[PATCH v2 08/10] xen/arm: Implement xen_rem_foreign_from_p2m

[Julien Grall <julien.grall@linaro.org>]

Signed-off-by: Julien Grall <julien.grall@linaro.org>

---
    Changes in v2:
        - Introduce the patch
---
 xen/arch/arm/mm.c         |   16 ++++++++++++++++
 xen/include/asm-arm/p2m.h |    6 +-----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 960c872..ba51f6e 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -968,6 +968,22 @@ void share_xen_page_with_privileged_guests(
     share_xen_page_with_guest(page, dom_xen, readonly);
 }
 
+int xenmem_rem_foreign_from_p2m(struct domain *d, unsigned long gpfn)
+{
+    unsigned long mfn = gmfn_to_mfn(d, gpfn);
+    if ( !mfn_valid(mfn) )
+    {
+        gdprintk(XENLOG_WARNING, "Invalid mfn for gpfn:%lx domid:%d\n",
+                 gpfn, d->domain_id);
+        return -EINVAL;
+    }
+
+    guest_physmap_remove_page(d, gpfn, mfn, 0);
+    put_page(mfn_to_page(mfn));
+
+    return 0;
+}
+
 static int xenmem_add_to_physmap_one(
     struct domain *d,
     uint16_t space,
diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
index b0d3aea..cdd80d8 100644
--- a/xen/include/asm-arm/p2m.h
+++ b/xen/include/asm-arm/p2m.h
@@ -152,11 +152,7 @@ static inline int get_page_and_type(struct page_info *page,
     return rc;
 }
 
-static inline int xenmem_rem_foreign_from_p2m(struct domain *d, 
-                                              unsigned long gpfn)
-{
-    return -ENOSYS;
-}
+int xenmem_rem_foreign_from_p2m(struct domain *d, unsigned long gpfn);
 
 #endif /* _XEN_P2M_H */
 
-- 
1.7.10.4