[PATCH V7 02/12] xen/mem_event: Cleanup mem_event names in rings, functions and domctls

[Tamas K Lengyel <tamas.lengyel@zentific.com>]

The name of one of the mem_event rings still implies it is used only
for memory accesses, which is no longer the case. It is also used to
deliver various HVM events, thus the name "monitor" is more appropriate
in this setting.

Couple functions incorrectly labeled as part of mem_event is also renamed
to reflect that they belong to mem_access.

The mem_event subop definitions are also shortened to be more meaningful.

The tool side changes are only mechanical renaming to match these new names.

Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
v6: Rename p2m_mem_event_emulate_check to p2m_mem_access_emulate_check
    Rename hvm_mem_event_emulate_one to hvm_mem_access_emulate_one
v5: Style fixes
v4: Shorted mem_event domctl subops.
v3: Style and comment fixes.
---
 tools/libxc/xc_domain_restore.c   | 14 ++++++-------
 tools/libxc/xc_domain_save.c      |  4 ++--
 tools/libxc/xc_hvm_build_x86.c    |  2 +-
 tools/libxc/xc_mem_access.c       |  8 ++++----
 tools/libxc/xc_mem_event.c        | 12 +++++------
 tools/libxc/xc_mem_paging.c       |  4 ++--
 tools/libxc/xc_memshr.c           |  4 ++--
 tools/libxc/xg_save_restore.h     |  2 +-
 xen/arch/x86/hvm/emulate.c        |  2 +-
 xen/arch/x86/hvm/hvm.c            |  4 ++--
 xen/arch/x86/hvm/vmx/vmcs.c       |  2 +-
 xen/arch/x86/mm/p2m.c             | 10 ++++-----
 xen/common/mem_access.c           | 10 ++++-----
 xen/common/mem_event.c            | 37 +++++++++++++++++----------------
 xen/include/asm-arm/p2m.h         |  6 +++---
 xen/include/asm-x86/hvm/emulate.h |  2 +-
 xen/include/asm-x86/p2m.h         |  4 ++--
 xen/include/public/domctl.h       | 43 +++++++++++++++++++++++----------------
 xen/include/public/hvm/params.h   |  2 +-
 xen/include/xen/sched.h           |  4 ++--
 20 files changed, 93 insertions(+), 83 deletions(-)

diff --git a/tools/libxc/xc_domain_restore.c b/tools/libxc/xc_domain_restore.c
index a382701..2ab9f46 100644
--- a/tools/libxc/xc_domain_restore.c
+++ b/tools/libxc/xc_domain_restore.c
@@ -734,7 +734,7 @@ typedef struct {
     uint64_t vcpumap[XC_SR_MAX_VCPUS/64];
     uint64_t identpt;
     uint64_t paging_ring_pfn;
-    uint64_t access_ring_pfn;
+    uint64_t monitor_ring_pfn;
     uint64_t sharing_ring_pfn;
     uint64_t vm86_tss;
     uint64_t console_pfn;
@@ -828,15 +828,15 @@ static int pagebuf_get_one(xc_interface *xch, struct restore_ctx *ctx,
         // DPRINTF("paging ring pfn address: %llx\n", buf->paging_ring_pfn);
         return pagebuf_get_one(xch, ctx, buf, fd, dom);
 
-    case XC_SAVE_ID_HVM_ACCESS_RING_PFN:
+    case XC_SAVE_ID_HVM_MONITOR_RING_PFN:
         /* Skip padding 4 bytes then read the mem access ring location. */
-        if ( RDEXACT(fd, &buf->access_ring_pfn, sizeof(uint32_t)) ||
-             RDEXACT(fd, &buf->access_ring_pfn, sizeof(uint64_t)) )
+        if ( RDEXACT(fd, &buf->monitor_ring_pfn, sizeof(uint32_t)) ||
+             RDEXACT(fd, &buf->monitor_ring_pfn, sizeof(uint64_t)) )
         {
             PERROR("error read the access ring pfn");
             return -1;
         }
-        // DPRINTF("access ring pfn address: %llx\n", buf->access_ring_pfn);
+        // DPRINTF("monitor ring pfn address: %llx\n", buf->monitor_ring_pfn);
         return pagebuf_get_one(xch, ctx, buf, fd, dom);
 
