x86/nestedhvm: provide some stubs for p2m code

Make two functions static inline so that they can be referenced in p2m
code. Check nestedhvm is enabled before calling
nestedhvm_vmcx_flushtlb (which also has a side effect of not issuing
unnecessary IPIs for non-nested case).

While moving, reformat code and use proper boolean.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/hvm/nestedhvm.c

@@ -26,13 +26,6 @@
 
 static unsigned long *shadow_io_bitmap[3];
 
-/* Nested HVM on/off per domain */
-bool nestedhvm_enabled(const struct domain *d)
-{
-    return is_hvm_domain(d) && d->arch.hvm_domain.params &&
-        d->arch.hvm_domain.params[HVM_PARAM_NESTEDHVM];
-}
-
 /* Nested VCPU */
 bool_t
 nestedhvm_vcpu_in_guestmode(struct vcpu *v)
@@ -120,20 +113,6 @@ nestedhvm_vmcx_flushtlb(struct p2m_domain *p2m)
     cpumask_clear(p2m->dirty_cpumask);
 }
 
-bool_t
-nestedhvm_is_n2(struct vcpu *v)
-{
-    if (!nestedhvm_enabled(v->domain)
-      || nestedhvm_vmswitch_in_progress(v)
-      || !nestedhvm_paging_mode_hap(v))
-        return 0;
-
-    if (nestedhvm_vcpu_in_guestmode(v))
-        return 1;
-
-    return 0;
-}
-
 /* Common shadow IO Permission bitmap */
 
 /* There four global patterns of io bitmap each guest can

xen/arch/x86/mm/p2m.c

@@ -1756,7 +1756,8 @@ p2m_flush_table_locked(struct p2m_domain *p2m)
     p2m->np2m_generation++;
 
     /* Make sure nobody else is using this p2m table */
-    nestedhvm_vmcx_flushtlb(p2m);
+    if ( nestedhvm_enabled(d) )
+        nestedhvm_vmcx_flushtlb(p2m);
 
     /* Zap the top level of the trie */
     mfn = pagetable_get_mfn(p2m_get_pagetable(p2m));

xen/include/asm-x86/hvm/nestedhvm.h

@@ -33,7 +33,11 @@ enum nestedhvm_vmexits {
 };
 
 /* Nested HVM on/off per domain */
-bool nestedhvm_enabled(const struct domain *d);
+static inline bool nestedhvm_enabled(const struct domain *d)
+{
+    return is_hvm_domain(d) && d->arch.hvm_domain.params &&
+        d->arch.hvm_domain.params[HVM_PARAM_NESTEDHVM];
+}
 
 /* Nested VCPU */
 int nestedhvm_vcpu_initialise(struct vcpu *v);
@@ -70,7 +74,15 @@ unsigned long *nestedhvm_vcpu_iomap_get(bool_t ioport_80, bool_t ioport_ed);
 
 void nestedhvm_vmcx_flushtlb(struct p2m_domain *p2m);
 
-bool_t nestedhvm_is_n2(struct vcpu *v);
+static inline bool nestedhvm_is_n2(struct vcpu *v)
+{
+    if ( !nestedhvm_enabled(v->domain) ||
+        nestedhvm_vmswitch_in_progress(v) ||
+        !nestedhvm_paging_mode_hap(v) )
+        return false;
+
+    return nestedhvm_vcpu_in_guestmode(v);
+}
 
 static inline void nestedhvm_set_cr(struct vcpu *v, unsigned int cr,
                                     unsigned long value)