@@ -5493,10 +5493,17 @@ int map_pages_to_xen(
} \
} while (0)
-/* Check if a (virt, mfn) tuple is aligned for a given slot level. */
-#define IS_LnE_ALIGNED(v, m, n) \
- IS_ALIGNED(PFN_DOWN(v) | mfn_x(m), \
- (1UL << (PAGETABLE_ORDER * ((n) - 1))) - 1)
+/*
+ * Check if a (virt, mfn) tuple is aligned for a given slot level. m must not
+ * be INVALID_MFN, since alignment is only relevant for present entries.
+ */
+#define IS_LnE_ALIGNED(v, m, n) ({ \
+ mfn_t m_ = m; \
+ \
+ ASSERT(!mfn_eq(m_, INVALID_MFN)); \
+ IS_ALIGNED(PFN_DOWN(v) | mfn_x(m_), \
+ (1UL << (PAGETABLE_ORDER * ((n) - 1))) - 1); \
+})
#define IS_L2E_ALIGNED(v, m) IS_LnE_ALIGNED(v, m, 2)
#define IS_L3E_ALIGNED(v, m) IS_LnE_ALIGNED(v, m, 3)
@@ -5517,7 +5524,8 @@ int map_pages_to_xen(
L3T_LOCK(current_l3page);
ol3e = *pl3e;
- if ( cpu_has_page1gb && IS_L3E_ALIGNED(virt, mfn) &&
+ if ( cpu_has_page1gb &&
+ (!(flags & _PAGE_PRESENT) || IS_L3E_ALIGNED(virt, mfn)) &&
nr_mfns >= (1UL << (L3_PAGETABLE_SHIFT - PAGE_SHIFT)) &&
!(flags & (_PAGE_PAT | MAP_SMALL_PAGES)) )
{
@@ -5636,7 +5644,7 @@ int map_pages_to_xen(
if ( !pl2e )
goto out;
- if ( IS_L2E_ALIGNED(virt, mfn) &&
+ if ( (!(flags & _PAGE_PRESENT) || IS_L2E_ALIGNED(virt, mfn)) &&
(nr_mfns >= (1u << PAGETABLE_ORDER)) &&
!(flags & (_PAGE_PAT|MAP_SMALL_PAGES)) )
{
INVALID_MFN is ~0, so by it having all bits as 1s it doesn't fulfill the super-page address alignment checks for L3 and L2 entries. Skip the alignment checks if the new entry is a non-present one. This fixes a regression introduced by 0b6b51a69f4d, where the switch from 0 to INVALID_MFN caused all super-pages to be shattered when attempting to remove mappings by passing INVALID_MFN instead of 0. Fixes: 0b6b51a69f4d ('xen/mm: Switch map_pages_to_xen to use MFN typesafe') Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> --- Changees since v2: - Remove unneeded page present check. Changes since v1: - Detect non-present entries from the flags contents rather than checking the mfn parameter. --- xen/arch/x86/mm.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)