According to Phoronix
, support for “Resizable BAR” or “ReBAR” is mentioned in the latest Linux kernel patch, which includes driver support for Intel-related graphics kernels on Linux platforms. The contents of the patch are described as:
Starting from DG2 we will have resizable BAR support for device local-memory, but in some cases the final BAR size might still be smaller than the total local-memory size. In such cases only part of local-memory will be CPU accessible, while the remainder is only accessible via the GPU. This series adds the basic enablers needed to ensure that the entire local-memory range is usable
The application for the relevant patch is currently under review, and support for Resizable BAR may be added to the Linux 5.18 kernel. Intel currently has support for Resizable BARs on desktop platforms starting with the 300 series chipsets. Since AMD and Nvidia offer similar technology on both desktops and laptops, I believe Intel’s Intel Arc-branded Alchemist graphics cards will eventually follow suit.
Recently, there is news that Intel’s first batch of ARC brand discrete graphics cards have been delayed, and will only be launched with the Alder Lake mobile version in the first quarter of 2022, and the desktop platform version will be launched in the second quarter of 2022. The main reason for Intel’s delay is the need to improve drivers and avoid direct competition with Nvidia GPUs in January.