Show HN: Device emulation outside QEMU using vfio-user and libvfio-user

VMMs like QEMU run the entire emulation inside a single process. That works fine until you want an implementation that doesn't align with QEMU's runtime environment, such as SPDK to handle multiple VMs' virtual disks and multiple physical disks from a single process. For this, we've built vfio-user, a protocol modelled after the kernel's VFIO framework that lets device emulation run in a separate process. In vfio-user, there's the vfio-user client, which runs in the VMM, and the vfio-user server