vDPA: Support for block devices in Linux and QEMU

The linked article is about vDPA devices and their use cases, including support for both physical and software-emulated devices. These devices follow the virtio specification for their datapath but have a vendor-specific control path, requiring only a small vDPA parent driver in the host kernel for the control path. The main advantage is the unified software stack for all vDPA devices, with support for both network and block devices and the ability to emulate virtio-blk devices to support different network backends. The article also discusses the use of libblkio and the generic vhost-vdpa-device-pci device offered by QEMU to attach vDPA block or generic devices to a VM, as well as the vdpa tool in iproute2 for device management. Finally, the article mentions enhancements like driver_ovveride and dynamic reconfiguration during runtime, as well as examples of using VDUSE and QEMU Storage Daemon with VMs or containers.