relocate mem_access and mem_event into common

In preparation to add support for ARM LPAE mem_event, relocate mem_access,
mem_event and auxiliary functions into common Xen code.
This patch makes no functional changes to the X86 side, for ARM mem_event
and mem_access functions are just defined as placeholder stubs, and are
actually enabled later in the series.

Edits that are only header path adjustments:
   xen/arch/x86/domctl.c
   xen/arch/x86/mm/hap/nested_ept.c
   xen/arch/x86/mm/hap/nested_hap.c
   xen/arch/x86/mm/mem_paging.c
   xen/arch/x86/mm/mem_sharing.c
   xen/arch/x86/mm/p2m-pod.c
   xen/arch/x86/mm/p2m-pt.c
   xen/arch/x86/mm/p2m.c
   xen/arch/x86/x86_64/compat/mm.c
   xen/arch/x86/x86_64/mm.c

Makefile adjustments for new/removed code:
   xen/common/Makefile
   xen/arch/x86/mm/Makefile

Relocated prepare_ring_for_helper and destroy_ring_for_helper functions:
   xen/include/xen/mm.h
   xen/common/memory.c
   xen/include/asm-x86/hvm/hvm.h
   xen/arch/x86/hvm/hvm.c

Code movement of mem_event and mem_access:
    xen/arch/x86/mm/mem_access.c -> xen/common/mem_access.c
    xen/arch/x86/mm/mem_event.c -> xen/common/mem_event.c
    xen/include/asm-x86/mem_access.h -> xen/include/xen/mem_access.h
    xen/include/asm-x86/mem_event.h -> xen/include/xen/mem_event.h

Signed-off-by: Tamas K Lengyel <tklengyel@sec.in.tum.de>
Acked-by: Tim Deegan <tim@xen.org>

MAINTAINERS

@@ -338,6 +338,12 @@ F:	xen/arch/x86/mm/mem_sharing.c
 F:	xen/arch/x86/mm/mem_paging.c
 F:	tools/memshr
 
+MEMORY EVENT AND ACCESS
+M:	Tim Deegan <tim@xen.org>
+S:	Supported
+F:	xen/common/mem_event.c
+F:	xen/common/mem_access.c
+
 XENTRACE
 M:	George Dunlap <george.dunlap@eu.citrix.com>
 S:	Supported

config/x86_32.mk

@@ -6,6 +6,10 @@ CONFIG_HVM := y
 CONFIG_MIGRATE := y
 CONFIG_XCUTILS := y
 
+HAS_MEM_ACCESS := y
+HAS_MEM_PAGING := y
+HAS_MEM_SHARING := y
+
 CFLAGS += -m32 -march=i686
 
 # Use only if calling $(LD) directly.

config/x86_64.mk

@@ -7,6 +7,10 @@ CONFIG_HVM := y
 CONFIG_MIGRATE := y
 CONFIG_XCUTILS := y
 
+HAS_MEM_ACCESS := y
+HAS_MEM_PAGING := y
+HAS_MEM_SHARING := y
+
 CONFIG_XEN_INSTALL_SUFFIX := .gz
 
 CFLAGS += -m64

xen/Rules.mk

@@ -57,6 +57,9 @@ CFLAGS-$(HAS_ACPI)      += -DHAS_ACPI
 CFLAGS-$(HAS_GDBSX)     += -DHAS_GDBSX
 CFLAGS-$(HAS_PASSTHROUGH) += -DHAS_PASSTHROUGH
 CFLAGS-$(HAS_DEVICE_TREE) += -DHAS_DEVICE_TREE
+CFLAGS-$(HAS_MEM_ACCESS)  += -DHAS_MEM_ACCESS
+CFLAGS-$(HAS_MEM_PAGING)  += -DHAS_MEM_PAGING
+CFLAGS-$(HAS_MEM_SHARING) += -DHAS_MEM_SHARING
 CFLAGS-$(HAS_PCI)       += -DHAS_PCI
 CFLAGS-$(HAS_IOPORTS)   += -DHAS_IOPORTS
 CFLAGS-$(HAS_PDX)       += -DHAS_PDX