     case XC_SAVE_ID_HVM_SHARING_RING_PFN:
@@ -1660,8 +1660,8 @@ int xc_domain_restore(xc_interface *xch, int io_fd, uint32_t dom,
                 xc_hvm_param_set(xch, dom, HVM_PARAM_IDENT_PT, pagebuf.identpt);
             if ( pagebuf.paging_ring_pfn )
                 xc_hvm_param_set(xch, dom, HVM_PARAM_PAGING_RING_PFN, pagebuf.paging_ring_pfn);
-            if ( pagebuf.access_ring_pfn )
-                xc_hvm_param_set(xch, dom, HVM_PARAM_ACCESS_RING_PFN, pagebuf.access_ring_pfn);
+            if ( pagebuf.monitor_ring_pfn )
+                xc_hvm_param_set(xch, dom, HVM_PARAM_MONITOR_RING_PFN, pagebuf.monitor_ring_pfn);
             if ( pagebuf.sharing_ring_pfn )
                 xc_hvm_param_set(xch, dom, HVM_PARAM_SHARING_RING_PFN, pagebuf.sharing_ring_pfn);
             if ( pagebuf.vm86_tss )
diff --git a/tools/libxc/xc_domain_save.c b/tools/libxc/xc_domain_save.c
index 254fdb3..949ef64 100644
--- a/tools/libxc/xc_domain_save.c
+++ b/tools/libxc/xc_domain_save.c
@@ -1664,9 +1664,9 @@ int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iter
             goto out;
         }
 
-        chunk.id = XC_SAVE_ID_HVM_ACCESS_RING_PFN;
+        chunk.id = XC_SAVE_ID_HVM_MONITOR_RING_PFN;
         chunk.data = 0;
-        xc_hvm_param_get(xch, dom, HVM_PARAM_ACCESS_RING_PFN, &chunk.data);
+        xc_hvm_param_get(xch, dom, HVM_PARAM_MONITOR_RING_PFN, &chunk.data);
 
         if ( (chunk.data != 0) &&
              wrexact(io_fd, &chunk, sizeof(chunk)) )
diff --git a/tools/libxc/xc_hvm_build_x86.c b/tools/libxc/xc_hvm_build_x86.c
index c81a25b..30a929d 100644
--- a/tools/libxc/xc_hvm_build_x86.c
+++ b/tools/libxc/xc_hvm_build_x86.c
@@ -497,7 +497,7 @@ static int setup_guest(xc_interface *xch,
                      special_pfn(SPECIALPAGE_CONSOLE));
     xc_hvm_param_set(xch, dom, HVM_PARAM_PAGING_RING_PFN,
                      special_pfn(SPECIALPAGE_PAGING));
-    xc_hvm_param_set(xch, dom, HVM_PARAM_ACCESS_RING_PFN,
+    xc_hvm_param_set(xch, dom, HVM_PARAM_MONITOR_RING_PFN,
                      special_pfn(SPECIALPAGE_ACCESS));
     xc_hvm_param_set(xch, dom, HVM_PARAM_SHARING_RING_PFN,
                      special_pfn(SPECIALPAGE_SHARING));
diff --git a/tools/libxc/xc_mem_access.c b/tools/libxc/xc_mem_access.c
index 55d0e9f..446394b 100644
--- a/tools/libxc/xc_mem_access.c
+++ b/tools/libxc/xc_mem_access.c
@@ -26,22 +26,22 @@
 
 void *xc_mem_access_enable(xc_interface *xch, domid_t domain_id, uint32_t *port)
 {
-    return xc_mem_event_enable(xch, domain_id, HVM_PARAM_ACCESS_RING_PFN,
+    return xc_mem_event_enable(xch, domain_id, HVM_PARAM_MONITOR_RING_PFN,
                                port, 0);
 }
 
 void *xc_mem_access_enable_introspection(xc_interface *xch, domid_t domain_id,
                                          uint32_t *port)
 {
-    return xc_mem_event_enable(xch, domain_id, HVM_PARAM_ACCESS_RING_PFN,
+    return xc_mem_event_enable(xch, domain_id, HVM_PARAM_MONITOR_RING_PFN,
                                port, 1);
 }
 
