[PATCH 02/12] hw/i386/intel_iommu: vtd_slpte_nonzero_rsvd(): reduce magic numbers

[Vladimir Sementsov-Ogievskiy]

Add a constant and clear assertion. The assertion also tells Coverity
that we are not going to overflow the array.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@yandex-team.ru>
---
 hw/i386/intel_iommu.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index c0ce896668..2233dbe13a 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -1028,12 +1028,17 @@ static dma_addr_t 
vtd_get_iova_pgtbl_base(IntelIOMMUState *s,
  *     vtd_spte_rsvd 4k pages
  *     vtd_spte_rsvd_large large pages
  */
-static uint64_t vtd_spte_rsvd[5];
-static uint64_t vtd_spte_rsvd_large[5];
+#define VTD_SPTE_RSVD_LEN 5
+static uint64_t vtd_spte_rsvd[VTD_SPTE_RSVD_LEN];
+static uint64_t vtd_spte_rsvd_large[VTD_SPTE_RSVD_LEN];
 
 static bool vtd_slpte_nonzero_rsvd(uint64_t slpte, uint32_t level)
 {
-    uint64_t rsvd_mask = vtd_spte_rsvd[level];
+    uint64_t rsvd_mask;
+
+    assert(level < VTD_SPTE_RSVD_LEN);
+
+    rsvd_mask = vtd_spte_rsvd[level];
 
     if ((level == VTD_SL_PD_LEVEL || level == VTD_SL_PDP_LEVEL) &&
         (slpte & VTD_SL_PT_PAGE_SIZE_MASK)) {
-- 
2.34.1