I am working on a disk burn-in utility, and I'd like to use qemu's blkdebug driver to simulate disk errors. I've added the qemu namespace to my domain. <domain xmlns:qemu="http://libvirt.org/schemas/domain/qemu/1.0" type="kvm"> I've set an alias for my SCSI controller. <controller type="scsi" index="0" model="virtio-scsi"> <driver queues="4" iothread="1"/> <alias name="ua-scsi0"/> <address type="pci" domain="0x0000" bus="0x07" slot="0x00" function="0x0"/> </controller> And I've added the qemu command-line options. <qemu:commandline> <qemu:arg value="-blockdev"/> <qemu:arg value="{"driver":"host_device","filename":"/dev/ram0","node-name":"ram-backend","cache":{"direct":true,"no-flush":false},"discard":"unmap"}"/> <qemu:arg value="-blockdev"/> <qemu:arg value="{"driver":"raw","file":"ram-backend","node-name":"raw-layer"}"/> <qemu:arg value="-blockdev"/> <qemu:arg value="{"driver":"blkdebug","config":"/var/lib/libvirt/images/test.conf","image":"raw-layer","node-name":"debug-disk"}"/> <qemu:arg value="-device"/> <qemu:arg value="scsi-hd,drive=debug-disk,id=scsi0-0-0-1,wwn=0x5000c50030000001,logical_block_size=4096,physical_block_size=4096,bus=ua-scsi0.0,channel=0,scsi-id=0,lun=1"/> </qemu:commandline> When I try to start the VM, I get this. Error starting domain: internal error: process exited while connecting to monitor: 2026-05-15T16:42:46.891789Z qemu-system-x86_64: -blockdev {"driver":"host_device","filename":"/dev/ram0","node-name":"ram-backend","cache":{"direct":true,"no-flush":false},"discard":"unmap"}: Could not open '/dev/ram0': No such file or directory /dev/ram0 definitely exists, and is owned by qemu:qemu. Google Gemini tells me that this is some sort of security feature, but it hasn't been able to suggest a non-janky way to work around it. (To me, changing the global libvirt configuration, rando trigger scripts, or creating some sort of redundant fake drive all fall into the janky category.) Is there really not a clean way to do this? -- ======================================================================== If your user interface is intuitive in retrospect ... it isn't intuitive ========================================================================