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>

8 files changed, 63 insertions, 41 deletions

diff --git a/tools/libxc/Makefile b/tools/libxc/Makefile
index 6b00abab50..29b47243c0 100644
--- a/tools/libxc/Makefile
+++ b/tools/libxc/Makefile
@@ -1,7 +1,7 @@
 XEN_ROOT = $(CURDIR)/../..
 include $(XEN_ROOT)/tools/Rules.mk
 
-MAJOR    = 4.0
+MAJOR    = 4.2
 MINOR    = 0
 
 CTRL_SRCS-y       :=
diff --git a/tools/libxc/xc_mem_access.c b/tools/libxc/xc_mem_access.c
index b9e66bbd07..6606878567 100644
--- a/tools/libxc/xc_mem_access.c
+++ b/tools/libxc/xc_mem_access.c
@@ -24,12 +24,29 @@
 #include "xc_private.h"
 
 
+int xc_mem_access_enable(xc_interface *xch, domid_t domain_id,
+                        void *shared_page, void *ring_page)
+{
+    return xc_mem_event_control(xch, domain_id,
+                                XEN_DOMCTL_MEM_EVENT_OP_ACCESS_ENABLE,
+                                XEN_DOMCTL_MEM_EVENT_OP_ACCESS,
+                                shared_page, ring_page, INVALID_MFN);
+}
+
+int xc_mem_access_disable(xc_interface *xch, domid_t domain_id)
+{
+    return xc_mem_event_control(xch, domain_id,
+                                XEN_DOMCTL_MEM_EVENT_OP_ACCESS_DISABLE,
+                                XEN_DOMCTL_MEM_EVENT_OP_ACCESS,
+                                NULL, NULL, INVALID_MFN);
+}
+
 int xc_mem_access_resume(xc_interface *xch, domid_t domain_id, unsigned long gfn)
 {
     return xc_mem_event_control(xch, domain_id,
                                 XEN_DOMCTL_MEM_EVENT_OP_ACCESS_RESUME,
-                                XEN_DOMCTL_MEM_EVENT_OP_ACCESS, NULL, NULL,
-                                gfn);
+                                XEN_DOMCTL_MEM_EVENT_OP_ACCESS,
+                                NULL, NULL, gfn);
 }
 
 /*
diff --git a/tools/libxc/xc_mem_event.c b/tools/libxc/xc_mem_event.c
index ef8d4caa20..b40d269709 100644
--- a/tools/libxc/xc_mem_event.c
+++ b/tools/libxc/xc_mem_event.c
@@ -42,18 +42,3 @@ int xc_mem_event_control(xc_interface *xch, domid_t domain_id, unsigned int op,
     return do_domctl(xch, &domctl);
 }
 
-int xc_mem_event_enable(xc_interface *xch, domid_t domain_id,
-                        void *shared_page, void *ring_page)
-{
-    return xc_mem_event_control(xch, domain_id,
-                                XEN_DOMCTL_MEM_EVENT_OP_ENABLE, 0,
-                                shared_page, ring_page, INVALID_MFN);
-}
-
-int xc_mem_event_disable(xc_interface *xch, domid_t domain_id)
-{
-    return xc_mem_event_control(xch, domain_id,
-                                XEN_DOMCTL_MEM_EVENT_OP_DISABLE, 0,
-                                NULL, NULL, INVALID_MFN);
-}
-
diff --git a/tools/libxc/xc_mem_paging.c b/tools/libxc/xc_mem_paging.c
index db5be452f5..f917403b39 100644
--- a/tools/libxc/xc_mem_paging.c
+++ b/tools/libxc/xc_mem_paging.c
@@ -24,36 +24,53 @@
 #include "xc_private.h"
 