xen/arch/x86/domctl.c

@@ -30,7 +30,7 @@
 #include <xen/hypercall.h> /* for arch_do_domctl */
 #include <xsm/xsm.h>
 #include <xen/iommu.h>
-#include <asm/mem_event.h>
+#include <xen/mem_event.h>
 #include <public/mem_event.h>
 #include <asm/mem_sharing.h>
 #include <asm/xstate.h>

xen/arch/x86/hvm/hvm.c

@@ -35,6 +35,9 @@
 #include <xen/paging.h>
 #include <xen/cpu.h>
 #include <xen/wait.h>
+#include <xen/mem_event.h>
+#include <xen/mem_access.h>
+#include <xen/rangeset.h>
 #include <asm/shadow.h>
 #include <asm/hap.h>
 #include <asm/current.h>
@@ -63,10 +66,7 @@
 #include <public/hvm/ioreq.h>
 #include <public/version.h>
 #include <public/memory.h>
-#include <asm/mem_event.h>
-#include <asm/mem_access.h>
 #include <public/mem_event.h>
-#include <xen/rangeset.h>
 #include <public/arch-x86/cpuid.h>
 
 bool_t __read_mostly hvm_enabled;
@@ -489,19 +489,6 @@ static void hvm_free_ioreq_gmfn(struct domain *d, unsigned long gmfn)
     clear_bit(i, &d->arch.hvm_domain.ioreq_gmfn.mask);
 }
 
-void destroy_ring_for_helper(
-    void **_va, struct page_info *page)
-{
-    void *va = *_va;
-
-    if ( va != NULL )
-    {
-        unmap_domain_page_global(va);
-        put_page_and_type(page);
-        *_va = NULL;
-    }
-}
-
 static void hvm_unmap_ioreq_page(struct hvm_ioreq_server *s, bool_t buf)
 {
     struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq;
@@ -509,50 +496,6 @@ static void hvm_unmap_ioreq_page(struct hvm_ioreq_server *s, bool_t buf)
     destroy_ring_for_helper(&iorp->va, iorp->page);
 }
 
-int prepare_ring_for_helper(
-    struct domain *d, unsigned long gmfn, struct page_info **_page,
-    void **_va)
-{
-    struct page_info *page;
-    p2m_type_t p2mt;
-    void *va;
-
-    page = get_page_from_gfn(d, gmfn, &p2mt, P2M_UNSHARE);
-    if ( p2m_is_paging(p2mt) )
-    {
-        if ( page )
-            put_page(page);
-        p2m_mem_paging_populate(d, gmfn);
-        return -ENOENT;
-    }
-    if ( p2m_is_shared(p2mt) )
-    {
-        if ( page )
-            put_page(page);
-        return -ENOENT;
-    }
-    if ( !page )
-        return -EINVAL;
-
-    if ( !get_page_type(page, PGT_writable_page) )
-    {
-        put_page(page);
-        return -EINVAL;
-    }
-
-    va = __map_domain_page_global(page);
-    if ( va == NULL )
-    {
-        put_page_and_type(page);
-        return -ENOMEM;
-    }
-
-    *_va = va;
-    *_page = page;
-
-    return 0;
-}
-
 static int hvm_map_ioreq_page(
     struct hvm_ioreq_server *s, bool_t buf, unsigned long gmfn)
 {

xen/arch/x86/hvm/vmx/vmcs.c

@@ -22,6 +22,10 @@
 #include <xen/lib.h>
 #include <xen/errno.h>
 #include <xen/domain_page.h>
+#include <xen/event.h>
+#include <xen/kernel.h>
+#include <xen/keyhandler.h>
+#include <xen/mem_event.h>
 #include <asm/current.h>
 #include <asm/cpufeature.h>
 #include <asm/processor.h>
@@ -34,12 +38,8 @@
 #include <asm/hvm/vmx/vvmx.h>
 #include <asm/hvm/vmx/vmcs.h>
 #include <asm/flushtlb.h>
-#include <xen/event.h>
-#include <xen/kernel.h>
-#include <xen/keyhandler.h>
 #include <asm/shadow.h>
 #include <asm/tboot.h>
-#include <asm/mem_event.h>
 
