[PATCH v9 2/4] libxl/libxc: Move libxl_get_numainfo()'s hypercall buffer management to libxc

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

xc_numainfo() is not expected to be used on a hot path and therefore
hypercall buffer management can be pushed into libxc. This will simplify
life for callers.

Also update error logging macros.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---
 tools/libxc/include/xenctrl.h     |    4 ++-
 tools/libxc/xc_misc.c             |   30 ++++++++++++++++-----
 tools/libxl/libxl.c               |   51 ++++++++++++------------------------
 tools/python/xen/lowlevel/xc/xc.c |   38 ++++++++++-----------------
 4 files changed, 57 insertions(+), 66 deletions(-)

diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index e4d608d..a404855 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -1240,6 +1240,7 @@ int xc_send_debug_keys(xc_interface *xch, char *keys);
 typedef xen_sysctl_physinfo_t xc_physinfo_t;
 typedef xen_sysctl_cputopo_t xc_cputopo_t;
 typedef xen_sysctl_numainfo_t xc_numainfo_t;
+typedef xen_sysctl_meminfo_t xc_meminfo_t;
 
 typedef uint32_t xc_cpu_to_node_t;
 typedef uint32_t xc_cpu_to_socket_t;
@@ -1251,7 +1252,8 @@ typedef uint32_t xc_node_to_node_dist_t;
 int xc_physinfo(xc_interface *xch, xc_physinfo_t *info);
 int xc_cputopoinfo(xc_interface *xch, unsigned *max_cpus,
                    xc_cputopo_t *cputopo);
-int xc_numainfo(xc_interface *xch, xc_numainfo_t *info);
+int xc_numainfo(xc_interface *xch, unsigned *max_nodes,
+                xc_meminfo_t *meminfo, uint32_t *distance);
 
 int xc_sched_id(xc_interface *xch,
                 int *sched_id);
diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c
index b3bdbef..e1b89eb 100644
--- a/tools/libxc/xc_misc.c
+++ b/tools/libxc/xc_misc.c
@@ -230,22 +230,38 @@ out:
     return ret;
 }
 
-int xc_numainfo(xc_interface *xch,
-                xc_numainfo_t *put_info)
+int xc_numainfo(xc_interface *xch, unsigned *max_nodes,
+                xc_meminfo_t *meminfo, uint32_t *distance)
 {
     int ret;
     DECLARE_SYSCTL;
+    DECLARE_HYPERCALL_BOUNCE(meminfo, *max_nodes * sizeof(*meminfo),
+                             XC_HYPERCALL_BUFFER_BOUNCE_OUT);
+    DECLARE_HYPERCALL_BOUNCE(distance,
+                             *max_nodes * *max_nodes * sizeof(*distance),
+                             XC_HYPERCALL_BUFFER_BOUNCE_OUT);
+
+    if ( (ret = xc_hypercall_bounce_pre(xch, meminfo)) )
+        goto out;
+    if ((ret = xc_hypercall_bounce_pre(xch, distance)) )
+        goto out;
+
+    sysctl.u.numainfo.num_nodes = *max_nodes;
+    set_xen_guest_handle(sysctl.u.numainfo.meminfo, meminfo);
+    set_xen_guest_handle(sysctl.u.numainfo.distance, distance);
 
     sysctl.cmd = XEN_SYSCTL_numainfo;
 
-    memcpy(&sysctl.u.numainfo, put_info, sizeof(*put_info));
+    if ( (ret = do_sysctl(xch, &sysctl)) != 0 )
+        goto out;
 
-    if ((ret = do_sysctl(xch, &sysctl)) != 0)
-        return ret;
+    *max_nodes = sysctl.u.numainfo.num_nodes;
 
-    memcpy(put_info, &sysctl.u.numainfo, sizeof(*put_info));
+out:
+    xc_hypercall_bounce_post(xch, meminfo);
+    xc_hypercall_bounce_post(xch, distance);
 
-    return 0;
+    return ret;
 }
 
 
diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 5f2fcff..5c88a88 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -5142,61 +5142,44 @@ libxl_cputopology *libxl_get_cpu_topology(libxl_ctx *ctx, int *nb_cpu_out)
 libxl_numainfo *libxl_get_numainfo(libxl_ctx *ctx, int *nr)
 {
     GC_INIT(ctx);
-    xc_numainfo_t ninfo;
-    DECLARE_HYPERCALL_BUFFER(xen_sysctl_meminfo_t, meminfo);
-    DECLARE_HYPERCALL_BUFFER(uint32_t, distance);
+    xc_meminfo_t *meminfo;
+    uint32_t *distance;
     libxl_numainfo *ret = NULL;
     int i, j;
+    unsigned num_nodes;
 
