Re: [PATCH v5 04/27] x86/fpu/xstate: Add XSAVES system states for shadow stack

From: Dave Hansen
Date: Fri Nov 09 2018 - 12:28:43 EST


On 11/9/18 9:20 AM, Dave Hansen wrote:
> 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?

Practically, though, I think it ends up always being aligned on an
8-byte boundary.