Return to

Qemu 6.2 breaks Looking Glass ivshmem KVMFR

Hello All,
Just wanted to give some heads up that it appears the Qemu 6.2 release breaks shared memory config for Looking Glass using ivshmem-plain.

Trying to run my windows VM gives this error:
error: internal error: qemu unexpectedly closed the monitor:

2021-12-18T15:25:11.382697Z qemu-system-x86_64: -device {“driver”:“pcie-root-port”,“port”:8,“chassis”:1,“id”:“pci.1”,“bus”:“pcie.0”,“multifunction”:true,“addr”:“0x1”}: PCI: slot 1 function 0 not available for pcie-root-port, in use by ivshmem-plain

reverting to qemu 6.1 runs fine.


The error you have here is not caused by ivshmem/qemu6.2 but rather a faulty launch configuration of QEMU. not availble for pcie-root-port means the bus number assignment given is already taken by your ivshmem-plane device, either libvirt is not ready for qemu 6.2, or needs updating, or your custom args/launch scripts are bugged.


The docs were just updated with a new way to set the KVMFR device in the XML that will solve this issue. Take a look here


Thanks!! The new syntax works.

Oh, good to know. Though, it is a bit frustrating they have us change the syntax like that.