[v3,8/9] x86/np2m: refactor p2m_get_nestedp2m_locked()

Commit Message

Sergey Dyasli Oct. 3, 2017, 3:21 p.m. UTC

Remove some code duplication.

Suggested-by: George Dunlap <[e-mail]>
Signed-off-by: Sergey Dyasli <[e-mail]>
Reviewed-by: George Dunlap <[e-mail]>
---
 xen/arch/x86/mm/p2m.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

Patch

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 90bf382a49..6c937c9e17 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -1829,6 +1829,7 @@  p2m_get_nestedp2m_locked(struct vcpu *v)
     struct p2m_domain *p2m;
     uint64_t np2m_base = nhvm_vcpu_p2m_base(v);
     unsigned int i;
+    bool needs_flush = true;
 
     /* Mask out low bits; this avoids collisions with P2M_BASE_EADDR */
     np2m_base &= ~(0xfffull);
@@ -1845,14 +1846,10 @@  p2m_get_nestedp2m_locked(struct vcpu *v)
         if ( p2m->np2m_base == np2m_base )
         {
             /* Check if np2m was flushed just before the lock */
-            if ( nv->np2m_generation != p2m->np2m_generation )
-                nvcpu_flush(v);
+            if ( nv->np2m_generation == p2m->np2m_generation )
+                needs_flush = false;
             /* np2m is up-to-date */
-            p2m->np2m_base = np2m_base;
-            assign_np2m(v, p2m);
-            nestedp2m_unlock(d);
-
-            return p2m;
+            goto found;
         }
         else if ( p2m->np2m_base != P2M_BASE_EADDR )
         {
@@ -1867,15 +1864,10 @@  p2m_get_nestedp2m_locked(struct vcpu *v)
     {
         p2m = d->arch.nested_p2m[i];
         p2m_lock(p2m);
+
         if ( p2m->np2m_base == np2m_base )
-        {
-            nvcpu_flush(v);
-            p2m->np2m_base = np2m_base;
-            assign_np2m(v, p2m);
-            nestedp2m_unlock(d);
+            goto found;
 
-            return p2m;
-        }
         p2m_unlock(p2m);
     }
 
@@ -1884,8 +1876,11 @@  p2m_get_nestedp2m_locked(struct vcpu *v)
     p2m = p2m_getlru_nestedp2m(d, NULL);
     p2m_flush_table(p2m);
     p2m_lock(p2m);
+
+ found:
+    if ( needs_flush )
+        nvcpu_flush(v);
     p2m->np2m_base = np2m_base;
-    nvcpu_flush(v);
     assign_np2m(v, p2m);
     nestedp2m_unlock(d);