xen-project/xen
1
0 Fork 1
mirror of https://github.com/xen-project/xen.git synced 2026-10-29 10:40:03 +01:00
Code Issues Activity

bitkeeper revision 1.1159.23.1 (411a606fwcWYG3KD9XAVULSlXBrivA)

Browse Source 
Writable pagetable fixes.
This commit is contained in:
cl349@freefall.cl.cam.ac.uk committed 2004-08-11 18:07:43 +00:00
1 parent 8892b94a8d
commit ccde3dfdbf
5 files changed
+133 -86
Download Patch File Download Diff File Expand all files Collapse all files

No files matched your search

xen/arch/x86/memory.c
+114 -81
View File
@@ -136,9 +136,14 @@ static struct {
#define GPS (percpu_info[smp_processor_id()].gps ? : current)
void init_percpu_info(void)
void ptwr_init_backpointers(void);
void arch_init_memory(void)
{
memset(percpu_info, 0, sizeof(percpu_info));
vm_assist_info[VMASST_TYPE_writeable_pagetables].enable =
ptwr_init_backpointers;
}
static void __invalidate_shadow_ldt(struct domain *d)
@@ -255,6 +260,17 @@ static int get_page_and_type_from_pagenr(unsigned long page_nr,
}
static inline void set_l1_page_va(unsigned long pfn,
unsigned long va_idx)
{
struct pfn_info *page;
page = &frame_table[pfn];
page->u.inuse.type_info &= ~PGT_va_mask;
page->u.inuse.type_info |= va_idx << PGT_va_shift;
}
/*
* We allow an L2 tables to map each other (a.k.a. linear page tables). It
* needs some special care with reference counst and access permissions:
@@ -413,9 +429,11 @@ static int alloc_l2_table(struct pfn_info *page)
pl2e = map_domain_mem(page_nr << PAGE_SHIFT);
for ( i = 0; i < DOMAIN_ENTRIES_PER_L2_PAGETABLE; i++ )
for ( i = 0; i < DOMAIN_ENTRIES_PER_L2_PAGETABLE; i++ ) {
if ( unlikely(!get_page_from_l2e(pl2e[i], page_nr)) )
goto fail;
set_l1_page_va(l2_pgentry_val(pl2e[i]) >> PAGE_SHIFT, i);
}
#if defined(__i386__)
/* Now we add our private high mappings. */
@@ -509,17 +527,6 @@ static inline int update_l2e(l2_pgentry_t *pl2e,
}
static inline void set_l1_page_va(unsigned long pfn,
unsigned long va_idx)
{
struct pfn_info *page;
page = &frame_table[pfn];
page->u.inuse.type_info &= ~PGT_va_mask;
page->u.inuse.type_info |= va_idx << PGT_va_shift;
}
/* Update the L2 entry at pl2e to new value nl2e. pl2e is within frame pfn. */
static int mod_l2_entry(l2_pgentry_t *pl2e,
l2_pgentry_t nl2e,
@@ -1266,32 +1273,33 @@ void ptwr_reconnect_disconnected(unsigned long addr)
l1_pgentry_t *pl1e;
int cpu = smp_processor_id();
int i;
unsigned long *writable_pte = (unsigned long *)&linear_pg_table
[ptwr_info[cpu].writable_l1>>PAGE_SHIFT];
#ifdef PTWR_TRACK_DOMAIN
if (ptwr_domain[cpu] != get_current()->domain)
printk("ptwr_reconnect_disconnected domain mismatch %d != %d\n",
ptwr_domain[cpu], get_current()->domain);
#endif
PTWR_PRINTK(("page fault in disconnected space: addr %08lx space %08lx\n",
addr, ptwr_info[cpu].disconnected << L2_PAGETABLE_SHIFT));
PTWR_PRINTK(("[A] page fault in disconnected space: addr %08lx space %08lx\n",
addr, ptwr_info[cpu].disconnected << L2_PAGETABLE_SHIFT));
