nvidia-uvm: Add support for kernel 6.18 get_dev_pagemap API change

[lxe]

The get_dev_pagemap() function signature changed in Linux kernel 6.18 to take only a single pfn parameter, removing the lock parameter.

This commit adds a conftest check to detect the API version and conditionally calls get_dev_pagemap() with the appropriate number of arguments.

[aritger]

Thanks for pull request. We have an equivalent change that will be included in an upcoming release.

[lxe]

Aww ok :(

[Qubitium]

Aww ok :(

Yeah. I feel your pain. Nvidia almost never merge public PRs. this repo is like their public commit squash dump.

It's only open as you can see it but good luck getting changes upstreamed.

[sergiomb2]

Thanks for pull request. We have an equivalent change that will be included in an upcoming release.

Yeah, can we have the official version? Usually, we also need to update the other old drivers with similar fixes.

[sergiomb2]

I just checked that nvidia-470xx does not need any backport to build with kernel 6.18.0-0.rc5, but when it does, we prefer to use a solution inspired by the code here. It is relatively easy to adapt to older drivers.
That said, if we could have just the kernel fixes in an independent commit, that would be fantastic.

Best regards