diff -Naur linux-2.6.28/arch/x86/include/asm/xen/hypercall.h linux-2.6.28-tmem/arch/x86/include/asm/xen/hypercall.h
--- linux-2.6.28/arch/x86/include/asm/xen/hypercall.h	2008-12-24 16:26:37.000000000 -0700
+++ linux-2.6.28-tmem/arch/x86/include/asm/xen/hypercall.h	2009-01-05 17:16:53.000000000 -0700
@@ -524,4 +524,11 @@
 	mcl->args[1] = esp;
 }
 
+static inline int
+HYPERVISOR_tmem_op(
+	struct tmem_op *op)
+{
+	return _hypercall1(int, tmem_op, op);
+}
+
 #endif /* _ASM_X86_XEN_HYPERCALL_H */
diff -Naur linux-2.6.28/arch/x86/xen/enlighten.c linux-2.6.28-tmem/arch/x86/xen/enlighten.c
--- linux-2.6.28/arch/x86/xen/enlighten.c	2008-12-24 16:26:37.000000000 -0700
+++ linux-2.6.28-tmem/arch/x86/xen/enlighten.c	2009-01-05 16:56:34.000000000 -0700
@@ -1712,3 +1712,34 @@
 	x86_64_start_reservations((char *)__pa_symbol(&boot_params));
 #endif
 }
+
+int xen_tmem_op(uint32_t tmem_cmd, uint32_t tmem_pool, uint64_t object,
+	uint32_t index, unsigned long gmfn, uint32_t offset, uint32_t len )
+{
+	struct tmem_op op;
+        int rc = 0;
+
+	op.cmd = tmem_cmd;
+	op.pool_id = tmem_pool;
+	op.object = object;
+	op.index = index;
+	op.offset = offset;
+	op.len = len;
+	set_xen_guest_handle(op.gmfn, (void *)gmfn);
+	rc = HYPERVISOR_tmem_op(&op);
+	return rc;
+}
+
+int xen_tmem_new_pool(uint32_t tmem_cmd, uint64_t uuid_lo,
+	uint64_t uuid_hi, uint32_t flags)
+{
+	struct tmem_op op;
+        int rc = 0;
+
+	op.cmd = tmem_cmd;
+	op.uuid[0] = uuid_lo;
+	op.uuid[1] = uuid_hi;
+	op.flags = flags;
+	rc = HYPERVISOR_tmem_op(&op);
+	return rc;
+}
diff -Naur linux-2.6.28/include/xen/interface/xen.h linux-2.6.28-tmem/include/xen/interface/xen.h
--- linux-2.6.28/include/xen/interface/xen.h	2008-12-24 16:26:37.000000000 -0700
+++ linux-2.6.28-tmem/include/xen/interface/xen.h	2009-01-05 17:39:11.000000000 -0700
@@ -58,6 +58,7 @@
 #define __HYPERVISOR_event_channel_op     32
 #define __HYPERVISOR_physdev_op           33
 #define __HYPERVISOR_hvm_op               34
+#define __HYPERVISOR_tmem_op              38
 
 /* Architecture-specific hypercall definitions. */
 #define __HYPERVISOR_arch_0               48
@@ -231,6 +232,29 @@
 #define MAX_VMASST_TYPE 3
 
 #ifndef __ASSEMBLY__
+struct tmem_op {
+    uint32_t cmd;
+    int32_t pool_id; /* private > 0; shared < 0; 0 is invalid */
+    union {
+        struct {  /* for cmd == TMEM_NEW_POOL */
+            uint64_t uuid[2];
+            uint32_t flags;
+        };
+        struct {
+            uint64_t object;
+            uint32_t index;
+            uint32_t offset;
+            uint32_t len;
+            uint32_t padding;
+            GUEST_HANDLE(void) gmfn; /* guest machine page frame */
+        };
+    };
+};
+typedef struct tmem_op tmem_op_t;
+DEFINE_GUEST_HANDLE_STRUCT(tmem_op_t);
+#endif
+
+#ifndef __ASSEMBLY__
 
 typedef uint16_t domid_t;