# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1236366890 0
# Node ID f1080b20cd15e06d5fc72062c35b627b2f947339
# Parent 0942baa2a088d47f6d4fdf531163172352b1013e
x86/mm: Do not set page's count_info directly
Page offline patch add several flag to page_info->count_info. However,
currently some code will try to set count_info after alloc_domheap_pages
without using "&" or "|" operation, this may cause the new flags lost, since
there are no protection. This patch try to make sure all write to
count_info will only impact specific field.
Also currently shadow code assume count_info is 0 for shadow page,
however, this is invalid after the new flags. Change some assert in
shadow code.
Signed-off-by: Jiang, Yunhong <yunhong.jiang@xxxxxxxxx>
---
xen/arch/x86/mm/hap/hap.c | 5 ++---
xen/arch/x86/mm/p2m.c | 4 ++--
xen/arch/x86/mm/shadow/common.c | 6 +++---
xen/arch/x86/mm/shadow/multi.c | 2 +-
xen/arch/x86/mm/shadow/private.h | 2 +-
5 files changed, 9 insertions(+), 10 deletions(-)
diff -r 0942baa2a088 -r f1080b20cd15 xen/arch/x86/mm/hap/hap.c
--- a/xen/arch/x86/mm/hap/hap.c Fri Mar 06 19:13:23 2009 +0000
+++ b/xen/arch/x86/mm/hap/hap.c Fri Mar 06 19:14:50 2009 +0000
@@ -152,7 +152,7 @@ static struct page_info *hap_alloc_p2m_p
d->arch.paging.hap.total_pages--;
d->arch.paging.hap.p2m_pages++;
page_set_owner(pg, d);
- pg->count_info = 1;
+ pg->count_info |= 1;
}
hap_unlock(d);
@@ -167,7 +167,7 @@ void hap_free_p2m_page(struct domain *d,
if ( (pg->count_info & PGC_count_mask) != 1 )
HAP_ERROR("Odd p2m page count c=%#lx t=%"PRtype_info"\n",
pg->count_info, pg->u.inuse.type_info);
- pg->count_info = 0;
+ pg->count_info &= ~PGC_count_mask;
/* Free should not decrement domain's total allocation, since
* these pages were allocated without an owner. */
page_set_owner(pg, NULL);
@@ -218,7 +218,6 @@ hap_set_allocation(struct domain *d, uns
ASSERT(pg);
d->arch.paging.hap.free_pages--;
d->arch.paging.hap.total_pages--;
- pg->count_info = 0;
free_domheap_page(pg);
}
diff -r 0942baa2a088 -r f1080b20cd15 xen/arch/x86/mm/p2m.c
--- a/xen/arch/x86/mm/p2m.c Fri Mar 06 19:13:23 2009 +0000
+++ b/xen/arch/x86/mm/p2m.c Fri Mar 06 19:14:50 2009 +0000
@@ -177,7 +177,7 @@ p2m_next_level(struct domain *d, mfn_t *
return 0;
page_list_add_tail(pg, &d->arch.p2m->pages);
pg->u.inuse.type_info = type | 1 | PGT_validated;
- pg->count_info = 1;
+ pg->count_info |= 1;
new_entry = l1e_from_pfn(mfn_x(page_to_mfn(pg)),
__PAGE_HYPERVISOR|_PAGE_USER);
@@ -216,7 +216,7 @@ p2m_next_level(struct domain *d, mfn_t *
return 0;
page_list_add_tail(pg, &d->arch.p2m->pages);
pg->u.inuse.type_info = PGT_l1_page_table | 1 | PGT_validated;
- pg->count_info = 1;
+ pg->count_info |= 1;
/* New splintered mappings inherit the flags of the old superpage,
* with a little reorganisation for the _PAGE_PSE_PAT bit. */
diff -r 0942baa2a088 -r f1080b20cd15 xen/arch/x86/mm/shadow/common.c
--- a/xen/arch/x86/mm/shadow/common.c Fri Mar 06 19:13:23 2009 +0000
+++ b/xen/arch/x86/mm/shadow/common.c Fri Mar 06 19:14:50 2009 +0000
@@ -1677,7 +1677,7 @@ sh_alloc_p2m_pages(struct domain *d)
* believed to be a concern.
*/
page_set_owner(&pg[i], d);
- pg[i].count_info = 1;
+ pg[i].count_info |= 1;
page_list_add_tail(&pg[i], &d->arch.paging.shadow.p2m_freelist);
}
return 1;
@@ -1721,7 +1721,7 @@ shadow_free_p2m_page(struct domain *d, s
SHADOW_ERROR("Odd p2m page count c=%#lx t=%"PRtype_info"\n",
pg->count_info, pg->u.inuse.type_info);
}
- pg->count_info = 0;
+ pg->count_info &= ~PGC_count_mask;
/* Free should not decrement domain's total allocation, since
* these pages were allocated without an owner. */
page_set_owner(pg, NULL);
@@ -1895,7 +1895,7 @@ static void sh_hash_audit_bucket(struct
while ( sp )
{
/* Not a shadow? */
- BUG_ON( sp->count_info != 0 );
+ BUG_ON( (sp->count_info & PGC_count_mask )!= 0 ) ;
/* Bogus type? */
BUG_ON( sp->u.sh.type == 0 );
BUG_ON( sp->u.sh.type > SH_type_max_shadow );
diff -r 0942baa2a088 -r f1080b20cd15 xen/arch/x86/mm/shadow/multi.c
--- a/xen/arch/x86/mm/shadow/multi.c Fri Mar 06 19:13:23 2009 +0000
+++ b/xen/arch/x86/mm/shadow/multi.c Fri Mar 06 19:14:50 2009 +0000
@@ -4281,7 +4281,7 @@ int sh_rm_write_access_from_sl1p(struct
sp = mfn_to_page(smfn);
- if ( sp->count_info != 0
+ if ( ((sp->count_info & PGC_count_mask) != 0)
|| (sp->u.sh.type != SH_type_l1_shadow
&& sp->u.sh.type != SH_type_fl1_shadow) )
goto fail;
diff -r 0942baa2a088 -r f1080b20cd15 xen/arch/x86/mm/shadow/private.h
--- a/xen/arch/x86/mm/shadow/private.h Fri Mar 06 19:13:23 2009 +0000
+++ b/xen/arch/x86/mm/shadow/private.h Fri Mar 06 19:14:50 2009 +0000
@@ -647,7 +647,7 @@ static inline void sh_put_ref(struct vcp
struct page_info *sp = mfn_to_page(smfn);
ASSERT(mfn_valid(smfn));
- ASSERT(sp->count_info == 0);
+ ASSERT(!(sp->count_info & PGC_count_mask));
/* If this is the entry in the up-pointer, remove it */
if ( entry_pa != 0
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