 
+int xc_mem_paging_enable(xc_interface *xch, domid_t domain_id,
+                        void *shared_page, void *ring_page)
+{
+    return xc_mem_event_control(xch, domain_id,
+                                XEN_DOMCTL_MEM_EVENT_OP_PAGING_ENABLE,
+                                XEN_DOMCTL_MEM_EVENT_OP_PAGING,
+                                shared_page, ring_page, INVALID_MFN);
+}
+
+int xc_mem_paging_disable(xc_interface *xch, domid_t domain_id)
+{
+    return xc_mem_event_control(xch, domain_id,
+                                XEN_DOMCTL_MEM_EVENT_OP_PAGING_DISABLE,
+                                XEN_DOMCTL_MEM_EVENT_OP_PAGING,
+                                NULL, NULL, INVALID_MFN);
+}
+
 int xc_mem_paging_nominate(xc_interface *xch, domid_t domain_id, unsigned long gfn)
 {
     return xc_mem_event_control(xch, domain_id,
                                 XEN_DOMCTL_MEM_EVENT_OP_PAGING_NOMINATE,
-                                XEN_DOMCTL_MEM_EVENT_OP_PAGING, NULL, NULL,
-                                gfn);
+                                XEN_DOMCTL_MEM_EVENT_OP_PAGING,
+                                NULL, NULL, gfn);
 }
 
 int xc_mem_paging_evict(xc_interface *xch, domid_t domain_id, unsigned long gfn)
 {
     return xc_mem_event_control(xch, domain_id,
                                 XEN_DOMCTL_MEM_EVENT_OP_PAGING_EVICT,
-                                XEN_DOMCTL_MEM_EVENT_OP_PAGING, NULL, NULL,
-                                gfn);
+                                XEN_DOMCTL_MEM_EVENT_OP_PAGING,
+                                NULL, NULL, gfn);
 }
 
 int xc_mem_paging_prep(xc_interface *xch, domid_t domain_id, unsigned long gfn)
 {
     return xc_mem_event_control(xch, domain_id,
                                 XEN_DOMCTL_MEM_EVENT_OP_PAGING_PREP,
-                                XEN_DOMCTL_MEM_EVENT_OP_PAGING, NULL, NULL,
-                                gfn);
+                                XEN_DOMCTL_MEM_EVENT_OP_PAGING,
+                                NULL, NULL, gfn);
 }
 
 int xc_mem_paging_resume(xc_interface *xch, domid_t domain_id, unsigned long gfn)
 {
     return xc_mem_event_control(xch, domain_id,
                                 XEN_DOMCTL_MEM_EVENT_OP_PAGING_RESUME,
-                                XEN_DOMCTL_MEM_EVENT_OP_PAGING, NULL, NULL,
-                                gfn);
+                                XEN_DOMCTL_MEM_EVENT_OP_PAGING,
+                                NULL, NULL, gfn);
 }
 
 
diff --git a/tools/libxc/xc_memshr.c b/tools/libxc/xc_memshr.c
index 8e5faf4bb4..eaa9d2771e 100644
--- a/tools/libxc/xc_memshr.c
+++ b/tools/libxc/xc_memshr.c
@@ -36,7 +36,7 @@ int xc_memshr_control(xc_interface *xch,
     domctl.interface_version = XEN_DOMCTL_INTERFACE_VERSION;
     domctl.domain = (domid_t)domid;
     op = &(domctl.u.mem_sharing_op);
-    op->op = XEN_DOMCTL_MEM_SHARING_OP_CONTROL;
+    op->op = XEN_DOMCTL_MEM_EVENT_OP_SHARING_CONTROL;
     op->u.enable = enable;
 
     return do_domctl(xch, &domctl);
@@ -55,7 +55,7 @@ int xc_memshr_nominate_gfn(xc_interface *xch,
     domctl.interface_version = XEN_DOMCTL_INTERFACE_VERSION;
     domctl.domain = (domid_t)domid;
     op = &(domctl.u.mem_sharing_op);
-    op->op = XEN_DOMCTL_MEM_SHARING_OP_NOMINATE_GFN;
+    op->op = XEN_DOMCTL_MEM_EVENT_OP_SHARING_NOMINATE_GFN;
     op->u.nominate.u.gfn = gfn;
 
