[Xen-devel] [PATCH 7/8] xen/arm: Set foreign page type to p2m_map_foreign

[Julien Grall <julien.grall@xxxxxxxxxx>]

Xen needs to know that the current page belongs to another domain. Also take
the refcount to this page.

Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
---
 xen/arch/arm/mm.c |   14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 960c872..bf383a7 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -977,6 +977,7 @@ static int xenmem_add_to_physmap_one(
 {
     unsigned long mfn = 0;
     int rc;
+    p2m_type_t t = p2m_ram_rw;
 
     switch ( space )
     {
@@ -1019,8 +1020,8 @@ static int xenmem_add_to_physmap_one(
         break;
     case XENMAPSPACE_gmfn_foreign:
     {
-        paddr_t maddr;
         struct domain *od;
+        struct page_info *page;
         od = rcu_lock_domain_by_any_id(foreign_domid);
         if ( od == NULL )
             return -ESRCH;
@@ -1032,15 +1033,18 @@ static int xenmem_add_to_physmap_one(
             return rc;
         }
 
-        maddr = p2m_lookup(od, pfn_to_paddr(idx));
-        if ( maddr == INVALID_PADDR )
+        /* Take refcount to the foreign domain page.
+         * Refcount will be release in XENMEM_remove_from_physmap */
+        page = get_page_from_gfn(od, idx, NULL, P2M_ALLOC);
+        if ( !page )
         {
             dump_p2m_lookup(od, pfn_to_paddr(idx));
             rcu_unlock_domain(od);
             return -EINVAL;
         }
 
-        mfn = maddr >> PAGE_SHIFT;
+        mfn = page_to_mfn(page);
+        t = p2m_map_foreign;
 
         rcu_unlock_domain(od);
         break;
@@ -1051,7 +1055,7 @@ static int xenmem_add_to_physmap_one(
     }
 
     /* Map at new location. */
-    rc = guest_physmap_add_page(d, gpfn, mfn, 0);
+    rc = guest_physmap_add_entry(d, gpfn, mfn, 0, t);
 
     return rc;
 }
-- 
1.7.10.4


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel