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Message-ID: <20101124173948.GA13253@dumpdata.com>
Date: Wed, 24 Nov 2010 12:39:48 -0500
From: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: weiyi.huang@...il.com, ian.campbell@...rix.com, bp@...en8.de,
pa@...ux.intel.com, jeremy@...p.org, linux-kernel@...r.kernel.org
Subject: [GIT PULL] 2.6.37-rc3 regression and a bug-fix for Xen subsystem.
Dear Linus,
Please pull the following git tree:
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git for-linus
which has changes since git commit e53beacd23d9cb47590da6a7a7f6d417b941a994:
Linus Torvalds (1):
Linux 2.6.37-rc2
The tree has two patches: one of them is innocuous removal of
a #include, while the other fixes a regression. Right after the merge window
opened for 2.6.37, 32-bit PAE Xen PV guests were not able to boot. Ian Campbell
came up with a nice fix that had been posted way back in October but we
completely forgot about the fix until about a week ago.
Huang Weiyi (1):
xen: remove duplicated #include
Ian Campbell (1):
xen: x86/32: perform initial startup on initial_page_table
arch/x86/xen/enlighten.c | 2 -
arch/x86/xen/mmu.c | 69 +++++++++++++++++++++++++++++++++++++--------
arch/x86/xen/setup.c | 1 -
3 files changed, 56 insertions(+), 16 deletions(-)
And the two patchs together:
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 235c0f4..ff82909 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1191,8 +1191,6 @@ asmlinkage void __init xen_start_kernel(void)
/* Allocate and initialize top and mid mfn levels for p2m structure */
xen_build_mfn_list_list();
- init_mm.pgd = pgd;
-
/* keep using Xen gdt for now; no urgent need to change it */
#ifdef CONFIG_X86_32
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 21ed8d7..c9cf23e 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -2119,44 +2119,83 @@ __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
return pgd;
}
#else /* !CONFIG_X86_64 */
-static RESERVE_BRK_ARRAY(pmd_t, level2_kernel_pgt, PTRS_PER_PMD);
+static RESERVE_BRK_ARRAY(pmd_t, initial_kernel_pmd, PTRS_PER_PMD);
+static RESERVE_BRK_ARRAY(pmd_t, swapper_kernel_pmd, PTRS_PER_PMD);
+
+static __init void xen_write_cr3_init(unsigned long cr3)
+{
+ unsigned long pfn = PFN_DOWN(__pa(swapper_pg_dir));
+
+ BUG_ON(read_cr3() != __pa(initial_page_table));
+ BUG_ON(cr3 != __pa(swapper_pg_dir));
+
+ /*
+ * We are switching to swapper_pg_dir for the first time (from
+ * initial_page_table) and therefore need to mark that page
+ * read-only and then pin it.
+ *
+ * Xen disallows sharing of kernel PMDs for PAE
+ * guests. Therefore we must copy the kernel PMD from
+ * initial_page_table into a new kernel PMD to be used in
+ * swapper_pg_dir.
+ */
+ swapper_kernel_pmd =
+ extend_brk(sizeof(pmd_t) * PTRS_PER_PMD, PAGE_SIZE);
+ memcpy(swapper_kernel_pmd, initial_kernel_pmd,
+ sizeof(pmd_t) * PTRS_PER_PMD);
+ swapper_pg_dir[KERNEL_PGD_BOUNDARY] =
+ __pgd(__pa(swapper_kernel_pmd) | _PAGE_PRESENT);
+ set_page_prot(swapper_kernel_pmd, PAGE_KERNEL_RO);
+
+ set_page_prot(swapper_pg_dir, PAGE_KERNEL_RO);
+ xen_write_cr3(cr3);
+ pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, pfn);
+
+ pin_pagetable_pfn(MMUEXT_UNPIN_TABLE,
+ PFN_DOWN(__pa(initial_page_table)));
+ set_page_prot(initial_page_table, PAGE_KERNEL);
+ set_page_prot(initial_kernel_pmd, PAGE_KERNEL);
+
+ pv_mmu_ops.write_cr3 = &xen_write_cr3;
+}
__init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
unsigned long max_pfn)
{
pmd_t *kernel_pmd;
- level2_kernel_pgt = extend_brk(sizeof(pmd_t) * PTRS_PER_PMD, PAGE_SIZE);
+ initial_kernel_pmd =
+ extend_brk(sizeof(pmd_t) * PTRS_PER_PMD, PAGE_SIZE);
max_pfn_mapped = PFN_DOWN(__pa(xen_start_info->pt_base) +
xen_start_info->nr_pt_frames * PAGE_SIZE +
512*1024);
kernel_pmd = m2v(pgd[KERNEL_PGD_BOUNDARY].pgd);
- memcpy(level2_kernel_pgt, kernel_pmd, sizeof(pmd_t) * PTRS_PER_PMD);
+ memcpy(initial_kernel_pmd, kernel_pmd, sizeof(pmd_t) * PTRS_PER_PMD);
- xen_map_identity_early(level2_kernel_pgt, max_pfn);
+ xen_map_identity_early(initial_kernel_pmd, max_pfn);
- memcpy(swapper_pg_dir, pgd, sizeof(pgd_t) * PTRS_PER_PGD);
- set_pgd(&swapper_pg_dir[KERNEL_PGD_BOUNDARY],
- __pgd(__pa(level2_kernel_pgt) | _PAGE_PRESENT));
+ memcpy(initial_page_table, pgd, sizeof(pgd_t) * PTRS_PER_PGD);
+ initial_page_table[KERNEL_PGD_BOUNDARY] =
+ __pgd(__pa(initial_kernel_pmd) | _PAGE_PRESENT);
- set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);
- set_page_prot(swapper_pg_dir, PAGE_KERNEL_RO);
+ set_page_prot(initial_kernel_pmd, PAGE_KERNEL_RO);
+ set_page_prot(initial_page_table, PAGE_KERNEL_RO);
set_page_prot(empty_zero_page, PAGE_KERNEL_RO);
pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
- xen_write_cr3(__pa(swapper_pg_dir));
-
- pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(swapper_pg_dir)));
+ pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE,
+ PFN_DOWN(__pa(initial_page_table)));
+ xen_write_cr3(__pa(initial_page_table));
memblock_x86_reserve_range(__pa(xen_start_info->pt_base),
__pa(xen_start_info->pt_base +
xen_start_info->nr_pt_frames * PAGE_SIZE),
"XEN PAGETABLES");
- return swapper_pg_dir;
+ return initial_page_table;
}
#endif /* CONFIG_X86_64 */
@@ -2290,7 +2329,11 @@ static const struct pv_mmu_ops xen_mmu_ops __initdata = {
.write_cr2 = xen_write_cr2,
.read_cr3 = xen_read_cr3,
+#ifdef CONFIG_X86_32
+ .write_cr3 = xen_write_cr3_init,
+#else
.write_cr3 = xen_write_cr3,
+#endif
.flush_tlb_user = xen_flush_tlb,
.flush_tlb_kernel = xen_flush_tlb,
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 769c4b0..d392486 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -23,7 +23,6 @@
#include <xen/interface/callback.h>
#include <xen/interface/memory.h>
#include <xen/interface/physdev.h>
-#include <xen/interface/memory.h>
#include <xen/features.h>
#include "xen-ops.h"
--
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