 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,
+                                XEN_MEM_EVENT_MONITOR_DISABLE,
+                                XEN_DOMCTL_MEM_EVENT_OP_MONITOR,
                                 NULL);
 }
 
diff --git a/tools/libxc/xc_mem_event.c b/tools/libxc/xc_mem_event.c
index 8c0be4e..4bb120d 100644
--- a/tools/libxc/xc_mem_event.c
+++ b/tools/libxc/xc_mem_event.c
@@ -115,20 +115,20 @@ void *xc_mem_event_enable(xc_interface *xch, domid_t domain_id, int param,
     switch ( param )
     {
     case HVM_PARAM_PAGING_RING_PFN:
-        op = XEN_DOMCTL_MEM_EVENT_OP_PAGING_ENABLE;
+        op = XEN_MEM_EVENT_PAGING_ENABLE;
         mode = XEN_DOMCTL_MEM_EVENT_OP_PAGING;
         break;
 
-    case HVM_PARAM_ACCESS_RING_PFN:
+    case HVM_PARAM_MONITOR_RING_PFN:
         if ( enable_introspection )
-            op = XEN_DOMCTL_MEM_EVENT_OP_ACCESS_ENABLE_INTROSPECTION;
+            op = XEN_MEM_EVENT_MONITOR_ENABLE_INTROSPECTION;
         else
-            op = XEN_DOMCTL_MEM_EVENT_OP_ACCESS_ENABLE;
-        mode = XEN_DOMCTL_MEM_EVENT_OP_ACCESS;
+            op = XEN_MEM_EVENT_MONITOR_ENABLE;
+        mode = XEN_DOMCTL_MEM_EVENT_OP_MONITOR;
         break;
 
     case HVM_PARAM_SHARING_RING_PFN:
-        op = XEN_DOMCTL_MEM_EVENT_OP_SHARING_ENABLE;
+        op = XEN_MEM_EVENT_SHARING_ENABLE;
         mode = XEN_DOMCTL_MEM_EVENT_OP_SHARING;
         break;
 
diff --git a/tools/libxc/xc_mem_paging.c b/tools/libxc/xc_mem_paging.c
index 8aa7d4d..5194423 100644
--- a/tools/libxc/xc_mem_paging.c
+++ b/tools/libxc/xc_mem_paging.c
@@ -34,7 +34,7 @@ int xc_mem_paging_enable(xc_interface *xch, domid_t domain_id,
     }
         
     return xc_mem_event_control(xch, domain_id,
-                                XEN_DOMCTL_MEM_EVENT_OP_PAGING_ENABLE,
+                                XEN_MEM_EVENT_PAGING_ENABLE,
                                 XEN_DOMCTL_MEM_EVENT_OP_PAGING,
                                 port);
 }
@@ -42,7 +42,7 @@ int xc_mem_paging_enable(xc_interface *xch, domid_t domain_id,
 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_MEM_EVENT_PAGING_DISABLE,
                                 XEN_DOMCTL_MEM_EVENT_OP_PAGING,
                                 NULL);
 }
diff --git a/tools/libxc/xc_memshr.c b/tools/libxc/xc_memshr.c
index d6a9539..4398630 100644
--- a/tools/libxc/xc_memshr.c
+++ b/tools/libxc/xc_memshr.c
@@ -53,7 +53,7 @@ int xc_memshr_ring_enable(xc_interface *xch,
     }
         