pl2e = &linear_l2_table[ptwr_info[cpu].disconnected];
if (__get_user(pte, ptwr_info[cpu].writable_l1))
if (__get_user(pte, writable_pte))
BUG();
pfn = pte >> PAGE_SHIFT;
page = &frame_table[pfn];
/* reconnect l1 page */
PTWR_PRINTK((" pl2e %p l2e %08lx pfn %08lx taf %08x/%08x/%u\n", pl2e,
l2_pgentry_val(*pl2e),
l1_pgentry_val(linear_pg_table[(unsigned long)pl2e >>
PAGE_SHIFT]) >> PAGE_SHIFT,
frame_table[pfn].u.inuse.type_info,
frame_table[pfn].u.inuse.count_info,
frame_table[pfn].u.inuse.domain->domain));
PTWR_PRINTK(("[A] pl2e %p l2e %08lx pfn %08lx taf %08x/%08x/%u\n",
pl2e, l2_pgentry_val(*pl2e),
l1_pgentry_val(linear_pg_table[(unsigned long)pl2e >>
PAGE_SHIFT]) >> PAGE_SHIFT,
frame_table[pfn].u.inuse.type_info,
frame_table[pfn].u.inuse.count_info,
frame_table[pfn].u.inuse.domain->domain));
nl2e = mk_l2_pgentry((l2_pgentry_val(*pl2e) & ~0x800) |
_PAGE_PRESENT);
nl2e = mk_l2_pgentry(l2_pgentry_val(*pl2e) | _PAGE_PRESENT);
pl1e = map_domain_mem(l2_pgentry_to_pagenr(nl2e) << PAGE_SHIFT);
for ( i = 0; i < ENTRIES_PER_L1_PAGETABLE; i++ ) {
l1_pgentry_t ol1e, nl1e;
@@ -1312,22 +1320,23 @@ void ptwr_reconnect_disconnected(unsigned long addr)
unmap_domain_mem(pl1e);
update_l2e(pl2e, *pl2e, nl2e);
PTWR_PRINTK(("now pl2e %p l2e %08lx taf %08x/%08x/%u\n", pl2e,
l2_pgentry_val(*pl2e),
frame_table[pfn].u.inuse.type_info,
frame_table[pfn].u.inuse.count_info,
frame_table[pfn].u.inuse.domain->domain));
PTWR_PRINTK(("[A] now pl2e %p l2e %08lx taf %08x/%08x/%u\n",
pl2e, l2_pgentry_val(*pl2e),
frame_table[pfn].u.inuse.type_info,
frame_table[pfn].u.inuse.count_info,
frame_table[pfn].u.inuse.domain->domain));
ptwr_info[cpu].disconnected = ENTRIES_PER_L2_PAGETABLE;
/* make pt page write protected */
if (__get_user(pte, ptwr_info[cpu].writable_l1))
if (__get_user(pte, writable_pte))
BUG();
PTWR_PRINTK(("writable_l1 at %p is %08lx\n", ptwr_info[cpu].writable_l1,
pte));
PTWR_PRINTK(("[A] writable_l1 at %p is %08lx\n",
writable_pte, pte));
pte &= ~_PAGE_RW;
if (__put_user(pte, ptwr_info[cpu].writable_l1))
if (__put_user(pte, writable_pte))
BUG();
PTWR_PRINTK(("writable_l1 at %p now %08lx\n", ptwr_info[cpu].writable_l1,
pte));
__flush_tlb_one(ptwr_info[cpu].writable_l1);
PTWR_PRINTK(("[A] writable_l1 at %p now %08lx\n",
writable_pte, pte));
/* and try again */
return;
}
@@ -1355,11 +1364,13 @@ void ptwr_flush_inactive(void)
}
#endif
for (idx = 0; idx < ptwr_info[cpu].writable_idx; idx++) {
if (__get_user(pte, ptwr_info[cpu].writables[idx]))
unsigned long *writable_pte = (unsigned long *)&linear_pg_table
[ptwr_info[cpu].writables[idx]>>PAGE_SHIFT];
if (__get_user(pte, writable_pte))
BUG();
pfn = pte >> PAGE_SHIFT;
page = &frame_table[pfn];
PTWR_PRINTK(("alloc l1 page %p\n", page));
PTWR_PRINTK(("[I] alloc l1 page %p\n", page));
pl1e = map_domain_mem(pfn << PAGE_SHIFT);
for ( i = 0; i < ENTRIES_PER_L1_PAGETABLE; i++ ) {
@@ -1376,13 +1387,14 @@ void ptwr_flush_inactive(void)
