# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1200407535 0
# Node ID fba4e7357744e96797916689e3274344b82a8e5f
# Parent 58dfcad8d56d3ebad2e8553c43db499ce727cb36
x86: Allow batched mmu updates which preserve accessed/dirty pte bits.
Signed-off-by: Bruce Rogers <brogers@xxxxxxxxxx>
Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
---
xen/arch/x86/mm.c | 110 +++++++++++++++++++++++++++++------------------
xen/include/public/xen.h | 11 +++-
2 files changed, 78 insertions(+), 43 deletions(-)
diff -r 58dfcad8d56d -r fba4e7357744 xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c Tue Jan 15 14:27:15 2008 +0000
+++ b/xen/arch/x86/mm.c Tue Jan 15 14:32:15 2008 +0000
@@ -1342,21 +1342,30 @@ static inline int update_intpte(intpte_t
intpte_t old,
intpte_t new,
unsigned long mfn,
- struct vcpu *v)
+ struct vcpu *v,
+ int preserve_ad)
{
int rv = 1;
#ifndef PTE_UPDATE_WITH_CMPXCHG
- rv = paging_write_guest_entry(v, p, new, _mfn(mfn));
-#else
+ if ( !preserve_ad )
+ {
+ rv = paging_write_guest_entry(v, p, new, _mfn(mfn));
+ }
+ else
+#endif
{
intpte_t t = old;
for ( ; ; )
{
- rv = paging_cmpxchg_guest_entry(v, p, &t, new, _mfn(mfn));
+ intpte_t _new = new;
+ if ( preserve_ad )
+ _new |= old & (_PAGE_ACCESSED | _PAGE_DIRTY);
+
+ rv = paging_cmpxchg_guest_entry(v, p, &t, _new, _mfn(mfn));
if ( unlikely(rv == 0) )
{
MEM_LOG("Failed to update %" PRIpte " -> %" PRIpte
- ": saw %" PRIpte, old, new, t);
+ ": saw %" PRIpte, old, _new, t);
break;
}
@@ -1369,20 +1378,19 @@ static inline int update_intpte(intpte_t
old = t;
}
}
-#endif
return rv;
}
/* Macro that wraps the appropriate type-changes around update_intpte().
* Arguments are: type, ptr, old, new, mfn, vcpu */
-#define UPDATE_ENTRY(_t,_p,_o,_n,_m,_v) \
+#define UPDATE_ENTRY(_t,_p,_o,_n,_m,_v,_ad) \
update_intpte(&_t ## e_get_intpte(*(_p)), \
_t ## e_get_intpte(_o), _t ## e_get_intpte(_n), \
- (_m), (_v))
+ (_m), (_v), (_ad))
/* Update the L1 entry at pl1e to new value nl1e. */
static int mod_l1_entry(l1_pgentry_t *pl1e, l1_pgentry_t nl1e,
- unsigned long gl1mfn)
+ unsigned long gl1mfn, int preserve_ad)
{
l1_pgentry_t ol1e;
struct vcpu *curr = current;
@@ -1393,7 +1401,7 @@ static int mod_l1_entry(l1_pgentry_t *pl
return 0;
if ( unlikely(paging_mode_refcounts(d)) )
- return UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, curr);
+ return UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, curr, preserve_ad);
if ( l1e_get_flags(nl1e) & _PAGE_PRESENT )
{
@@ -1415,12 +1423,14 @@ static int mod_l1_entry(l1_pgentry_t *pl
/* Fast path for identical mapping, r/w and presence. */
if ( !l1e_has_changed(ol1e, nl1e, _PAGE_RW | _PAGE_PRESENT) )
- return UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, curr);
+ return UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, curr,
