Re: [CXL volatile MEM] - Qemu command to turn on HMAT and NUMA fails with assertion

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Samarth Saxena (samarths@cadence.com) wrote:
> Hi All,
> 
> I am trying the following command to run Qemu with Kernel 5.14.

cc'ing in Ben who I think owns the CXL stuff.

> qemu-system-x86_64 -M q35,accel=kvm,nvdimm=on,cxl=on,hmat=on -m 8448M,slots=2,maxmem=16G -smp 8,sockets=2,cores=2,threads=2 -hda /lan/dscratch/singhabh/shradha/ubuntu-20.10-64_with_orig_driver_backup.qcow2 -enable-kvm -usbdevice tablet -L $VB_ROOT/etc/vm/common/ -object memory-backend-ram,id=cxl-ram,share=on,size=256M -device "pxb-cxl,id=cxl.0,bus=pcie.0,bus_nr=52,uid=0,len-window-base=1,window-base[0]=0x4c0000000,memdev[0]=cxl-ram" -device cxl-rp,id=rp0,bus=cxl.0,addr=0.0,chassis=0,slot=0 -device cxl-type3,bus=rp0,memdev=cxl-ram,id=cxl-vmem0,size=256M -numa node,nodeid=0,memdev=cxl-ram -object memory-backend-ram,id=other-ram,size=8G,prealloc=n,share=off -numa node,nodeid=1,memdev=other-ram,initiator=0 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=0,socket-id=1

You probably need to state which qemu tree and version you're using
here.

> I get the following crash before the machine starts to boot.
> 
> qemu-system-x86_64: ../softmmu/memory.c:2443: memory_region_add_subregion_common: Assertion `!subregion->container' failed.

It's probably best to check with Ben, but you'll want a backtrace and
figure out which subregion and region you're dealing with.

Dave

> 
> Please help me find what's wrong here.
> 
> Regards,
> [CadenceLogoRed185Regcopy1583174817new51584636989.png]<https://www.cadence.com/en_US/home.html>
> Samarth Saxena
> Sr Principal Software Engineer
> T: +911204308300
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> 
> 
> 
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK