bitkeeper revision 1.15.1.10 (3e352084u4K_4YmnX6nhqxaJQrO-hQ)

Merge labyrinth.cl.cam.ac.uk:/usr/groups/xeno/BK/xeno
into labyrinth.cl.cam.ac.uk:/usr/groups/xeno/users/akw27/xeno

6 files changed, 194 insertions, 87 deletions

diff --git a/.rootkeys b/.rootkeys
index 84ae52496a..206a24d82b 100644
--- a/.rootkeys
+++ b/.rootkeys
@@ -39,6 +39,7 @@
 3ddb79bdrqnW93GR9gZk1OJe1qK-iQ xen-2.4.16/common/brlock.c
 3ddb79bdLX_P6iB7ILiblRLWvebapg xen-2.4.16/common/dom0_ops.c
 3ddb79bdYO5D8Av12NHqPeSviav7cg xen-2.4.16/common/domain.c
+3e32af9aRnYGl4GMOaDKp7JdfhOGhg xen-2.4.16/common/domain_page.c
 3ddb79bdeyutmaXEfpQvvxj7eQ0fCw xen-2.4.16/common/event.c
 3ddb79bd9drcFPVxd4w2GPOIjLlXpA xen-2.4.16/common/kernel.c
 3ddb79bduhSEZI8xa7IbGQCpap5y2A xen-2.4.16/common/lib.c
diff --git a/xen-2.4.16/Makefile b/xen-2.4.16/Makefile
index d057dcf7e0..846c0e6f12 100644
--- a/xen-2.4.16/Makefile
+++ b/xen-2.4.16/Makefile
@@ -24,7 +24,6 @@ $(TARGET): make-links
 	$(MAKE) -C net
 	$(MAKE) -C drivers
 	$(MAKE) -C arch/$(ARCH)
-	gzip -f -9 < $(TARGET) > $(TARGET).gz
 
 make-links:
 	ln -sf xeno include/linux
diff --git a/xen-2.4.16/common/domain.c b/xen-2.4.16/common/domain.c
index ea14a5ea21..1128cdfa15 100644
--- a/xen-2.4.16/common/domain.c
+++ b/xen-2.4.16/common/domain.c
@@ -410,7 +410,7 @@ int setup_guestos(struct task_struct *p, dom0_newdomain_t *params)
     unsigned int ft_size = 0;
     start_info_t  *virt_startinfo_address;
     unsigned long long time;
-    l2_pgentry_t *l2tab;
+    l2_pgentry_t *l2tab, *l2start;
     l1_pgentry_t *l1tab = NULL;
     struct pfn_info *page = NULL;
     net_ring_t *net_ring;
@@ -465,7 +465,7 @@ int setup_guestos(struct task_struct *p, dom0_newdomain_t *params)
      * filled in by now !!
      */
     phys_l2tab = ALLOC_FRAME_FROM_DOMAIN();
-    l2tab = map_domain_mem(phys_l2tab);
+    l2start = l2tab = map_domain_mem(phys_l2tab);
     memcpy(l2tab, idle_pg_table[p->processor], PAGE_SIZE);
     l2tab[PERDOMAIN_VIRT_START >> L2_PAGETABLE_SHIFT] =
         mk_l2_pgentry(__pa(p->mm.perdomain_pt) | __PAGE_HYPERVISOR);
@@ -486,17 +486,16 @@ int setup_guestos(struct task_struct *p, dom0_newdomain_t *params)
     if(dom == 0)
         ft_size = frame_table_size; 
 