     return xc_mem_event_control(xch, domid,
-                                XEN_DOMCTL_MEM_EVENT_OP_SHARING_ENABLE,
+                                XEN_MEM_EVENT_SHARING_ENABLE,
                                 XEN_DOMCTL_MEM_EVENT_OP_SHARING,
                                 port);
 }
@@ -62,7 +62,7 @@ int xc_memshr_ring_disable(xc_interface *xch,
                            domid_t domid)
 {
     return xc_mem_event_control(xch, domid,
-                                XEN_DOMCTL_MEM_EVENT_OP_SHARING_DISABLE,
+                                XEN_MEM_EVENT_SHARING_DISABLE,
                                 XEN_DOMCTL_MEM_EVENT_OP_SHARING,
                                 NULL);
 }
diff --git a/tools/libxc/xg_save_restore.h b/tools/libxc/xg_save_restore.h
index bdd9009..10348aa 100644
--- a/tools/libxc/xg_save_restore.h
+++ b/tools/libxc/xg_save_restore.h
@@ -256,7 +256,7 @@
 #define XC_SAVE_ID_HVM_GENERATION_ID_ADDR -14
 /* Markers for the pfn's hosting these mem event rings */
 #define XC_SAVE_ID_HVM_PAGING_RING_PFN  -15
-#define XC_SAVE_ID_HVM_ACCESS_RING_PFN  -16
+#define XC_SAVE_ID_HVM_MONITOR_RING_PFN -16
 #define XC_SAVE_ID_HVM_SHARING_RING_PFN -17
 #define XC_SAVE_ID_TOOLSTACK          -18 /* Optional toolstack specific info */
 /* These are a pair; it is an error for one to exist without the other */
diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c
index c657bc6..7e8b891 100644
--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -1528,7 +1528,7 @@ int hvm_emulate_one_no_write(
     return _hvm_emulate_one(hvmemul_ctxt, &hvm_emulate_ops_no_write);
 }
 
-void hvm_mem_event_emulate_one(bool_t nowrite, unsigned int trapnr,
+void hvm_mem_access_emulate_one(bool_t nowrite, unsigned int trapnr,
     unsigned int errcode)
 {
     struct hvm_emulate_ctxt ctx = {{ 0 }};
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 5b925ff..870ab36 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -6402,7 +6402,7 @@ static int hvm_memory_event_traps(uint64_t parameters, mem_event_request_t *req)
     if ( !(parameters & HVMPME_MODE_MASK) )
         return 0;
 
-    rc = mem_event_claim_slot(d, &d->mem_event->access);
+    rc = mem_event_claim_slot(d, &d->mem_event->monitor);
     if ( rc == -ENOSYS )
     {
         /* If there was no ring to handle the event, then
@@ -6419,7 +6419,7 @@ static int hvm_memory_event_traps(uint64_t parameters, mem_event_request_t *req)
     }
 
     hvm_mem_event_fill_regs(req);
-    mem_event_put_request(d, &d->mem_event->access, req);
+    mem_event_put_request(d, &d->mem_event->monitor, req);
 
     return 1;
 }
diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index d614638..e0a33e3 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -715,7 +715,7 @@ void vmx_disable_intercept_for_msr(struct vcpu *v, u32 msr, int type)
         return;
 
     if ( unlikely(d->arch.hvm_domain.introspection_enabled) &&
-         mem_event_check_ring(&d->mem_event->access) )
+         mem_event_check_ring(&d->mem_event->monitor) )
     {
         unsigned int i;
 
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index ac0a2be..b5df7e5 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -1399,7 +1399,7 @@ static void p2m_mem_event_fill_regs(mem_event_request_t *req)
     req->regs.x86.cs_arbytes = seg.attr.bytes;
 }
 
-void p2m_mem_event_emulate_check(struct vcpu *v,
+void p2m_mem_access_emulate_check(struct vcpu *v,
                                  const mem_event_response_t *rsp)
 {
     /* Mark vcpu for skipping one instruction upon rescheduling. */
@@ -1501,7 +1501,7 @@ bool_t p2m_mem_access_check(paddr_t gpa, unsigned long gla,
     gfn_unlock(p2m, gfn, 0);
 
