libxl: expose cpu topology as a single list of cpu->{node,core,socket} maps.

Rather than the previous tripple list which is more complicated to work with
and harder for language bindings.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Committed-by: Ian Jackson <Ian.Jackson@eu.citrix.com>

10 files changed, 128 insertions, 128 deletions

diff --git a/tools/libxl/gentest.py b/tools/libxl/gentest.py
index 06d35369cf..be05bfb49d 100644
--- a/tools/libxl/gentest.py
+++ b/tools/libxl/gentest.py
@@ -195,6 +195,7 @@ static void libxl_string_list_rand_init(libxl_string_list *p)
     *p = l;
 }
 
+#if 0 /* To be remove in a subsequent patch */
 static void libxl_cpuarray_rand_init(libxl_cpuarray *p)
 {
     int i;
@@ -209,6 +210,7 @@ static void libxl_cpuarray_rand_init(libxl_cpuarray *p)
             p->array[i] = r;
     }
 }
+#endif
 """)
     for ty in builtins + types:
         if ty.typename not in handcoded:
diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index a5d87c7cc3..6fcd319b58 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -2755,57 +2755,68 @@ int libxl_get_physinfo(libxl_ctx *ctx, libxl_physinfo *physinfo)
     return 0;
 }
 
-int libxl_get_topologyinfo(libxl_ctx *ctx, libxl_topologyinfo *info)
+libxl_cputopology *libxl_get_cpu_topology(libxl_ctx *ctx, int *nr)
 {
     xc_topologyinfo_t tinfo;
     DECLARE_HYPERCALL_BUFFER(xc_cpu_to_core_t, coremap);
     DECLARE_HYPERCALL_BUFFER(xc_cpu_to_socket_t, socketmap);
     DECLARE_HYPERCALL_BUFFER(xc_cpu_to_node_t, nodemap);
+    libxl_cputopology *ret = NULL;
     int i;
-    int rc = 0;
+    int max_cpus;
 
-    rc += libxl_cpuarray_alloc(ctx, &info->coremap);
-    rc += libxl_cpuarray_alloc(ctx, &info->socketmap);
-    rc += libxl_cpuarray_alloc(ctx, &info->nodemap);
-    if (rc)
-        goto fail;
+    max_cpus = libxl_get_max_cpus(ctx);
+    if (max_cpus == 0)
+    {
+        LIBXL__LOG(ctx, XTL_ERROR, "Unable to determine number of CPUS");
+        return NULL;
+    }
 
-    coremap = xc_hypercall_buffer_alloc(ctx->xch, coremap, sizeof(*coremap) * info->coremap.entries);
-    socketmap = xc_hypercall_buffer_alloc(ctx->xch, socketmap, sizeof(*socketmap) * info->socketmap.entries);
-    nodemap = xc_hypercall_buffer_alloc(ctx->xch, nodemap, sizeof(*nodemap) * info->nodemap.entries);
-    if ((coremap == NULL) || (socketmap == NULL) || (nodemap == NULL))
+    coremap = xc_hypercall_buffer_alloc
+        (ctx->xch, coremap, sizeof(*coremap) * max_cpus);
+    socketmap = xc_hypercall_buffer_alloc
+        (ctx->xch, socketmap, sizeof(*socketmap) * max_cpus);
+    nodemap = xc_hypercall_buffer_alloc
+        (ctx->xch, nodemap, sizeof(*nodemap) * max_cpus);
+    if ((coremap == NULL) || (socketmap == NULL) || (nodemap == NULL)) {
+        LIBXL__LOG_ERRNOVAL(ctx, XTL_ERROR, ENOMEM,
+                            "Unable to allocate hypercall arguments");
         goto fail;
+    }
 
     set_xen_guest_handle(tinfo.cpu_to_core, coremap);
     set_xen_guest_handle(tinfo.cpu_to_socket, socketmap);
     set_xen_guest_handle(tinfo.cpu_to_node, nodemap);
-    tinfo.max_cpu_index = info->coremap.entries - 1;
-    if (xc_topologyinfo(ctx->xch, &tinfo) != 0)
+    tinfo.max_cpu_index = max_cpus - 1;
+    if (xc_topologyinfo(ctx->xch, &tinfo) != 0) {
+        LIBXL__LOG_ERRNO(ctx, XTL_ERROR, "Topology info hypercall failed");
         goto fail;
+    }
 
