diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
index e1a08cb..10c20fe 100644
--- a/hw/i386/intel_iommu_internal.h
+++ b/hw/i386/intel_iommu_internal.h
@@ -296,12 +296,28 @@ typedef enum VTDFaultReason {
 
 #define VTD_CONTEXT_CACHE_GEN_MAX       0xffffffffUL
 
+/* Interrupt Entry Cache Invalidation Descriptor: VT-d 6.5.2.7. */
+struct VTDInvDescIEC {
+    uint32_t type:4;            /* Should always be 0x4 */
+    uint32_t granularity:1;     /* If set, it's global IR invalidation */
+    uint32_t resved_1:22;
+    uint32_t index_mask:5;      /* 2^N for continuous int invalidation */
+    uint32_t index:16;          /* Start index to invalidate */
+    uint32_t reserved_2:16;
+};
+typedef struct VTDInvDescIEC VTDInvDescIEC;
+
 /* Queued Invalidation Descriptor */
-struct VTDInvDesc {
-    uint64_t lo;
-    uint64_t hi;
+union VTDInvDesc {
+    struct {
+        uint64_t lo;
+        uint64_t hi;
+    };
+    union {
+        VTDInvDescIEC iec;
+    };
 };
-typedef struct VTDInvDesc VTDInvDesc;
+typedef union VTDInvDesc VTDInvDesc;
 
 /* Masks for struct VTDInvDesc */
 #define VTD_INV_DESC_TYPE               0xf
diff --git a/include/hw/i386/x86-iommu.h b/include/hw/i386/x86-iommu.h
index fa6ce31..c48e8dd 100644
--- a/include/hw/i386/x86-iommu.h
+++ b/include/hw/i386/x86-iommu.h
@@ -46,9 +46,28 @@ struct X86IOMMUClass {
                      MSIMessage *dst, uint16_t sid);
 };
 
+/**
+ * iec_notify_fn - IEC (Interrupt Entry Cache) notifier hook,
+ *                 triggered when IR invalidation happens.
+ * @private: private data
+ * @global: whether this is a global IEC invalidation
+ * @index: IRTE index to invalidate (start from)
+ * @mask: invalidation mask
+ */
+typedef void (*iec_notify_fn)(void *private, bool global,
+                              uint32_t index, uint32_t mask);
+
+struct IEC_Notifier {
+    iec_notify_fn iec_notify;
+    void *private;
+    QLIST_ENTRY(IEC_Notifier) list;
+};
+typedef struct IEC_Notifier IEC_Notifier;
+
 struct X86IOMMUState {
     SysBusDevice busdev;
     bool intr_supported;        /* Whether vIOMMU supports IR */
+    QLIST_HEAD(, IEC_Notifier) iec_notifiers; /* IEC notify list */
 };
 
 /**
@@ -57,4 +76,25 @@ struct X86IOMMUState {
  */
 X86IOMMUState *x86_iommu_get_default(void);
 
+/**
+ * x86_iommu_iec_register_notifier - register IEC (Interrupt Entry
+ *                                   Cache) notifiers
+ * @iommu: IOMMU device to register
+ * @fn: IEC notifier hook function
+ * @data: notifier private data
+ */
+void x86_iommu_iec_register_notifier(X86IOMMUState *iommu,
+                                     iec_notify_fn fn, void *data);
+
+/**
+ * x86_iommu_iec_notify_all - Notify IEC invalidations
+ * @iommu: IOMMU device that sends the notification
+ * @global: whether this is a global invalidation. If true, @index
+ *          and @mask are undefined.
+ * @index: starting index of interrupt entry to invalidate
+ * @mask: index mask for the invalidation
+ */
+void x86_iommu_iec_notify_all(X86IOMMUState *iommu, bool global,
+                              uint32_t index, uint32_t mask);
+
 #endif
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 064d2ab..abd39cb 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -904,6 +904,12 @@ static void vtd_root_table_setup(IntelIOMMUState *s)
                 (s->root_extended ? "(extended)" : ""));
 }
 
+static void vtd_iec_notify_all(IntelIOMMUState *s, bool global,
+                               uint32_t index, uint32_t mask)
+{
+    x86_iommu_iec_notify_all(X86_IOMMU_DEVICE(s), global, index, mask);
+}
+
 static void vtd_interrupt_remap_table_setup(IntelIOMMUState *s)
 {
     uint64_t value = 0;
@@ -911,7 +917,8 @@ static void vtd_interrupt_remap_table_setup(IntelIOMMUState *s)
     s->intr_size = 1UL << ((value & VTD_IRTA_SIZE_MASK) + 1);
     s->intr_root = value & VTD_IRTA_ADDR_MASK;
 
