# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1203938646 0
# Node ID cb3e47897b85b34de1b2b3bee5812318618972a2
# Parent 746fc8fe9d75313c7be8c7e77786f5ce9226920d
x86: Foreign mappings of HVM-guest pages should not affect type count,
even when the mapping is made via a grant reference.
Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
---
xen/common/grant_table.c | 24 +++++++++++++++---------
xen/include/asm-ia64/grant_table.h | 6 ++++--
xen/include/asm-powerpc/grant_table.h | 11 ++++-------
xen/include/asm-x86/grant_table.h | 14 ++++++--------
4 files changed, 29 insertions(+), 26 deletions(-)
diff -r 746fc8fe9d75 -r cb3e47897b85 xen/common/grant_table.c
--- a/xen/common/grant_table.c Mon Feb 25 10:56:23 2008 +0000
+++ b/xen/common/grant_table.c Mon Feb 25 11:24:06 2008 +0000
@@ -350,10 +350,10 @@ __gnttab_map_grant_ref(
else
{
if ( unlikely(!mfn_valid(frame)) ||
- unlikely(!((op->flags & GNTMAP_readonly) ?
- get_page(mfn_to_page(frame), rd) :
+ unlikely(!(gnttab_host_mapping_get_page_type(op, ld, rd) ?
get_page_and_type(mfn_to_page(frame), rd,
- PGT_writable_page))) )
+ PGT_writable_page) :
+ get_page(mfn_to_page(frame), rd))) )
{
if ( !rd->is_dying )
gdprintk(XENLOG_WARNING, "Could not pin grant frame %lx\n",
@@ -367,7 +367,7 @@ __gnttab_map_grant_ref(
rc = create_grant_host_mapping(op->host_addr, frame, op->flags, 0);
if ( rc != GNTST_okay )
{
- if ( !(op->flags & GNTMAP_readonly) )
+ if ( gnttab_host_mapping_get_page_type(op, ld, rd) )
put_page_type(mfn_to_page(frame));
put_page(mfn_to_page(frame));
goto undo_out;
@@ -604,7 +604,7 @@ __gnttab_unmap_common_complete(struct gn
if ( !is_iomem_page(op->frame) )
{
- if ( !(op->flags & GNTMAP_readonly) )
+ if ( gnttab_host_mapping_get_page_type(op, ld, rd) )
put_page_type(mfn_to_page(op->frame));
put_page(mfn_to_page(op->frame));
}
@@ -1662,8 +1662,9 @@ gnttab_release_mappings(
{
BUG_ON(!(act->pin & GNTPIN_hstr_mask));
act->pin -= GNTPIN_hstr_inc;
- if ( !is_iomem_page(act->frame) )
- gnttab_release_put_page(mfn_to_page(act->frame));
+ if ( gnttab_release_host_mappings &&
+ !is_iomem_page(act->frame) )
+ put_page(mfn_to_page(act->frame));
}
}
else
@@ -1680,8 +1681,13 @@ gnttab_release_mappings(
{
BUG_ON(!(act->pin & GNTPIN_hstw_mask));
act->pin -= GNTPIN_hstw_inc;
- if ( !is_iomem_page(act->frame) )
- gnttab_release_put_page_and_type(mfn_to_page(act->frame));
+ if ( gnttab_release_host_mappings &&
+ !is_iomem_page(act->frame) )
+ {
+ if ( gnttab_host_mapping_get_page_type(map, d, rd) )
+ put_page_type(mfn_to_page(act->frame));
+ put_page(mfn_to_page(act->frame));
+ }
}
if ( (act->pin & (GNTPIN_devw_mask|GNTPIN_hstw_mask)) == 0 )
diff -r 746fc8fe9d75 -r cb3e47897b85 xen/include/asm-ia64/grant_table.h
--- a/xen/include/asm-ia64/grant_table.h Mon Feb 25 10:56:23 2008 +0000
+++ b/xen/include/asm-ia64/grant_table.h Mon Feb 25 11:24:06 2008 +0000
@@ -65,8 +65,10 @@ static inline void gnttab_clear_flag(uns
clear_bit(nr, addr);
}
-#define gnttab_release_put_page(page) put_page((page))
-#define gnttab_release_put_page_and_type(page) put_page_and_type((page))
+#define gnttab_host_mapping_get_page_type(op, ld, rd) \
+ (!((op)->flags & GNTMAP_readonly))
+
+#define gnttab_release_host_mappings 1
static inline int replace_grant_supported(void)
{
diff -r 746fc8fe9d75 -r cb3e47897b85 xen/include/asm-powerpc/grant_table.h
--- a/xen/include/asm-powerpc/grant_table.h Mon Feb 25 10:56:23 2008 +0000
+++ b/xen/include/asm-powerpc/grant_table.h Mon Feb 25 11:24:06 2008 +0000
@@ -76,17 +76,14 @@ static inline uint cpu_foreign_map_order
return 34 - PAGE_SHIFT;
}
-#if 0
+#define gnttab_host_mapping_get_page_type(op, ld, rd) \
+ (!((op)->flags & GNTMAP_readonly))
+
/*
* without put_page()/put_page_and_type() page might be leaked.
* with put_page()/put_page_and_type() freed page might be accessed.
*/
-#define gnttab_release_put_page(page) put_page((page))
-#define gnttab_release_put_page_and_type(page) put_page_and_type((page))
-#else
-#define gnttab_release_put_page(page) do { } while (0)
-#define gnttab_release_put_page_and_type(page) do { } while (0)
-#endif
+#define gnttab_release_host_mappings 0
static inline int replace_grant_supported(void)
{
diff -r 746fc8fe9d75 -r cb3e47897b85 xen/include/asm-x86/grant_table.h
--- a/xen/include/asm-x86/grant_table.h Mon Feb 25 10:56:23 2008 +0000
+++ b/xen/include/asm-x86/grant_table.h Mon Feb 25 11:24:06 2008 +0000
@@ -38,15 +38,13 @@ static inline void gnttab_clear_flag(uns
clear_bit(nr, addr);
}
-#define gnttab_release_put_page(page) \
- do { \
- /* Done implicitly when page tables are destroyed. */ \
- } while (0)
+/* Foreign mappings of HHVM-guest pages do not modify the type count. */
+#define gnttab_host_mapping_get_page_type(op, ld, rd) \
+ (!((op)->flags & GNTMAP_readonly) && \
+ (((ld) == (rd)) || !paging_mode_external(rd)))
-#define gnttab_release_put_page_and_type(page) \
- do { \
- /* Done implicitly when page tables are destroyed. */ \
- } while (0)
+/* Done implicitly when page tables are destroyed. */
+#define gnttab_release_host_mappings 0
static inline int replace_grant_supported(void)
{
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