libcxl doesn't handle a mmio read of 0xfffffff... (all 1's) correctly

[fbarrat]

cxl_mmio_read32() and cxl_mmio_read64() consider it an error if a mmio read returns 0xfffffff... (all 1's).
By default when reading 0xffffff, it raises SIGBUS, which terminates the process.

Instead, libcxl should consider 0xffffff... as a hint that an error might have occurred and run extra checks to know for sure. It is similar to what the kernel is doing. The issue is how to do it from userland.

[fbarrat]

Until it is fixed, AFU won't be able to return 0xffffff.... (all 1's) to a mmio request.

[vaibhav92]

Pull req #25 has been opened with a possible fix for this issue