-    phys_l2tab += l2_table_offset(virt_load_address)*sizeof(l2_pgentry_t);    
+    l2tab += l2_table_offset(virt_load_address);
     for ( cur_address  = start_address;
           cur_address != (end_address + PAGE_SIZE + ft_size);
           cur_address += PAGE_SIZE )
     {
         if ( !((unsigned long)l1tab & (PAGE_SIZE-1)) )
         {
+            if ( l1tab != NULL ) unmap_domain_mem(l1tab-1);
             phys_l1tab = ALLOC_FRAME_FROM_DOMAIN();
-            l2tab = map_domain_mem(phys_l2tab);
-            *l2tab = mk_l2_pgentry(phys_l1tab|L2_PROT);
-            phys_l2tab += sizeof(l2_pgentry_t);
+            *l2tab++ = mk_l2_pgentry(phys_l1tab|L2_PROT);
             l1tab = map_domain_mem(phys_l1tab);
             clear_page(l1tab);
             l1tab += l1_table_offset(
@@ -512,43 +511,39 @@ int setup_guestos(struct task_struct *p, dom0_newdomain_t *params)
             page->type_count = page->tot_count = 1;
         }
     }
+    unmap_domain_mem(l1tab-1);
     
     /* Pages that are part of page tables must be read-only. */
     vaddr = virt_load_address + alloc_address - start_address;
-    phys_l2tab = pagetable_val(p->mm.pagetable) +
-        (l2_table_offset(vaddr) * sizeof(l2_pgentry_t));
-    l2tab = map_domain_mem(phys_l2tab);
-    phys_l1tab = l2_pgentry_to_phys(*l2tab) +
-        (l1_table_offset(vaddr) * sizeof(l1_pgentry_t));
-    phys_l2tab += sizeof(l2_pgentry_t);
-    l1tab = map_domain_mem(phys_l1tab);
+    l2tab = l2start + l2_table_offset(vaddr);
+    l1tab = map_domain_mem(l2_pgentry_to_phys(*l2tab));
+    l1tab += l1_table_offset(vaddr);
+    l2tab++;
     for ( cur_address  = alloc_address;
           cur_address != end_address;
           cur_address += PAGE_SIZE )
     {
-        *l1tab++ = mk_l1_pgentry(l1_pgentry_val(*l1tab) & ~_PAGE_RW);
         if ( !((unsigned long)l1tab & (PAGE_SIZE-1)) )
         {
-            l2tab = map_domain_mem(phys_l2tab);
-            phys_l1tab = l2_pgentry_to_phys(*l2tab);
-            phys_l2tab += sizeof(l2_pgentry_t);
-            l1tab = map_domain_mem(phys_l1tab);
+            unmap_domain_mem(l1tab-1);
+            l1tab = map_domain_mem(l2_pgentry_to_phys(*l2tab));
+            l2tab++;
         }
+        *l1tab++ = mk_l1_pgentry(l1_pgentry_val(*l1tab) & ~_PAGE_RW);
         page = frame_table + (cur_address >> PAGE_SHIFT);
         page->flags = dom | PGT_l1_page_table;
         page->tot_count++;
     }
+    unmap_domain_mem(l1tab-1);
     page->flags = dom | PGT_l2_page_table;
 
     /* Map in the the shared info structure. */
     virt_shinfo_address = end_address - start_address + virt_load_address;
-    phys_l2tab = pagetable_val(p->mm.pagetable) +
-        (l2_table_offset(virt_shinfo_address) * sizeof(l2_pgentry_t));
-    l2tab = map_domain_mem(phys_l2tab);
-    phys_l1tab = l2_pgentry_to_phys(*l2tab) +
-        (l1_table_offset(virt_shinfo_address) * sizeof(l1_pgentry_t));
-    l1tab = map_domain_mem(phys_l1tab);
+    l2tab = l2start + l2_table_offset(virt_shinfo_address);
+    l1tab = map_domain_mem(l2_pgentry_to_phys(*l2tab));
+    l1tab += l1_table_offset(virt_shinfo_address);
     *l1tab = mk_l1_pgentry(__pa(p->shared_info)|L1_PROT);
+    unmap_domain_mem(l1tab);
 
