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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 3/3] x86/mm: More discriptive names for page de/validation functions
The functions alloc_page_type(), alloc_lN_table(), free_page_type()
and free_lN_table() are confusingly named: nothing is being allocated
or freed. Rather, the page being passed in is being either validated
or devalidated for use as the specific type; in the specific case of
pagetables, these may be promoted or demoted (i.e., grab appropriate
references for PTEs).
Rename alloc_page_type() and free_page_type() to validate_page() and
devalidate_page(). Also rename alloc_segdesc_page() to
validate_segdesc_page(), since this is what it's doing.
Rename alloc_lN_table() and free_lN_table() to promote_lN_table() and
demote_lN_table(), respectively.
After this change:
- get / put type consistenly refer to increasing or decreasing the count
- validate / devalidate consistently refers to actions done when a
type count goes 0 -> 1 or 1 -> 0
- promote / demote consistenly refers to acquiring or freeing
resources (in the form of type refs and general references) in order
to allow a page to be used as a pagetable.
No functional change.
Signed-off-by: George Dunlap <george.dunlap@xxxxxxxxxx>
---
v2:
- Rebase onto staging
- Also rename alloc_segdesc_page
- Drop superfluous '_type' from validate_page / devalidate_page
- Use promote / demote for _lN_table
CC: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CC: Jan Beulich <jbeulich@xxxxxxxx>
---
xen/arch/x86/domain.c | 2 +-
xen/arch/x86/mm.c | 66 ++++++++++++++++++++--------------------
xen/include/asm-x86/mm.h | 4 +--
3 files changed, 36 insertions(+), 36 deletions(-)
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index bed19fc4dc..7cb7fd31dd 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -2032,7 +2032,7 @@ static int relinquish_memory(
if ( likely(y == x) )
{
/* No need for atomic update of type_info here: noone else
updates it. */
- switch ( ret = free_page_type(page, x, 1) )
+ switch ( ret = devalidate_page(page, x, 1) )
{
case 0:
break;
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 55f9a581b4..a711e8c78d 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -587,7 +587,7 @@ const char __section(".bss.page_aligned.const")
__aligned(PAGE_SIZE)
#ifdef CONFIG_PV
-static int alloc_segdesc_page(struct page_info *page)
+static int validate_segdesc_page(struct page_info *page)
{
const struct domain *owner = page_get_owner(page);
seg_desc_t *descs = __map_domain_page(page);
@@ -1363,7 +1363,7 @@ static int put_page_from_l4e(l4_pgentry_t l4e, mfn_t
l4mfn, unsigned int flags)
return put_pt_page(l4e_get_page(l4e), mfn_to_page(l4mfn), flags);
}
-static int alloc_l1_table(struct page_info *page)
+static int promote_l1_table(struct page_info *page)
{
struct domain *d = page_get_owner(page);
l1_pgentry_t *pl1e;
@@ -1405,7 +1405,7 @@ static int alloc_l1_table(struct page_info *page)
fail:
gdprintk(XENLOG_WARNING,
- "Failure %d in alloc_l1_table: slot %#x\n", ret, i);
+ "Failure %d in promote_l1_table: slot %#x\n", ret, i);
out:
while ( i-- > 0 )
put_page_from_l1e(pl1e[i], d);
@@ -1438,7 +1438,7 @@ static int create_pae_xen_mappings(struct domain *d,
l3_pgentry_t *pl3e)
* 1. Cannot appear in slots != 3 because get_page_type() checks the
* PGT_pae_xen_l2 flag, which is asserted iff the L2 appears in slot 3
* 2. Cannot appear in another page table's L3:
- * a. alloc_l3_table() calls this function and this check will fail
+ * a. promote_l3_table() calls this function and this check will fail
* b. mod_l3_entry() disallows updates to slot 3 in an existing table
*/
page = l3e_get_page(l3e3);
@@ -1454,7 +1454,7 @@ static int create_pae_xen_mappings(struct domain *d,
l3_pgentry_t *pl3e)
return 1;
}
-static int alloc_l2_table(struct page_info *page, unsigned long type)
+static int promote_l2_table(struct page_info *page, unsigned long type)
{
struct domain *d = page_get_owner(page);
mfn_t l2mfn = page_to_mfn(page);
@@ -1466,8 +1466,8 @@ static int alloc_l2_table(struct page_info *page,
unsigned long type)
pl2e = map_domain_page(l2mfn);
/*
- * NB that alloc_l2_table will never set partial_pte on an l2; but
- * free_l2_table might if a linear_pagetable entry is interrupted
+ * NB that promote_l2_table will never set partial_pte on an l2; but
+ * demote_l2_table might if a linear_pagetable entry is interrupted
* partway through de-validation. In that circumstance,
* get_page_from_l2e() will always return -EINVAL; and we must
* retain the type ref by doing the normal partial_flags tracking.
