Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
lguest: populate initial_page_table
lguest: restore boot speed
lguest: fix crash lguest_time_init
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index bcece91..f0bea76 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -620,13 +620,13 @@
__PAGE_ALIGNED_BSS
.align PAGE_SIZE_asm
#ifdef CONFIG_X86_PAE
-initial_pg_pmd:
+ENTRY(initial_pg_pmd)
.fill 1024*KPMDS,4,0
#else
ENTRY(initial_page_table)
.fill 1024,4,0
#endif
-initial_pg_fixmap:
+ENTRY(initial_pg_fixmap)
.fill 1024,4,0
ENTRY(empty_zero_page)
.fill 4096,1,0
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index 73b1e1a..4996cf5 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -531,7 +531,10 @@
{
lguest_data.pgdir = cr3;
lazy_hcall1(LHCALL_NEW_PGTABLE, cr3);
- cr3_changed = true;
+
+ /* These two page tables are simple, linear, and used during boot */
+ if (cr3 != __pa(swapper_pg_dir) && cr3 != __pa(initial_page_table))
+ cr3_changed = true;
}
static unsigned long lguest_read_cr3(void)
@@ -703,9 +706,9 @@
* to forget all of them. Fortunately, this is very rare.
*
* ... except in early boot when the kernel sets up the initial pagetables,
- * which makes booting astonishingly slow: 1.83 seconds! So we don't even tell
- * the Host anything changed until we've done the first page table switch,
- * which brings boot back to 0.25 seconds.
+ * which makes booting astonishingly slow: 48 seconds! So we don't even tell
+ * the Host anything changed until we've done the first real page table switch,
+ * which brings boot back to 4.3 seconds.
*/
static void lguest_set_pte(pte_t *ptep, pte_t pteval)
{
@@ -1002,7 +1005,7 @@
clockevents_register_device(&lguest_clockevent);
/* Finally, we unblock the timer interrupt. */
- enable_lguest_irq(0);
+ clear_bit(0, lguest_data.blocked_interrupts);
}
/*
@@ -1349,9 +1352,6 @@
*/
switch_to_new_gdt(0);
- /* We actually boot with all memory mapped, but let's say 128MB. */
- max_pfn_mapped = (128*1024*1024) >> PAGE_SHIFT;
-
/*
* The Host<->Guest Switcher lives at the top of our address space, and
* the Host told us how big it is when we made LGUEST_INIT hypercall:
diff --git a/arch/x86/lguest/i386_head.S b/arch/x86/lguest/i386_head.S
index 4f420c2f..e7d5382 100644
--- a/arch/x86/lguest/i386_head.S
+++ b/arch/x86/lguest/i386_head.S
@@ -4,6 +4,7 @@
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
#include <asm/processor-flags.h>
+#include <asm/pgtable.h>
/*G:020
* Our story starts with the kernel booting into startup_32 in
@@ -37,9 +38,113 @@
/* Set up the initial stack so we can run C code. */
movl $(init_thread_union+THREAD_SIZE),%esp
+ call init_pagetables
+
/* Jumps are relative: we're running __PAGE_OFFSET too low. */
jmp lguest_init+__PAGE_OFFSET
+/*
+ * Initialize page tables. This creates a PDE and a set of page
+ * tables, which are located immediately beyond __brk_base. The variable
+ * _brk_end is set up to point to the first "safe" location.
+ * Mappings are created both at virtual address 0 (identity mapping)
+ * and PAGE_OFFSET for up to _end.
+ *
+ * FIXME: This code is taken verbatim from arch/x86/kernel/head_32.S: they
+ * don't have a stack at this point, so we can't just use call and ret.
+ */
+init_pagetables:
+#if PTRS_PER_PMD > 1
+#define PAGE_TABLE_SIZE(pages) (((pages) / PTRS_PER_PMD) + PTRS_PER_PGD)
+#else
+#define PAGE_TABLE_SIZE(pages) ((pages) / PTRS_PER_PGD)
+#endif
+#define pa(X) ((X) - __PAGE_OFFSET)
+
+/* Enough space to fit pagetables for the low memory linear map */
+MAPPING_BEYOND_END = \
+ PAGE_TABLE_SIZE(((1<<32) - __PAGE_OFFSET) >> PAGE_SHIFT) << PAGE_SHIFT
+#ifdef CONFIG_X86_PAE
+
+ /*
+ * In PAE mode initial_page_table is statically defined to contain
+ * enough entries to cover the VMSPLIT option (that is the top 1, 2 or 3
+ * entries). The identity mapping is handled by pointing two PGD entries
+ * to the first kernel PMD.
+ *
+ * Note the upper half of each PMD or PTE are always zero at this stage.
+ */
+
+#define KPMDS (((-__PAGE_OFFSET) >> 30) & 3) /* Number of kernel PMDs */
+
+ xorl %ebx,%ebx /* %ebx is kept at zero */
+
+ movl $pa(__brk_base), %edi
+ movl $pa(initial_pg_pmd), %edx
+ movl $PTE_IDENT_ATTR, %eax
+10:
+ leal PDE_IDENT_ATTR(%edi),%ecx /* Create PMD entry */
+ movl %ecx,(%edx) /* Store PMD entry */
+ /* Upper half already zero */
+ addl $8,%edx
+ movl $512,%ecx
+11:
+ stosl
+ xchgl %eax,%ebx
+ stosl
+ xchgl %eax,%ebx
+ addl $0x1000,%eax
+ loop 11b
+
+ /*
+ * End condition: we must map up to the end + MAPPING_BEYOND_END.
+ */
+ movl $pa(_end) + MAPPING_BEYOND_END + PTE_IDENT_ATTR, %ebp
+ cmpl %ebp,%eax
+ jb 10b
+1:
+ addl $__PAGE_OFFSET, %edi
+ movl %edi, pa(_brk_end)
+ shrl $12, %eax
+ movl %eax, pa(max_pfn_mapped)
+
+ /* Do early initialization of the fixmap area */
+ movl $pa(initial_pg_fixmap)+PDE_IDENT_ATTR,%eax
+ movl %eax,pa(initial_pg_pmd+0x1000*KPMDS-8)
+#else /* Not PAE */
+
+page_pde_offset = (__PAGE_OFFSET >> 20);
+
+ movl $pa(__brk_base), %edi
+ movl $pa(initial_page_table), %edx
+ movl $PTE_IDENT_ATTR, %eax
+10:
+ leal PDE_IDENT_ATTR(%edi),%ecx /* Create PDE entry */
+ movl %ecx,(%edx) /* Store identity PDE entry */
+ movl %ecx,page_pde_offset(%edx) /* Store kernel PDE entry */
+ addl $4,%edx
+ movl $1024, %ecx
+11:
+ stosl
+ addl $0x1000,%eax
+ loop 11b
+ /*
+ * End condition: we must map up to the end + MAPPING_BEYOND_END.
+ */
+ movl $pa(_end) + MAPPING_BEYOND_END + PTE_IDENT_ATTR, %ebp
+ cmpl %ebp,%eax
+ jb 10b
+ addl $__PAGE_OFFSET, %edi
+ movl %edi, pa(_brk_end)
+ shrl $12, %eax
+ movl %eax, pa(max_pfn_mapped)
+
+ /* Do early initialization of the fixmap area */
+ movl $pa(initial_pg_fixmap)+PDE_IDENT_ATTR,%eax
+ movl %eax,pa(initial_page_table+0xffc)
+#endif
+ ret
+
/*G:055
* We create a macro which puts the assembler code between lgstart_ and lgend_
* markers. These templates are put in the .text section: they can't be