# HG changeset patch
# User Ian.Campbell@xxxxxxxxxxxxx
# Node ID 0eb38397e60845e72c60fbf0820c65491262d250
# Parent 31083f13ae47f55bc86407450c37eb1e6d8656e7
Introduce XENFEAT_writable_mmu_structures.
This feature flag indicates to the guest that it is allowable to
use writable LDT, GDT and page table pages.
Signed-off-by: Ian Campbell <Ian.Campbell@xxxxxxxxxxxxx>
Index: xen-features/xen/include/public/version.h
===================================================================
--- xen-features.orig/xen/include/public/version.h 2006-01-27
11:27:14.000000000 +0000
+++ xen-features/xen/include/public/version.h 2006-01-27 11:27:14.000000000
+0000
@@ -45,6 +45,9 @@
uint32_t submap; /* OUT: 32-bit submap */
} xen_feature_info_t;
+#define _XENFEAT_writable_mmu_structures 0
+#define XENFEAT_writable_mmu_structures (1UL<<_XENFEAT_writable_mmu_structures)
+
#define XENFEAT_NR_SUBMAPS 1
#endif /* __XEN_PUBLIC_VERSION_H__ */
Index: xen-features/linux-2.6-xen-sparse/arch/xen/i386/mm/pgtable.c
===================================================================
--- xen-features.orig/linux-2.6-xen-sparse/arch/xen/i386/mm/pgtable.c
2006-01-27 11:27:14.000000000 +0000
+++ xen-features/linux-2.6-xen-sparse/arch/xen/i386/mm/pgtable.c
2006-01-27 11:27:14.000000000 +0000
@@ -24,6 +24,7 @@
#include <asm/io.h>
#include <asm/mmu_context.h>
+#include <asm-xen/features.h>
#include <asm-xen/foreign_page.h>
#include <asm/hypervisor.h>
@@ -391,24 +392,42 @@
#ifndef CONFIG_XEN_SHADOW_MODE
void make_lowmem_mmu_page_readonly(void *va)
{
- pte_t *pte = virt_to_ptep(va);
- int rc = HYPERVISOR_update_va_mapping(
+ pte_t *pte;
+ int rc;
+
+ if (xen_feature(writable_mmu_structures))
+ return;
+
+ pte = virt_to_ptep(va);
+ rc = HYPERVISOR_update_va_mapping(
(unsigned long)va, pte_wrprotect(*pte), 0);
BUG_ON(rc);
}
void make_lowmem_mmu_page_writable(void *va)
{
- pte_t *pte = virt_to_ptep(va);
- int rc = HYPERVISOR_update_va_mapping(
+ pte_t *pte;
+ int rc;
+
+ if (xen_feature(writable_mmu_structures))
+ return;
+
+ pte = virt_to_ptep(va);
+ rc = HYPERVISOR_update_va_mapping(
(unsigned long)va, pte_mkwrite(*pte), 0);
BUG_ON(rc);
}
void make_mmu_page_readonly(void *va)
{
- pte_t *pte = virt_to_ptep(va);
- int rc = HYPERVISOR_update_va_mapping(
+ pte_t *pte;
+ int rc;
+
+ if (xen_feature(writable_mmu_structures))
+ return;
+
+ pte = virt_to_ptep(va);
+ rc = HYPERVISOR_update_va_mapping(
(unsigned long)va, pte_wrprotect(*pte), 0);
if (rc) /* fallback? */
xen_l1_entry_update(pte, pte_wrprotect(*pte));
@@ -426,8 +445,14 @@
void make_mmu_page_writable(void *va)
{
- pte_t *pte = virt_to_ptep(va);
- int rc = HYPERVISOR_update_va_mapping(
+ pte_t *pte;
+ int rc;
+
+ if (xen_feature(writable_mmu_structures))
+ return;
+
+ pte = virt_to_ptep(va);
+ rc = HYPERVISOR_update_va_mapping(
(unsigned long)va, pte_mkwrite(*pte), 0);
if (rc) /* fallback? */
xen_l1_entry_update(pte, pte_mkwrite(*pte));
@@ -443,6 +468,9 @@
void make_mmu_pages_readonly(void *va, unsigned int nr)
{
+ if (xen_feature(writable_mmu_structures))
+ return;
+
while (nr-- != 0) {
make_mmu_page_readonly(va);
va = (void *)((unsigned long)va + PAGE_SIZE);
@@ -451,6 +479,8 @@
void make_mmu_pages_writable(void *va, unsigned int nr)
{
+ if (xen_feature(writable_mmu_structures))
+ return;
while (nr-- != 0) {
make_mmu_page_writable(va);
va = (void *)((unsigned long)va + PAGE_SIZE);
Index: xen-features/linux-2.6-xen-sparse/arch/xen/x86_64/mm/init.c
===================================================================
--- xen-features.orig/linux-2.6-xen-sparse/arch/xen/x86_64/mm/init.c
2006-01-27 11:27:14.000000000 +0000
+++ xen-features/linux-2.6-xen-sparse/arch/xen/x86_64/mm/init.c 2006-01-27
11:27:18.000000000 +0000
@@ -40,6 +40,8 @@
#include <asm/proto.h>
#include <asm/smp.h>
+#include <asm-xen/features.h>
+
#ifndef Dprintk
#define Dprintk(x...)