 static bool_t __read_mostly opt_vpid_enabled = 1;
 boolean_param("vpid", opt_vpid_enabled);

xen/arch/x86/mm/Makefile

@@ -6,10 +6,8 @@ obj-y += p2m.o p2m-pt.o p2m-ept.o p2m-pod.o
 obj-y += guest_walk_2.o
 obj-y += guest_walk_3.o
 obj-$(x86_64) += guest_walk_4.o
-obj-$(x86_64) += mem_event.o
 obj-$(x86_64) += mem_paging.o
 obj-$(x86_64) += mem_sharing.o
-obj-$(x86_64) += mem_access.o
 
 guest_walk_%.o: guest_walk.c Makefile
 	$(CC) $(CFLAGS) -DGUEST_PAGING_LEVELS=$* -c $< -o $@

xen/arch/x86/mm/hap/nested_ept.c

@@ -17,14 +17,14 @@
  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  * Place - Suite 330, Boston, MA 02111-1307 USA.
  */
+#include <xen/mem_event.h>
+#include <xen/event.h>
+#include <public/mem_event.h>
 #include <asm/domain.h>
 #include <asm/page.h>
 #include <asm/paging.h>
 #include <asm/p2m.h>
-#include <asm/mem_event.h>
-#include <public/mem_event.h>
 #include <asm/mem_sharing.h>
-#include <xen/event.h>
 #include <asm/hap.h>
 #include <asm/hvm/support.h>
 

xen/arch/x86/mm/hap/nested_hap.c

@@ -19,14 +19,14 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include <xen/mem_event.h>
+#include <xen/event.h>
+#include <public/mem_event.h>
 #include <asm/domain.h>
 #include <asm/page.h>
 #include <asm/paging.h>
 #include <asm/p2m.h>
-#include <asm/mem_event.h>
-#include <public/mem_event.h>
 #include <asm/mem_sharing.h>
-#include <xen/event.h>
 #include <asm/hap.h>
 #include <asm/hvm/support.h>
 

xen/arch/x86/mm/mem_paging.c

@@ -22,7 +22,7 @@
 
 
 #include <asm/p2m.h>
-#include <asm/mem_event.h>
+#include <xen/mem_event.h>
 
 
 int mem_paging_memop(struct domain *d, xen_mem_event_op_t *mec)

xen/arch/x86/mm/mem_sharing.c

@@ -27,12 +27,12 @@
 #include <xen/mm.h>
 #include <xen/grant_table.h>
 #include <xen/sched.h>
+#include <xen/rcupdate.h>
+#include <xen/mem_event.h>
 #include <asm/page.h>
 #include <asm/string.h>
 #include <asm/p2m.h>
-#include <asm/mem_event.h>
 #include <asm/atomic.h>
-#include <xen/rcupdate.h>
 #include <asm/event.h>
 #include <xsm/xsm.h>
 

xen/arch/x86/mm/p2m-pod.c

@@ -20,16 +20,16 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include <xen/iommu.h>
+#include <xen/mem_event.h>
+#include <xen/event.h>
+#include <public/mem_event.h>
 #include <asm/domain.h>
 #include <asm/page.h>
 #include <asm/paging.h>
 #include <asm/p2m.h>
 #include <asm/hvm/vmx/vmx.h> /* ept_p2m_init() */
-#include <xen/iommu.h>
-#include <asm/mem_event.h>
-#include <public/mem_event.h>
 #include <asm/mem_sharing.h>
-#include <xen/event.h>
 #include <asm/hvm/nestedhvm.h>
 #include <asm/hvm/svm/amd-iommu-proto.h>
 

xen/arch/x86/mm/p2m-pt.c

@@ -25,16 +25,16 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include <xen/iommu.h>
+#include <xen/mem_event.h>
+#include <xen/event.h>
+#include <xen/trace.h>
+#include <public/mem_event.h>
 #include <asm/domain.h>
 #include <asm/page.h>
 #include <asm/paging.h>
 #include <asm/p2m.h>
-#include <xen/iommu.h>
-#include <asm/mem_event.h>
-#include <public/mem_event.h>
 #include <asm/mem_sharing.h>
-#include <xen/event.h>
-#include <xen/trace.h>
 #include <asm/hvm/nestedhvm.h>
 #include <asm/hvm/svm/amd-iommu-proto.h>
 