-    for (i = 0; i <= tinfo.max_cpu_index; i++) {
-        if (i < info->coremap.entries)
-            info->coremap.array[i] = (coremap[i] == INVALID_TOPOLOGY_ID) ?
-                LIBXL_CPUARRAY_INVALID_ENTRY : coremap[i];
-        if (i < info->socketmap.entries)
-            info->socketmap.array[i] = (socketmap[i] == INVALID_TOPOLOGY_ID) ?
-                LIBXL_CPUARRAY_INVALID_ENTRY : socketmap[i];
-        if (i < info->nodemap.entries)
-            info->nodemap.array[i] = (nodemap[i] == INVALID_TOPOLOGY_ID) ?
-                LIBXL_CPUARRAY_INVALID_ENTRY : nodemap[i];
+    ret = malloc(sizeof(libxl_cputopology) * max_cpus);
+    if (ret == NULL) {
+        LIBXL__LOG_ERRNOVAL(ctx, XTL_ERROR, ENOMEM,
+                            "Unable to allocate return value");
+        goto fail;
     }
 
-    xc_hypercall_buffer_free(ctx->xch, coremap);
-    xc_hypercall_buffer_free(ctx->xch, socketmap);
-    xc_hypercall_buffer_free(ctx->xch, nodemap);
-    return 0;
+    for (i = 0; i <= max_cpus; i++) {
+#define V(map, i) (map[i] == INVALID_TOPOLOGY_ID) ? \
+    LIBXL_CPUTOPOLOGY_INVALID_ENTRY : map[i]
+        ret[i].core = V(coremap, i);
+        ret[i].socket = V(socketmap, i);
+        ret[i].node = V(nodemap, i);
+#undef V
+    }
 
 fail:
     xc_hypercall_buffer_free(ctx->xch, coremap);
     xc_hypercall_buffer_free(ctx->xch, socketmap);
     xc_hypercall_buffer_free(ctx->xch, nodemap);
-    libxl_topologyinfo_dispose(info);
-    return ERROR_FAIL;
+
+    if (ret)
+        *nr = max_cpus;
+    return ret;
 }
 
 const libxl_version_info* libxl_get_version_info(libxl_ctx *ctx)
@@ -3604,30 +3615,30 @@ int libxl_cpupool_cpuadd(libxl_ctx *ctx, uint32_t poolid, int cpu)
 int libxl_cpupool_cpuadd_node(libxl_ctx *ctx, uint32_t poolid, int node, int *cpus)
 {
     int rc = 0;
-    int cpu;
+    int cpu, nr;
     libxl_cpumap freemap;
-    libxl_topologyinfo topology;
+    libxl_cputopology *topology;
 
     if (libxl_get_freecpus(ctx, &freemap)) {
         return ERROR_FAIL;
     }
 
-    if (libxl_get_topologyinfo(ctx, &topology)) {
+    topology = libxl_get_cpu_topology(ctx, &nr);
+    if (!topology) {
         rc = ERROR_FAIL;
         goto out;
     }
 
     *cpus = 0;
-    for (cpu = 0; cpu < topology.nodemap.entries; cpu++) {
-        if (libxl_cpumap_test(&freemap, cpu) &&
-            (topology.nodemap.array[cpu] == node) &&
+    for (cpu = 0; cpu < nr; cpu++) {
+        if (libxl_cpumap_test(&freemap, cpu) && (topology[cpu].node == node) &&
             !libxl_cpupool_cpuadd(ctx, poolid, cpu)) {
                 (*cpus)++;
         }
+        libxl_cputopology_dispose(&topology[cpu]);
     }
 
-    libxl_topologyinfo_dispose(&topology);
-
+    free(topology);
 out:
     libxl_cpumap_dispose(&freemap);
     return rc;
@@ -3651,8 +3662,8 @@ int libxl_cpupool_cpuremove_node(libxl_ctx *ctx, uint32_t poolid, int node, int
     int ret = 0;
     int n_pools;
     int p;
-    int cpu;
-    libxl_topologyinfo topology;
+    int cpu, nr_cpus;
+    libxl_cputopology *topology;
     libxl_cpupoolinfo *poolinfo;
 
     poolinfo = libxl_list_cpupool(ctx, &n_pools);
@@ -3660,7 +3671,8 @@ int libxl_cpupool_cpuremove_node(libxl_ctx *ctx, uint32_t poolid, int node, int
         return ERROR_NOMEM;
     }
 
