Jan Beulich
2012-Sep-11 11:37 UTC
[PATCH 2/2] x86-64: construct static, uniform parts of page tables at build time
... rather than at boot time, removing unnecessary redundancy between
EFI and legacy boot code.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/xen/arch/x86/boot/head.S
+++ b/xen/arch/x86/boot/head.S
@@ -123,46 +123,19 @@ __start:
/* Check for availability of long mode. */
bt $29,%edx
jnc bad_cpu
- /* Initialise L2 identity-map and xen page table entries (16MB). */
- mov $sym_phys(l2_xenmap),%esi
+ /* Initialise L2 boot-map page table entries (16MB). */
mov $sym_phys(l2_bootmap),%edx
- mov $0x1e3,%eax /* PRESENT+RW+A+D+2MB+GLOBAL */
+ mov $PAGE_HYPERVISOR|_PAGE_PSE,%eax
mov $8,%ecx
-1: mov %eax,(%esi)
- add $8,%esi
- mov %eax,(%edx)
+1: mov %eax,(%edx)
add $8,%edx
add $(1<<L2_PAGETABLE_SHIFT),%eax
loop 1b
- /* Initialise L2 fixmap page directory entry. */
- mov $(sym_phys(l1_fixmap)+7),%eax
- mov %eax,sym_phys(l2_fixmap) + l2_table_offset(FIXADDR_TOP-1)*8
- /* Initialise L3 identity-map page directory entries. */
- mov $sym_phys(l3_identmap),%edi
- mov $(sym_phys(l2_identmap)+7),%eax
- mov $4,%ecx
-1: mov %eax,(%edi)
- add $8,%edi
- add $PAGE_SIZE,%eax
- loop 1b
- /* Initialise L3 xen-map and fixmap page directory entries. */
- mov $(sym_phys(l2_xenmap)+7),%eax
- mov %eax,sym_phys(l3_xenmap) + l3_table_offset(XEN_VIRT_START)*8
- mov $(sym_phys(l2_fixmap)+7),%eax
- mov %eax,sym_phys(l3_xenmap) + l3_table_offset(FIXADDR_TOP-1)*8
/* Initialise L3 boot-map page directory entry. */
- mov $(sym_phys(l2_bootmap)+7),%eax
+ mov $sym_phys(l2_bootmap)+__PAGE_HYPERVISOR,%eax
mov %eax,sym_phys(l3_bootmap) + 0*8
- /* Hook identity-map, xen-map, and boot-map L3 tables into PML4. */
- mov $(sym_phys(l3_bootmap)+7),%eax
- mov %eax,sym_phys(idle_pg_table) + 0*8
- mov $(sym_phys(l3_identmap)+7),%eax
- mov %eax,sym_phys(idle_pg_table) +
l4_table_offset(DIRECTMAP_VIRT_START)*8
- mov $(sym_phys(l3_xenmap)+7),%eax
- mov %eax,sym_phys(idle_pg_table) +
l4_table_offset(XEN_VIRT_START)*8
/* Hook 4kB mappings of first 2MB of memory into L2. */
mov $sym_phys(l1_identmap)+__PAGE_HYPERVISOR,%edi
- mov %edi,sym_phys(l2_identmap)
mov %edi,sym_phys(l2_xenmap)
mov %edi,sym_phys(l2_bootmap)
#endif
--- a/xen/arch/x86/boot/x86_64.S
+++ b/xen/arch/x86/boot/x86_64.S
@@ -128,10 +128,13 @@ ENTRY(boot_cpu_compat_gdt_table)
.quad 0x0000910000000000 /* per-CPU entry (limit == cpu) */
.align PAGE_SIZE, 0
+ .globl __page_tables_start, __page_tables_end
+__page_tables_start:
+
/* Mapping of first 16 megabytes of memory. */
.globl l2_identmap
l2_identmap:
- .quad 0
+ .quad sym_phys(l1_identmap) + __PAGE_HYPERVISOR
pfn = 0
.rept 7
pfn = pfn + (1 << PAGETABLE_ORDER)
@@ -139,3 +142,68 @@ l2_identmap:
.endr
.fill 4 * L2_PAGETABLE_ENTRIES - 8, 8, 0
.size l2_identmap, . - l2_identmap
+
+ .globl l2_xenmap
+l2_xenmap:
+ idx = 0
+ .rept 8
+ .quad sym_phys(__image_base__) + (idx << L2_PAGETABLE_SHIFT) +
(PAGE_HYPERVISOR | _PAGE_PSE)
+ idx = idx + 1
+ .endr
+ .fill L2_PAGETABLE_ENTRIES - 8, 8, 0
+ .size l2_xenmap, . - l2_xenmap
+
+l2_fixmap:
+ idx = 0
+ .rept L2_PAGETABLE_ENTRIES