xen/arch/x86/mm/p2m.c

@@ -24,16 +24,16 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include <xen/iommu.h>
+#include <xen/mem_event.h>
+#include <xen/event.h>
+#include <public/mem_event.h>
 #include <asm/domain.h>
 #include <asm/page.h>
 #include <asm/paging.h>
 #include <asm/p2m.h>
 #include <asm/hvm/vmx/vmx.h> /* ept_p2m_init() */
-#include <xen/iommu.h>
-#include <asm/mem_event.h>
-#include <public/mem_event.h>
 #include <asm/mem_sharing.h>
-#include <xen/event.h>
 #include <asm/hvm/nestedhvm.h>
 #include <asm/hvm/svm/amd-iommu-proto.h>
 #include <xsm/xsm.h>

xen/arch/x86/x86_64/compat/mm.c

@@ -1,10 +1,10 @@
 #include <xen/event.h>
+#include <xen/mem_event.h>
+#include <xen/mem_access.h>
 #include <xen/multicall.h>
 #include <compat/memory.h>
 #include <compat/xen.h>
-#include <asm/mem_event.h>
 #include <asm/mem_sharing.h>
-#include <asm/mem_access.h>
 
 int compat_set_gdt(XEN_GUEST_HANDLE_PARAM(uint) frame_list, unsigned int entries)
 {

xen/arch/x86/x86_64/mm.c

@@ -26,6 +26,8 @@
 #include <xen/nodemask.h>
 #include <xen/guest_access.h>
 #include <xen/hypercall.h>
+#include <xen/mem_event.h>
+#include <xen/mem_access.h>
 #include <asm/current.h>
 #include <asm/asm_defns.h>
 #include <asm/page.h>
@@ -35,9 +37,7 @@
 #include <asm/msr.h>
 #include <asm/setup.h>
 #include <asm/numa.h>
-#include <asm/mem_event.h>
 #include <asm/mem_sharing.h>
-#include <asm/mem_access.h>
 #include <public/memory.h>
 
 unsigned int __read_mostly m2p_compat_vstart = __HYPERVISOR_COMPAT_VIRT_START;

xen/common/Makefile

@@ -53,6 +53,8 @@ obj-y += radix-tree.o
 obj-y += rbtree.o
 obj-y += lzo.o
 obj-$(HAS_PDX) += pdx.o
+obj-$(HAS_MEM_ACCESS) += mem_access.o
+obj-$(HAS_MEM_ACCESS) += mem_event.o
 
 obj-bin-$(CONFIG_X86) += $(foreach n,decompress bunzip2 unxz unlzma unlzo unlz4 earlycpio,$(n).init.o)
 

xen/common/domain.c

@@ -15,6 +15,7 @@
 #include <xen/domain.h>
 #include <xen/mm.h>
 #include <xen/event.h>
+#include <xen/mem_event.h>
 #include <xen/time.h>
 #include <xen/console.h>
 #include <xen/softirq.h>

xen/common/mem_access.c

@@ -1,5 +1,5 @@
 /******************************************************************************
- * arch/x86/mm/mem_access.c
+ * mem_access.c
  *
  * Memory access support.
  *
@@ -24,11 +24,11 @@
 #include <xen/sched.h>
 #include <xen/guest_access.h>
 #include <xen/hypercall.h>
+#include <xen/mem_event.h>
+#include <public/memory.h>
 #include <asm/p2m.h>
-#include <asm/mem_event.h>
 #include <xsm/xsm.h>
 
