Hello! Ian and I have run into what looks like a bug in arch/x86/include/uapi/asm/kvm.h, but it also looks so obvious that we surely must be doing something wrong. So I request enlightenment.
We discovered this problem on the 4.5.2 release, but the relevant code appears unchanged from 2013 until current trunk. When I run "make ARCH=x86 headers_install", and then write a simple C file that #includes "asm/kvm.h" from the resulting tree, I get a compiler error: the BIT() macro used on line 219 of that file is undefined: https://github.com/torvalds/linux/blob/master/arch/x86/include/uapi/asm/kvm.h#L219 I attempted to find where it was supposed to be defined, and the only match for "define BIT(" in the whole tree is in include/linux/bitops.h: https://github.com/torvalds/linux/blob/master/include/linux/bitops.h#L6 However, that's not in a "uapi" directory, and it's not listed in include/uapi/linux/Kbuild, so "make headers_install" doesn't install it. Further, kvm.h doesn't reference it with a #include, so even if it were installed, it wouldn't be included. It seems that we must be missing something obvious. But what? Thanks, - Brooks P.S. The change that appears to have added this reference is this one, signed-off-on by Borislav and Paolo, which is why I've added you to the cc line. https://github.com/torvalds/linux/commit/9c15bb1d0a8411f9bb3395d21d5309bde7da0c1c
