cxl create-region not working for --type=ram

[hextag]

The following 4 devices are shown in QEMU VM when I do 'cxl list'.

[root@fedora dev]# cxl list
[
  {
    "memdevs":[
      {
        "memdev":"mem3",
        "ram_size":268435456,
        "serial":0,
        "host":"0000:c2:00.0"
      },
      {
        "memdev":"mem2",
        "ram_size":268435456,
        "serial":0,
        "host":"0000:c3:00.0"
      },
      {
        "memdev":"mem1",
        "pmem_size":268435456,
        "serial":0,
        "host":"0000:36:00.0"
      },
      {
        "memdev":"mem0",
        "pmem_size":268435456,
        "serial":0,
        "host":"0000:37:00.0"
      }
    ]
  },
  {
    "regions":[
      {
        "region":"region0",
        "resource":328833433600,
        "size":536870912,
        "type":"pmem",
        "interleave_ways":2,
        "interleave_granularity":8192,
        "decode_state":"commit"
      }
    ]
  }
]

I want to create a region from devices mem2 and mem3( which are listed as ram in cxl list) and create a device node from this region to access in SysRAM mode. However, I get failure when I use create region command

cxl create-region -m -d decoder0.0 -w 2 -g 8192 mem2 mem3 --type=ram

cxl region: collect_memdevs: no active memdevs found: decoder: decoder0.0 filter: mem2,mem3
cxl region: cmd_create_region: created 0 regions

I tried to enable these devices using cxl enable-memdev but it doesn't help to resolve the above error,

cxl enable-memdev mem2
cxl enable-memdev mem3

Earlier I created a region (region0) as you can see in cxl list output from memory devices mem0 and mem1 both listed as pmem.

I created a namespace for this region0 using 'sudo ndctl create-namespace --mode=devdax --force --region=region0'

daxctl list shows this device node which is devdax.

[root@fedora dev]# daxctl list
[                                                                                                                                                                                             {
    "chardev":"dax0.0",
    "size":526385152,
    "target_node":32,
    "align":2097152,
    "mode":"devdax"
  }
]

The above dax0.0 node is created from mem0 and mem1 both for which are listed as pmem in cxl list. I'm able to read and write to this node.

When I try to re-configure the above dax0.0 to system-ram mode, I get the following error and hence I want to create a new region and a new device node in SysRAM from the other two devices (mem2 and mem3) which are listed as ram in cxl list output.

[root@fedora dev]# daxctl reconfigure-device -m system-ram dax0.0
dax0.0: error: kernel policy will auto-online memory, aborting
error reconfiguring devices: Device or resource busy

How do I go about SysRAM emulation ? Can anyone please help me here.