XSAVE vs. XSAVEOPT in fpusave / fpu_kern_enter?

[Rang, Anton]

Hi,

While glancing at fpu_kern_enter, I noticed that fpusave() uses the XSAVE instruction, but not XSAVEOPT. The instance in cpu_switch.S is patched if XSAVEOPT is available, but should we also be able to use XSAVEOPT in fpusave as well?  I can't see any reason why not, but I'm not 100% sure that the save area is set up properly in all cases.

Anton