On 11/9/18 9:17 AM, Matthew Wilcox wrote: >> But, later versions of the hardware have instructions that don't have >> static offsets for the state components (when the XSAVES/XSAVEC >> instructions are used). So, for those, the structure embedding isn't >> used at *all* since some state might not be present. > But *when present*, this structure is always aligned on an 8-byte > boundary, right? There's no guarantee of that. There is an "aligned" attribute for each XSAVE state component, but I do not believe it is set for anything yet.
