mem_event: use different ringbuffers for share, paging and access

Up to now a single ring buffer was used for mem_share, xenpaging and
xen-access.  Each helper would have to cooperate and pull only its own
requests from the ring.  Unfortunately this was not implemented. And
even if it was, it would make the whole concept fragile because a crash
or early exit of one helper would stall the others.

What happend up to now is that active xenpaging + memory_sharing would
push memsharing requests in the buffer. xenpaging is not prepared for
such requests.

This patch creates an independet ring buffer for mem_share, xenpaging
and xen-access and adds also new functions to enable xenpaging and
xen-access. The xc_mem_event_enable/xc_mem_event_disable functions will
be removed. The various XEN_DOMCTL_MEM_EVENT_* macros were cleaned up.
Due to the removal the API changed, so the SONAME will be changed too.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Tim Deegan <tim@xen.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 2bda1edd7b..c6b3a5916f 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -317,8 +317,12 @@ struct domain
     /* Non-migratable and non-restoreable? */
     bool_t disable_migrate;
 
+    /* Memory sharing support */
+    struct mem_event_domain mem_share;
     /* Memory paging support */
-    struct mem_event_domain mem_event;
+    struct mem_event_domain mem_paging;
+    /* Memory access support */
+    struct mem_event_domain mem_access;
 
     /* Currently computed from union of all vcpu cpu-affinity masks. */
     nodemask_t node_affinity;