[PATCHv6 04/19] x86/xen: Provide pre-built page tables only for XEN_PV and XEN_PVH

From: Kirill A. Shutemov
Date: Wed Aug 23 2017 - 08:04:28 EST


Looks like we only need pre-built page tables for XEN_PV and XEN_PVH
cases. Let's not provide them for other configurations.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
---
arch/x86/kernel/head_64.S | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 513cbb012ecc..2be7d1e7fcf1 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -37,11 +37,12 @@
*
*/

-#define p4d_index(x) (((x) >> P4D_SHIFT) & (PTRS_PER_P4D-1))
#define pud_index(x) (((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1))

+#if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH)
PGD_PAGE_OFFSET = pgd_index(__PAGE_OFFSET_BASE)
PGD_START_KERNEL = pgd_index(__START_KERNEL_map)
+#endif
L3_START_KERNEL = pud_index(__START_KERNEL_map)

.text
@@ -361,10 +362,7 @@ NEXT_PAGE(early_dynamic_pgts)

.data

-#ifndef CONFIG_XEN
-NEXT_PAGE(init_top_pgt)
- .fill 512,8,0
-#else
+#if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH)
NEXT_PAGE(init_top_pgt)
.quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
.org init_top_pgt + PGD_PAGE_OFFSET*8, 0
@@ -381,6 +379,9 @@ NEXT_PAGE(level2_ident_pgt)
* Don't set NX because code runs from these pages.
*/
PMDS(0, __PAGE_KERNEL_IDENT_LARGE_EXEC, PTRS_PER_PMD)
+#else
+NEXT_PAGE(init_top_pgt)
+ .fill 512,8,0
#endif

#ifdef CONFIG_X86_5LEVEL
--
2.14.1