[Xen-devel] [PATCH v4 8/9] libxl/libxc: Move libxl_get_numainfo()'s hypercall buffer management to libxc

[Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>]

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@xxxxxxxxxx>
---

Changes in v4:
* Update commit message
* Make max_nodes argument in xc_numainfo an unsigned
* Replace error logging macros

 tools/libxc/include/xenctrl.h     |    4 ++-
 tools/libxc/xc_misc.c             |   29 +++++++++++++++++++------
 tools/libxl/libxl.c               |   42 +++++++++++-------------------------
 tools/python/xen/lowlevel/xc/xc.c |   27 ++++++++---------------
 4 files changed, 47 insertions(+), 55 deletions(-)

diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index 5550916..09b0ec2 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -1228,6 +1228,7 @@ 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;
@@ -1239,7 +1240,8 @@ 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, uint8_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 bc6eed2..58d3883 100644
--- a/tools/libxc/xc_misc.c
+++ b/tools/libxc/xc_misc.c
@@ -204,22 +204,37 @@ 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, uint8_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);
 
-    sysctl.cmd = XEN_SYSCTL_numainfo;
+    if ((ret = xc_hypercall_bounce_pre(xch, meminfo)))
+        goto out;
+    if ((ret = xc_hypercall_bounce_pre(xch, distance)))
+        goto out;
 
-    memcpy(&sysctl.u.numainfo, put_info, sizeof(*put_info));
+    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;
     if ((ret = do_sysctl(xch, &sysctl)) != 0)
-        return ret;
+        goto out;
 
-    memcpy(put_info, &sysctl.u.numainfo, sizeof(*put_info));
+    *max_nodes = sysctl.u.numainfo.num_nodes;
 
-    return 0;
+out:
+    xc_hypercall_bounce_post(xch, meminfo);
+    xc_hypercall_bounce_post(xch, distance);
+
+    return ret;
 }
 
 
diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 9d7d9f5..b37b3bd 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -5081,41 +5081,29 @@ 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(uint8_t, distance);
+    xc_meminfo_t *meminfo;
+    uint8_t *distance;
     libxl_numainfo *ret = NULL;
     int i, j, max_nodes;
+    unsigned num_nodes;
 
     max_nodes = libxl_get_max_nodes(ctx);
-    if (max_nodes < 0)
-    {
-        LIBXL__LOG(ctx, XTL_ERROR, "Unable to determine number of NODES");
-        ret = NULL;
+    if (max_nodes < 0) {
+        LOG(ERROR, "Unable to determine number of NODES");
         goto out;
     }
 
-    meminfo = xc_hypercall_buffer_alloc(ctx->xch, meminfo,
-                                        sizeof(*meminfo) * max_nodes);
-    distance = xc_hypercall_buffer_alloc(ctx->xch, distance,
-                                         sizeof(*distance) *
-                                         max_nodes * max_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) * max_nodes);
+    distance = libxl__zalloc(gc, sizeof(*distance) * max_nodes * max_nodes);
 
-    set_xen_guest_handle(ninfo.meminfo, meminfo);
-    set_xen_guest_handle(ninfo.distance, distance);
-    ninfo.num_nodes = max_nodes;
-    if (xc_numainfo(ctx->xch, &ninfo) != 0) {
-        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "getting numainfo");
-        goto fail;
+    num_nodes = max_nodes;
+    if (xc_numainfo(ctx->xch, &num_nodes, meminfo, distance) != 0) {
+        LOGE(ERROR, "getting numainfo");
+        goto out;
     }
 
-    if (ninfo.num_nodes < max_nodes)
-        max_nodes = ninfo.num_nodes;
+    if (num_nodes < max_nodes)
+        max_nodes = num_nodes;
 
     *nr = max_nodes;
 
@@ -5136,10 +5124,6 @@ libxl_numainfo *libxl_get_numainfo(libxl_ctx *ctx, int 
*nr)
 #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 20c4d39..dacf49e 100644
--- a/tools/python/xen/lowlevel/xc/xc.c
+++ b/tools/python/xen/lowlevel/xc/xc.c
@@ -1297,32 +1297,23 @@ out:
 static PyObject *pyxc_numainfo(XcObject *self)
 {
 #define MAX_NODES 32
-    xc_numainfo_t ninfo = { 0 };
     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(uint8_t, distance);
+    xc_meminfo_t *meminfo;
+    uint8_t *distance;
 
-    meminfo = xc_hypercall_buffer_alloc(self->xc_handle, meminfo,
-                                        sizeof(*meminfo) * MAX_NODES);
-    if ( meminfo == NULL )
+    num_nodes = MAX_NODES;
+    meminfo = calloc(num_nodes, sizeof(*meminfo));
+    distance = calloc(num_nodes * num_nodes, sizeof(*distance));
+    if ( meminfo == NULL || distance == NULL)
         goto out;
-    distance = xc_hypercall_buffer_alloc(self->xc_handle, distance,
-                                         sizeof(*distance) * MAX_NODES * 
MAX_NODES);
-    if ( distance == NULL )
-        goto out;
-
-    set_xen_guest_handle(ninfo.meminfo, meminfo);
-    set_xen_guest_handle(ninfo.distance, distance);
-    ninfo.num_nodes = MAX_NODES;
 
-    if ( xc_numainfo(self->xc_handle, &ninfo) != 0 )
+    if ( xc_numainfo(self->xc_handle, &num_nodes, meminfo, distance) != 0 )
         goto out;
 
-    num_nodes = ninfo.num_nodes;
     if ( num_nodes > MAX_NODES )
         num_nodes = MAX_NODES;
 
@@ -1389,8 +1380,8 @@ 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);
 #undef MAX_NODE_INDEX
 }
-- 
1.7.1


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