-
 int mem_access_memop(unsigned long cmd,
                      XEN_GUEST_HANDLE_PARAM(xen_mem_access_op_t) arg)
 {
@@ -121,7 +121,7 @@ int mem_access_send_req(struct domain *d, mem_event_request_t *req)
     mem_event_put_request(d, &d->mem_event->access, req);
 
     return 0;
-} 
+}
 
 /*
  * Local variables:

xen/common/mem_event.c

@@ -1,5 +1,5 @@
 /******************************************************************************
- * arch/x86/mm/mem_event.c
+ * mem_event.c
  *
  * Memory event support.
  *
@@ -21,14 +21,21 @@
  */
 
 
-#include <asm/domain.h>
+#include <xen/sched.h>
 #include <xen/event.h>
 #include <xen/wait.h>
+#include <xen/mem_event.h>
+#include <xen/mem_access.h>
 #include <asm/p2m.h>
-#include <asm/mem_event.h>
+
+#ifdef HAS_MEM_PAGING
 #include <asm/mem_paging.h>
-#include <asm/mem_access.h>
+#endif
+
+#ifdef HAS_MEM_SHARING
 #include <asm/mem_sharing.h>
+#endif
+
 #include <xsm/xsm.h>
 
 /* for public/io/ring.h macros */
@@ -419,26 +426,32 @@ int __mem_event_claim_slot(struct domain *d, struct mem_event_domain *med,
         return mem_event_grab_slot(med, (current->domain != d));
 }
 
+#ifdef HAS_MEM_PAGING
 /* Registered with Xen-bound event channel for incoming notifications. */
 static void mem_paging_notification(struct vcpu *v, unsigned int port)
 {
     if ( likely(v->domain->mem_event->paging.ring_page != NULL) )
         p2m_mem_paging_resume(v->domain);
 }
+#endif
 
+#ifdef HAS_MEM_ACCESS
 /* 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) )
         p2m_mem_access_resume(v->domain);
 }
+#endif
 
+#ifdef HAS_MEM_SHARING
 /* Registered with Xen-bound event channel for incoming notifications. */
 static void mem_sharing_notification(struct vcpu *v, unsigned int port)
 {
     if ( likely(v->domain->mem_event->share.ring_page != NULL) )
         mem_sharing_sharing_resume(v->domain);
 }
+#endif
 
 int do_mem_event_op(int op, uint32_t domain, void *arg)
 {
@@ -455,12 +468,16 @@ int do_mem_event_op(int op, uint32_t domain, void *arg)
 
     switch (op)
     {
+#ifdef HAS_MEM_PAGING
         case XENMEM_paging_op:
             ret = mem_paging_memop(d, (xen_mem_event_op_t *) arg);
             break;
+#endif
+#ifdef HAS_MEM_SHARING
         case XENMEM_sharing_op:
             ret = mem_sharing_memop(d, (xen_mem_sharing_op_t *) arg);
             break;
+#endif
         default:
             ret = -ENOSYS;
     }
@@ -473,6 +490,7 @@ int do_mem_event_op(int op, uint32_t domain, void *arg)
 /* Clean up on domain destruction */
 void mem_event_cleanup(struct domain *d)
 {
+#ifdef HAS_MEM_PAGING
     if ( d->mem_event->paging.ring_page ) {
         /* Destroying the wait queue head means waking up all
          * queued vcpus. This will drain the list, allowing
@@ -484,14 +502,19 @@ void mem_event_cleanup(struct domain *d)
         destroy_waitqueue_head(&d->mem_event->paging.wq);
         (void)mem_event_disable(d, &d->mem_event->paging);
     }
+#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);
     }
+#endif
+#ifdef HAS_MEM_SHARING
     if ( d->mem_event->share.ring_page ) {
         destroy_waitqueue_head(&d->mem_event->share.wq);
         (void)mem_event_disable(d, &d->mem_event->share);
     }
+#endif
 }
 
 int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,
@@ -528,6 +551,7 @@ int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,
 
     switch ( mec->mode )
     {
+#ifdef HAS_MEM_PAGING
     case XEN_DOMCTL_MEM_EVENT_OP_PAGING:
     {
         struct mem_event_domain *med = &d->mem_event->paging;
@@ -578,7 +602,9 @@ int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,
         }
     }
     break;
+#endif
 