     ret = do_domctl(xch, &domctl);
@@ -77,7 +77,7 @@ int xc_memshr_nominate_gref(xc_interface *xch,
     domctl.interface_version = XEN_DOMCTL_INTERFACE_VERSION;
     domctl.domain = (domid_t)domid;
     op = &(domctl.u.mem_sharing_op);
-    op->op = XEN_DOMCTL_MEM_SHARING_OP_NOMINATE_GREF;
+    op->op = XEN_DOMCTL_MEM_EVENT_OP_SHARING_NOMINATE_GREF;
     op->u.nominate.u.grant_ref = gref;
 
     ret = do_domctl(xch, &domctl);
@@ -97,7 +97,7 @@ int xc_memshr_share(xc_interface *xch,
     domctl.interface_version = XEN_DOMCTL_INTERFACE_VERSION;
     domctl.domain = 0;
     op = &(domctl.u.mem_sharing_op);
-    op->op = XEN_DOMCTL_MEM_SHARING_OP_SHARE;
+    op->op = XEN_DOMCTL_MEM_EVENT_OP_SHARING_SHARE;
     op->u.share.source_handle = source_handle;
     op->u.share.client_handle = client_handle;
 
@@ -114,7 +114,7 @@ int xc_memshr_domain_resume(xc_interface *xch,
     domctl.interface_version = XEN_DOMCTL_INTERFACE_VERSION;
     domctl.domain = (domid_t)domid;
     op = &(domctl.u.mem_sharing_op);
-    op->op = XEN_DOMCTL_MEM_SHARING_OP_RESUME;
+    op->op = XEN_DOMCTL_MEM_EVENT_OP_SHARING_RESUME;
 
     return do_domctl(xch, &domctl);
 }
@@ -130,7 +130,7 @@ int xc_memshr_debug_gfn(xc_interface *xch,
     domctl.interface_version = XEN_DOMCTL_INTERFACE_VERSION;
     domctl.domain = (domid_t)domid;
     op = &(domctl.u.mem_sharing_op);
-    op->op = XEN_DOMCTL_MEM_SHARING_OP_DEBUG_GFN;
+    op->op = XEN_DOMCTL_MEM_EVENT_OP_SHARING_DEBUG_GFN;
     op->u.debug.u.gfn = gfn;
 
     return do_domctl(xch, &domctl);
@@ -147,7 +147,7 @@ int xc_memshr_debug_mfn(xc_interface *xch,
     domctl.interface_version = XEN_DOMCTL_INTERFACE_VERSION;
     domctl.domain = (domid_t)domid;
     op = &(domctl.u.mem_sharing_op);
-    op->op = XEN_DOMCTL_MEM_SHARING_OP_DEBUG_MFN;
+    op->op = XEN_DOMCTL_MEM_EVENT_OP_SHARING_DEBUG_MFN;
     op->u.debug.u.mfn = mfn;
 
     return do_domctl(xch, &domctl);
@@ -164,7 +164,7 @@ int xc_memshr_debug_gref(xc_interface *xch,
     domctl.interface_version = XEN_DOMCTL_INTERFACE_VERSION;
     domctl.domain = (domid_t)domid;
     op = &(domctl.u.mem_sharing_op);
-    op->op = XEN_DOMCTL_MEM_SHARING_OP_DEBUG_GREF;
+    op->op = XEN_DOMCTL_MEM_EVENT_OP_SHARING_DEBUG_GREF;
     op->u.debug.u.gref = gref;
 
     return do_domctl(xch, &domctl);
diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
index 1b82ee0818..4bcb9bd6c9 100644
--- a/tools/libxc/xenctrl.h
+++ b/tools/libxc/xenctrl.h
@@ -1758,16 +1758,19 @@ int xc_mem_event_control(xc_interface *xch, domid_t domain_id, unsigned int op,
                          unsigned int mode, void *shared_page,
                           void *ring_page, unsigned long gfn);
 