-    if (libxl_get_topologyinfo(ctx, &topology)) {
+    topology = libxl_get_cpu_topology(ctx, &nr_cpus);
+    if (!topology) {
         ret = ERROR_FAIL;
         goto out;
     }
@@ -3668,8 +3680,8 @@ int libxl_cpupool_cpuremove_node(libxl_ctx *ctx, uint32_t poolid, int node, int
     *cpus = 0;
     for (p = 0; p < n_pools; p++) {
         if (poolinfo[p].poolid == poolid) {
-            for (cpu = 0; cpu < topology.nodemap.entries; cpu++) {
-                if ((topology.nodemap.array[cpu] == node) &&
+            for (cpu = 0; cpu < nr_cpus; cpu++) {
+                if ((topology[cpu].node == node) &&
                     libxl_cpumap_test(&poolinfo[p].cpumap, cpu) &&
                     !libxl_cpupool_cpuremove(ctx, poolid, cpu)) {
                         (*cpus)++;
@@ -3678,7 +3690,9 @@ int libxl_cpupool_cpuremove_node(libxl_ctx *ctx, uint32_t poolid, int node, int
         }
     }
 
-    libxl_topologyinfo_dispose(&topology);
+    for (cpu = 0; cpu < nr_cpus; cpu++)
+        libxl_cputopology_dispose(&topology[cpu]);
+    free(topology);
 
 out:
     for (p = 0; p < n_pools; p++) {
diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index ea5997be04..fd1a8048b3 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -576,7 +576,9 @@ int libxl_userdata_retrieve(libxl_ctx *ctx, uint32_t domid,
    */
 
 int libxl_get_physinfo(libxl_ctx *ctx, libxl_physinfo *physinfo);
-int libxl_get_topologyinfo(libxl_ctx *ctx, libxl_topologyinfo *info);
+#define LIBXL_CPUTOPOLOGY_INVALID_ENTRY (~(uint32_t)0)
+libxl_cputopology *libxl_get_cpu_topology(libxl_ctx *ctx, int *nr);
+void libxl_cputopology_list_free(libxl_cputopology *, int nr);
 libxl_vcpuinfo *libxl_list_vcpu(libxl_ctx *ctx, uint32_t domid,
                                        int *nb_vcpu, int *nrcpus);
 int libxl_set_vcpuaffinity(libxl_ctx *ctx, uint32_t domid, uint32_t vcpuid,
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index 617dad6374..0cd6678a0b 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -376,10 +376,10 @@ libxl_physinfo = Struct("physinfo", [
     ("phys_cap", uint32),
     ], dispose_fn=None, dir=DIR_OUT)
 
-libxl_topologyinfo = Struct("topologyinfo", [
-    ("coremap", libxl_cpuarray),   # cpu to core map
-    ("socketmap", libxl_cpuarray), # cpu to socket map
-    ("nodemap", libxl_cpuarray),   # cpu to node map
+libxl_cputopology = Struct("cputopology", [
+    ("core", uint32),
+    ("socket", uint32),
+    ("node", uint32),
     ])
 
 libxl_sched_credit = Struct("sched_credit", [
diff --git a/tools/libxl/libxl_utils.c b/tools/libxl/libxl_utils.c
index dbe8891ee9..c92151abc1 100644
--- a/tools/libxl/libxl_utils.c
+++ b/tools/libxl/libxl_utils.c
@@ -557,6 +557,14 @@ int libxl__enum_from_string(const libxl_enum_string_table *t,
     return ERROR_FAIL;
 }
 
+void libxl_cputopology_list_free(libxl_cputopology *list, int nr)
+{
+    int i;
+    for (i = 0; i < nr; i++)
+        libxl_cputopology_dispose(&list[i]);
+    free(list);
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index faa69f2da1..7ea31635a1 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -3833,10 +3833,11 @@ static void output_physinfo(void)
 
 static void output_topologyinfo(void)
 {
-    libxl_topologyinfo info;
-    int i;
+    libxl_cputopology *info;
+    int i, nr;
 
