Meet muser, a framework built on top of vfio/mdev for implementing PCI devices in userspace. It consists of a kernel module that acts as the mediated device and a userspace library where the core of the device is implemented. Applications using libmuser must only provide a description and callbacks for read/write.
muser abstracts the complexity yet allows tremendous flexibility. It manages interrupts, the PCI config space, memory translation, handles interaction with vfio/mdev and much more. While allowing customization where needed (for power users), it can also offer bindings for various languages. To prove simplicity, we will write and test a device live during the talk!
This is very useful with QEMU, where devices presented via vfio can be directly passed to VMs. It also enables a single userspace process to manage devices for multiple VMs, which has performance benefits.
I'm a software engineer at Nutanix working on storage virtualization. I'm currently working on the vfio-user protocol and libvfio-user, which allows us to use SPDK as a virtual NVMe controller outside QEMU in order to achieve high performance, low latency, and higher CPU efficien... Read More →