     /* Otherwise, check if there is a memory event listener, and send the message along */
-    if ( !mem_event_check_ring(&d->mem_event->access) || !req_ptr ) 
+    if ( !mem_event_check_ring(&d->mem_event->monitor) || !req_ptr ) 
     {
         /* No listener */
         if ( p2m->access_required ) 
@@ -1546,9 +1546,9 @@ bool_t p2m_mem_access_check(paddr_t gpa, unsigned long gla,
 
     if ( v->arch.mem_event.emulate_flags )
     {
-        hvm_mem_event_emulate_one((v->arch.mem_event.emulate_flags &
-                                   MEM_ACCESS_EMULATE_NOWRITE) != 0,
-                                  TRAP_invalid_op, HVM_DELIVER_NO_ERROR_CODE);
+        hvm_mem_access_emulate_one((v->arch.mem_event.emulate_flags &
+                                    MEM_ACCESS_EMULATE_NOWRITE) != 0,
+                                   TRAP_invalid_op, HVM_DELIVER_NO_ERROR_CODE);
 
         v->arch.mem_event.emulate_flags = 0;
         return 1;
diff --git a/xen/common/mem_access.c b/xen/common/mem_access.c
index 9c5b7a6..19be7d7 100644
--- a/xen/common/mem_access.c
+++ b/xen/common/mem_access.c
@@ -34,7 +34,7 @@ void mem_access_resume(struct domain *d)
     mem_event_response_t rsp;
 
     /* Pull all responses off the ring. */
-    while ( mem_event_get_response(d, &d->mem_event->access, &rsp) )
+    while ( mem_event_get_response(d, &d->mem_event->monitor, &rsp) )
     {
         struct vcpu *v;
 
@@ -53,7 +53,7 @@ void mem_access_resume(struct domain *d)
 
         v = d->vcpu[rsp.vcpu_id];
 
-        p2m_mem_event_emulate_check(v, &rsp);
+        p2m_mem_access_emulate_check(v, &rsp);
 
         /* Unpause domain. */
         if ( rsp.flags & MEM_EVENT_FLAG_VCPU_PAUSED )
@@ -85,7 +85,7 @@ int mem_access_memop(unsigned long cmd,
         goto out;
 
     rc = -ENODEV;
-    if ( unlikely(!d->mem_event->access.ring_page) )
+    if ( unlikely(!d->mem_event->monitor.ring_page) )
         goto out;
 
     switch ( mao.op )
@@ -152,11 +152,11 @@ int mem_access_memop(unsigned long cmd,
 
 int mem_access_send_req(struct domain *d, mem_event_request_t *req)
 {
-    int rc = mem_event_claim_slot(d, &d->mem_event->access);
+    int rc = mem_event_claim_slot(d, &d->mem_event->monitor);
     if ( rc < 0 )
         return rc;
 
-    mem_event_put_request(d, &d->mem_event->access, req);
+    mem_event_put_request(d, &d->mem_event->monitor, req);
 
