Re: CXL volatile memory is not listed

[Fan Ni <fan.ni@gmx.us>]

On Wed, Aug 09, 2023 at 04:21:47AM +0530, Maverickk 78 wrote:
> Hello,
>
> I am running qemu-system-x86_64
>
> qemu-system-x86_64 --version
> QEMU emulator version 8.0.92 (v8.1.0-rc2-80-g0450cf0897)
>
> qemu-system-x86_64 \
> -m 2G,slots=4,maxmem=4G \
> -smp 4 \
> -machine type=q35,accel=kvm,cxl=on \
> -enable-kvm \
> -nographic \
> -device pxb-cxl,id=cxl.0,bus=pcie.0,bus_nr=52 \
> -device cxl-rp,id=rp0,bus=cxl.0,chassis=0,port=0,slot=0 \
> -object memory-backend-file,id=mem0,mem-path=/tmp/mem0,size=1G,share=true \
> -device cxl-type3,bus=rp0,volatile-memdev=mem0,id=cxl-mem0 \
> -M cxl-fmw.0.targets.0=cxl.0,cxl-fmw.0.size=1G
>
>
> I was expecting the CXL memory to be listed in "System Ram", the lsmem
> shows only 2G memory which is System RAM, it's not listing the CXL
> memory.
>
> Do I need to pass any particular parameter in the kernel command line?
>
> Is there any documentation available? I followed the inputs provided in
>
> https://lore.kernel.org/linux-mm/Y+CSOeHVLKudN0A6@kroah.com/T/
>
> Is there any documentation/blog listed?

If I remember it correctly, for volatile cxl memory, we need to create a
region and then it will be discovered as system memory and shows up.

Try to create a region with "cxl create-region".

Fan
>