[RFC,08/12] x86/np2m: add p2m_get_nestedp2m_locked()

Commit Message

Sergey Dyasli July 18, 2017, 10:34 a.m. UTC

The new function returns still write-locked np2m.

Signed-off-by: Sergey Dyasli <[e-mail]>
---
 xen/arch/x86/mm/p2m.c     | 12 +++++++++---
 xen/include/asm-x86/p2m.h |  2 ++
 2 files changed, 11 insertions(+), 3 deletions(-)

Patch

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 4b83d4a4f1..364fdd8c13 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -1824,7 +1824,7 @@  static void nvcpu_flush(struct vcpu *v)
 }
 
 struct p2m_domain *
-p2m_get_nestedp2m(struct vcpu *v)
+p2m_get_nestedp2m_locked(struct vcpu *v)
 {
     struct nestedvcpu *nv = &vcpu_nestedhvm(v);
     struct domain *d = v->domain;
@@ -1849,7 +1849,6 @@  p2m_get_nestedp2m(struct vcpu *v)
                 nvcpu_flush(v);
             p2m->np2m_base = np2m_base;
             assign_np2m(v, p2m);
-            p2m_unlock(p2m);
             nestedp2m_unlock(d);
 
             return p2m;
@@ -1865,12 +1864,19 @@  p2m_get_nestedp2m(struct vcpu *v)
     p2m->np2m_base = np2m_base;
     nvcpu_flush(v);
     assign_np2m(v, p2m);
-    p2m_unlock(p2m);
     nestedp2m_unlock(d);
 
     return p2m;
 }
 
+struct p2m_domain *p2m_get_nestedp2m(struct vcpu *v)
+{
+    struct p2m_domain *p2m = p2m_get_nestedp2m_locked(v);
+    p2m_unlock(p2m);
+
+    return p2m;
+}
+
 struct p2m_domain *
 p2m_get_p2m(struct vcpu *v)
 {
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index 801a11a960..936d1142c8 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -364,6 +364,8 @@  struct p2m_domain {
  * Updates vCPU's n2pm to match its EPTP in VMCS12 and returns that np2m.
  */
 struct p2m_domain *p2m_get_nestedp2m(struct vcpu *v);
+/* Similar to the above except that returned p2m is still write-locked */
+struct p2m_domain *p2m_get_nestedp2m_locked(struct vcpu *v);
 
 /* If vcpu is in host mode then behaviour matches p2m_get_hostp2m().
  * If vcpu is in guest mode then behaviour matches p2m_get_nestedp2m().