diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 2d5b95c41a..977fc8de98 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -4799,7 +4799,8 @@ static uint64_t vtd_mem_read(void *opaque, hwaddr addr, unsigned size)
 
     /* Invalidation Queue Address Register, 64-bit */
     case DMAR_IQA_REG:
-        val = s->iq | (vtd_get_quad(s, DMAR_IQA_REG) & VTD_IQA_QS);
+        val = s->iq | (vtd_get_quad(s, DMAR_IQA_REG) & VTD_IQA_QS
+                | VTD_IQA_DW_MASK );
         if (size == 4) {
             val = val & ((1ULL << 32) - 1);
         }