+ preserve_ad);
if ( unlikely(!get_page_from_l1e(nl1e, FOREIGNDOM)) )
return 0;
- if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, curr)) )
+ if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, curr,
+ preserve_ad)) )
{
put_page_from_l1e(nl1e, d);
return 0;
@@ -1428,7 +1438,8 @@ static int mod_l1_entry(l1_pgentry_t *pl
}
else
{
- if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, curr)) )
+ if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, curr,
+ preserve_ad)) )
return 0;
}
@@ -1441,7 +1452,8 @@ static int mod_l2_entry(l2_pgentry_t *pl
static int mod_l2_entry(l2_pgentry_t *pl2e,
l2_pgentry_t nl2e,
unsigned long pfn,
- unsigned long type)
+ unsigned long type,
+ int preserve_ad)
{
l2_pgentry_t ol2e;
struct vcpu *curr = current;
@@ -1469,18 +1481,20 @@ static int mod_l2_entry(l2_pgentry_t *pl
/* Fast path for identical mapping and presence. */
if ( !l2e_has_changed(ol2e, nl2e, _PAGE_PRESENT))
- return UPDATE_ENTRY(l2, pl2e, ol2e, nl2e, pfn, curr);
+ return UPDATE_ENTRY(l2, pl2e, ol2e, nl2e, pfn, curr, preserve_ad);
if ( unlikely(!get_page_from_l2e(nl2e, pfn, d)) )
return 0;
- if ( unlikely(!UPDATE_ENTRY(l2, pl2e, ol2e, nl2e, pfn, curr)) )
+ if ( unlikely(!UPDATE_ENTRY(l2, pl2e, ol2e, nl2e, pfn, curr,
+ preserve_ad)) )
{
put_page_from_l2e(nl2e, pfn);
return 0;
}
}
- else if ( unlikely(!UPDATE_ENTRY(l2, pl2e, ol2e, nl2e, pfn, curr)) )
+ else if ( unlikely(!UPDATE_ENTRY(l2, pl2e, ol2e, nl2e, pfn, curr,
+ preserve_ad)) )
{
return 0;
}
@@ -1494,7 +1508,8 @@ static int mod_l2_entry(l2_pgentry_t *pl
/* Update the L3 entry at pl3e to new value nl3e. pl3e is within frame pfn. */
static int mod_l3_entry(l3_pgentry_t *pl3e,
l3_pgentry_t nl3e,
- unsigned long pfn)
+ unsigned long pfn,
+ int preserve_ad)
{
l3_pgentry_t ol3e;
struct vcpu *curr = current;
@@ -1532,18 +1547,20 @@ static int mod_l3_entry(l3_pgentry_t *pl
/* Fast path for identical mapping and presence. */
if (!l3e_has_changed(ol3e, nl3e, _PAGE_PRESENT))
- return UPDATE_ENTRY(l3, pl3e, ol3e, nl3e, pfn, curr);
+ return UPDATE_ENTRY(l3, pl3e, ol3e, nl3e, pfn, curr, preserve_ad);
if ( unlikely(!get_page_from_l3e(nl3e, pfn, d)) )
return 0;
- if ( unlikely(!UPDATE_ENTRY(l3, pl3e, ol3e, nl3e, pfn, curr)) )
+ if ( unlikely(!UPDATE_ENTRY(l3, pl3e, ol3e, nl3e, pfn, curr,
+ preserve_ad)) )
{
put_page_from_l3e(nl3e, pfn);
return 0;
}
}
- else if ( unlikely(!UPDATE_ENTRY(l3, pl3e, ol3e, nl3e, pfn, curr)) )
+ else if ( unlikely(!UPDATE_ENTRY(l3, pl3e, ol3e, nl3e, pfn, curr,
+ preserve_ad)) )
{
return 0;
}
@@ -1564,7 +1581,8 @@ static int mod_l3_entry(l3_pgentry_t *pl
/* Update the L4 entry at pl4e to new value nl4e. pl4e is within frame pfn. */
static int mod_l4_entry(l4_pgentry_t *pl4e,
l4_pgentry_t nl4e,
- unsigned long pfn)
+ unsigned long pfn,
+ int preserve_ad)
