[Xen-changelog] Fix MPT mapping for x86/64. Also i386 no longer needs

[Xen patchbot -unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID f7cdd99d11065bf684002bce8415eda97f09e5df
# Parent  98a6eb458c783cbbb8f19e5713a4ad8a1ea830c6
Fix MPT mapping for x86/64. Also i386 no longer needs
4MB mapping for PAE, as xenlinux can handle faults when
accessing unmapped sections of the table.

Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>

diff -r 98a6eb458c78 -r f7cdd99d1106 xen/arch/x86/x86_32/mm.c
--- a/xen/arch/x86/x86_32/mm.c  Thu Aug 25 16:25:26 2005
+++ b/xen/arch/x86/x86_32/mm.c  Thu Aug 25 17:15:41 2005
@@ -93,15 +93,10 @@
 
     /*
      * Allocate and map the machine-to-phys table and create read-only mapping 
-     * of MPT for guest-OS use.  Without PAE we'll end up with one 4MB page, 
-     * with PAE we'll allocate 2MB pages depending on the amount of memory 
-     * installed, but at least 4MB to cover 4GB address space.  This is needed 
-     * to make PCI I/O memory address lookups work in guests.
+     * of MPT for guest-OS use.
      */
     mpt_size  = (max_page * 4) + (1UL << L2_PAGETABLE_SHIFT) - 1UL;
     mpt_size &= ~((1UL << L2_PAGETABLE_SHIFT) - 1UL);
-    if ( mpt_size < (4 << 20) )
-        mpt_size = 4 << 20;
     for ( i = 0; i < (mpt_size >> L2_PAGETABLE_SHIFT); i++ )
     {
         if ( (pg = alloc_domheap_pages(NULL, PAGETABLE_ORDER, 0)) == NULL )
diff -r 98a6eb458c78 -r f7cdd99d1106 xen/arch/x86/x86_64/mm.c
--- a/xen/arch/x86/x86_64/mm.c  Thu Aug 25 16:25:26 2005
+++ b/xen/arch/x86/x86_64/mm.c  Thu Aug 25 17:15:41 2005
@@ -74,7 +74,7 @@
 
 void __init paging_init(void)
 {
-    unsigned long i;
+    unsigned long i, mpt_size;
     l3_pgentry_t *l3_ro_mpt;
     l2_pgentry_t *l2_ro_mpt;
     struct pfn_info *pg;
@@ -98,16 +98,17 @@
      * Allocate and map the machine-to-phys table.
      * This also ensures L3 is present for fixmaps.
      */
-    for ( i = 0; i < max_page; i += ((1UL << L2_PAGETABLE_SHIFT) / 4) )
-    {
-        pg = alloc_domheap_pages(NULL, PAGETABLE_ORDER, 0);
-        if ( pg == NULL )
+    mpt_size  = (max_page * 4) + (1UL << L2_PAGETABLE_SHIFT) - 1UL;
+    mpt_size &= ~((1UL << L2_PAGETABLE_SHIFT) - 1UL);
+    for ( i = 0; i < (mpt_size >> L2_PAGETABLE_SHIFT); i++ )
+    {
+        if ( (pg = alloc_domheap_pages(NULL, PAGETABLE_ORDER, 0)) == NULL )
             panic("Not enough memory for m2p table\n");
         map_pages_to_xen(
-            RDWR_MPT_VIRT_START + i*8, page_to_pfn(pg), 
+            RDWR_MPT_VIRT_START + (i << L2_PAGETABLE_SHIFT), page_to_pfn(pg), 
             1UL << PAGETABLE_ORDER,
             PAGE_HYPERVISOR);
-        memset((void *)(RDWR_MPT_VIRT_START + i*8), 0x55,
+        memset((void *)(RDWR_MPT_VIRT_START + (i << L2_PAGETABLE_SHIFT)), 0x55,
                1UL << L2_PAGETABLE_SHIFT);
         *l2_ro_mpt++ = l2e_from_page(
             pg, _PAGE_GLOBAL|_PAGE_PSE|_PAGE_USER|_PAGE_PRESENT);

_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog