3 files changed, 40 insertions, 3 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index d9faaa26c104..ce67dc8f36af 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -880,6 +880,8 @@ static __init void setup_shared_info(void)
         /* In UP this is as good a place as any to set up shared info */
         xen_setup_vcpu_info_placement();
 #endif
+
+        xen_setup_mfn_list_list();
 }
 
 static __init void xen_pagetable_setup_done(pgd_t *base)
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index da7b45b05066..4740cda36563 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -69,6 +69,13 @@ static unsigned long *p2m_top[TOP_ENTRIES]
         __attribute__((section(".data.page_aligned"))) =
                 { [ 0 ... TOP_ENTRIES - 1] = &p2m_missing[0] };
 
+/* Arrays of p2m arrays expressed in mfns used for save/restore */
+static unsigned long p2m_top_mfn[TOP_ENTRIES]
+        __attribute__((section(".bss.page_aligned")));
+
+static unsigned long p2m_top_mfn_list[TOP_ENTRIES / P2M_ENTRIES_PER_PAGE]
+        __attribute__((section(".bss.page_aligned")));
+
 static inline unsigned p2m_top_index(unsigned long pfn)
 {
         BUG_ON(pfn >= MAX_DOMAIN_PAGES);
@@ -80,11 +87,35 @@ static inline unsigned p2m_index(unsigned long pfn)
         return pfn % P2M_ENTRIES_PER_PAGE;
 }
 
+/* Build the parallel p2m_top_mfn structures */
+void xen_setup_mfn_list_list(void)
+{
+        unsigned pfn, idx;
+
+        for(pfn = 0; pfn < MAX_DOMAIN_PAGES; pfn += P2M_ENTRIES_PER_PAGE) {
+                unsigned topidx = p2m_top_index(pfn);
+
+                p2m_top_mfn[topidx] = virt_to_mfn(p2m_top[topidx]);
+        }
+
+        for(idx = 0; idx < ARRAY_SIZE(p2m_top_mfn_list); idx++) {
+                unsigned topidx = idx * P2M_ENTRIES_PER_PAGE;
+                p2m_top_mfn_list[idx] = virt_to_mfn(&p2m_top_mfn[topidx]);
+        }
+
+        BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
+
+        HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
+                virt_to_mfn(p2m_top_mfn_list);
+        HYPERVISOR_shared_info->arch.max_pfn = xen_start_info->nr_pages;
+}
+
+/* Set up p2m_top to point to the domain-builder provided p2m pages */
 void __init xen_build_dynamic_phys_to_machine(void)
 {
-        unsigned pfn;
         unsigned long *mfn_list = (unsigned long *)xen_start_info->mfn_list;
         unsigned long max_pfn = min(MAX_DOMAIN_PAGES, xen_start_info->nr_pages);
+        unsigned pfn;
 
         for(pfn = 0; pfn < max_pfn; pfn += P2M_ENTRIES_PER_PAGE) {
                 unsigned topidx = p2m_top_index(pfn);
@@ -105,7 +136,7 @@ unsigned long get_phys_to_machine(unsigned long pfn)
         return p2m_top[topidx][idx];
 }
 
-static void alloc_p2m(unsigned long **pp)
+static void alloc_p2m(unsigned long **pp, unsigned long *mfnp)
 {
         unsigned long *p;
         unsigned i;
@@ -118,6 +149,8 @@ static void alloc_p2m(unsigned long **pp)
 
         if (cmpxchg(pp, p2m_missing, p) != p2m_missing)
                 free_page((unsigned long)p);
+        else
+                *mfnp = virt_to_mfn(p);
 }
 
 void set_phys_to_machine(unsigned long pfn, unsigned long mfn)
@@ -139,7 +172,7 @@ void set_phys_to_machine(unsigned long pfn, unsigned long mfn)
                 /* no need to allocate a page to store an invalid entry */
                 if (mfn == INVALID_P2M_ENTRY)
                         return;
-                alloc_p2m(&p2m_top[topidx]);
+                alloc_p2m(&p2m_top[topidx], &p2m_top_mfn[topidx]);
         }
 
         idx = p2m_index(pfn);
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 826d6e4c3dac..a1bc89a8f169 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -18,6 +18,8 @@ extern struct start_info *xen_start_info;
 extern struct shared_info xen_dummy_shared_info;
 extern struct shared_info *HYPERVISOR_shared_info;
 
+void xen_setup_mfn_list_list(void);
+
 char * __init xen_memory_setup(void);
 void __init xen_arch_setup(void);
 void __init xen_init_IRQ(void);