diff --git a/tools/include/libxl.h b/tools/include/libxl.h
index b9ba16d..deb5022 100644
--- a/tools/include/libxl.h
+++ b/tools/include/libxl.h
@@ -874,6 +874,14 @@ typedef struct libxl__ctx libxl_ctx;
 #define LIBXL_HAVE_DOMINFO_NEVER_STOP 1
 
 /*
+ * LIBXL_HAVE_DOMINFO_GPADDR_BITS
+ *
+ * If this is defined, libxl_dominfo will contain an uint8 field called
+ * gpaddr_bits, containing the guest physical address space size.
+ */
+#define LIBXL_HAVE_DOMINFO_GPADDR_BITS 1
+
+/*
  * LIBXL_HAVE_QXL
  *
  * If defined, then the libxl_vga_interface_type will contain another value:
diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index a306399..07b96e6 100644
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -462,6 +462,7 @@ typedef struct xc_dominfo {
     unsigned int  max_vcpu_id;
     xen_domain_handle_t handle;
     unsigned int  cpupool;
+    uint8_t       gpaddr_bits;
     struct xen_arch_domainconfig arch_config;
 } xc_dominfo_t;
 
diff --git a/tools/libs/ctrl/xc_domain.c b/tools/libs/ctrl/xc_domain.c
index 23322b7..b155d6a 100644
--- a/tools/libs/ctrl/xc_domain.c
+++ b/tools/libs/ctrl/xc_domain.c
@@ -396,6 +396,7 @@ int xc_domain_getinfo(xc_interface *xch,
         info->nr_online_vcpus = domctl.u.getdomaininfo.nr_online_vcpus;
         info->max_vcpu_id = domctl.u.getdomaininfo.max_vcpu_id;
         info->cpupool = domctl.u.getdomaininfo.cpupool;
+        info->gpaddr_bits = domctl.u.getdomaininfo.gpaddr_bits;
         info->arch_config = domctl.u.getdomaininfo.arch_config;
 
         memcpy(info->handle, domctl.u.getdomaininfo.handle,
diff --git a/tools/libs/light/libxl_domain.c b/tools/libs/light/libxl_domain.c
index 51a6127..544a9bf 100644
--- a/tools/libs/light/libxl_domain.c
+++ b/tools/libs/light/libxl_domain.c
@@ -306,6 +306,7 @@ void libxl__xcinfo2xlinfo(libxl_ctx *ctx,
     xlinfo->vcpu_max_id = xcinfo->max_vcpu_id;
     xlinfo->vcpu_online = xcinfo->nr_online_vcpus;
     xlinfo->cpupool = xcinfo->cpupool;
+    xlinfo->gpaddr_bits = xcinfo->gpaddr_bits;
     xlinfo->domain_type = (xcinfo->flags & XEN_DOMINF_hvm_guest) ?
         LIBXL_DOMAIN_TYPE_HVM : LIBXL_DOMAIN_TYPE_PV;
 }
diff --git a/tools/libs/light/libxl_types.idl b/tools/libs/light/libxl_types.idl
index 3f9fff6..2df7258 100644
--- a/tools/libs/light/libxl_types.idl
+++ b/tools/libs/light/libxl_types.idl
@@ -357,6 +357,7 @@ libxl_dominfo = Struct("dominfo",[
     ("vcpu_max_id", uint32),
     ("vcpu_online", uint32),
     ("cpupool",     uint32),
+    ("gpaddr_bits", uint8),
     ("domain_type", libxl_domain_type),
     ], dir=DIR_OUT)
 
diff --git a/xen/arch/arm/domctl.c b/xen/arch/arm/domctl.c
index b7d27f3..6245af6 100644
--- a/xen/arch/arm/domctl.c
+++ b/xen/arch/arm/domctl.c
@@ -20,6 +20,8 @@ void arch_get_domain_info(const struct domain *d,
 {
     /* All ARM domains use hardware assisted paging. */
     info->flags |= XEN_DOMINF_hap;
+
+    info->gpaddr_bits = p2m_ipa_bits;
 }
 
 static int handle_vuart_init(struct domain *d, 
diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index 26a76d2..7d102e0 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -151,6 +151,7 @@ void arch_get_domain_info(const struct domain *d,
         info->flags |= XEN_DOMINF_hap;
 
     info->arch_config.emulation_flags = d->arch.emulation_flags;
+    info->gpaddr_bits = hap_paddr_bits;
 }
 
 static int do_vmtrace_op(struct domain *d, struct xen_domctl_vmtrace_op *op,
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 4cb3f66..b93f776 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -38,7 +38,7 @@
 #include "hvm/save.h"
 #include "memory.h"
 
-#define XEN_DOMCTL_INTERFACE_VERSION 0x00000014
+#define XEN_DOMCTL_INTERFACE_VERSION 0x00000015
 
 /*
  * NB. xen_domctl.domain is an IN/OUT parameter for this operation.
@@ -150,6 +150,7 @@ struct xen_domctl_getdomaininfo {
     uint32_t ssidref;
     xen_domain_handle_t handle;
     uint32_t cpupool;
+    uint8_t gpaddr_bits; /* Guest physical address space size. */
     struct xen_arch_domainconfig arch_config;
 };
 typedef struct xen_domctl_getdomaininfo xen_domctl_getdomaininfo_t;
