QEMU v5.2 released [UPDATE Feb 24, 2021]

QEMU v5.2 is out. A highlight from a KVM on Z perspective:

• PCI passthrough support now includes any PCI devices other than RoCE Express cards, e.g. including NVME devices. However, ISM devices as needed for SMC-D, require extra support an cannot be used at this point.
• virtiofs support vi virtio-fs-ccw: Shared Filesystem allowing KVM guests to access host directories.
  Use cases:
• Container image access in lightweight VMs (e.g. in Kata Containers)
• CI/CD and development enablement
• Filesystem as a service, to easily switch backends
To use, define in the host as follows:
  <domain>
    <memoryBacking>
      <access mode='shared'/>
    </memoryBacking>
    <devices>
      <filesystem type='mount'
            accessmode='passthrough'>
        <driver type='virtiofs'/>
        <source dir='/<hostpath>'/>
        <target dir='mount_tag'/>
      </filesystem>
      ...
    </devices>
    ...
  </domain>
Then mount in guests as follows:
  # mount -t virtiofs mount_tag /mnt/<path>
Requires Linux kernel 5.4 and libvirt v7.0.

For further details, see the Release Notes.

UPDATE: A previous version had falsely listed ISM devices as supported.