@@ -1494,7 +1494,7 @@ static int alloc_l2_table(struct page_info *page,
unsigned long type)
/*
* It shouldn't be possible for get_page_from_l2e to return
* -ERESTART, since we never call this with PTF_preemptible.
- * (alloc_l1_table may return -EINTR on an L1TF-vulnerable
+ * (promote_l1_table may return -EINTR on an L1TF-vulnerable
* entry.)
*
* NB that while on a "clean" promotion, we can never get
@@ -1515,12 +1515,12 @@ static int alloc_l2_table(struct page_info *page,
unsigned long type)
else if ( rc < 0 && rc != -EINTR )
{
gdprintk(XENLOG_WARNING,
- "Failure %d in alloc_l2_table: slot %#x\n", rc, i);
+ "Failure %d in promote_l2_table: slot %#x\n", rc, i);
ASSERT(current->arch.old_guest_table == NULL);
if ( i )
{
/*
- * alloc_l1_table() doesn't set old_guest_table; it does
+ * promote_l1_table() doesn't set old_guest_table; it does
* its own tear-down immediately on failure. If it
* did we'd need to check it and set partial_flags as we
* do in alloc_l[34]_table().
@@ -1553,7 +1553,7 @@ static int alloc_l2_table(struct page_info *page,
unsigned long type)
return rc;
}
-static int alloc_l3_table(struct page_info *page)
+static int promote_l3_table(struct page_info *page)
{
struct domain *d = page_get_owner(page);
mfn_t l3mfn = page_to_mfn(page);
@@ -1626,7 +1626,7 @@ static int alloc_l3_table(struct page_info *page)
if ( rc < 0 && rc != -ERESTART && rc != -EINTR )
{
gdprintk(XENLOG_WARNING,
- "Failure %d in alloc_l3_table: slot %#x\n", rc, i);
+ "Failure %d in promote_l3_table: slot %#x\n", rc, i);
if ( i )
{
page->nr_validated_ptes = i;
@@ -1677,7 +1677,7 @@ void init_xen_pae_l2_slots(l2_pgentry_t *l2t, const
struct domain *d)
* Fill an L4 with Xen entries.
*
* This function must write all ROOT_PAGETABLE_PV_XEN_SLOTS, to clobber any
- * values a guest may have left there from alloc_l4_table().
+ * values a guest may have left there from promote_l4_table().
*
* l4t and l4mfn are mandatory, but l4mfn doesn't need to be the mfn under
* *l4t. All other parameters are optional and will either fill or zero the
@@ -1780,7 +1780,7 @@ void zap_ro_mpt(mfn_t mfn)
}
#ifdef CONFIG_PV
-static int alloc_l4_table(struct page_info *page)
+static int promote_l4_table(struct page_info *page)
{
struct domain *d = page_get_owner(page);
mfn_t l4mfn = page_to_mfn(page);
@@ -1819,7 +1819,7 @@ static int alloc_l4_table(struct page_info *page)
{
if ( rc != -EINTR )
gdprintk(XENLOG_WARNING,
- "Failure %d in alloc_l4_table: slot %#x\n", rc, i);
+ "Failure %d in promote_l4_table: slot %#x\n", rc, i);
if ( i )
{
page->nr_validated_ptes = i;
@@ -1875,7 +1875,7 @@ static int alloc_l4_table(struct page_info *page)
return rc;
}
-static void free_l1_table(struct page_info *page)
+static void demote_l1_table(struct page_info *page)
{
struct domain *d = page_get_owner(page);
l1_pgentry_t *pl1e;
@@ -1890,7 +1890,7 @@ static void free_l1_table(struct page_info *page)
}
-static int free_l2_table(struct page_info *page)
+static int demote_l2_table(struct page_info *page)
{
struct domain *d = page_get_owner(page);
mfn_t l2mfn = page_to_mfn(page);
@@ -1942,7 +1942,7 @@ static int free_l2_table(struct page_info *page)
return rc;
}
-static int free_l3_table(struct page_info *page)
+static int demote_l3_table(struct page_info *page)
{
struct domain *d = page_get_owner(page);
mfn_t l3mfn = page_to_mfn(page);
@@ -1989,7 +1989,7 @@ static int free_l3_table(struct page_info *page)
return rc > 0 ? 0 : rc;
}
-static int free_l4_table(struct page_info *page)