#endif
@@ -72,6 +74,9 @@
pte_t pte, *ptep;
unsigned long *page = (unsigned long *) init_level4_pgt;
+ if (xen_feature(writable_mmu_structures))
+ return;
+
addr = (unsigned long) page[pgd_index(_va)];
addr_to_page(addr, page);
@@ -93,6 +98,9 @@
pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t pte, *ptep;
unsigned long addr = (unsigned long) va;
+ if (xen_feature(writable_mmu_structures))
+ return;
+
pgd = pgd_offset_k(addr);
pud = pud_offset(pgd, addr);
pmd = pmd_offset(pud, addr);
@@ -111,6 +119,9 @@
pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t pte, *ptep;
unsigned long addr = (unsigned long) va;
+ if (xen_feature(writable_mmu_structures))
+ return;
+
pgd = pgd_offset_k(addr);
pud = pud_offset(pgd, addr);
pmd = pmd_offset(pud, addr);
@@ -126,6 +137,9 @@
void make_mmu_pages_readonly(void *va, unsigned nr)
{
+ if (xen_feature(writable_mmu_structures))
+ return;
+
while (nr-- != 0) {
make_mmu_page_readonly(va);
va = (void*)((unsigned long)va + PAGE_SIZE);
@@ -134,6 +148,8 @@
void make_mmu_pages_writable(void *va, unsigned nr)
{
+ if (xen_feature(writable_mmu_structures))
+ return;
while (nr-- != 0) {
make_mmu_page_writable(va);
va = (void*)((unsigned long)va + PAGE_SIZE);
@@ -385,6 +401,9 @@
{
int readonly = 0;
+ if (xen_feature(writable_mmu_structures))
+ return 0;
+
/* Make old and new page tables read-only. */
if ((paddr >= (xen_start_info->pt_base - __START_KERNEL_map))
&& (paddr < ((table_start << PAGE_SHIFT) + tables_space)))
diff -r 31083f13ae47 -r 0eb38397e608
linux-2.6-xen-sparse/arch/xen/i386/mm/pgtable.c
--- a/linux-2.6-xen-sparse/arch/xen/i386/mm/pgtable.c Fri Jan 27 11:31:12 2006
+++ b/linux-2.6-xen-sparse/arch/xen/i386/mm/pgtable.c Fri Jan 27 11:31:14 2006
@@ -24,6 +24,7 @@
#include <asm/io.h>
#include <asm/mmu_context.h>
+#include <asm-xen/features.h>
#include <asm-xen/foreign_page.h>
#include <asm/hypervisor.h>
@@ -391,24 +392,42 @@
#ifndef CONFIG_XEN_SHADOW_MODE
void make_lowmem_mmu_page_readonly(void *va)
{
- pte_t *pte = virt_to_ptep(va);
- int rc = HYPERVISOR_update_va_mapping(
+ pte_t *pte;
+ int rc;
+
+ if (xen_feature(writable_mmu_structures))
+ return;
+
+ pte = virt_to_ptep(va);
+ rc = HYPERVISOR_update_va_mapping(
(unsigned long)va, pte_wrprotect(*pte), 0);
BUG_ON(rc);
}
void make_lowmem_mmu_page_writable(void *va)
{
- pte_t *pte = virt_to_ptep(va);
- int rc = HYPERVISOR_update_va_mapping(
+ pte_t *pte;
+ int rc;
+
+ if (xen_feature(writable_mmu_structures))
+ return;
+
+ pte = virt_to_ptep(va);
+ rc = HYPERVISOR_update_va_mapping(
(unsigned long)va, pte_mkwrite(*pte), 0);
BUG_ON(rc);
}
void make_mmu_page_readonly(void *va)
{
- pte_t *pte = virt_to_ptep(va);
- int rc = HYPERVISOR_update_va_mapping(
+ pte_t *pte;
+ int rc;
+
+ if (xen_feature(writable_mmu_structures))
+ return;
+
+ pte = virt_to_ptep(va);
+ rc = HYPERVISOR_update_va_mapping(
(unsigned long)va, pte_wrprotect(*pte), 0);
if (rc) /* fallback? */
xen_l1_entry_update(pte, pte_wrprotect(*pte));
@@ -426,8 +445,14 @@
void make_mmu_page_writable(void *va)
{
- pte_t *pte = virt_to_ptep(va);
