Re: x86/fpu/xsave: protection key test failures

[Andy Lutomirski]

On 5/25/21 2:37 PM, Babu Moger wrote:

> Investigation so far.
> 1. The test fails on AMD(Milan) systems. Test appears to pass on Intel
> systems. Tested on old Intel system available here.

Ten cents says that you have discovered that AMD returns a synthesized
value for XINUSE[PKRU] and that write_pkru() is buggy.

Any volunteers to fix the if (!pk) case in write_pkru() and see if the
problem goes away?  (Or at least to print something for the if (!pk)
case and seee if it gets printed?)

--Andy