x86-iommu: introduce IEC notifiers

This patch introduces x86 IOMMU IEC (Interrupt Entry Cache)
invalidation notifier list. When vIOMMU receives IEC invalidate
request, all the registered units will be notified with specific
invalidation requests.

Intel IOMMU is the first provider that generates such a event.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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 @@
                      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 @@
  */
 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