-    set_xen_guest_handle(ninfo.meminfo, HYPERCALL_BUFFER_NULL);
-    set_xen_guest_handle(ninfo.distance, HYPERCALL_BUFFER_NULL);
-    if (xc_numainfo(ctx->xch, &ninfo) != 0) {
-        LIBXL__LOG(ctx, XTL_ERROR, "Unable to determine number of NODES");
-        ret = NULL;
+    if (xc_numainfo(ctx->xch, &num_nodes, NULL, NULL)) {
+        LOGE(ERROR, "Unable to determine number of nodes");
         goto out;
     }
 
-    meminfo = xc_hypercall_buffer_alloc(ctx->xch, meminfo,
-                                        sizeof(*meminfo) * ninfo.num_nodes);
-    distance = xc_hypercall_buffer_alloc(ctx->xch, distance,
-                                         sizeof(*distance) *
-                                         ninfo.num_nodes * ninfo.num_nodes);
-    if ((meminfo == NULL) || (distance == NULL)) {
-        LIBXL__LOG_ERRNOVAL(ctx, XTL_ERROR, ENOMEM,
-                            "Unable to allocate hypercall arguments");
-        goto fail;
-    }
+    meminfo = libxl__zalloc(gc, sizeof(*meminfo) * num_nodes);
+    distance = libxl__zalloc(gc, sizeof(*distance) * num_nodes * num_nodes);
 
-    set_xen_guest_handle(ninfo.meminfo, meminfo);
-    set_xen_guest_handle(ninfo.distance, distance);
-    if (xc_numainfo(ctx->xch, &ninfo) != 0) {
-        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "getting numainfo");
-        goto fail;
+    if (xc_numainfo(ctx->xch, &num_nodes, meminfo, distance)) {
+        LOGE(ERROR, "getting numainfo");
+        goto out;
     }
 
-    *nr = ninfo.num_nodes;
+    *nr = num_nodes;
 
-    ret = libxl__zalloc(NOGC, sizeof(libxl_numainfo) * ninfo.num_nodes);
-    for (i = 0; i < ninfo.num_nodes; i++)
-        ret[i].dists = libxl__calloc(NOGC, ninfo.num_nodes, sizeof(*distance));
+    ret = libxl__zalloc(NOGC, sizeof(libxl_numainfo) * num_nodes);
+    for (i = 0; i < num_nodes; i++)
+        ret[i].dists = libxl__calloc(NOGC, num_nodes, sizeof(*distance));
 
-    for (i = 0; i < ninfo.num_nodes; i++) {
+    for (i = 0; i < num_nodes; i++) {
 #define V(val, invalid) (val == invalid) ? \
        LIBXL_NUMAINFO_INVALID_ENTRY : val
         ret[i].size = V(meminfo[i].memsize, XEN_INVALID_MEM_SZ);
         ret[i].free = V(meminfo[i].memfree, XEN_INVALID_MEM_SZ);
-        ret[i].num_dists = ninfo.num_nodes;
+        ret[i].num_dists = num_nodes;
         for (j = 0; j < ret[i].num_dists; j++) {
-            unsigned idx = i * ninfo.num_nodes + j;
+            unsigned idx = i * num_nodes + j;
             ret[i].dists[j] = V(distance[idx], XEN_INVALID_NODE_DIST);
         }
 #undef V
     }
 
- fail:
-    xc_hypercall_buffer_free(ctx->xch, meminfo);
-    xc_hypercall_buffer_free(ctx->xch, distance);
-
  out:
     GC_FREE;
     return ret;
diff --git a/tools/python/xen/lowlevel/xc/xc.c b/tools/python/xen/lowlevel/xc/xc.c
index 21ba57d..fbd93db 100644
--- a/tools/python/xen/lowlevel/xc/xc.c
+++ b/tools/python/xen/lowlevel/xc/xc.c
@@ -1293,33 +1293,23 @@ out:
 