-    if (libxl_get_topologyinfo(ctx, &info)) {
+    info = libxl_get_cpu_topology(ctx, &nr);
+    if (info == NULL) {
         fprintf(stderr, "libxl_get_topologyinfo failed.\n");
         return;
     }
@@ -3844,15 +3845,15 @@ static void output_topologyinfo(void)
     printf("cpu_topology           :\n");
     printf("cpu:    core    socket     node\n");
 
-    for (i = 0; i < info.coremap.entries; i++) {
-        if (info.coremap.array[i] != LIBXL_CPUARRAY_INVALID_ENTRY)
-            printf("%3d:    %4d     %4d     %4d\n", i, info.coremap.array[i],
-                info.socketmap.array[i], info.nodemap.array[i]);
+    for (i = 0; i < nr; i++) {
+        if (info[i].core != LIBXL_CPUTOPOLOGY_INVALID_ENTRY)
+            printf("%3d:    %4d     %4d     %4d\n", i,
+                   info[i].core, info[i].socket, info[i].node);
     }
 
-    printf("numa_info              : none\n");
+    libxl_cputopology_list_free(info, nr);
 
-    libxl_topologyinfo_dispose(&info);
+    printf("numa_info              : none\n");
 
     return;
 }
@@ -5350,7 +5351,7 @@ int main_cpupoolcreate(int argc, char **argv)
     libxl_cpumap freemap;
     libxl_cpumap cpumap;
     libxl_uuid uuid;
-    libxl_topologyinfo topology;
+    libxl_cputopology *topology;
 
     while (1) {
         opt = getopt_long(argc, argv, "hnf:", long_options, &option_index);
@@ -5459,16 +5460,18 @@ int main_cpupoolcreate(int argc, char **argv)
         return -ERROR_FAIL;
     }
     if (!xlu_cfg_get_list(config, "nodes", &nodes, 0, 0)) {
+        int nr;
         n_cpus = 0;
         n_nodes = 0;
-        if (libxl_get_topologyinfo(ctx, &topology)) {
+        topology = libxl_get_cpu_topology(ctx, &nr);
+        if (topology == NULL) {
             fprintf(stderr, "libxl_get_topologyinfo failed\n");
             return -ERROR_FAIL;
         }
         while ((buf = xlu_cfg_get_listitem(nodes, n_nodes)) != NULL) {
             n = atoi(buf);
-            for (i = 0; i < topology.nodemap.entries; i++) {
-                if ((topology.nodemap.array[i] == n) &&
+            for (i = 0; i < nr; i++) {
+                if ((topology[i].node == n) &&
                     libxl_cpumap_test(&freemap, i)) {
                     libxl_cpumap_set(&cpumap, i);
                     n_cpus++;
@@ -5477,7 +5480,7 @@ int main_cpupoolcreate(int argc, char **argv)
             n_nodes++;
         }
 
-        libxl_topologyinfo_dispose(&topology);
+        libxl_cputopology_list_free(topology, nr);
 
         if (n_cpus == 0) {
             fprintf(stderr, "no free cpu found\n");
@@ -5799,11 +5802,12 @@ int main_cpupoolnumasplit(int argc, char **argv)
     int schedid;
     int n_pools;
     int node;
+    int n_cpus;
     char name[16];
     libxl_uuid uuid;
     libxl_cpumap cpumap;
     libxl_cpupoolinfo *poolinfo;
-    libxl_topologyinfo topology;
+    libxl_cputopology *topology;
     libxl_dominfo info;
 
     if ((opt = def_getopt(argc, argv, "", "cpupool-numa-split", 0)) != -1)
@@ -5825,21 +5829,22 @@ int main_cpupoolnumasplit(int argc, char **argv)
         return -ERROR_FAIL;
     }
 
-    if (libxl_get_topologyinfo(ctx, &topology)) {
+    topology = libxl_get_cpu_topology(ctx, &n_cpus);
+    if (topology == NULL) {
         fprintf(stderr, "libxl_get_topologyinfo failed\n");
         return -ERROR_FAIL;
     }
 
     if (libxl_cpumap_alloc(ctx, &cpumap)) {
         fprintf(stderr, "Failed to allocate cpumap\n");
-        libxl_topologyinfo_dispose(&topology);
+        libxl_cputopology_list_free(topology, n_cpus);
         return -ERROR_FAIL;
     }
 
