Re: [PATCH 1/8] x86/spec-ctrl: Fix confusion between SPEC_CTRL_EXIT_TO_XEN{,_IST}

[Jan Beulich <jbeulich@xxxxxxxx>]

On 13.09.2023 22:27, Andrew Cooper wrote:
> c/s 3fffaf9c13e9 ("x86/entry: Avoid using alternatives in NMI/#MC paths")
> dropped the only user, leaving behind the (incorrect) implication that Xen had
> split exit paths.
> 
> Delete the unused SPEC_CTRL_EXIT_TO_XEN and rename SPEC_CTRL_EXIT_TO_XEN_IST
> to SPEC_CTRL_EXIT_TO_XEN for consistency.
> 
> No functional change.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
albeit ...

> @@ -256,11 +255,6 @@
>      ALTERNATIVE "", __stringify(DO_SPEC_CTRL_ENTRY maybexen=1),         \
>          X86_FEATURE_SC_MSR_PV
>  
> -/* Use when exiting to Xen context. */
> -#define SPEC_CTRL_EXIT_TO_XEN                                           \
> -    ALTERNATIVE "",                                                     \
> -        DO_SPEC_CTRL_EXIT_TO_XEN, X86_FEATURE_SC_MSR_PV
> -
>  /* Use when exiting to PV guest context. */
>  #define SPEC_CTRL_EXIT_TO_PV                                            \
>      ALTERNATIVE "",                                                     \
> @@ -328,7 +322,7 @@ UNLIKELY_DISPATCH_LABEL(\@_serialise):
>  .endm
>  
>  /* Use when exiting to Xen in IST context. */
> -.macro SPEC_CTRL_EXIT_TO_XEN_IST
> +.macro SPEC_CTRL_EXIT_TO_XEN

... with the comment her updated (either by dropping "in IST" or by
explicitly mentioning both cases).

Jan