-int xc_mem_event_enable(xc_interface *xch, domid_t domain_id,
+int xc_mem_paging_enable(xc_interface *xch, domid_t domain_id,
                         void *shared_page, void *ring_page);
-int xc_mem_event_disable(xc_interface *xch, domid_t domain_id);
-
+int xc_mem_paging_disable(xc_interface *xch, domid_t domain_id);
 int xc_mem_paging_nominate(xc_interface *xch, domid_t domain_id,
                            unsigned long gfn);
 int xc_mem_paging_evict(xc_interface *xch, domid_t domain_id, unsigned long gfn);
 int xc_mem_paging_prep(xc_interface *xch, domid_t domain_id, unsigned long gfn);
 int xc_mem_paging_resume(xc_interface *xch, domid_t domain_id,
                          unsigned long gfn);
+
+int xc_mem_access_enable(xc_interface *xch, domid_t domain_id,
+                        void *shared_page, void *ring_page);
+int xc_mem_access_disable(xc_interface *xch, domid_t domain_id);
 int xc_mem_access_resume(xc_interface *xch, domid_t domain_id,
                          unsigned long gfn);
 
diff --git a/tools/tests/xen-access/xen-access.c b/tools/tests/xen-access/xen-access.c
index 2b3265e2fe..4394f8f203 100644
--- a/tools/tests/xen-access/xen-access.c
+++ b/tools/tests/xen-access/xen-access.c
@@ -241,7 +241,7 @@ xenaccess_t *xenaccess_init(xc_interface **xch_r, domid_t domain_id)
     mem_event_ring_lock_init(&xenaccess->mem_event);
 
     /* Initialise Xen */
-    rc = xc_mem_event_enable(xenaccess->xc_handle, xenaccess->mem_event.domain_id,
+    rc = xc_mem_access_enable(xenaccess->xc_handle, xenaccess->mem_event.domain_id,
                              xenaccess->mem_event.shared_page,
                              xenaccess->mem_event.ring_page);
     if ( rc != 0 )
@@ -351,7 +351,7 @@ int xenaccess_teardown(xc_interface *xch, xenaccess_t *xenaccess)
         return 0;
 
     /* Tear down domain xenaccess in Xen */
-    rc = xc_mem_event_disable(xenaccess->xc_handle, xenaccess->mem_event.domain_id);
+    rc = xc_mem_access_disable(xenaccess->xc_handle, xenaccess->mem_event.domain_id);
     if ( rc != 0 )
     {
         ERROR("Error tearing down domain xenaccess in xen");
diff --git a/tools/xenpaging/xenpaging.c b/tools/xenpaging/xenpaging.c
index ebdba23db2..e2cbc614d0 100644
--- a/tools/xenpaging/xenpaging.c
+++ b/tools/xenpaging/xenpaging.c
@@ -234,7 +234,7 @@ static xenpaging_t *xenpaging_init(domid_t domain_id, int num_pages)
                    PAGE_SIZE);
     
     /* Initialise Xen */
-    rc = xc_mem_event_enable(xch, paging->mem_event.domain_id,
+    rc = xc_mem_paging_enable(xch, paging->mem_event.domain_id,
                              paging->mem_event.shared_page,
                              paging->mem_event.ring_page);
     if ( rc != 0 )
@@ -353,7 +353,7 @@ static int xenpaging_teardown(xenpaging_t *paging)
     xch = paging->xc_handle;
     paging->xc_handle = NULL;
     /* Tear down domain paging in Xen */
-    rc = xc_mem_event_disable(xch, paging->mem_event.domain_id);
+    rc = xc_mem_paging_disable(xch, paging->mem_event.domain_id);
     if ( rc != 0 )
     {
         ERROR("Error tearing down domain paging in xen");