Re: [PATCH RFC V2 17/17] x86/entry: Preserve PKRS MSR across exceptions

Andy Lutomirski
2020-07-22T16:22:00Z

On Fri, Jul 17, 2020 at 12:21 AM <ira.weiny@intel.com> wrote:
>
> From: Ira Weiny <ira.weiny@intel.com>
>
> The PKRS MSR is not managed by XSAVE. It is already preserved through a
> context switch but this support leaves exception handling code open to
> memory accesses which the interrupted process has allowed.
>
> Close this hole by preserve the current task's PKRS MSR, reset the PKRS
> MSR value on exception entry, and then restore the state on exception
> exit.

Should this live in pt_regs?

--Andy