I have read this.
But I am working with PCI UIO, and I therefore need continuous physical memory. I am talking (among other things) virtio, so the presence of an IOMMU won't help here. PCI-VFIO has a much nicer and secured approach, I agree, but the IOMMU virtualisation techniques are not mature, as far as I understand.
Writing a PCI-UIO virtio driver in user space running on a guest requires physical contiguous memory. Besides, not all HW have IOMMUs, so even for such simpler hosts systems, VFIO cannot be used, and there is a need for contiguous physical memory...
So, in short, as long as IOMMUs are not everywhere and are not properly emmulated on virtualizers, it seems allocation of contiguous physical memory from user space is needed.
I am aware that user can READ the page mapping from /proc/<pid>/... and that allows for a try and error approach which dpdk is using...
But it feels that contigous physical memory allocation should typically a job from a kernel module... And that I cannot be the first one facing this situation...
Does such a kernel module exist?
