[RFC PATCH V5 07/15] evtchn: define 3-level event channel registration interface

[Wei Liu <wei.liu2@citrix.com>]

This event channel op has two sub-commands:
* REGISTER_BITMAPS: register the shared pending / mask bitmaps
* REGISTER_L2_SELECTOR: register L2 selector for the specific vcpu.

The guest should issue REGISTER_BITMAPS first. If the registration of bitmaps
succeed, it can issue REGISTER_L2_SELECTOR.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 xen/include/public/event_channel.h |   34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/xen/include/public/event_channel.h b/xen/include/public/event_channel.h
index 594ea76..59a9780 100644
--- a/xen/include/public/event_channel.h
+++ b/xen/include/public/event_channel.h
@@ -72,6 +72,7 @@
 #define EVTCHNOP_unmask           9
 #define EVTCHNOP_reset           10
 #define EVTCHNOP_query_extended_abis 11
+#define EVTCHNOP_register_3level 12
 /* ` } */
 
 typedef uint32_t evtchn_port_t;
@@ -272,6 +273,39 @@ struct evtchn_query_extended_abis {
 typedef struct evtchn_query_extended_abis evtchn_query_extended_abis_t;
 
 /*
+ * EVTCHNOP_register_3level: Register 3-level event channel.
+ */
+/*
+ * 64 bit guests need 8 pages for evtchn_pending and evtchn_mask for
+ * 256k event channels while 32 bit ones only need 1 page for 32k
+ * event channels.
+ */
+#define EVTCHN_MAX_L3_PAGES 8
+/*
+ * A guest should register the bitmaps first, then register L2 selector for
+ * individual cpu.
+ */
+#define REGISTER_BITMAPS     1
+#define REGISTER_L2_SELECTOR 2
+struct evtchn_register_3level {
+    /* IN parameters. */
+    uint32_t cmd;
+    union {
+        struct {
+            uint32_t nr_pages;
+            XEN_GUEST_HANDLE(xen_pfn_t) evtchn_pending;
+            XEN_GUEST_HANDLE(xen_pfn_t) evtchn_mask;
+        } bitmaps;
+        struct {
+            uint32_t  cpu_id;
+            xen_pfn_t mfn;     /* mfn of L2 selector */
+            xen_pfn_t offset;  /* offset of L2 selector within page */
+        } l2_selector;
+    } u;
+};
+typedef struct evtchn_register_3level evtchn_register_3level_t;
+
+/*
  * ` enum neg_errnoval
  * ` HYPERVISOR_event_channel_op_compat(struct evtchn_op *op)
  * `
-- 
1.7.10.4