unmap_domain_mem(pl1e);
/* make pt page writable */
PTWR_PRINTK(("writable_l1 at %p is %08lx\n",
ptwr_info[cpu].writables[idx], pte));
PTWR_PRINTK(("[I] writable_l1 at %p is %08lx\n",
writable_pte, pte));
pte &= ~_PAGE_RW;
if (__put_user(pte, ptwr_info[cpu].writables[idx]))
if (__put_user(pte, writable_pte))
BUG();
PTWR_PRINTK(("writable_l1 at %p now %08lx\n",
ptwr_info[cpu].writables[idx], pte));
__flush_tlb_one(ptwr_info[cpu].writables[idx]);
PTWR_PRINTK(("[I] writable_l1 at %p now %08lx\n",
writable_pte, pte));
}
ptwr_info[cpu].writable_idx = 0;
}
@@ -1398,7 +1410,7 @@ int ptwr_do_page_fault(unsigned long addr)
#if 0
PTWR_PRINTK(("get user %p for va %08lx\n",
&linear_pg_table[addr>>PAGE_SHIFT], addr));
&linear_pg_table[addr>>PAGE_SHIFT], addr));
#endif
if (l2_pgentry_val(linear_l2_table[addr >> L2_PAGETABLE_SHIFT]) &
_PAGE_PRESENT &&
@@ -1407,7 +1419,7 @@ int ptwr_do_page_fault(unsigned long addr)
pfn = pte >> PAGE_SHIFT;
#if 0
PTWR_PRINTK(("check pte %08lx = pfn %08lx for va %08lx\n", pte, pfn,
addr));
addr));
#endif
page = &frame_table[pfn];
if ((page->u.inuse.type_info & PGT_type_mask) == PGT_l1_page_table) {
@@ -1419,22 +1431,21 @@ int ptwr_do_page_fault(unsigned long addr)
pl2e = &linear_l2_table[(page->u.inuse.type_info &
PGT_va_mask) >> PGT_va_shift];
PTWR_PRINTK(("page_fault on l1 pt at va %08lx, pt for %08x, "
"pfn %08lx\n", addr,
((page->u.inuse.type_info & PGT_va_mask) >>
PGT_va_shift) << L2_PAGETABLE_SHIFT, pfn));
"pfn %08lx\n", addr,
((page->u.inuse.type_info & PGT_va_mask) >>
PGT_va_shift) << L2_PAGETABLE_SHIFT, pfn));
if (l2_pgentry_val(*pl2e) >> PAGE_SHIFT != pfn) {
l1_pgentry_t *pl1e;
PTWR_PRINTK(("freeing l1 page %p taf %08x/%08x\n", page,
page->u.inuse.type_info,
page->u.inuse.count_info));
PTWR_PRINTK(("[I] freeing l1 page %p taf %08x/%08x\n", page,
page->u.inuse.type_info,
page->u.inuse.count_info));
if (ptwr_info[cpu].writable_idx == PTWR_NR_WRITABLES)
ptwr_flush_inactive();
ptwr_info[cpu].writables[ptwr_info[cpu].writable_idx] =
(unsigned long *)&linear_pg_table[addr>>PAGE_SHIFT];
ptwr_info[cpu].writables[ptwr_info[cpu].writable_idx] = addr;
pl1e = map_domain_mem(pfn << PAGE_SHIFT);
memcpy(&ptwr_info[cpu].writable_page[
ptwr_info[cpu].writable_idx][0],
ptwr_info[cpu].writable_idx][0],
pl1e, ENTRIES_PER_L1_PAGETABLE * sizeof(l1_pgentry_t));
unmap_domain_mem(pl1e);
@@ -1444,28 +1455,26 @@ int ptwr_do_page_fault(unsigned long addr)
l1_pgentry_t *pl1e;
if (ptwr_info[cpu].disconnected != ENTRIES_PER_L2_PAGETABLE)
ptwr_reconnect_disconnected(addr);
PTWR_PRINTK((" pl2e %p l2e %08lx pfn %08lx "
"taf %08x/%08x/%u\n", pl2e, l2_pgentry_val(*pl2e),
l1_pgentry_val(linear_pg_table[(unsigned long)pl2e
>> PAGE_SHIFT]) >>
PAGE_SHIFT,
frame_table[pfn].u.inuse.type_info,
frame_table[pfn].u.inuse.count_info,
frame_table[pfn].u.inuse.domain->domain));
PTWR_PRINTK(("[A] pl2e %p l2e %08lx pfn %08lx "
"taf %08x/%08x/%u\n", pl2e, l2_pgentry_val(*pl2e),
