diff mbox series

[RFC,48/84] x86_64/mm: map and unmap page tables in subarch_init_memory

Message ID 931bc9eed0fa7f6fa9ca81f4c7c8c436d18b6819.1569489002.git.hongyax@amazon.com (mailing list archive)
State New, archived
Headers show
Series Remove direct map from Xen | expand

Commit Message

Xia, Hongyan Sept. 26, 2019, 9:46 a.m. UTC 
From: Wei Liu <wei.liu2@citrix.com>

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 xen/arch/x86/x86_64/mm.c | 31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)
diff mbox series

Patch

diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c
index bbdf1ee47c..7483f8f23d 100644
--- a/xen/arch/x86/x86_64/mm.c
+++ b/xen/arch/x86/x86_64/mm.c
@@ -930,8 +930,8 @@  static int extend_frame_table(struct mem_hotadd_info *info)
 void __init subarch_init_memory(void)
 {
     unsigned long i, n, v, m2p_start_mfn;
-    l3_pgentry_t l3e;
-    l2_pgentry_t l2e;
+    l3_pgentry_t l3e, *l3t;
+    l2_pgentry_t l2e, *l2t;
 
     BUILD_BUG_ON(RDWR_MPT_VIRT_START & ((1UL << L3_PAGETABLE_SHIFT) - 1));
     BUILD_BUG_ON(RDWR_MPT_VIRT_END   & ((1UL << L3_PAGETABLE_SHIFT) - 1));
@@ -941,14 +941,22 @@  void __init subarch_init_memory(void)
           v += n << PAGE_SHIFT )
     {
         n = L2_PAGETABLE_ENTRIES * L1_PAGETABLE_ENTRIES;
-        l3e = l4e_to_l3e(idle_pg_table[l4_table_offset(v)])[
-            l3_table_offset(v)];
+
+        l3t = map_xen_pagetable_new(
+            l4e_get_mfn(idle_pg_table[l4_table_offset(v)]));
+        l3e = l3t[l3_table_offset(v)];
+        UNMAP_XEN_PAGETABLE_NEW(l3t);
+
         if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) )
             continue;
         if ( !(l3e_get_flags(l3e) & _PAGE_PSE) )
         {
             n = L1_PAGETABLE_ENTRIES;
-            l2e = l3e_to_l2e(l3e)[l2_table_offset(v)];
+
+            l2t = map_xen_pagetable_new(l3e_get_mfn(l3e));
+            l2e = l2t[l2_table_offset(v)];
+            UNMAP_XEN_PAGETABLE_NEW(l2t);
+
             if ( !(l2e_get_flags(l2e) & _PAGE_PRESENT) )
                 continue;
             m2p_start_mfn = l2e_get_pfn(l2e);
@@ -967,11 +975,18 @@  void __init subarch_init_memory(void)
           v != RDWR_COMPAT_MPT_VIRT_END;
           v += 1 << L2_PAGETABLE_SHIFT )
     {
-        l3e = l4e_to_l3e(idle_pg_table[l4_table_offset(v)])[
-            l3_table_offset(v)];
+        l3t = map_xen_pagetable_new(
+            l4e_get_mfn(idle_pg_table[l4_table_offset(v)]));
+        l3e = l3t[l3_table_offset(v)];
+        UNMAP_XEN_PAGETABLE_NEW(l3t);
+
         if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) )
             continue;
-        l2e = l3e_to_l2e(l3e)[l2_table_offset(v)];
+
+        l2t = map_xen_pagetable_new(l3e_get_mfn(l3e));
+        l2e = l2t[l2_table_offset(v)];
+        UNMAP_XEN_PAGETABLE_NEW(l2t);
+
         if ( !(l2e_get_flags(l2e) & _PAGE_PRESENT) )
             continue;
         m2p_start_mfn = l2e_get_pfn(l2e);