-    /* TODO: invalidate interrupt entry cache */
+    /* Notify global invalidation */
+    vtd_iec_notify_all(s, true, 0, 0);
 
     VTD_DPRINTF(CSR, "int remap table addr 0x%"PRIx64 " size %"PRIu32,
                 s->intr_root, s->intr_size);
@@ -1413,6 +1420,21 @@ static bool vtd_process_iotlb_desc(IntelIOMMUState *s, VTDInvDesc *inv_desc)
     return true;
 }
 
+static bool vtd_process_inv_iec_desc(IntelIOMMUState *s,
+                                     VTDInvDesc *inv_desc)
+{
+    VTD_DPRINTF(INV, "inv ir glob %d index %d mask %d",
+                inv_desc->iec.granularity,
+                inv_desc->iec.index,
+                inv_desc->iec.index_mask);
+
+    vtd_iec_notify_all(s, !inv_desc->iec.granularity,
+                       inv_desc->iec.index,
+                       inv_desc->iec.index_mask);
+
+    return true;
+}
+
 static bool vtd_process_inv_desc(IntelIOMMUState *s)
 {
     VTDInvDesc inv_desc;
@@ -1453,12 +1475,12 @@ static bool vtd_process_inv_desc(IntelIOMMUState *s)
         break;
 
     case VTD_INV_DESC_IEC:
-        VTD_DPRINTF(INV, "Interrupt Entry Cache Invalidation "
-                    "not implemented yet");
-        /*
-         * Since currently we do not cache interrupt entries, we can
-         * just mark this descriptor as "good" and move on.
-         */
+        VTD_DPRINTF(INV, "Invalidation Interrupt Entry Cache "
+                    "Descriptor hi 0x%"PRIx64 " lo 0x%"PRIx64,
+                    inv_desc.hi, inv_desc.lo);
+        if (!vtd_process_inv_iec_desc(s, &inv_desc)) {
+            return false;
+        }
         break;
 
     default:
diff --git a/hw/i386/x86-iommu.c b/hw/i386/x86-iommu.c
index 4280839..ce26b2a 100644
--- a/hw/i386/x86-iommu.c
+++ b/hw/i386/x86-iommu.c
@@ -22,6 +22,33 @@
 #include "hw/boards.h"
 #include "hw/i386/x86-iommu.h"
 #include "qemu/error-report.h"
+#include "trace.h"
+
+void x86_iommu_iec_register_notifier(X86IOMMUState *iommu,
+                                     iec_notify_fn fn, void *data)
+{
+    IEC_Notifier *notifier = g_new0(IEC_Notifier, 1);
+
+    notifier->iec_notify = fn;
+    notifier->private = data;
+
+    QLIST_INSERT_HEAD(&iommu->iec_notifiers, notifier, list);
+}
+
+void x86_iommu_iec_notify_all(X86IOMMUState *iommu, bool global,
+                              uint32_t index, uint32_t mask)
+{
+    IEC_Notifier *notifier;
+
+    trace_x86_iommu_iec_notify(global, index, mask);
+
+    QLIST_FOREACH(notifier, &iommu->iec_notifiers, list) {
+        if (notifier->iec_notify) {
+            notifier->iec_notify(notifier->private, global,
+                                 index, mask);
+        }
+    }
+}
 
 /* Default X86 IOMMU device */
 static X86IOMMUState *x86_iommu_default = NULL;
@@ -46,7 +73,9 @@ X86IOMMUState *x86_iommu_get_default(void)
 
 static void x86_iommu_realize(DeviceState *dev, Error **errp)
 {
+    X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(dev);
     X86IOMMUClass *x86_class = X86_IOMMU_GET_CLASS(dev);
+    QLIST_INIT(&x86_iommu->iec_notifiers);
     if (x86_class->realize) {
         x86_class->realize(dev, errp);
     }
diff --git a/hw/i386/trace-events b/hw/i386/trace-events
index ea77bc2..b4882c1 100644
--- a/hw/i386/trace-events
+++ b/hw/i386/trace-events
@@ -10,3 +10,6 @@ xen_pv_mmio_write(uint64_t addr) "WARNING: write to Xen PV Device MMIO space (ad
 # hw/i386/pc.c
 mhp_pc_dimm_assigned_slot(int slot) "0x%d"
 mhp_pc_dimm_assigned_address(uint64_t addr) "0x%"PRIx64
+
+# hw/i386/x86-iommu.c
+x86_iommu_iec_notify(bool global, uint32_t index, uint32_t mask) "Notify IEC invalidation: global=%d index=%" PRIu32 " mask=%" PRIu32
