[PATCH 1/5] x86/PV: consistently inline {,un}adjust_guest_l<N>e()

[Jan Beulich <jbeulich@xxxxxxxx>]

Commit 8a74707a7c ("x86/nospec: Use always_inline to fix code gen for
evaluate_nospec") converted inline to always_inline for
adjust_guest_l[134]e(), but left adjust_guest_l2e() and
unadjust_guest_l3e() alone without saying why these two would differ in
the needed / wanted treatment. Adjust these two as well.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
Actually I question the need for always_inline here, for two reasons:
1) All that's guarded are updates to local variables, depending on
   merely the values held by these local variables (really: function
   arguments) on input. As a result it would look to me as if we wanted
   evaluate_nospec()-free variants of is_pv{,_32bit}_domain() and alike,
   to be used e.g. here.
2) These functions don't act as predicates, and hence the concern
   expressed in said commit doesn't apply here: Callers wouldn't observe
   misplaced LFENCEs, as they don't use the results of these helpers for
   further (direct) code flow control.
---
So far I've observed only clang to not inline the two functions when
just "inline" is in place.

--- a/xen/arch/x86/pv/mm.h
+++ b/xen/arch/x86/pv/mm.h
@@ -99,8 +99,8 @@ static always_inline l1_pgentry_t adjust
     return l1e;
 }
 
-static inline l2_pgentry_t adjust_guest_l2e(l2_pgentry_t l2e,
-                                            const struct domain *d)
+static always_inline l2_pgentry_t adjust_guest_l2e(l2_pgentry_t l2e,
+                                                   const struct domain *d)
 {
     if ( likely(l2e_get_flags(l2e) & _PAGE_PRESENT) &&
          likely(!is_pv_32bit_domain(d)) )
@@ -119,8 +119,8 @@ static always_inline l3_pgentry_t adjust
     return l3e;
 }
 
-static inline l3_pgentry_t unadjust_guest_l3e(l3_pgentry_t l3e,
-                                              const struct domain *d)
+static always_inline l3_pgentry_t unadjust_guest_l3e(l3_pgentry_t l3e,
+                                                     const struct domain *d)
 {
     if ( unlikely(is_pv_32bit_domain(d)) &&
          likely(l3e_get_flags(l3e) & _PAGE_PRESENT) )