+#ifdef HAS_MEM_ACCESS
     case XEN_DOMCTL_MEM_EVENT_OP_ACCESS: 
     {
         struct mem_event_domain *med = &d->mem_event->access;
@@ -627,7 +653,9 @@ int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,
         }
     }
     break;
+#endif
 
+#ifdef HAS_MEM_SHARING
     case XEN_DOMCTL_MEM_EVENT_OP_SHARING: 
     {
         struct mem_event_domain *med = &d->mem_event->share;
@@ -666,6 +694,7 @@ int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,
         }
     }
     break;
+#endif
 
     default:
         rc = -ENOSYS;

xen/common/memory.c

@@ -1104,6 +1104,69 @@ long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
     return rc;
 }
 
+void destroy_ring_for_helper(
+    void **_va, struct page_info *page)
+{
+    void *va = *_va;
+
+    if ( va != NULL )
+    {
+        unmap_domain_page_global(va);
+        put_page_and_type(page);
+        *_va = NULL;
+    }
+}
+
+int prepare_ring_for_helper(
+    struct domain *d, unsigned long gmfn, struct page_info **_page,
+    void **_va)
+{
+    struct page_info *page;
+    p2m_type_t p2mt;
+    void *va;
+
+    page = get_page_from_gfn(d, gmfn, &p2mt, P2M_UNSHARE);
+
+#ifdef HAS_MEM_PAGING
+    if ( p2m_is_paging(p2mt) )
+    {
+        if ( page )
+            put_page(page);
+        p2m_mem_paging_populate(d, gmfn);
+        return -ENOENT;
+    }
+#endif
+#ifdef HAS_MEM_SHARING
+    if ( p2m_is_shared(p2mt) )
+    {
+        if ( page )
+            put_page(page);
+        return -ENOENT;
+    }
+#endif
+
+    if ( !page )
+        return -EINVAL;
+
+    if ( !get_page_type(page, PGT_writable_page) )
+    {
+        put_page(page);
+        return -EINVAL;
+    }
+
+    va = __map_domain_page_global(page);
+    if ( va == NULL )
+    {
+        put_page_and_type(page);
+        return -ENOMEM;
+    }
+
+    *_va = va;
+    *_page = page;
+
+    return 0;
+}
+
 /*
  * Local variables:
  * mode: C

xen/include/asm-arm/mm.h

@@ -300,7 +300,6 @@ struct page_info *get_page_from_gva(struct domain *d, vaddr_t va,
     })
 
 static inline void put_gfn(struct domain *d, unsigned long gfn) {}
-static inline void mem_event_cleanup(struct domain *d) {}
 static inline int relinquish_shared_pages(struct domain *d)
 {
     return 0;

xen/include/asm-x86/hvm/hvm.h

@@ -228,12 +228,6 @@ int hvm_vcpu_cacheattr_init(struct vcpu *v);
 void hvm_vcpu_cacheattr_destroy(struct vcpu *v);
 void hvm_vcpu_reset_state(struct vcpu *v, uint16_t cs, uint16_t ip);
 
-/* Prepare/destroy a ring for a dom0 helper. Helper with talk
- * with Xen on behalf of this hvm domain. */
-int prepare_ring_for_helper(struct domain *d, unsigned long gmfn, 
-                            struct page_info **_page, void **_va);
-void destroy_ring_for_helper(void **_va, struct page_info *page);
-
 bool_t hvm_send_assist_req(ioreq_t *p);
 void hvm_broadcast_assist_req(ioreq_t *p);
 

xen/include/asm-x86/mm.h

@@ -609,8 +609,6 @@ unsigned int domain_clamp_alloc_bitsize(struct domain *d, unsigned int bits);
 
 unsigned long domain_get_maximum_gpfn(struct domain *d);
 
-void mem_event_cleanup(struct domain *d);
-
 extern struct domain *dom_xen, *dom_io, *dom_cow;	/* for vmcoreinfo */
 
 /* Definition of an mm lock: spinlock with extra fields for debugging */

xen/include/xen/mem_access.h

@@ -1,5 +1,5 @@
 /******************************************************************************
- * include/asm-x86/mem_access.h
+ * mem_access.h
  *
  * Memory access support.
  *
@@ -23,10 +23,31 @@
 #ifndef _XEN_ASM_MEM_ACCESS_H
 #define _XEN_ASM_MEM_ACCESS_H
 