{
struct vcpu *curr = current;
struct domain *d = curr->domain;
@@ -1592,18 +1610,20 @@ static int mod_l4_entry(l4_pgentry_t *pl
/* Fast path for identical mapping and presence. */
if (!l4e_has_changed(ol4e, nl4e, _PAGE_PRESENT))
- return UPDATE_ENTRY(l4, pl4e, ol4e, nl4e, pfn, curr);
+ return UPDATE_ENTRY(l4, pl4e, ol4e, nl4e, pfn, curr, preserve_ad);
if ( unlikely(!get_page_from_l4e(nl4e, pfn, d)) )
return 0;
- if ( unlikely(!UPDATE_ENTRY(l4, pl4e, ol4e, nl4e, pfn, curr)) )
+ if ( unlikely(!UPDATE_ENTRY(l4, pl4e, ol4e, nl4e, pfn, curr,
+ preserve_ad)) )
{
put_page_from_l4e(nl4e, pfn);
return 0;
}
}
- else if ( unlikely(!UPDATE_ENTRY(l4, pl4e, ol4e, nl4e, pfn, curr)) )
+ else if ( unlikely(!UPDATE_ENTRY(l4, pl4e, ol4e, nl4e, pfn, curr,
+ preserve_ad)) )
{
return 0;
}
@@ -1946,7 +1966,7 @@ int new_guest_cr3(unsigned long mfn)
l4e_from_pfn(
mfn,
(_PAGE_PRESENT|_PAGE_RW|_PAGE_USER|_PAGE_ACCESSED)),
- pagetable_get_pfn(v->arch.guest_table));
+ pagetable_get_pfn(v->arch.guest_table), 0);
if ( unlikely(!okay) )
{
MEM_LOG("Error while installing new compat baseptr %lx", mfn);
@@ -2458,13 +2478,16 @@ int do_mmu_update(
{
/*
* MMU_NORMAL_PT_UPDATE: Normal update to any level of page table.
+ * MMU_UPDATE_PT_PRESERVE_AD: As above but also preserve (OR)
+ * current A/D bits.
*/
case MMU_NORMAL_PT_UPDATE:
-
+ case MMU_PT_UPDATE_PRESERVE_AD:
rc = xsm_mmu_normal_update(d, req.val);
if ( rc )
break;
+ req.ptr -= cmd;
gmfn = req.ptr >> PAGE_SHIFT;
mfn = gmfn_to_mfn(d, gmfn);
@@ -2501,20 +2524,23 @@ int do_mmu_update(
case PGT_l1_page_table:
{
l1_pgentry_t l1e = l1e_from_intpte(req.val);
- okay = mod_l1_entry(va, l1e, mfn);
+ okay = mod_l1_entry(va, l1e, mfn,
+ cmd == MMU_PT_UPDATE_PRESERVE_AD);
}
break;
case PGT_l2_page_table:
{
l2_pgentry_t l2e = l2e_from_intpte(req.val);
- okay = mod_l2_entry(va, l2e, mfn, type_info);
+ okay = mod_l2_entry(va, l2e, mfn, type_info,
+ cmd == MMU_PT_UPDATE_PRESERVE_AD);
}
break;
#if CONFIG_PAGING_LEVELS >= 3
case PGT_l3_page_table:
{
l3_pgentry_t l3e = l3e_from_intpte(req.val);
- okay = mod_l3_entry(va, l3e, mfn);
+ okay = mod_l3_entry(va, l3e, mfn,
+ cmd == MMU_PT_UPDATE_PRESERVE_AD);
}
break;
#endif
@@ -2522,7 +2548,8 @@ int do_mmu_update(
case PGT_l4_page_table:
{
l4_pgentry_t l4e = l4e_from_intpte(req.val);
- okay = mod_l4_entry(va, l4e, mfn);
+ okay = mod_l4_entry(va, l4e, mfn,
+ cmd == MMU_PT_UPDATE_PRESERVE_AD);
}
break;
#endif
@@ -2652,7 +2679,7 @@ static int create_grant_pte_mapping(
}
ol1e = *(l1_pgentry_t *)va;
- if ( !UPDATE_ENTRY(l1, (l1_pgentry_t *)va, ol1e, nl1e, mfn, v) )
+ if ( !UPDATE_ENTRY(l1, (l1_pgentry_t *)va, ol1e, nl1e, mfn, v, 0) )
{
put_page_type(page);
rc = GNTST_general_error;
@@ -2720,9 +2747,11 @@ static int destroy_grant_pte_mapping(
}
/* Delete pagetable entry. */