     /* Set up shared info area. */
     rdtscll(time);
@@ -565,13 +560,11 @@ int setup_guestos(struct task_struct *p, dom0_newdomain_t *params)
             cur_address < virt_ftable_end_addr;
             cur_address += PAGE_SIZE)
         {
-            phys_l2tab = pagetable_val(p->mm.pagetable) +
-                (l2_table_offset(cur_address) * sizeof(l2_pgentry_t));
-            l2tab = map_domain_mem(phys_l2tab);
-            phys_l1tab = l2_pgentry_to_phys(*l2tab) + 
-                (l1_table_offset(cur_address) * sizeof(l1_pgentry_t)); 
-            l1tab = map_domain_mem(phys_l1tab);
+            l2tab = l2start + l2_table_offset(cur_address);
+            l1tab = map_domain_mem(l2_pgentry_to_phys(*l2tab));
+            l1tab += l1_table_offset(cur_address);
             *l1tab = mk_l1_pgentry(__pa(ft_mapping)|L1_PROT);
+            unmap_domain_mem(l1tab);
             ft_mapping += PAGE_SIZE;
         }
     }
@@ -580,6 +573,8 @@ int setup_guestos(struct task_struct *p, dom0_newdomain_t *params)
         (alloc_address - start_address - PAGE_SIZE + virt_load_address);
     virt_stack_address  = (unsigned long)virt_startinfo_address;
 
+    unmap_domain_mem(l2start);
+
     /* Install the new page tables. */
     __cli();
     __write_cr3_counted(pagetable_val(p->mm.pagetable));
diff --git a/xen-2.4.16/common/domain_page.c b/xen-2.4.16/common/domain_page.c
new file mode 100644
index 0000000000..2e37b72c5c
--- /dev/null
+++ b/xen-2.4.16/common/domain_page.c
@@ -0,0 +1,67 @@
+/******************************************************************************
+ * domain_page.h
+ * 
+ * Allow temporary mapping of domain pages. Based on ideas from the
+ * Linux PKMAP code -- the copyrights and credits are retained below.
+ */
+
+/*
+ * (C) 1999 Andrea Arcangeli, SuSE GmbH, andrea@suse.de
+ *          Gerhard Wichert, Siemens AG, Gerhard.Wichert@pdb.siemens.de *
+ * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
+ */
+
+#include <xeno/config.h>
+#include <xeno/sched.h>
+#include <xeno/mm.h>
+#include <asm/domain_page.h>
+#include <asm/pgalloc.h>
+
+static unsigned int map_idx[NR_CPUS];
+
+/* Use a spare PTE bit to mark entries ready for recycling. */
+#define READY_FOR_TLB_FLUSH (1<<10)
+
+static void flush_all_ready_maps(void)
+{
+    unsigned long *cache = mapcache[smp_processor_id()];
+
+    /* A bit skanky -- depends on having an aligned PAGE_SIZE set of PTEs. */
+    do { if ( (*cache & READY_FOR_TLB_FLUSH) ) *cache = 0; }
+    while ( ((unsigned long)(++cache) & ~PAGE_MASK) != 0 );
+
+    local_flush_tlb();
+}
+
+
+void *map_domain_mem(unsigned long pa)
+{
+    unsigned long va;
+    int cpu = smp_processor_id();
+    unsigned int idx;
+    unsigned long *cache = mapcache[cpu];
+    unsigned long flags;
+
+    local_irq_save(flags);
+
+    for ( ; ; )
+    {
+        idx = map_idx[cpu] = (map_idx[cpu] + 1) & (MAPCACHE_ENTRIES - 1);
+        if ( idx == 0 ) flush_all_ready_maps();
+        if ( cache[idx] == 0 ) break;
+    }
+
+    cache[idx] = (pa & PAGE_MASK) | PAGE_HYPERVISOR;
+
+    local_irq_restore(flags);
+
+    va = MAPCACHE_VIRT_START + (idx << PAGE_SHIFT) + (pa & ~PAGE_MASK);
+    return (void *)va;
+}
+
+void unmap_domain_mem(void *va)
+{
+    unsigned int idx;
+    idx = ((unsigned long)va - MAPCACHE_VIRT_START) >> PAGE_SHIFT;
+    mapcache[smp_processor_id()][idx] |= READY_FOR_TLB_FLUSH;
+}
diff --git a/xen-2.4.16/common/memory.c b/xen-2.4.16/common/memory.c
index 836e27abac..2e6697a0b8 100644
--- a/xen-2.4.16/common/memory.c
+++ b/xen-2.4.16/common/memory.c
@@ -182,13 +182,17 @@
 #define MEM_LOG(_f, _a...) ((void)0)
 #endif
 
