on my Macbook Pro using QEMU 7.1.0. The 
documentation example seems to throw an error for me in that the aarch64 virt 
machine does not seem to have a .cxl property. Am I doing something wrong here 
in my invocation? Any help would be appreciated.

batesste@armagh qemu % qemu-system-aarch64 --version    
QEMU emulator version 7.1.0
Copyright (c) 2003-2022 Fabrice Bellard and the QEMU Project developers

batesste@armagh qemu-minimal % ./run-cxl-aarch64
qemu-system-aarch64: Property 'virt-7.1-machine.cxl' not found

batesste@armagh qemu-minimal % cat run-cxl-aarch64
#!/bin/bash
# Copyright (c) Stephen Bates, 2022
#
# run-cxl-aarch64
# ---------------
#
# A shell script to boot up a VM that has CXL enabled end-points on my
# M1-based Macbook Pro. As of this point the versioning is:
#
# QEMU: 7.1.0.
# Kernel:
# Distro: Ubuntu 22.04
#
# Based on somewhat outdated instruction from [1].
#
# [1]: 
https://people.kernel.org/jic23/howto-test-cxl-enablement-on-arm64-using-qemu


qemu-system-aarch64 \
    -M virt,accel=hvf,cxl=on \
    -m 4g,maxmem=8G,slots=8 \
    -cpu max \
    -smp 4 \
    -nographic \
    -bios ./images/QEMU_EFI.fd \
    -drive file=./images/qemu-cxl.qcow2,format=qcow2 \
    -drive file=./images/qemu-cxl-seed.raw,format=raw,media=cdrom \
    -object 
memory-backend-file,id=cxl-mem1,share=on,mem-path=/tmp/cxltest.raw,size=256M \
    -object 
memory-backend-file,id=cxl-lsa1,share=on,mem-path=/tmp/lsa.raw,size=256M \
    -device pxb-cxl,bus_nr=12,bus=pcie.0,id=cxl.1 \
    -device cxl-rp,port=0,bus=cxl.1,id=root_port13,chassis=0,slot=2 \
    -device cxl-type3,bus=root_port13,memdev=cxl-mem1,lsa=cxl-lsa1,id=cxl-pmem0 
\
    -M cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=4G

-- 

Cheers

Stephen Bates, PhD.