pci_p2pdma_add_resource of bar memory rejected by memory hotplug as out of range

From: Kit Chow
Date: Wed Mar 05 2025 - 15:26:28 EST


Hello,

I am getting the following failure when I call pci_p2pdma_add_resource() with a valid bar memory address range:

[65246.333251] Hotplug memory [0x202ffc000000-0x202ffdc00000] exceeds maximum addressable range [0x0-0xaffffffffff]

I see this failure in 6.8.0.51-generic and 6.8.0.54-generic. This was not an issue in earlier 6.8 and 5.15 kernels.

fwiw, I also get this failure with with 6.13.5-061305-generic.

Do you know what might be causing the schrinkage in the memory hot plug range? And is there a workaround for this?

Thank you,
Kit