+/* Domain 0 is allowed to submit requests on behalf of others. */
+#define DOMAIN_OKAY(_f) \
+    ((((_f) & PG_domain_mask) == current->domain) || (current->domain == 0))
+
 /* 'get' checks parameter for validity before inc'ing refcnt. */
 static int get_l2_table(unsigned long page_nr);
 static int get_l1_table(unsigned long page_nr);
 static int get_page(unsigned long page_nr, int writeable);
 static int inc_page_refcnt(unsigned long page_nr, unsigned int type);
 /* 'put' does no checking because if refcnt not zero, entity must be valid. */
-static int  put_l2_table(unsigned long page_nr);
+static void put_l2_table(unsigned long page_nr);
 static void put_l1_table(unsigned long page_nr);
 static void put_page(unsigned long page_nr, int writeable);
 static int dec_page_refcnt(unsigned long page_nr, unsigned int type);
@@ -248,14 +252,14 @@ static int inc_page_refcnt(unsigned long page_nr, unsigned int type)
     if ( page_nr >= max_page )
     {
         MEM_LOG("Page out of range (%08lx>%08lx)", page_nr, max_page);
-        return(-1);
+        return -1;
     }
     page = frame_table + page_nr;
     flags = page->flags;
-    if ( (flags & PG_domain_mask) != current->domain )
+    if ( !DOMAIN_OKAY(flags) )
     {
         MEM_LOG("Bad page domain (%ld)", flags & PG_domain_mask);
-        return(-1);
+        return -1;
     }
     if ( (flags & PG_type_mask) != type )
     {
@@ -264,13 +268,13 @@ static int inc_page_refcnt(unsigned long page_nr, unsigned int type)
             MEM_LOG("Page %08lx bad type/count (%08lx!=%08x) cnt=%ld",
                     page_nr << PAGE_SHIFT,
                     flags & PG_type_mask, type, page_type_count(page));
-            return(-1);
+            return -1;
         }
         page->flags |= type;
     }
 
     get_page_tot(page);
-    return(get_page_type(page));
+    return get_page_type(page);
 }
 
 /* Return new refcnt, or -1 on error. */
@@ -282,21 +286,46 @@ static int dec_page_refcnt(unsigned long page_nr, unsigned int type)
     if ( page_nr >= max_page )
     {
         MEM_LOG("Page out of range (%08lx>%08lx)", page_nr, max_page);
-        return(-1);
+        return -1;
     }
     page = frame_table + page_nr;
-    if ( (page->flags & (PG_type_mask | PG_domain_mask)) != 
-         (type | current->domain) ) 
+    if ( !DOMAIN_OKAY(page->flags) || 
+         ((page->flags & PG_type_mask) != type) ) 
     {
         MEM_LOG("Bad page type/domain (dom=%ld) (type %ld != expected %d)",
                 page->flags & PG_domain_mask, page->flags & PG_type_mask,
                 type);
-        return(-1);
+        return -1;
     }
     ASSERT(page_type_count(page) != 0);
     if ( (ret = put_page_type(page)) == 0 ) page->flags &= ~PG_type_mask;
     put_page_tot(page);
-    return(ret);
+    return ret;
+}
+
+
+/* We allow a L2 table to map itself, to achieve a linear pagetable. */
+/* NB. There's no need for a put_twisted_l2_table() function!! */
+static int get_twisted_l2_table(unsigned long entry_pfn, l2_pgentry_t l2e)
+{
+    unsigned long l2v = l2_pgentry_val(l2e);
+
+    /* Clearly the mapping must be read-only :-) */
+    if ( (l2v & _PAGE_RW) )
+    {
+        MEM_LOG("Attempt to install twisted L2 entry with write permissions");
+        return -1;
+    }
+
+    /* This is a sufficient final check. */
+    if ( (l2v >> PAGE_SHIFT) != entry_pfn )
+    {
+        MEM_LOG("L2 tables may not map _other_ L2 tables!\n");
+        return -1;
+    }
+    
+    /* We don't bump the reference counts. */
+    return 0;
 }
 
