DMA Transfers to PCIe Bar Memory

[Dmitry Kozlyuk]

2024-11-06 15:50 (UTC+0000), Wieckowski, Jacob:
> Is DMA access to the bar memory of a PCIe device with DPDK possible?
> If so, which example project could be used as a reference to gain a better understanding of this topic?

Hi,

BAR (base address register) is a place in PCI configuration space,
so one really doesn't "DMA transfers to PCIe BAR memory" to be precise.
Read https://wiki.osdev.org/PCI_Express to explore the topic.

DPDK drivers write to BARs to configure devices,
specifically to setup memory-mapped IO which is used for DMA.
Take a look at this project, which is a toy version of DPDK,
and thus it is easier to grasp:
https://github.com/ixy-languages/ixy-languages