After much pain and reading the entire VSR deployment guide for SROS 20, I have a working model that neither the CPM nor the IOM crashes. SROS 20 seems to be quite a bit more temperamental when it comes to hardware, creating a fun set of crash / reboot loops with a variety of fairly cryptic errors. Since I have seen this asked in multiple forums and other online outlets I will put my working configurations here so others don’t need to fight it. Once I work out the integrated model I’ll post that too. These settings were all verified as working in Eve-NG, but should be universal across anything that runs them as qemu/libvirt.

Distributed Model

CPM Hardware:

TimOS Line:

slot=A chassis=SR-12 card=cpm5

QEMU custom options:

-machine type=pc,accel=kvm -serial mon:stdio -nographic -no-user-config -nodefaults -rtc base=utc

Other:
CPU = 8
RAM – 10240
Ethernet = 6 (probably could be 2)

IOM Hardware

TimOS Line:

slot=1 chassis=SR-12 card=iom3-xp-c mda/1=m10-1gb+1-10gb

QEMU custom options:

-machine type=pc,accel=kvm -serial mon:stdio -nographic -no-user-config -nodefaults -rtc base=utc

Other:
CPU = 8
RAM – 10240
Ethernet = 12
QEMU Version 4.1.0
QEMU arch = x86_64
QEMU NIC = e1000

Settings for SROS 16

CPM Options
KVM:

slot=A chassis=SR-12e card=cpm5 

4 x CPU
8192MB RAM
Everything else is default except the license file

IOM Options:

slot=1 chassis=SR-12e card=iom4-e-b mda/1=me2-100gb-qsfp28

4 x CPU
8192MB RAM
Everything else is default

#--------------------------------------------------
echo "Card Configuration"
#--------------------------------------------------
    card 1
        card-type iom4-e-b
        mda 1
            mda-type me2-100gb-qsfp28
            no shutdown
        exit
        no shutdown                   
    exit

The order of configuration matters (dug, I should have remembered that).

/configure sfm 1 sfm-type m-sfm5-12e
/configure card 1 card-type "iom4-e-b”
/configure card 1 mda 1 mda-type "me2-100gb-qsfp28"