 
@@ -306,7 +335,7 @@ static int get_l2_table(unsigned long page_nr)
     int i, ret=0;
     
     ret = inc_page_refcnt(page_nr, PGT_l2_page_table);
-    if ( ret != 0 ) return((ret < 0) ? ret : 0);
+    if ( ret != 0 ) return (ret < 0) ? ret : 0;
     
     /* NEW level-2 page table! Deal with every PDE in the table. */
     p_l2_entry = map_domain_mem(page_nr << PAGE_SHIFT);
@@ -318,12 +347,13 @@ static int get_l2_table(unsigned long page_nr)
         {
             MEM_LOG("Bad L2 page type settings %04lx",
                     l2_pgentry_val(l2_entry) & (_PAGE_GLOBAL|_PAGE_PSE));
-            return(-1);
+            ret = -1;
+            goto out;
         }
+        /* Assume we're mapping an L1 table, falling back to twisted L2. */
         ret = get_l1_table(l2_pgentry_to_pagenr(l2_entry));
-        if ( ret ) return(ret);
-        p_l2_entry = map_domain_mem((page_nr << PAGE_SHIFT) + 
-                                    ((i+1) * sizeof(l2_pgentry_t)));
+        if ( ret ) ret = get_twisted_l2_table(page_nr, l2_entry);
+        if ( ret ) goto out;
     }
 
     /* Now we simply slap in our high mapping. */
@@ -334,7 +364,9 @@ static int get_l2_table(unsigned long page_nr)
               DOMAIN_ENTRIES_PER_L2_PAGETABLE] =
         mk_l2_pgentry(__pa(current->mm.perdomain_pt) | __PAGE_HYPERVISOR);
 
-    return(ret);
+ out:
+    unmap_domain_mem(p_l2_entry);
+    return ret;
 }
 
 static int get_l1_table(unsigned long page_nr)
@@ -344,7 +376,7 @@ static int get_l1_table(unsigned long page_nr)
 
     /* Update ref count for page pointed at by PDE. */
     ret = inc_page_refcnt(page_nr, PGT_l1_page_table);
-    if ( ret != 0 ) return((ret < 0) ? ret : 0);
+    if ( ret != 0 ) return (ret < 0) ? ret : 0;
 
     /* NEW level-1 page table! Deal with every PTE in the table. */
     p_l1_entry = map_domain_mem(page_nr << PAGE_SHIFT);
@@ -358,14 +390,18 @@ static int get_l1_table(unsigned long page_nr)
             MEM_LOG("Bad L1 page type settings %04lx",
                     l1_pgentry_val(l1_entry) &
                     (_PAGE_GLOBAL|_PAGE_PAT));
-            return(-1);
+            ret = -1;
+            goto out;
         }
         ret = get_page(l1_pgentry_to_pagenr(l1_entry),
                        l1_pgentry_val(l1_entry) & _PAGE_RW);
-        if ( ret ) return(ret);
+        if ( ret ) goto out;
     }
 
-    return(ret);
+ out:
+    /* Make sure we unmap the right page! */
+    unmap_domain_mem(p_l1_entry-1);
+    return ret;
 }
 
 static int get_page(unsigned long page_nr, int writeable)
@@ -381,7 +417,7 @@ static int get_page(unsigned long page_nr, int writeable)
     }
     page = frame_table + page_nr;
     flags = page->flags;
-    if ( (flags & PG_domain_mask) != current->domain )
+    if ( !DOMAIN_OKAY(flags) )
     {
         MEM_LOG("Bad page domain (%ld)", flags & PG_domain_mask);
         return(-1);
@@ -408,28 +444,23 @@ static int get_page(unsigned long page_nr, int writeable)
     return(0);
 }
 