- int rc = HYPERVISOR_update_va_mapping(
+ pte_t *pte;
+ int rc;
+
+ if (xen_feature(writable_mmu_structures))
+ return;
+
+ pte = virt_to_ptep(va);
+ rc = HYPERVISOR_update_va_mapping(
(unsigned long)va, pte_mkwrite(*pte), 0);
if (rc) /* fallback? */
xen_l1_entry_update(pte, pte_mkwrite(*pte));
@@ -443,6 +468,9 @@
void make_mmu_pages_readonly(void *va, unsigned int nr)
{
+ if (xen_feature(writable_mmu_structures))
+ return;
+
while (nr-- != 0) {
make_mmu_page_readonly(va);
va = (void *)((unsigned long)va + PAGE_SIZE);
@@ -451,6 +479,8 @@
void make_mmu_pages_writable(void *va, unsigned int nr)
{
+ if (xen_feature(writable_mmu_structures))
+ return;
while (nr-- != 0) {
make_mmu_page_writable(va);
va = (void *)((unsigned long)va + PAGE_SIZE);
diff -r 31083f13ae47 -r 0eb38397e608
linux-2.6-xen-sparse/arch/xen/x86_64/mm/init.c
--- a/linux-2.6-xen-sparse/arch/xen/x86_64/mm/init.c Fri Jan 27 11:31:12 2006
+++ b/linux-2.6-xen-sparse/arch/xen/x86_64/mm/init.c Fri Jan 27 11:31:14 2006
@@ -40,6 +40,8 @@
#include <asm/proto.h>
#include <asm/smp.h>
+#include <asm-xen/features.h>
+
#ifndef Dprintk
#define Dprintk(x...)
#endif
@@ -72,6 +74,9 @@
pte_t pte, *ptep;
unsigned long *page = (unsigned long *) init_level4_pgt;
+ if (xen_feature(writable_mmu_structures))
+ return;
+
addr = (unsigned long) page[pgd_index(_va)];
addr_to_page(addr, page);
@@ -92,6 +97,9 @@
{
pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t pte, *ptep;
unsigned long addr = (unsigned long) va;
+
+ if (xen_feature(writable_mmu_structures))
+ return;
pgd = pgd_offset_k(addr);
pud = pud_offset(pgd, addr);
@@ -111,6 +119,9 @@
pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t pte, *ptep;
unsigned long addr = (unsigned long) va;
+ if (xen_feature(writable_mmu_structures))
+ return;
+
pgd = pgd_offset_k(addr);
pud = pud_offset(pgd, addr);
pmd = pmd_offset(pud, addr);
@@ -126,6 +137,9 @@
void make_mmu_pages_readonly(void *va, unsigned nr)
{
+ if (xen_feature(writable_mmu_structures))
+ return;
+
while (nr-- != 0) {
make_mmu_page_readonly(va);
va = (void*)((unsigned long)va + PAGE_SIZE);
@@ -134,6 +148,8 @@
void make_mmu_pages_writable(void *va, unsigned nr)
{
+ if (xen_feature(writable_mmu_structures))
+ return;
while (nr-- != 0) {
make_mmu_page_writable(va);
va = (void*)((unsigned long)va + PAGE_SIZE);
@@ -384,6 +400,9 @@
static inline int make_readonly(unsigned long paddr)
{
int readonly = 0;
+
+ if (xen_feature(writable_mmu_structures))
+ return 0;
/* Make old and new page tables read-only. */
if ((paddr >= (xen_start_info->pt_base - __START_KERNEL_map))
diff -r 31083f13ae47 -r 0eb38397e608 xen/include/public/version.h
--- a/xen/include/public/version.h Fri Jan 27 11:31:12 2006
+++ b/xen/include/public/version.h Fri Jan 27 11:31:14 2006
@@ -45,6 +45,9 @@
uint32_t submap; /* OUT: 32-bit submap */
} xen_feature_info_t;
+#define _XENFEAT_writable_mmu_structures 0
+#define XENFEAT_writable_mmu_structures (1UL<<_XENFEAT_writable_mmu_structures)
+
#define XENFEAT_NR_SUBMAPS 1
#endif /* __XEN_PUBLIC_VERSION_H__ */
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