Currently we only have BIOS as a boot option for vSRX and that is conflicting with Qemu v8.1.

When vSRX3.0 system is deployed on QEMU version 8.1 and above, SMBIOS in this QEMU version entry point is set to 64 bits by default and freeBSD starts supporting 64 bits entry point in BSD version 13, which means that vSRX3.0 with JunOS version before 24.2 will face this issue where system will return a null pointer for SMBIOS when required and this null entry will cause kernel panic and system will crash.

Starting version 24.2, two vSRX images will be available on the download portal, one with BIOS boot option and the other with UEFI boot option.

Below is the workaround if using a BIOs image,

Configure Qemu system to use 32 bits entry point:
For virt-install add the following argument:
--qemu-commandline="-machine smbios-entry-point-type=32"

For virsh, add the following to the <domain> section: 
<qemu:commandline>   
<qemu:arg value='-machine'/>   
<qemu:arg value='smbios-entry-point-type=32'/>  
</qemu:commandline>