 static PyObject *pyxc_numainfo(XcObject *self)
 {
-    xc_numainfo_t ninfo = { 0 };
-    unsigned i, j;
+    unsigned i, j, num_nodes;
     uint64_t free_heap;
     PyObject *ret_obj = NULL, *node_to_node_dist_list_obj;
     PyObject *node_to_memsize_obj, *node_to_memfree_obj;
     PyObject *node_to_dma32_mem_obj, *node_to_node_dist_obj;
-    DECLARE_HYPERCALL_BUFFER(xen_sysctl_meminfo_t, meminfo);
-    DECLARE_HYPERCALL_BUFFER(uint32_t, distance);
+    xc_meminfo_t *meminfo = NULL;
+    uint32_t *distance = NULL;
 
-    set_xen_guest_handle(ninfo.meminfo, HYPERCALL_BUFFER_NULL);
-    set_xen_guest_handle(ninfo.distance, HYPERCALL_BUFFER_NULL);
-    if ( xc_numainfo(self->xc_handle, &ninfo) != 0 )
+    if ( xc_numainfo(self->xc_handle, &num_nodes, NULL, NULL) != 0 )
         goto out;
 
-    meminfo = xc_hypercall_buffer_alloc(self->xc_handle, meminfo,
-                                        sizeof(*meminfo) * ninfo.num_nodes);
-    if ( meminfo == NULL )
-        goto out;
-    distance = xc_hypercall_buffer_alloc(self->xc_handle, distance,
-                                         sizeof(*distance) *
-                                         ninfo.num_nodes * ninfo.num_nodes);
-    if ( distance == NULL )
+    meminfo = calloc(num_nodes, sizeof(*meminfo));
+    distance = calloc(num_nodes * num_nodes, sizeof(*distance));
+    if ( (meminfo == NULL) || (distance == NULL) )
         goto out;
 
-    set_xen_guest_handle(ninfo.meminfo, meminfo);
-    set_xen_guest_handle(ninfo.distance, distance);
-    if ( xc_numainfo(self->xc_handle, &ninfo) != 0 )
+    if ( xc_numainfo(self->xc_handle, &num_nodes, meminfo, distance) != 0 )
         goto out;
 
     /* Construct node-to-* lists. */
@@ -1327,7 +1317,7 @@ static PyObject *pyxc_numainfo(XcObject *self)
     node_to_memfree_obj = PyList_New(0);
     node_to_dma32_mem_obj = PyList_New(0);
     node_to_node_dist_list_obj = PyList_New(0);
-    for ( i = 0; i < ninfo.num_nodes; i++ )
+    for ( i = 0; i < num_nodes; i++ )
     {
         PyObject *pyint;
         unsigned invalid_node;
@@ -1351,9 +1341,9 @@ static PyObject *pyxc_numainfo(XcObject *self)
         /* Node to Node Distance */
         node_to_node_dist_obj = PyList_New(0);
         invalid_node = (meminfo[i].memsize == XEN_INVALID_MEM_SZ);
-        for ( j = 0; j < ninfo.num_nodes; j++ )
+        for ( j = 0; j < num_nodes; j++ )
         {
-            uint32_t dist = distance[i * ninfo.num_nodes + j];
+            uint32_t dist = distance[i * num_nodes + j];
             if ( invalid_node || (dist == XEN_INVALID_NODE_DIST) )
             {
                 PyList_Append(node_to_node_dist_obj, Py_None);
@@ -1369,7 +1359,7 @@ static PyObject *pyxc_numainfo(XcObject *self)
         Py_DECREF(node_to_node_dist_obj);
     }
 
-    ret_obj = Py_BuildValue("{s:i}", "max_node_index", ninfo.num_nodes + 1);
+    ret_obj = Py_BuildValue("{s:i}", "max_node_index", num_nodes + 1);
 
     PyDict_SetItemString(ret_obj, "node_memsize", node_to_memsize_obj);
     Py_DECREF(node_to_memsize_obj);
@@ -1385,8 +1375,8 @@ static PyObject *pyxc_numainfo(XcObject *self)
     Py_DECREF(node_to_node_dist_list_obj);
 
 out:
-    xc_hypercall_buffer_free(self->xc_handle, meminfo);
-    xc_hypercall_buffer_free(self->xc_handle, distance);
+    free(meminfo);
+    free(distance);
     return ret_obj ? ret_obj : pyxc_error_to_exception(self->xc_handle);
 }
 
-- 
1.7.1