- if ( unlikely(!UPDATE_ENTRY(l1,
- (l1_pgentry_t *)va, ol1e, l1e_empty(), mfn,
- d->vcpu[0] /* Change if we go to per-vcpu shadows. */)) )
+ if ( unlikely(!UPDATE_ENTRY
+ (l1,
+ (l1_pgentry_t *)va, ol1e, l1e_empty(), mfn,
+ d->vcpu[0] /* Change if we go to per-vcpu shadows. */,
+ 0)) )
{
MEM_LOG("Cannot delete PTE entry at %p", va);
put_page_type(page);
@@ -2758,7 +2787,7 @@ static int create_grant_va_mapping(
return GNTST_general_error;
}
ol1e = *pl1e;
- okay = UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, v);
+ okay = UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, v, 0);
guest_unmap_l1e(v, pl1e);
pl1e = NULL;
@@ -2796,7 +2825,7 @@ static int replace_grant_va_mapping(
}
/* Delete pagetable entry. */
- if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, v)) )
+ if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, v, 0)) )
{
MEM_LOG("Cannot delete PTE entry at %p", (unsigned long *)pl1e);
rc = GNTST_general_error;
@@ -2860,7 +2889,8 @@ int replace_grant_host_mapping(
}
ol1e = *pl1e;
- if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, l1e_empty(), gl1mfn, curr)) )
+ if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, l1e_empty(),
+ gl1mfn, curr, 0)) )
{
MEM_LOG("Cannot delete PTE entry at %p", (unsigned long *)pl1e);
guest_unmap_l1e(curr, pl1e);
@@ -2948,7 +2978,7 @@ int do_update_va_mapping(unsigned long v
pl1e = guest_map_l1e(v, va, &gl1mfn);
- if ( unlikely(!pl1e || !mod_l1_entry(pl1e, val, gl1mfn)) )
+ if ( unlikely(!pl1e || !mod_l1_entry(pl1e, val, gl1mfn, 0)) )
rc = -EINVAL;
if ( pl1e )
@@ -3517,7 +3547,7 @@ static int ptwr_emulated_update(
else
{
ol1e = *pl1e;
- if ( !UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, mfn, v) )
+ if ( !UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, mfn, v, 0) )
BUG();
}
diff -r 58dfcad8d56d -r fba4e7357744 xen/include/public/xen.h
--- a/xen/include/public/xen.h Tue Jan 15 14:27:15 2008 +0000
+++ b/xen/include/public/xen.h Tue Jan 15 14:32:15 2008 +0000
@@ -168,9 +168,14 @@
* ptr[:2] -- Machine address within the frame whose mapping to modify.
* The frame must belong to the FD, if one is specified.
* val -- Value to write into the mapping entry.
- */
-#define MMU_NORMAL_PT_UPDATE 0 /* checked '*ptr = val'. ptr is MA. */
-#define MMU_MACHPHYS_UPDATE 1 /* ptr = MA of frame to modify entry for */
+ *
+ * ptr[1:0] == MMU_PT_UPDATE_PRESERVE_AD:
+ * As MMU_NORMAL_PT_UPDATE above, but A/D bits currently in the PTE are ORed
+ * with those in @val.
+ */
+#define MMU_NORMAL_PT_UPDATE 0 /* checked '*ptr = val'. ptr is MA. */
+#define MMU_MACHPHYS_UPDATE 1 /* ptr = MA of frame to modify entry for */
+#define MMU_PT_UPDATE_PRESERVE_AD 2 /* atomically: *ptr = val | (*ptr&(A|D)) */
/*
* MMU EXTENDED OPERATIONS
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