+static int demote_l4_table(struct page_info *page)
{
struct domain *d = page_get_owner(page);
mfn_t l4mfn = page_to_mfn(page);
@@ -2589,7 +2589,7 @@ static void get_page_light(struct page_info *page)
while ( unlikely(y != x) );
}
-static int alloc_page_type(struct page_info *page, unsigned long type,
+static int validate_page(struct page_info *page, unsigned long type,
int preemptible)
{
#ifdef CONFIG_PV
@@ -2603,25 +2603,25 @@ static int alloc_page_type(struct page_info *page,
unsigned long type,
switch ( type & PGT_type_mask )
{
case PGT_l1_page_table:
- rc = alloc_l1_table(page);
+ rc = promote_l1_table(page);
break;
case PGT_l2_page_table:
ASSERT(preemptible);
- rc = alloc_l2_table(page, type);
+ rc = promote_l2_table(page, type);
break;
case PGT_l3_page_table:
ASSERT(preemptible);
- rc = alloc_l3_table(page);
+ rc = promote_l3_table(page);
break;
case PGT_l4_page_table:
ASSERT(preemptible);
- rc = alloc_l4_table(page);
+ rc = promote_l4_table(page);
break;
case PGT_seg_desc_page:
- rc = alloc_segdesc_page(page);
+ rc = validate_segdesc_page(page);
break;
default:
- printk("Bad type in alloc_page_type %lx t=%" PRtype_info " c=%lx\n",
+ printk("Bad type in validate_page %lx t=%" PRtype_info " c=%lx\n",
type, page->u.inuse.type_info,
page->count_info);
rc = -EINVAL;
@@ -2669,7 +2669,7 @@ static int alloc_page_type(struct page_info *page,
unsigned long type,
}
-int free_page_type(struct page_info *page, unsigned long type,
+int devalidate_page(struct page_info *page, unsigned long type,
int preemptible)
{
#ifdef CONFIG_PV
@@ -2697,20 +2697,20 @@ int free_page_type(struct page_info *page, unsigned
long type,
switch ( type & PGT_type_mask )
{
case PGT_l1_page_table:
- free_l1_table(page);
+ demote_l1_table(page);
rc = 0;
break;
case PGT_l2_page_table:
ASSERT(preemptible);
- rc = free_l2_table(page);
+ rc = demote_l2_table(page);
break;
case PGT_l3_page_table:
ASSERT(preemptible);
- rc = free_l3_table(page);
+ rc = demote_l3_table(page);
break;
case PGT_l4_page_table:
ASSERT(preemptible);
- rc = free_l4_table(page);
+ rc = demote_l4_table(page);
break;
default:
gdprintk(XENLOG_WARNING, "type %" PRtype_info " mfn %" PRI_mfn "\n",
@@ -2730,7 +2730,7 @@ int free_page_type(struct page_info *page, unsigned long
type,
static int _put_final_page_type(struct page_info *page, unsigned long type,
bool preemptible, struct page_info *ptpg)
{
- int rc = free_page_type(page, type, preemptible);
+ int rc = devalidate_page(page, type, preemptible);
if ( ptpg && PGT_type_equal(type, ptpg->u.inuse.type_info) &&
(type & PGT_validated) && rc != -EINTR )
@@ -3013,7 +3013,7 @@ static int _get_page_type(struct page_info *page,
unsigned long type,
page->partial_flags = 0;
page->linear_pt_count = 0;
}
- rc = alloc_page_type(page, type, preemptible);
+ rc = validate_page(page, type, preemptible);
}
out:
diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
index 320c6cd196..1479ba6703 100644
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -355,8 +355,8 @@ static inline void *__page_to_virt(const struct page_info
*pg)
(PAGE_SIZE / (sizeof(*pg) & -sizeof(*pg))));
}
-int free_page_type(struct page_info *page, unsigned long type,
- int preemptible);
+int devalidate_page(struct page_info *page, unsigned long type,
+ int preemptible);
void init_xen_pae_l2_slots(l2_pgentry_t *l2t, const struct domain *d);
void init_xen_l4_slots(l4_pgentry_t *l4t, mfn_t l4mfn,
--
2.24.0
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