     /* Reset Pool-0 to 1st node: first add cpus, then remove cpus to avoid
        a cpupool without cpus in between */
 
-    node = topology.nodemap.array[0];
+    node = topology[0].node;
     if (libxl_cpupool_cpuadd_node(ctx, 0, node, &n)) {
         fprintf(stderr, "error on adding cpu to Pool 0\n");
         return -ERROR_FAIL;
@@ -5853,9 +5858,9 @@ int main_cpupoolnumasplit(int argc, char **argv)
     }
 
     n = 0;
-    for (c = 0; c < topology.nodemap.entries; c++) {
-        if (topology.nodemap.array[c] == node) {
-            topology.nodemap.array[c] = LIBXL_CPUARRAY_INVALID_ENTRY;
+    for (c = 0; c < n_cpus; c++) {
+        if (topology[c].node == node) {
+            topology[c].node = LIBXL_CPUTOPOLOGY_INVALID_ENTRY;
             libxl_cpumap_set(&cpumap, n);
             n++;
         }
@@ -5880,12 +5885,12 @@ int main_cpupoolnumasplit(int argc, char **argv)
     }
     memset(cpumap.map, 0, cpumap.size);
 
-    for (c = 0; c < topology.nodemap.entries; c++) {
-        if (topology.nodemap.array[c] == LIBXL_CPUARRAY_INVALID_ENTRY) {
+    for (c = 0; c < n_cpus; c++) {
+        if (topology[c].node == LIBXL_CPUTOPOLOGY_INVALID_ENTRY) {
             continue;
         }
 
-        node = topology.nodemap.array[c];
+        node = topology[c].node;
         ret = -libxl_cpupool_cpuremove_node(ctx, 0, node, &n);
         if (ret) {
             fprintf(stderr, "error on removing cpu from Pool 0\n");
@@ -5907,15 +5912,15 @@ int main_cpupoolnumasplit(int argc, char **argv)
             goto out;
         }
 
-        for (p = c; p < topology.nodemap.entries; p++) {
-            if (topology.nodemap.array[p] == node) {
-                topology.nodemap.array[p] = LIBXL_CPUARRAY_INVALID_ENTRY;
+        for (p = c; p < n_cpus; p++) {
+            if (topology[p].node == node) {
+                topology[p].node = LIBXL_CPUTOPOLOGY_INVALID_ENTRY;
             }
         }
     }
 
 out:
-    libxl_topologyinfo_dispose(&topology);
+    libxl_cputopology_list_free(topology, n_cpus);
     libxl_cpumap_dispose(&cpumap);
 
     return ret;
diff --git a/tools/ocaml/libs/xl/genwrap.py b/tools/ocaml/libs/xl/genwrap.py
index f83581848b..22cca80bcb 100644
--- a/tools/ocaml/libs/xl/genwrap.py
+++ b/tools/ocaml/libs/xl/genwrap.py
@@ -29,6 +29,8 @@ functions = { # ( name , [type1,type2,....] )
     "device_pci":     DEVICE_FUNCTIONS,
     "physinfo":       [ ("get",            ["unit", "t"]),
                       ],
+    "cputopology":    [ ("get",            ["unit", "t array"]),
+                      ],
     "sched_credit":   [ ("domain_get",     ["domid", "t"]),
                         ("domain_set",     ["domid", "t", "unit"]),
                       ],
@@ -266,7 +268,6 @@ if __name__ == '__main__':
         "domain_create_info",
         "domain_build_info",
         "vcpuinfo",
-        "topologyinfo",
         "event",
         ]
 
diff --git a/tools/ocaml/libs/xl/xenlight.ml.in b/tools/ocaml/libs/xl/xenlight.ml.in
index 162b4a96bb..c47623c3fc 100644
--- a/tools/ocaml/libs/xl/xenlight.ml.in
+++ b/tools/ocaml/libs/xl/xenlight.ml.in
@@ -19,17 +19,6 @@ type domid = int
 
 (* @@LIBXL_TYPES@@ *)
 
