[patch 09/21] Xen-paravirt: Allow paravirt backend to select PGD allocation alignment

Jeremy Fitzhardinge
2007-02-16T04:45:46Z

[-- Attachment #1: pgd-alignment.patch --]
[-- Type: text/plain, Size: 2133 bytes --]

Xen requires pgds to be page-aligned, so make this a parameter which
can be set in the paravirt_ops structure.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>

--
arch/i386/kernel/paravirt.c | 1 +
arch/i386/mm/init.c | 2 +-
include/asm-i386/paravirt.h | 5 ++++-
include/asm-i386/pgtable.h | 6 ++++++
4 files changed, 12 insertions(+), 2 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -573,6 +573,7 @@ struct paravirt_ops paravirt_ops = {
.paravirt_enabled = 0,
.kernel_rpl = 0,
.shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */
+ .pgd_alignment = sizeof(pgd_t) * PTRS_PER_PGD,

.patch = native_patch,
.banner = default_banner,
===================================================================
--- a/arch/i386/mm/init.c
+++ b/arch/i386/mm/init.c
@@ -745,7 +745,7 @@ void __init pgtable_cache_init(void)
}
pgd_cache = kmem_cache_create("pgd",
PTRS_PER_PGD*sizeof(pgd_t),
- PTRS_PER_PGD*sizeof(pgd_t),
+ PGD_ALIGNMENT,
0, NULL, NULL);
if (!pgd_cache)
panic("pgtable_cache_init(): Cannot create pgd cache");
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -33,9 +33,12 @@ struct mm_struct;
struct mm_struct;
struct paravirt_ops
{
+ int paravirt_enabled;
unsigned int kernel_rpl;
+
int shared_kernel_pmd;
- int paravirt_enabled;
+ int pgd_alignment;
+
const char *name;

/*
===================================================================
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -270,6 +270,12 @@ static inline void vmalloc_sync_all(void
#define pte_update_defer(mm, addr, ptep) do { } while (0)
#endif

+#ifdef CONFIG_PARAVIRT
+#define PGD_ALIGNMENT (paravirt_ops.pgd_alignment)
+#else
+#define PGD_ALIGNMENT (sizeof(pgd_t) * PTRS_PER_PGD)
+#endif
+
/*
* We only update the dirty/accessed state if we set
* the dirty bit by hand in the kernel, since the hardware

--