In this talk we present FlexAlloc: a lean block allocator focused on bridging the gap between raw block device access in user space and data management through monolithic file systems.

Flexible Data Placement (FDP) represents the latest development in mainstream data placement technology for NVMe. Although its use-cases resemble those of other NVMe features, such as Streams and ZNS, the differences have significant implications for the implementation within host storage stacks and applications. As host stacks adopt various data placement technologies, the risk of bloated codebases and redundant implementations rises, increasing maintenance costs for large mainline projects.

In order to develop open source CXL ecosystem software it has proven useful to emulate CXL features within the QEMU project. In this talk, I will introduce the current major CXL features that QEMU can emulate and walk you through how to set up a Linux + QEMU CXL environment that will enable testing and developing new CXL features. In addition, I will highlight some of the limitations of QEMU CXL emulation.

In order to develop open source CXL ecosystem software it has proven useful to emulate CXL features within the QEMU project. In this talk, I will introduce the current major CXL features that QEMU can emulate and walk you through how to set up a Linux + QEMU CXL environment that will enable testing and developing new CXL features. In addition, I will highlight some of the limitations of QEMU CXL emulation.

As with any emerging technology, developing open-source software for CXL is challenging and emulation of features is a key path forward. In this talk, we will introduce the current major CXL features that QEMU can emulate and walk you through how to set up a Linux + QEMU CXL environment to enable testing and developing new CXL features. Some limitations exist, as with any platform, which we will discuss along with the latest developments in support for dynamic capacity devices (DCD) and switches.