-module Topologyinfo = struct
-	type t =
-	{
-		core : int;
-		socket : int;
-		node : int;
-	}
-	external get : unit -> t array = "stub_xl_topologyinfo"
-end
-
-
 external send_trigger : domid -> trigger -> int -> unit = "stub_xl_send_trigger"
 external send_sysrq : domid -> char -> unit = "stub_xl_send_sysrq"
 external send_debug_keys : domid -> string -> unit = "stub_xl_send_debug_keys"
diff --git a/tools/ocaml/libs/xl/xenlight.mli.in b/tools/ocaml/libs/xl/xenlight.mli.in
index ea919a7a00..4717bac3f7 100644
--- a/tools/ocaml/libs/xl/xenlight.mli.in
+++ b/tools/ocaml/libs/xl/xenlight.mli.in
@@ -19,16 +19,6 @@ type domid = int
 
 (* @@LIBXL_TYPES@@ *)
 
-module Topologyinfo : sig
-	type t =
-	{
-		core : int;
-		socket : int;
-		node : int;
-	}
-	external get : unit -> t array = "stub_xl_topologyinfo"
-end
-
 external send_trigger : domid -> trigger -> int -> unit = "stub_xl_send_trigger"
 external send_sysrq : domid -> char -> unit = "stub_xl_send_sysrq"
 external send_debug_keys : domid -> string -> unit = "stub_xl_send_debug_keys"
diff --git a/tools/ocaml/libs/xl/xenlight_stubs.c b/tools/ocaml/libs/xl/xenlight_stubs.c
index d3e4751a36..38977b5122 100644
--- a/tools/ocaml/libs/xl/xenlight_stubs.c
+++ b/tools/ocaml/libs/xl/xenlight_stubs.c
@@ -210,28 +210,6 @@ static value Val_hwcap(libxl_hwcap *c_val)
 
 #include "_libxl_types.inc"
 
-static value Val_topologyinfo(libxl_topologyinfo *c_val)
-{
-	CAMLparam0();
-	CAMLlocal3(v, topology, topologyinfo);
-	int i;
-
-	topologyinfo = caml_alloc_tuple(c_val->coremap.entries);
-	for (i = 0; i < c_val->coremap.entries; i++) {
-		v = Val_none;
-		if (c_val->coremap.array[i] != LIBXL_CPUARRAY_INVALID_ENTRY) {
-			topology = caml_alloc_tuple(3);
-			Store_field(topology, 0, Val_int(c_val->coremap.array[i]));
-			Store_field(topology, 1, Val_int(c_val->socketmap.array[i]));
-			Store_field(topology, 2, Val_int(c_val->nodemap.array[i]));
-			v = Val_some(topology);
-		}
-		Store_field(topologyinfo, i, v);
-	}
-
-	CAMLreturn(topologyinfo);
-}
-
 value stub_xl_device_disk_add(value info, value domid)
 {
 	CAMLparam2(info, domid);
@@ -462,22 +440,33 @@ value stub_xl_physinfo_get(value unit)
 	CAMLreturn(physinfo);
 }
 
-value stub_xl_topologyinfo(value unit)
+value stub_xl_cputopology_get(value unit)
 {
 	CAMLparam1(unit);
-	CAMLlocal1(topologyinfo);
-	libxl_topologyinfo c_topologyinfo;
-	int ret;
+	CAMLlocal2(topology, v);
+	libxl_cputopology *c_topology;
+	int i, nr, ret;
 	INIT_STRUCT();
 
 	INIT_CTX();
-	ret = libxl_get_topologyinfo(ctx, &c_topologyinfo);
+
+	c_topology = libxl_get_cpu_topology(ctx, &nr);
 	if (ret != 0)
 		failwith_xl("topologyinfo", &lg);
-	FREE_CTX();
 
-	topologyinfo = Val_topologyinfo(&c_topologyinfo);
-	CAMLreturn(topologyinfo);
+	topology = caml_alloc_tuple(nr);
+	for (i = 0; i < nr; i++) {
+		if (c_topology[i].core != LIBXL_CPUTOPOLOGY_INVALID_ENTRY)
+			v = Val_some(Val_cputopology(&gc, &lg, &c_topology[i]));
+		else
+			v = Val_none;
+		Store_field(topology, i, v);
+	}
+
+	libxl_cputopology_list_free(c_topology, nr);
+
+	FREE_CTX();
+	CAMLreturn(topology);
 }
 
 value stub_xl_sched_credit_domain_get(value domid)