     return 0;
 }
diff --git a/xen/common/mem_event.c b/xen/common/mem_event.c
index 8ab06ce..b96d9fb 100644
--- a/xen/common/mem_event.c
+++ b/xen/common/mem_event.c
@@ -444,7 +444,7 @@ static void mem_paging_notification(struct vcpu *v, unsigned int port)
 /* Registered with Xen-bound event channel for incoming notifications. */
 static void mem_access_notification(struct vcpu *v, unsigned int port)
 {
-    if ( likely(v->domain->mem_event->access.ring_page != NULL) )
+    if ( likely(v->domain->mem_event->monitor.ring_page != NULL) )
         mem_access_resume(v->domain);
 }
 #endif
@@ -496,7 +496,8 @@ int do_mem_event_op(int op, uint32_t domain, void *arg)
 void mem_event_cleanup(struct domain *d)
 {
 #ifdef HAS_MEM_PAGING
-    if ( d->mem_event->paging.ring_page ) {
+    if ( d->mem_event->paging.ring_page )
+    {
         /* Destroying the wait queue head means waking up all
          * queued vcpus. This will drain the list, allowing
          * the disable routine to complete. It will also drop
@@ -509,13 +510,15 @@ void mem_event_cleanup(struct domain *d)
     }
 #endif
 #ifdef HAS_MEM_ACCESS
-    if ( d->mem_event->access.ring_page ) {
-        destroy_waitqueue_head(&d->mem_event->access.wq);
-        (void)mem_event_disable(d, &d->mem_event->access);
+    if ( d->mem_event->monitor.ring_page )
+    {
+        destroy_waitqueue_head(&d->mem_event->monitor.wq);
+        (void)mem_event_disable(d, &d->mem_event->monitor);
     }
 #endif
 #ifdef HAS_MEM_SHARING
-    if ( d->mem_event->share.ring_page ) {
+    if ( d->mem_event->share.ring_page )
+    {
         destroy_waitqueue_head(&d->mem_event->share.wq);
         (void)mem_event_disable(d, &d->mem_event->share);
     }
@@ -564,7 +567,7 @@ int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,
 
         switch( mec->op )
         {
-        case XEN_DOMCTL_MEM_EVENT_OP_PAGING_ENABLE:
+        case XEN_MEM_EVENT_PAGING_ENABLE:
         {
             struct p2m_domain *p2m = p2m_get_hostp2m(d);
 
@@ -594,7 +597,7 @@ int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,
         }
         break;
 
-        case XEN_DOMCTL_MEM_EVENT_OP_PAGING_DISABLE:
+        case XEN_MEM_EVENT_PAGING_DISABLE:
         {
             if ( med->ring_page )
                 rc = mem_event_disable(d, med);
@@ -610,32 +613,32 @@ int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,
 #endif
 
 #ifdef HAS_MEM_ACCESS
-    case XEN_DOMCTL_MEM_EVENT_OP_ACCESS:
+    case XEN_DOMCTL_MEM_EVENT_OP_MONITOR:
     {
-        struct mem_event_domain *med = &d->mem_event->access;
+        struct mem_event_domain *med = &d->mem_event->monitor;
         rc = -EINVAL;
 
         switch( mec->op )
         {
-        case XEN_DOMCTL_MEM_EVENT_OP_ACCESS_ENABLE:
-        case XEN_DOMCTL_MEM_EVENT_OP_ACCESS_ENABLE_INTROSPECTION:
+        case XEN_MEM_EVENT_MONITOR_ENABLE:
+        case XEN_MEM_EVENT_MONITOR_ENABLE_INTROSPECTION:
         {
             rc = -ENODEV;
             if ( !p2m_mem_event_sanity_check(d) )
                 break;
 
             rc = mem_event_enable(d, mec, med, _VPF_mem_access,
-                                    HVM_PARAM_ACCESS_RING_PFN,
+                                    HVM_PARAM_MONITOR_RING_PFN,
                                     mem_access_notification);
 
-            if ( mec->op == XEN_DOMCTL_MEM_EVENT_OP_ACCESS_ENABLE_INTROSPECTION
+            if ( mec->op == XEN_MEM_EVENT_MONITOR_ENABLE_INTROSPECTION
                  && !rc )
                 p2m_setup_introspection(d);
 
         }
         break;
 
-        case XEN_DOMCTL_MEM_EVENT_OP_ACCESS_DISABLE:
+        case XEN_MEM_EVENT_MONITOR_DISABLE:
         {
             if ( med->ring_page )
             {
@@ -661,7 +664,7 @@ int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,
 
         switch( mec->op )
         {
-        case XEN_DOMCTL_MEM_EVENT_OP_SHARING_ENABLE:
+        case XEN_MEM_EVENT_SHARING_ENABLE:
         {
             rc = -EOPNOTSUPP;
             /* pvh fixme: p2m_is_foreign types need addressing */
@@ -679,7 +682,7 @@ int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,
         }
         break;
 
