[PATCH v2 1/2] xen: introduce arch_iommu_grant_(un)map_page

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

Introduce two arch specific functions to create a new p2m mapping of
granted pages at pfn == mfn.
The x86 implementation just returns ENOSYS.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 xen/arch/arm/p2m.c        |   19 +++++++++++++++++++
 xen/include/asm-arm/p2m.h |    4 ++++
 xen/include/asm-x86/p2m.h |   13 +++++++++++++
 3 files changed, 36 insertions(+)

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 9960e17..c38af59 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -555,6 +555,25 @@ void guest_physmap_remove_page(struct domain *d,
                       pfn_to_paddr(mfn), MATTR_MEM, p2m_invalid);
 }
 
+int arch_grant_map_page_identity(struct domain *d, unsigned long frame,
+                                 bool_t writeable)
+{
+    p2m_type_t t;
+
+    if ( writeable )
+        t = p2m_ram_rw;
+    else
+        t = p2m_ram_ro;
+
+    return guest_physmap_add_entry(d, frame, frame, 0, t);
+}
+
+int arch_grant_unmap_page_identity(struct domain *d, unsigned long frame)
+{
+    guest_physmap_remove_page(d, frame, frame, 0);
+    return 0;
+}
+
 int p2m_alloc_table(struct domain *d)
 {
     struct p2m_domain *p2m = &d->arch.p2m;
diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
index 911d32d..b682f51 100644
--- a/xen/include/asm-arm/p2m.h
+++ b/xen/include/asm-arm/p2m.h
@@ -181,6 +181,10 @@ static inline int get_page_and_type(struct page_info *page,
     return rc;
 }
 
+int arch_grant_map_page_identity(struct domain *d, unsigned long frame,
+                                 bool_t writeable);
+int arch_grant_unmap_page_identity(struct domain *d, unsigned long frame);
+
 #endif /* _XEN_P2M_H */
 
 /*
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index 0ddbadb..faead11 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -717,6 +717,19 @@ static inline unsigned int p2m_get_iommu_flags(p2m_type_t p2mt)
 
     return flags;
 }
+ 
+static inline int arch_grant_map_page_identity(struct domain *d,
+                                               unsigned long frame,
+                                               bool_t writeable)
+{
+    return -ENOSYS;
+}
+
+static inline int arch_grant_unmap_page_identity(struct domain *d,
+                                                 unsigned long frame)
+{
+    return -ENOSYS;
+}
 
 #endif /* _XEN_P2M_H */
 
-- 
1.7.10.4