[PATCH v5 1/4] iommu_pt: Fix pgsize_bitmap calculation in get_info for smaller vasz's

[Ankit Soni]

To properly enforce the domain VA limit, clamp pgsize_bitmap using the
requested max_vasz_lg2 in get_info().
Apply the same VA limit as get_info() in the kunit possible_sizes test so
assertions stay consistent with the domain bitmap.

Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Ankit Soni <Ankit.Soni@xxxxxxx>
---
 drivers/iommu/generic_pt/iommu_pt.h         |  8 ++++++--
 drivers/iommu/generic_pt/kunit_generic_pt.h | 10 +++++++---
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/generic_pt/iommu_pt.h b/drivers/iommu/generic_pt/iommu_pt.h
index 3e33fe64feab..f150e3a7f545 100644
--- a/drivers/iommu/generic_pt/iommu_pt.h
+++ b/drivers/iommu/generic_pt/iommu_pt.h
@@ -1084,8 +1084,12 @@ static void NS(get_info)(struct pt_iommu *iommu_table,
 			pgsize_bitmap |= pt_possible_sizes(&pts);
 	}
 
-	/* Hide page sizes larger than the maximum OA */
-	info->pgsize_bitmap = oalog2_mod(pgsize_bitmap, common->max_oasz_lg2);
+	/*
+	 * Hide page sizes larger than the maximum. -1 because a whole table
+	 * pgsize is not allowed
+	 */
+	info->pgsize_bitmap = log2_mod(pgsize_bitmap, common->max_vasz_lg2 - 1);
+	info->pgsize_bitmap = oalog2_mod(info->pgsize_bitmap, common->max_oasz_lg2);
 }
 
 static void NS(deinit)(struct pt_iommu *iommu_table)
diff --git a/drivers/iommu/generic_pt/kunit_generic_pt.h b/drivers/iommu/generic_pt/kunit_generic_pt.h
index 68278bf15cfe..3672f1c7e4cb 100644
--- a/drivers/iommu/generic_pt/kunit_generic_pt.h
+++ b/drivers/iommu/generic_pt/kunit_generic_pt.h
@@ -427,6 +427,9 @@ static void test_lvl_possible_sizes(struct kunit *test, struct pt_state *pts,
 {
 	unsigned int num_items_lg2 = safe_pt_num_items_lg2(pts);
 	pt_vaddr_t pgsize_bitmap = pt_possible_sizes(pts);
+	/* Matches get_info() */
+	pt_vaddr_t limited_pgsize_bitmap =
+		log2_mod(pgsize_bitmap, pts->range->common->max_vasz_lg2 - 1);
 	unsigned int isz_lg2 = pt_table_item_lg2sz(pts);
 
 	if (!pt_can_have_leaf(pts)) {
@@ -437,7 +440,8 @@ static void test_lvl_possible_sizes(struct kunit *test, struct pt_state *pts,
 	/* No bits for sizes that would be outside this table */
 	KUNIT_ASSERT_EQ(test, log2_mod(pgsize_bitmap, isz_lg2), 0);
 	KUNIT_ASSERT_EQ(
-		test, fvalog2_div(pgsize_bitmap, num_items_lg2 + isz_lg2), 0);
+		test,
+		fvalog2_div(limited_pgsize_bitmap, num_items_lg2 + isz_lg2), 0);
 
 	/*
 	 * Non contiguous must be supported. AMDv1 has a HW bug where it does
@@ -452,8 +456,8 @@ static void test_lvl_possible_sizes(struct kunit *test, struct pt_state *pts,
 	/* A contiguous entry should not span the whole table */
 	if (num_items_lg2 + isz_lg2 != PT_VADDR_MAX_LG2)
 		KUNIT_ASSERT_FALSE(
-			test,
-			pgsize_bitmap & log2_to_int(num_items_lg2 + isz_lg2));
+			test, limited_pgsize_bitmap &
+					log2_to_int(num_items_lg2 + isz_lg2));
 }
 
 static void test_entry_possible_sizes(struct kunit *test)
-- 
2.43.0