-        case XEN_DOMCTL_MEM_EVENT_OP_SHARING_DISABLE:
+        case XEN_MEM_EVENT_SHARING_DISABLE:
         {
             if ( med->ring_page )
                 rc = mem_event_disable(d, med);
diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
index da36504..299ee06 100644
--- a/xen/include/asm-arm/p2m.h
+++ b/xen/include/asm-arm/p2m.h
@@ -71,11 +71,11 @@ typedef enum {
 } p2m_type_t;
 
 static inline
-void p2m_mem_event_emulate_check(struct vcpu *v,
-                                 const mem_event_response_t *rsp)
+void p2m_mem_access_emulate_check(struct vcpu *v,
+                                  const mem_event_response_t *rsp)
 {
     /* Not supported on ARM. */
-};
+}
 
 static inline
 void p2m_setup_introspection(struct domain *d)
diff --git a/xen/include/asm-x86/hvm/emulate.h b/xen/include/asm-x86/hvm/emulate.h
index 5411302..b3971c8 100644
--- a/xen/include/asm-x86/hvm/emulate.h
+++ b/xen/include/asm-x86/hvm/emulate.h
@@ -38,7 +38,7 @@ int hvm_emulate_one(
     struct hvm_emulate_ctxt *hvmemul_ctxt);
 int hvm_emulate_one_no_write(
     struct hvm_emulate_ctxt *hvmemul_ctxt);
-void hvm_mem_event_emulate_one(bool_t nowrite,
+void hvm_mem_access_emulate_one(bool_t nowrite,
     unsigned int trapnr,
     unsigned int errcode);
 void hvm_emulate_prepare(
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index e93c551..79ee62e 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -609,8 +609,8 @@ int p2m_get_mem_access(struct domain *d, unsigned long pfn,
 
 /* Check for emulation and mark vcpu for skipping one instruction
  * upon rescheduling if required. */
-void p2m_mem_event_emulate_check(struct vcpu *v,
-                                 const mem_event_response_t *rsp);
+void p2m_mem_access_emulate_check(struct vcpu *v,
+                                  const mem_event_response_t *rsp);
 
 /* Enable arch specific introspection options (such as MSR interception). */
 void p2m_setup_introspection(struct domain *d);
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index ca0e51e..79f92c2 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -762,7 +762,7 @@ struct xen_domctl_gdbsx_domstatus {
  * pager<->hypervisor interface. Use XENMEM_paging_op*
  * to perform per-page operations.
  *
- * The XEN_DOMCTL_MEM_EVENT_OP_PAGING_ENABLE domctl returns several
+ * The XEN_MEM_EVENT_PAGING_ENABLE domctl returns several
  * non-standard error codes to indicate why paging could not be enabled:
  * ENODEV - host lacks HAP support (EPT/NPT) or HAP is disabled in guest
  * EMLINK - guest has iommu passthrough enabled
@@ -771,33 +771,40 @@ struct xen_domctl_gdbsx_domstatus {
  */
 #define XEN_DOMCTL_MEM_EVENT_OP_PAGING            1
 
-#define XEN_DOMCTL_MEM_EVENT_OP_PAGING_ENABLE     0
-#define XEN_DOMCTL_MEM_EVENT_OP_PAGING_DISABLE    1
+#define XEN_MEM_EVENT_PAGING_ENABLE               0
+#define XEN_MEM_EVENT_PAGING_DISABLE              1
 
