x86/p2m: allocate logdirty_ranges for altp2ms

For now, only do allocation/deallocation; keeping them in sync
will be done in subsequent patches.

Logdirty synchronization will only be done for active altp2ms;
so allocate logdirty rangesets (copying the host logdirty
rangeset) when an altp2m is activated, and free it when
deactivated.

Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Tested-by: Tamas K Lengyel <tamas@tklengyel.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index fea449791019e5667c7414e43e1405f846fe89f8..96a6d3e9a6e29b3fd215935524917ec698bb9ad4 100644 (file)
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -2265,6 +2265,40 @@ void p2m_flush_altp2m(struct domain *d)
     altp2m_list_unlock(d);
 }
 
+static int p2m_activate_altp2m(struct domain *d, unsigned int idx)
+{
+    struct p2m_domain *hostp2m, *p2m;
+    int rc;
+
+    ASSERT(idx < MAX_ALTP2M);
+
+    p2m = d->arch.altp2m_p2m[idx];
+    hostp2m = p2m_get_hostp2m(d);
+
+    p2m_lock(p2m);
+
+    rc = p2m_init_logdirty(p2m);
+
+    if ( rc )
+        goto out;
+
+    /* The following is really just a rangeset copy. */
+    rc = rangeset_merge(p2m->logdirty_ranges, hostp2m->logdirty_ranges);
+
+    if ( rc )
+    {
+        p2m_free_logdirty(p2m);
+        goto out;
+    }
+
+    p2m_init_altp2m_ept(d, idx);
+
+ out:
+    p2m_unlock(p2m);
+
+    return rc;
+}
+
 int p2m_init_altp2m_by_id(struct domain *d, unsigned int idx)
 {
     int rc = -EINVAL;
@@ -2275,10 +2309,7 @@ int p2m_init_altp2m_by_id(struct domain *d, unsigned int idx)
     altp2m_list_lock(d);
 
     if ( d->arch.altp2m_eptp[idx] == mfn_x(INVALID_MFN) )
-    {
-        p2m_init_altp2m_ept(d, idx);
-        rc = 0;
-    }
+        rc = p2m_activate_altp2m(d, idx);
 
     altp2m_list_unlock(d);
     return rc;
@@ -2296,9 +2327,10 @@ int p2m_init_next_altp2m(struct domain *d, uint16_t *idx)
         if ( d->arch.altp2m_eptp[i] != mfn_x(INVALID_MFN) )
             continue;
 
-        p2m_init_altp2m_ept(d, i);
-        *idx = i;
-        rc = 0;
+        rc = p2m_activate_altp2m(d, i);
+
+        if ( !rc )
+            *idx = i;
 
         break;
     }