+ .if idx == l2_table_offset(FIXADDR_TOP - 1)
+ .quad sym_phys(l1_fixmap) + __PAGE_HYPERVISOR
+ .else
+ .quad 0
+ .endif
+ idx = idx + 1
+ .endr
+ .size l2_fixmap, . - l2_fixmap
+
+ .globl l3_identmap
+l3_identmap:
+ idx = 0
+ .rept 4
+ .quad sym_phys(l2_identmap) + (idx << PAGE_SHIFT) +
__PAGE_HYPERVISOR
+ idx = idx + 1
+ .endr
+ .fill L3_PAGETABLE_ENTRIES - 4, 8, 0
+ .size l3_identmap, . - l3_identmap
+
+l3_xenmap:
+ idx = 0
+ .rept L3_PAGETABLE_ENTRIES
+ .if idx == l3_table_offset(XEN_VIRT_START)
+ .quad sym_phys(l2_xenmap) + __PAGE_HYPERVISOR
+ .elseif idx == l3_table_offset(FIXADDR_TOP - 1)
+ .quad sym_phys(l2_fixmap) + __PAGE_HYPERVISOR
+ .else
+ .quad 0
+ .endif
+ idx = idx + 1
+ .endr
+ .size l3_xenmap, . - l3_xenmap
+
+/* Top-level master (and idle-domain) page directory. */
+ .globl idle_pg_table
+idle_pg_table:
+ .quad sym_phys(l3_bootmap) + __PAGE_HYPERVISOR
+ idx = 1
+ .rept L4_PAGETABLE_ENTRIES - 1
+ .if idx == l4_table_offset(DIRECTMAP_VIRT_START)
+ .quad sym_phys(l3_identmap) + __PAGE_HYPERVISOR
+ .elseif idx == l4_table_offset(XEN_VIRT_START)
+ .quad sym_phys(l3_xenmap) + __PAGE_HYPERVISOR
+ .else
+ .quad 0
+ .endif
+ idx = idx + 1
+ .endr
+ .size idle_pg_table, . - idle_pg_table
+
+__page_tables_end:
--- a/xen/arch/x86/efi/boot.c
+++ b/xen/arch/x86/efi/boot.c
@@ -573,6 +573,10 @@ static int __init set_color(u32 mask, in
return max(*pos + *sz, bpp);
}
+extern const intpte_t __page_tables_start[], __page_tables_end[];
+#define in_page_tables(v) ((intpte_t *)(v) >= __page_tables_start &&
\
+ (intpte_t *)(v) < __page_tables_end)
+
#define PE_BASE_RELOC_ABS 0
#define PE_BASE_RELOC_HIGHLOW 3
#define PE_BASE_RELOC_DIR64 10
@@ -604,11 +608,19 @@ static void __init relocate_image(unsign
break;
case PE_BASE_RELOC_HIGHLOW:
if ( delta )
+ {
*(u32 *)addr += delta;
+ if ( in_page_tables(addr) )
+ *(u32 *)addr += xen_phys_start;
+ }
break;
case PE_BASE_RELOC_DIR64:
if ( delta )
+ {
*(u64 *)addr += delta;
+ if ( in_page_tables(addr) )
+ *(intpte_t *)addr += xen_phys_start;
+ }
break;
default:
blexit(L"Unsupported relocation type\r\n");
@@ -1113,43 +1125,21 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SY
*(u16 *)(*trampoline_ptr + (long)trampoline_ptr)
trampoline_phys >> 4;
- /* Initialise L2 identity-map and xen page table entries (16MB). */
+ /* Initialise L2 identity-map and boot-map page table entries (16MB). */
for ( i = 0; i < 8; ++i )
{
unsigned int slot = (xen_phys_start >> L2_PAGETABLE_SHIFT) + i;
paddr_t addr = slot << L2_PAGETABLE_SHIFT;
l2_identmap[slot] = l2e_from_paddr(addr, PAGE_HYPERVISOR|_PAGE_PSE);
- l2_xenmap[i] = l2e_from_paddr(addr, PAGE_HYPERVISOR|_PAGE_PSE);
slot &= L2_PAGETABLE_ENTRIES - 1;
l2_bootmap[slot] = l2e_from_paddr(addr, __PAGE_HYPERVISOR|_PAGE_PSE);
}
- /* Initialise L2 fixmap page directory entry. */
- l2_fixmap[l2_table_offset(FIXADDR_TOP - 1)] -
l2e_from_paddr((UINTN)l1_fixmap, __PAGE_HYPERVISOR);
- /* Initialise L3 identity-map page directory entries. */
- for ( i = 0; i < ARRAY_SIZE(l2_identmap) / L2_PAGETABLE_ENTRIES; ++i )
- l3_identmap[i] = l3e_from_paddr((UINTN)(l2_identmap +
- i * L2_PAGETABLE_ENTRIES),
- __PAGE_HYPERVISOR);