l1_pgentry_val(linear_pg_table[(unsigned long)pl2e
>> PAGE_SHIFT]) >>
PAGE_SHIFT,
frame_table[pfn].u.inuse.type_info,
frame_table[pfn].u.inuse.count_info,
frame_table[pfn].u.inuse.domain->domain));
/* disconnect l1 page */
nl2e = mk_l2_pgentry((l2_pgentry_val(*pl2e) &
~_PAGE_PRESENT) | 0x800);
nl2e = mk_l2_pgentry((l2_pgentry_val(*pl2e) & ~_PAGE_PRESENT));
update_l2e(pl2e, *pl2e, nl2e);
ptwr_info[cpu].disconnected =
(page->u.inuse.type_info & PGT_va_mask) >> PGT_va_shift;
PTWR_PRINTK(("now pl2e %p l2e %08lx "
"taf %08x/%08x/%u\n", pl2e, l2_pgentry_val(*pl2e),
frame_table[pfn].u.inuse.type_info,
frame_table[pfn].u.inuse.count_info,
frame_table[pfn].u.inuse.domain->domain));
ptwr_info[cpu].writable_l1 =
(unsigned long *)&linear_pg_table[addr>>PAGE_SHIFT];
(page->u.inuse.type_info & PGT_va_mask) >> PGT_va_shift;
PTWR_PRINTK(("[A] now pl2e %p l2e %08lx "
"taf %08x/%08x/%u\n", pl2e, l2_pgentry_val(*pl2e),
frame_table[pfn].u.inuse.type_info,
frame_table[pfn].u.inuse.count_info,
frame_table[pfn].u.inuse.domain->domain));
ptwr_info[cpu].writable_l1 = addr;
pl1e = map_domain_mem(l2_pgentry_to_pagenr(nl2e) <<
PAGE_SHIFT);
memcpy(&ptwr_info[cpu].disconnected_page[0], pl1e,
@@ -1475,7 +1484,7 @@ int ptwr_do_page_fault(unsigned long addr)
/* make pt page writable */
pte |= _PAGE_RW;
PTWR_PRINTK(("update %p pte to %08lx\n",
&linear_pg_table[addr>>PAGE_SHIFT], pte));
&linear_pg_table[addr>>PAGE_SHIFT], pte));
if (__put_user(pte, (unsigned long *)
&linear_pg_table[addr>>PAGE_SHIFT]))
BUG();
@@ -1485,6 +1494,28 @@ int ptwr_do_page_fault(unsigned long addr)
return 0;
}
void ptwr_init_backpointers(void)
{
struct pfn_info *page;
unsigned long pde, pfn;
int va_idx;
for (va_idx = 0; va_idx < DOMAIN_ENTRIES_PER_L2_PAGETABLE; va_idx++) {
/* check if entry valid */
pde = l2_pgentry_val(linear_l2_table[va_idx]);
if ((pde & _PAGE_PRESENT) == 0)
continue;
pfn = pde >> PAGE_SHIFT;
page = &frame_table[pfn];
/* assert that page is an l1_page_table XXXcl maybe l2? */
if ((page->u.inuse.type_info & PGT_type_mask) != PGT_l1_page_table) {
BUG();
}
page->u.inuse.type_info &= ~PGT_va_mask;
page->u.inuse.type_info |= va_idx << PGT_va_shift;
}
}
#ifndef NDEBUG
void ptwr_status(void)
{
@@ -1495,14 +1526,16 @@ void ptwr_status(void)
int cpu = smp_processor_id();
for (i = 0; i < ptwr_info[cpu].writable_idx; i++) {
if (__get_user(pte, ptwr_info[cpu].writables[i]))
unsigned long *writable_pte = (unsigned long *)&linear_pg_table
[ptwr_info[cpu].writables[i]>>PAGE_SHIFT];
if (__get_user(pte, writable_pte))
BUG();
pfn = pte >> PAGE_SHIFT;
page = &frame_table[pfn];
printk("need to alloc l1 page %p\n", page);
/* make pt page writable */
printk("need to make read-only l1-page at %p is %08lx\n",
ptwr_info[cpu].writables[i], pte);
writable_pte, pte);
}
if (ptwr_info[cpu].disconnected == ENTRIES_PER_L2_PAGETABLE)
@@ -1518,11 +1551,11 @@ void ptwr_status(void)
page = &frame_table[pfn];
PTWR_PRINTK((" pl2e %p l2e %08lx pfn %08lx taf %08x/%08x/%u\n", pl2e,