+#include <public/memory.h>
+
+#ifdef HAS_MEM_ACCESS
+
 int mem_access_memop(unsigned long cmd,
                      XEN_GUEST_HANDLE_PARAM(xen_mem_access_op_t) arg);
 int mem_access_send_req(struct domain *d, mem_event_request_t *req);
 
+#else
+
+static inline
+int mem_access_memop(unsigned long cmd,
+                     XEN_GUEST_HANDLE_PARAM(xen_mem_access_op_t) arg)
+{
+    return -ENOSYS;
+}
+
+static inline
+int mem_access_send_req(struct domain *d, mem_event_request_t *req)
+{
+    return -ENOSYS;
+}
+
+#endif /* HAS_MEM_ACCESS */
+
 #endif /* _XEN_ASM_MEM_ACCESS_H */
 
 /*

xen/include/xen/mem_event.h

@@ -1,5 +1,5 @@
 /******************************************************************************
- * include/asm-x86/mem_event.h
+ * mem_event.h
  *
  * Common interface for memory event support.
  *
@@ -24,6 +24,13 @@
 #ifndef __MEM_EVENT_H__
 #define __MEM_EVENT_H__
 
+#include <xen/sched.h>
+
+#ifdef HAS_MEM_ACCESS
+
+/* Clean up on domain destruction */
+void mem_event_cleanup(struct domain *d);
+
 /* Returns whether a ring has been set up */
 bool_t mem_event_check_ring(struct mem_event_domain *med);
 
@@ -69,6 +76,60 @@ int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,
 void mem_event_vcpu_pause(struct vcpu *v);
 void mem_event_vcpu_unpause(struct vcpu *v);
 
+#else
+
+static inline void mem_event_cleanup(struct domain *d) {}
+
+static inline bool_t mem_event_check_ring(struct mem_event_domain *med)
+{
+    return 0;
+}
+
+static inline int mem_event_claim_slot(struct domain *d,
+                                        struct mem_event_domain *med)
+{
+    return -ENOSYS;
+}
+
+static inline int mem_event_claim_slot_nosleep(struct domain *d,
+                                        struct mem_event_domain *med)
+{
+    return -ENOSYS;
+}
+
+static inline
+void mem_event_cancel_slot(struct domain *d, struct mem_event_domain *med)
+{}
+
+static inline
+void mem_event_put_request(struct domain *d, struct mem_event_domain *med,
+                            mem_event_request_t *req)
+{}
+
+static inline
+int mem_event_get_response(struct domain *d, struct mem_event_domain *med,
+                           mem_event_response_t *rsp)
+{
+    return -ENOSYS;
+}
+
+static inline int do_mem_event_op(int op, uint32_t domain, void *arg)
+{
+    return -ENOSYS;
+}
+
+static inline
+int mem_event_domctl(struct domain *d, xen_domctl_mem_event_op_t *mec,
+                     XEN_GUEST_HANDLE_PARAM(void) u_domctl)
+{
+    return -ENOSYS;
+}
+
+static inline void mem_event_vcpu_pause(struct vcpu *v) {}
+static inline void mem_event_vcpu_unpause(struct vcpu *v) {}
+
+#endif /* HAS_MEM_ACCESS */
+
 #endif /* __MEM_EVENT_H__ */
 
 

xen/include/xen/mm.h

@@ -371,4 +371,10 @@ int guest_remove_page(struct domain *d, unsigned long gmfn);
 /* TRUE if the whole page at @mfn is of the requested RAM type(s) above. */
 int page_is_ram_type(unsigned long mfn, unsigned long mem_type);
 
+/* Prepare/destroy a ring for a dom0 helper. Helper with talk
+ * with Xen on behalf of this domain. */
+int prepare_ring_for_helper(struct domain *d, unsigned long gmfn,
+                            struct page_info **_page, void **_va);
+void destroy_ring_for_helper(void **_va, struct page_info *page);
+
 #endif /* __XEN_MM_H__ */