-static int put_l2_table(unsigned long page_nr)
+static void put_l2_table(unsigned long page_nr)
 {
     l2_pgentry_t *p_l2_entry, l2_entry;
-    int i, ret;
+    int i;
 
-    ret = dec_page_refcnt(page_nr, PGT_l2_page_table);
-    if ( ret != 0 ) return((ret < 0) ? ret : 0);
+    if ( dec_page_refcnt(page_nr, PGT_l2_page_table) ) return;
 
     /* We had last reference to level-2 page table. Free the PDEs. */
     p_l2_entry = map_domain_mem(page_nr << PAGE_SHIFT);
-    for ( i = 0; i < HYPERVISOR_ENTRIES_PER_L2_PAGETABLE; i++ )
+    for ( i = 0; i < DOMAIN_ENTRIES_PER_L2_PAGETABLE; i++ )
     {
         l2_entry = *p_l2_entry++;
         if ( (l2_pgentry_val(l2_entry) & _PAGE_PRESENT) )
-        { 
             put_l1_table(l2_pgentry_to_pagenr(l2_entry));
-            p_l2_entry = map_domain_mem((page_nr << PAGE_SHIFT) + 
-                                        ((i+1) * sizeof(l2_pgentry_t)));
-        }
     }
 
-    return(0);
+    unmap_domain_mem(p_l2_entry);
 }
 
 static void put_l1_table(unsigned long page_nr)
@@ -437,7 +468,7 @@ static void put_l1_table(unsigned long page_nr)
     l1_pgentry_t *p_l1_entry, l1_entry;
     int i;
 
-    if ( dec_page_refcnt(page_nr, PGT_l1_page_table) != 0 ) return;
+    if ( dec_page_refcnt(page_nr, PGT_l1_page_table) ) return;
 
     /* We had last reference to level-1 page table. Free the PTEs. */
     p_l1_entry = map_domain_mem(page_nr << PAGE_SHIFT);
@@ -450,6 +481,9 @@ static void put_l1_table(unsigned long page_nr)
                      l1_pgentry_val(l1_entry) & _PAGE_RW);
         }
     }
+
+    /* Make sure we unmap the right page! */
+    unmap_domain_mem(p_l1_entry-1);
 }
 
 static void put_page(unsigned long page_nr, int writeable)
@@ -457,7 +491,7 @@ static void put_page(unsigned long page_nr, int writeable)
     struct pfn_info *page;
     ASSERT(page_nr < max_page);
     page = frame_table + page_nr;
-    ASSERT((page->flags & PG_domain_mask) == current->domain);
+    ASSERT(DOMAIN_OKAY(page->flags));
     ASSERT((!writeable) || 
            ((page_type_count(page) != 0) && 
             ((page->flags & PG_type_mask) == PGT_writeable_page)));
@@ -485,12 +519,6 @@ static int mod_l2_entry(unsigned long pa, l2_pgentry_t new_l2_entry)
         goto fail;
     }
 
-    /*
-     * Write the new value while pointer is still valid. The mapping cache 
-     * entry for p_l2_entry may get clobbered by {put,get}_l1_table.
-     */
-    *p_l2_entry = new_l2_entry;
-
     if ( (l2_pgentry_val(new_l2_entry) & _PAGE_PRESENT) )
     {
         if ( (l2_pgentry_val(new_l2_entry) & (_PAGE_GLOBAL|_PAGE_PSE)) )
@@ -509,7 +537,9 @@ static int mod_l2_entry(unsigned long pa, l2_pgentry_t new_l2_entry)
                 put_l1_table(l2_pgentry_to_pagenr(old_l2_entry));
             }
             
