x86/paging: invlpg() hook returns boolean

... so make its return type reflect this.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/mm/hap/hap.c
+++ b/xen/arch/x86/mm/hap/hap.c
@@ -680,7 +680,7 @@ static int hap_page_fault(struct vcpu *v
  * HAP guests can handle invlpg without needing any action from Xen, so
  * should not be intercepting it.
  */
-static int hap_invlpg(struct vcpu *v, unsigned long va)
+static bool_t hap_invlpg(struct vcpu *v, unsigned long va)
 {
     if (nestedhvm_enabled(v->domain)) {
         /* Emulate INVLPGA:
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -3510,11 +3510,12 @@ propagate:
 }
 
 
-static int
-sh_invlpg(struct vcpu *v, unsigned long va)
-/* Called when the guest requests an invlpg.  Returns 1 if the invlpg
+/*
+ * Called when the guest requests an invlpg.  Returns 1 if the invlpg
  * instruction should be issued on the hardware, or 0 if it's safe not
- * to do so. */
+ * to do so.
+ */
+static bool_t sh_invlpg(struct vcpu *v, unsigned long va)
 {
     mfn_t sl1mfn;
     shadow_l2e_t sl2e;
--- a/xen/arch/x86/mm/shadow/none.c
+++ b/xen/arch/x86/mm/shadow/none.c
@@ -32,10 +32,10 @@ static int _page_fault(struct vcpu *v, u
     return 0;
 }
 
-static int _invlpg(struct vcpu *v, unsigned long va)
+static bool_t _invlpg(struct vcpu *v, unsigned long va)
 {
     ASSERT_UNREACHABLE();
-    return -EOPNOTSUPP;
+    return 1;
 }
 
 static unsigned long _gva_to_gfn(struct vcpu *v, struct p2m_domain *p2m,
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4392,8 +4392,7 @@ static int __do_update_va_mapping(
         switch ( (bmap_ptr = flags & ~UVMF_FLUSHTYPE_MASK) )
         {
         case UVMF_LOCAL:
-            if ( !paging_mode_enabled(d) ||
-                 (paging_invlpg(v, va) != 0) ) 
+            if ( !paging_mode_enabled(d) || paging_invlpg(v, va) )
                 flush_tlb_one_local(va);
             break;
         case UVMF_ALL:
--- a/xen/include/asm-x86/paging.h
+++ b/xen/include/asm-x86/paging.h
@@ -104,7 +104,7 @@ struct shadow_paging_mode {
 struct paging_mode {
     int           (*page_fault            )(struct vcpu *v, unsigned long va,
                                             struct cpu_user_regs *regs);
-    int           (*invlpg                )(struct vcpu *v, unsigned long va);
+    bool_t        (*invlpg                )(struct vcpu *v, unsigned long va);
     unsigned long (*gva_to_gfn            )(struct vcpu *v,
                                             struct p2m_domain *p2m,
                                             unsigned long va,
@@ -243,7 +243,7 @@ paging_fault(unsigned long va, struct cp
 /* Handle invlpg requests on vcpus.
  * Returns 1 if the invlpg instruction should be issued on the hardware,
  * or 0 if it's safe not to do so. */
-static inline int paging_invlpg(struct vcpu *v, unsigned long va)
+static inline bool_t paging_invlpg(struct vcpu *v, unsigned long va)
 {
     return (paging_mode_external(v->domain) ? is_canonical_address(va)
                                             : __addr_ok(va)) &&