l2_pgentry_val(*pl2e),
l1_pgentry_val(linear_pg_table[(unsigned long)pl2e >>
PAGE_SHIFT]) >> PAGE_SHIFT,
frame_table[l2_pgentry_to_pagenr(*pl2e)].u.inuse.type_info,
frame_table[pfn].u.inuse.type_info,
frame_table[pfn].u.inuse.domain->domain));
l2_pgentry_val(*pl2e),
l1_pgentry_val(linear_pg_table[(unsigned long)pl2e >>
PAGE_SHIFT]) >> PAGE_SHIFT,
frame_table[l2_pgentry_to_pagenr(*pl2e)].u.inuse.type_info,
frame_table[pfn].u.inuse.type_info,
frame_table[pfn].u.inuse.domain->domain));
}
#endif
xen/common/kernel.c
+7 -1
View File
@@ -30,6 +30,8 @@ unsigned long xenheap_phys_end;
xmem_cache_t *domain_struct_cachep;
vm_assist_info_t vm_assist_info[MAX_VMASST_TYPE + 1];
struct e820entry {
unsigned long addr_lo, addr_hi; /* start of memory segment */
unsigned long size_lo, size_hi; /* size of memory segment */
@@ -353,16 +355,20 @@ long do_xen_version(int cmd)
long do_vm_assist(unsigned int cmd, unsigned int type)
{
if ( type > (sizeof(unsigned long) * 8) )
if ( type > MAX_VMASST_TYPE )
return -EINVAL;
switch ( cmd )
{
case VMASST_CMD_enable:
set_bit(type, &current->vm_assist);
if (vm_assist_info[type].enable)
(*vm_assist_info[type].enable)();
return 0;
case VMASST_CMD_disable:
clear_bit(type, &current->vm_assist);
if (vm_assist_info[type].disable)
(*vm_assist_info[type].disable)();
return 0;
}
xen/common/memory.c
+2 -2
View File
@@ -37,13 +37,13 @@ struct pfn_info *frame_table;
unsigned long frame_table_size;
unsigned long max_page;
extern void init_percpu_info(void);
extern void arch_init_memory(void);
void __init init_frametable(void *frametable_vstart, unsigned long nr_pages)
{
unsigned long mfn;
init_percpu_info();
arch_init_memory();
max_page = nr_pages;
frame_table_size = nr_pages * sizeof(struct pfn_info);
xen/include/asm-x86/mm.h
+9 -2
View File
@@ -330,13 +330,20 @@ int memguard_is_guarded(void *p);
#endif
typedef struct {
void (*enable)(void);
void (*disable)(void);
} vm_assist_info_t;
extern vm_assist_info_t vm_assist_info[];
/* Writable Pagetables */
#define PTWR_NR_WRITABLES 1
typedef struct {
unsigned long disconnected;
l1_pgentry_t disconnected_page[ENTRIES_PER_L1_PAGETABLE];
unsigned long *writable_l1;
unsigned long *writables[PTWR_NR_WRITABLES];
unsigned long writable_l1;
unsigned long writables[PTWR_NR_WRITABLES];
int writable_idx;
l1_pgentry_t writable_page[PTWR_NR_WRITABLES][ENTRIES_PER_L1_PAGETABLE];
#ifdef PTWR_TRACK_DOMAIN
xen/include/hypervisor-ifs/hypervisor-if.h
+1
View File
@@ -190,6 +190,7 @@
#define VMASST_TYPE_4gb_segments 0
#define VMASST_TYPE_4gb_segments_notify 1
#define VMASST_TYPE_writeable_pagetables 2
#define MAX_VMASST_TYPE 2
#ifndef __ASSEMBLY__
Reference in new issue
xen-project/xen
Block a user
Blocking a user prevents them from interacting with repositories, such as opening or commenting on pull requests or issues. Learn more about blocking a user.

The note is not visible to the blocked user.