-            if ( get_l1_table(l2_pgentry_to_pagenr(new_l2_entry)) )
+            /* Assume we're mapping an L1 table, falling back to twisted L2. */
+            if ( get_l1_table(l2_pgentry_to_pagenr(new_l2_entry)) &&
+                 get_twisted_l2_table(pa >> PAGE_SHIFT, new_l2_entry) )
                 goto fail;
         } 
     }
@@ -518,16 +548,13 @@ static int mod_l2_entry(unsigned long pa, l2_pgentry_t new_l2_entry)
         put_l1_table(l2_pgentry_to_pagenr(old_l2_entry));
     }
     
-    return(0);
+    *p_l2_entry = new_l2_entry;
+    unmap_domain_mem(p_l2_entry);
+    return 0;
 
  fail:
-    /*
-     * On failure we put the old value back. We need to regrab the
-     * mapping of the physical page frame.
-     */
-    p_l2_entry = map_domain_mem(pa);
-    *p_l2_entry = old_l2_entry;
-    return(-1);
+    unmap_domain_mem(p_l2_entry);
+    return -1;
 }
 
 
@@ -572,12 +599,13 @@ static int mod_l1_entry(unsigned long pa, l1_pgentry_t new_l1_entry)
                  l1_pgentry_val(old_l1_entry) & _PAGE_RW);
     }
 
-    /* p_l1_entry is still valid here */
     *p_l1_entry = new_l1_entry;
+    unmap_domain_mem(p_l1_entry);
+    return 0;
 
-    return(0);
  fail:
-    return(-1);
+    unmap_domain_mem(p_l1_entry);
+    return -1;
 }
 
 
@@ -615,7 +643,7 @@ static int do_extended_command(unsigned long ptr, unsigned long val)
         break;
 
     case PGEXT_UNPIN_TABLE:
-        if ( (page->flags & PG_domain_mask) != current->domain )
+        if ( !DOMAIN_OKAY(page->flags) )
         {
             err = 1;
             MEM_LOG("Page %08lx bad domain (dom=%ld)",
@@ -701,7 +729,7 @@ int do_process_page_updates(page_update_request_t *updates, int count)
         case PGREQ_NORMAL:
             page = frame_table + pfn;
             flags = page->flags;
-            if ( (flags & PG_domain_mask) == current->domain )
+            if ( DOMAIN_OKAY(flags) )
             {
                 switch ( (flags & PG_type_mask) )
                 {
@@ -731,8 +759,9 @@ int do_process_page_updates(page_update_request_t *updates, int count)
             flags = page->flags;
             if ( (flags | current->domain) == PGT_l1_page_table )
             {
-                
-                *(unsigned long *)map_domain_mem(cur.ptr) = cur.val;
+                unsigned long *va = map_domain_mem(cur.ptr);
+                *va = cur.val;
+                unmap_domain_mem(va);
                 err = 0;
             }
             else
diff --git a/xen-2.4.16/include/asm-i386/domain_page.h b/xen-2.4.16/include/asm-i386/domain_page.h
index a8e4c71013..bae558c377 100644
--- a/xen-2.4.16/include/asm-i386/domain_page.h
+++ b/xen-2.4.16/include/asm-i386/domain_page.h
@@ -9,6 +9,21 @@
 
 extern unsigned long *mapcache[NR_CPUS];
 #define MAPCACHE_ENTRIES        1024
+
+/*
+ * Maps a given physical address, returning corresponding virtual address.
+ * The entire page containing that VA is now accessible until a 
+ * corresponding call to unmap_domain_mem().
+ */
+extern void *map_domain_mem(unsigned long pa);
+
+/*
+ * Pass a VA within a page previously mapped with map_domain_mem().
+ * That page will then be removed from the mapping lists.
+ */
+extern void unmap_domain_mem(void *va);
+
+#if 0
 #define MAPCACHE_HASH(_pfn)     ((_pfn) & (MAPCACHE_ENTRIES-1))
 static inline void *map_domain_mem(unsigned long pa)
 {
@@ -25,3 +40,4 @@ static inline void *map_domain_mem(unsigned long pa)
     }
     return va;
 }
+#endif