Re: [PATCH 4/4] x86/xen: drop USERGS_SYSRET64 paravirt call

[Andy Lutomirski]

On Mon, Nov 16, 2020 at 7:23 AM Juergen Gross <jgross@xxxxxxxx> wrote:
>
> USERGS_SYSRET64 is used to return from a syscall via sysret, but
> a Xen PV guest will nevertheless use the iret hypercall, as there
> is no sysret PV hypercall defined.
>
> So instead of testing all the prerequisites for doing a sysret and
> then mangling the stack for Xen PV again for doing an iret just use
> the iret exit from the beginning.
>
> This can easily be done via an ALTERNATIVE like it is done for the
> sysenter compat case already.
>
> While at it remove to stale sysret32 remnants.

s/to/the/