Mailing List Archive

# HG changeset patch
# User Keir Fraser <keir@xensource.com>
# Date 1187968754 -3600
# Node ID f279d776fcb0fd3d06c96e6e9b46d71bc1156968
# Parent 1892f4a9822fe0993c758a4c4719082a0dd5baa6
x86: Fix paging_init() to not overwrite existing page-directory entry
for fixmap area.
Signed-off-by: Keir Fraser <keir@xensource.com>
---
xen/arch/x86/x86_32/mm.c | 15 +++++++++------
xen/arch/x86/x86_64/mm.c | 8 ++++----
2 files changed, 13 insertions(+), 10 deletions(-)

diff -r 1892f4a9822f -r f279d776fcb0 xen/arch/x86/x86_32/mm.c
--- a/xen/arch/x86/x86_32/mm.c Fri Aug 17 16:48:10 2007 +0100
+++ b/xen/arch/x86/x86_32/mm.c Fri Aug 24 16:19:14 2007 +0100
@@ -68,7 +68,6 @@ l2_pgentry_t *virt_to_xen_l2e(unsigned l

void __init paging_init(void)
{
- void *ioremap_pt;
unsigned long v;
struct page_info *pg;
int i;
@@ -115,13 +114,17 @@ void __init paging_init(void)
for ( i = 0; i < (mpt_size / BYTES_PER_LONG); i++)
set_gpfn_from_mfn(i, 0x55555555);

- /* Create page tables for ioremap(). */
+ /* Create page tables for ioremap()/map_domain_page_global(). */
for ( i = 0; i < (IOREMAP_MBYTES >> (L2_PAGETABLE_SHIFT - 20)); i++ )
{
- ioremap_pt = alloc_xenheap_page();
- clear_page(ioremap_pt);
- l2e_write(&idle_pg_table_l2[l2_linear_offset(IOREMAP_VIRT_START) + i],
- l2e_from_page(virt_to_page(ioremap_pt), __PAGE_HYPERVISOR));
+ void *p;
+ l2_pgentry_t *pl2e;
+ pl2e = &idle_pg_table_l2[l2_linear_offset(IOREMAP_VIRT_START) + i];
+ if ( l2e_get_flags(*pl2e) & _PAGE_PRESENT )
+ continue;
+ p = alloc_xenheap_page();
+ clear_page(p);
+ l2e_write(pl2e, l2e_from_page(virt_to_page(p), __PAGE_HYPERVISOR));
}
}

diff -r 1892f4a9822f -r f279d776fcb0 xen/arch/x86/x86_64/mm.c
--- a/xen/arch/x86/x86_64/mm.c Fri Aug 17 16:48:10 2007 +0100
+++ b/xen/arch/x86/x86_64/mm.c Fri Aug 24 16:19:14 2007 +0100
@@ -100,15 +100,15 @@ void __init paging_init(void)
unsigned long i, mpt_size, va;
l3_pgentry_t *l3_ro_mpt;
l2_pgentry_t *l2_ro_mpt = NULL;
- struct page_info *l1_pg, *l2_pg;
+ struct page_info *l1_pg, *l2_pg, *l3_pg;

/* Create user-accessible L2 directory to map the MPT for guests. */
- if ( (l2_pg = alloc_domheap_page(NULL)) == NULL )
+ if ( (l3_pg = alloc_domheap_page(NULL)) == NULL )
goto nomem;
- l3_ro_mpt = page_to_virt(l2_pg);
+ l3_ro_mpt = page_to_virt(l3_pg);
clear_page(l3_ro_mpt);
l4e_write(&idle_pg_table[l4_table_offset(RO_MPT_VIRT_START)],
- l4e_from_page(l2_pg, __PAGE_HYPERVISOR | _PAGE_USER));
+ l4e_from_page(l3_pg, __PAGE_HYPERVISOR | _PAGE_USER));

/*
* Allocate and map the machine-to-phys table.

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