- /* Initialise L3 xen-map and fixmap page directory entries. */
- l3_xenmap[l3_table_offset(XEN_VIRT_START)] -
l3e_from_paddr((UINTN)l2_xenmap, __PAGE_HYPERVISOR);
- l3_xenmap[l3_table_offset(FIXADDR_TOP - 1)] -
l3e_from_paddr((UINTN)l2_fixmap, __PAGE_HYPERVISOR);
/* Initialise L3 boot-map page directory entries. */
l3_bootmap[l3_table_offset(xen_phys_start)]
l3e_from_paddr((UINTN)l2_bootmap, __PAGE_HYPERVISOR);
l3_bootmap[l3_table_offset(xen_phys_start + (8 << L2_PAGETABLE_SHIFT)
- 1)] l3e_from_paddr((UINTN)l2_bootmap, __PAGE_HYPERVISOR);
- /* Hook identity-map, xen-map, and boot-map L3 tables into PML4. */
- idle_pg_table[0] = l4e_from_paddr((UINTN)l3_bootmap, __PAGE_HYPERVISOR);
- idle_pg_table[l4_table_offset(DIRECTMAP_VIRT_START)] -
l4e_from_paddr((UINTN)l3_identmap, __PAGE_HYPERVISOR);
- idle_pg_table[l4_table_offset(XEN_VIRT_START)] -
l4e_from_paddr((UINTN)l3_xenmap, __PAGE_HYPERVISOR);
- /* Hook 4kB mappings of first 2MB of memory into L2. */
- l2_identmap[0] = l2e_from_paddr((UINTN)l1_identmap, __PAGE_HYPERVISOR);
if ( gop )
{
--- a/xen/arch/x86/x86_64/mm.c
+++ b/xen/arch/x86/x86_64/mm.c
@@ -49,24 +49,6 @@ unsigned int __read_mostly pfn_pdx_hole_
unsigned int __read_mostly m2p_compat_vstart = __HYPERVISOR_COMPAT_VIRT_START;
-/* Top-level master (and idle-domain) page directory. */
-l4_pgentry_t __attribute__ ((__section__ (".bss.page_aligned")))
- idle_pg_table[L4_PAGETABLE_ENTRIES];
-
-/* Enough page directories to map bottom 4GB of the memory map. */
-l3_pgentry_t __attribute__ ((__section__ (".bss.page_aligned")))
- l3_identmap[L3_PAGETABLE_ENTRIES];
-
-/* Enough page directories to map the Xen text and static data. */
-l3_pgentry_t __attribute__ ((__section__ (".bss.page_aligned")))
- l3_xenmap[L3_PAGETABLE_ENTRIES];
-l2_pgentry_t __attribute__ ((__section__ (".bss.page_aligned")))
- l2_xenmap[L2_PAGETABLE_ENTRIES];
-
-/* Enough page directories to map the early fixmap space. */
-l2_pgentry_t __attribute__ ((__section__ (".bss.page_aligned")))
- l2_fixmap[L2_PAGETABLE_ENTRIES];
-
/* Enough page directories to map into the bottom 1GB. */
l3_pgentry_t __attribute__ ((__section__ (".bss.page_aligned")))
l3_bootmap[L3_PAGETABLE_ENTRIES];
--- a/xen/arch/x86/xen.lds.S
+++ b/xen/arch/x86/xen.lds.S
@@ -42,6 +42,10 @@ PHDRS
}
SECTIONS
{
+#if defined(__x86_64__) && !defined(EFI)
+ . = __XEN_VIRT_START;
+ __image_base__ = .;
+#endif
. = __XEN_VIRT_START + 0x100000;
_start = .;
.text : {
--- a/xen/include/asm-x86/page.h
+++ b/xen/include/asm-x86/page.h
@@ -304,11 +304,8 @@ extern l2_pgentry_t idle_pg_table_l2[
extern l2_pgentry_t *compat_idle_pg_table_l2;
extern unsigned int m2p_compat_vstart;
extern l2_pgentry_t l2_xenmap[L2_PAGETABLE_ENTRIES],
- l2_fixmap[L2_PAGETABLE_ENTRIES],
l2_bootmap[L2_PAGETABLE_ENTRIES];
-extern l3_pgentry_t l3_xenmap[L3_PAGETABLE_ENTRIES],
- l3_identmap[L3_PAGETABLE_ENTRIES],
- l3_bootmap[L3_PAGETABLE_ENTRIES];
+extern l3_pgentry_t l3_bootmap[L3_PAGETABLE_ENTRIES];
#endif
extern l2_pgentry_t l2_identmap[4*L2_PAGETABLE_ENTRIES];
extern l1_pgentry_t l1_identmap[L1_PAGETABLE_ENTRIES],
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