@@ -36,6 +36,8 @@ static const paddr_t level_masks[] =
{ ZEROETH_MASK, FIRST_MASK, SECOND_MASK, THIRD_MASK };
static const uint8_t level_shifts[] =
{ ZEROETH_SHIFT, FIRST_SHIFT, SECOND_SHIFT, THIRD_SHIFT };
+static const uint8_t level_orders[] =
+ { ZEROETH_ORDER, FIRST_ORDER, SECOND_ORDER, THIRD_ORDER };
static bool_t p2m_valid(lpae_t pte)
{
@@ -204,6 +206,37 @@ static void p2m_flush_tlb_sync(struct p2m_domain *p2m)
}
/*
+ * Find and map the root page table. The caller is responsible for
+ * unmapping the table.
+ *
+ * The function will return NULL if the offset of the root table is
+ * invalid.
+ */
+static lpae_t *p2m_get_root_pointer(struct p2m_domain *p2m,
+ gfn_t gfn)
+{
+ unsigned int root_table;
+
+ if ( P2M_ROOT_PAGES == 1 )
+ return __map_domain_page(p2m->root);
+
+ /*
+ * Concatenated root-level tables. The table number will be the
+ * offset at the previous level. It is not possible to
+ * concatenate a level-0 root.
+ */
+ ASSERT(P2M_ROOT_LEVEL > 0);
+
+ root_table = gfn_x(gfn) >> (level_orders[P2M_ROOT_LEVEL - 1]);
+ root_table &= LPAE_ENTRY_MASK;
+
+ if ( root_table >= P2M_ROOT_PAGES )
+ return NULL;
+
+ return __map_domain_page(p2m->root + root_table);
+}
+
+/*
* Lookup the MFN corresponding to a domain's GFN.
*
* There are no processor functions to do a stage 2 only lookup therefore we
@@ -226,7 +259,7 @@ static mfn_t __p2m_lookup(struct domain *d, gfn_t gfn, p2m_type_t *t)
mfn_t mfn = INVALID_MFN;
paddr_t mask = 0;
p2m_type_t _t;
- unsigned int level, root_table;
+ unsigned int level;
ASSERT(p2m_is_locked(p2m));
BUILD_BUG_ON(THIRD_MASK != PAGE_MASK);
@@ -236,22 +269,9 @@ static mfn_t __p2m_lookup(struct domain *d, gfn_t gfn, p2m_type_t *t)
*t = p2m_invalid;
- if ( P2M_ROOT_PAGES > 1 )
- {
- /*
- * Concatenated root-level tables. The table number will be
- * the offset at the previous level. It is not possible to
- * concatenate a level-0 root.
- */
- ASSERT(P2M_ROOT_LEVEL > 0);
- root_table = offsets[P2M_ROOT_LEVEL - 1];
- if ( root_table >= P2M_ROOT_PAGES )
- goto err;
- }
- else
- root_table = 0;
-
- map = __map_domain_page(p2m->root + root_table);
+ map = p2m_get_root_pointer(p2m, gfn);
+ if ( !map )
+ return INVALID_MFN;
ASSERT(P2M_ROOT_LEVEL < 4);
@@ -286,7 +306,6 @@ static mfn_t __p2m_lookup(struct domain *d, gfn_t gfn, p2m_type_t *t)
*t = pte.p2m.type;
}
-err:
return mfn;
}
@@ -457,15 +457,19 @@ static inline int gva_to_ipa(vaddr_t va, paddr_t *paddr, unsigned int flags)
#define LPAE_ENTRY_MASK (LPAE_ENTRIES - 1)
#define THIRD_SHIFT (PAGE_SHIFT)
+#define THIRD_ORDER (THIRD_SHIFT - PAGE_SHIFT)
#define THIRD_SIZE ((paddr_t)1 << THIRD_SHIFT)
#define THIRD_MASK (~(THIRD_SIZE - 1))
#define SECOND_SHIFT (THIRD_SHIFT + LPAE_SHIFT)
+#define SECOND_ORDER (SECOND_SHIFT - PAGE_SHIFT)
#define SECOND_SIZE ((paddr_t)1 << SECOND_SHIFT)
#define SECOND_MASK (~(SECOND_SIZE - 1))
#define FIRST_SHIFT (SECOND_SHIFT + LPAE_SHIFT)
+#define FIRST_ORDER (FIRST_SHIFT - PAGE_SHIFT)
#define FIRST_SIZE ((paddr_t)1 << FIRST_SHIFT)
#define FIRST_MASK (~(FIRST_SIZE - 1))
#define ZEROETH_SHIFT (FIRST_SHIFT + LPAE_SHIFT)
+#define ZEROETH_ORDER (ZEROETH_SHIFT - PAGE_SHIFT)
#define ZEROETH_SIZE ((paddr_t)1 << ZEROETH_SHIFT)
#define ZEROETH_MASK (~(ZEROETH_SIZE - 1))
Mapping the root table is always done the same way. To avoid duplicating the code in a later patch, move the code in a separate helper. Signed-off-by: Julien Grall <julien.grall@arm.com> --- Changes in v2: - Use level_orders rather than level_shifts - PAGE_SHIFT - Move the definition of level_orders in this patch * use uint8_t rather than unsigned * define *_ORDER in term of *_SHIFT --- xen/arch/arm/p2m.c | 55 +++++++++++++++++++++++++++++++--------------- xen/include/asm-arm/page.h | 4 ++++ 2 files changed, 41 insertions(+), 18 deletions(-)