 /*
- * Access permissions.
+ * Monitor helper.
  *
  * As with paging, use the domctl for teardown/setup of the
  * helper<->hypervisor interface.
  *
- * There are HVM hypercalls to set the per-page access permissions of every
- * page in a domain.  When one of these permissions--independent, read, 
- * write, and execute--is violated, the VCPU is paused and a memory event 
- * is sent with what happened.  (See public/mem_event.h) .
+ * The monitor interface can be used to register for various VM events. For
+ * example, there are HVM hypercalls to set the per-page access permissions
+ * of every page in a domain.  When one of these permissions--independent,
+ * read, write, and execute--is violated, the VCPU is paused and a memory event
+ * is sent with what happened. The memory event handler can then resume the
+ * VCPU and redo the access with a XENMEM_access_op_resume hypercall.
  *
- * The memory event handler can then resume the VCPU and redo the access 
- * with a XENMEM_access_op_resume hypercall.
+ * See public/mem_event.h for the list of available events that can be
+ * subscribed to via the monitor interface.
  *
- * The XEN_DOMCTL_MEM_EVENT_OP_ACCESS_ENABLE domctl returns several
+ * To enable MOV-TO-MSR interception on x86, it is necessary to enable this
+ * interface with the XEN_MEM_EVENT_MONITOR_ENABLE_INTROSPECTION
+ * operator.
+ *
+ * The XEN_MEM_EVENT_MONITOR_ENABLE* domctls return several
  * non-standard error codes to indicate why access could not be enabled:
  * ENODEV - host lacks HAP support (EPT/NPT) or HAP is disabled in guest
  * EBUSY  - guest has or had access enabled, ring buffer still active
+ *
  */
-#define XEN_DOMCTL_MEM_EVENT_OP_ACCESS                        2
+#define XEN_DOMCTL_MEM_EVENT_OP_MONITOR                        2
 
-#define XEN_DOMCTL_MEM_EVENT_OP_ACCESS_ENABLE                 0
-#define XEN_DOMCTL_MEM_EVENT_OP_ACCESS_DISABLE                1
-#define XEN_DOMCTL_MEM_EVENT_OP_ACCESS_ENABLE_INTROSPECTION   2
+#define XEN_MEM_EVENT_MONITOR_ENABLE                           0
+#define XEN_MEM_EVENT_MONITOR_DISABLE                          1
+#define XEN_MEM_EVENT_MONITOR_ENABLE_INTROSPECTION             2
 
 /*
  * Sharing ENOMEM helper.
@@ -814,13 +821,13 @@ struct xen_domctl_gdbsx_domstatus {
  */
 #define XEN_DOMCTL_MEM_EVENT_OP_SHARING           3
 
-#define XEN_DOMCTL_MEM_EVENT_OP_SHARING_ENABLE    0
-#define XEN_DOMCTL_MEM_EVENT_OP_SHARING_DISABLE   1
+#define XEN_MEM_EVENT_SHARING_ENABLE              0
+#define XEN_MEM_EVENT_SHARING_DISABLE             1
 
 /* Use for teardown/setup of helper<->hypervisor interface for paging, 
  * access and sharing.*/
 struct xen_domctl_mem_event_op {
-    uint32_t       op;           /* XEN_DOMCTL_MEM_EVENT_OP_*_* */
+    uint32_t       op;           /* XEN_MEM_EVENT_*_* */
     uint32_t       mode;         /* XEN_DOMCTL_MEM_EVENT_OP_* */
 
     uint32_t port;              /* OUT: event channel for ring */
diff --git a/xen/include/public/hvm/params.h b/xen/include/public/hvm/params.h
index a2d43bc..6efcc0b 100644
--- a/xen/include/public/hvm/params.h
+++ b/xen/include/public/hvm/params.h
@@ -182,7 +182,7 @@
 
 /* Params for the mem event rings */
 #define HVM_PARAM_PAGING_RING_PFN   27
-#define HVM_PARAM_ACCESS_RING_PFN   28
+#define HVM_PARAM_MONITOR_RING_PFN  28
 #define HVM_PARAM_SHARING_RING_PFN  29
 
 /* SHUTDOWN_* action in case of a triple fault */
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index ccd7ed8..76e41f3 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -288,8 +288,8 @@ struct mem_event_per_domain
     struct mem_event_domain share;
     /* Memory paging support */
     struct mem_event_domain paging;
-    /* Memory access support */
-    struct mem_event_domain access;
+    /* VM event monitor support */
+    struct mem_event_domain monitor;
 };
 
 struct evtchn_port_ops;
-- 
2.1.4