[PATCH V3] xl: create VFB for PV guest when VNC is specified

[Wei Liu <wei.liu2@citrix.com>]

This replicates a Xend behavior, when you specify:

  vnc=1
  vnclisten=XXXX
  vncpasswd=XXXX

in a PV guest's config file, it creates a VFB for you.

Fixes bug #25.
http://bugs.xenproject.org/xen/bug/25

Reported-by: Konrad Wilk <konrad.wilk@oracle.com>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>

---
Changes in V3:
* ARRAY_EXTEND macro
* make parse_top_level_vnc_options a function

Changes in V2:
* use macros to reduce code duplication
* vfb=[] take precedence over top level VNC options
---
 tools/libxl/xl_cmdimpl.c |   89 ++++++++++++++++++++++++++++++++++++----------
 1 file changed, 70 insertions(+), 19 deletions(-)

diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index bd26bcc..6a22e17 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -315,6 +315,13 @@ static void *xrealloc(void *ptr, size_t sz) {
     return r;
 }
 
+#define ARRAY_EXTEND(array,count)                                       \
+    do {                                                                \
+        (array) = xrealloc((array),                                     \
+                           sizeof(typeof(*(array))) * ((count) + 1));   \
+        (count) = (count) + 1;                                          \
+    } while (0)
+
 #define LOG(_f, _a...)   dolog(__FILE__, __LINE__, __func__, _f "\n", ##_a)
 
 static void dolog(const char *file, int line, const char *func, char *fmt, ...)
@@ -686,6 +693,22 @@ static int vcpupin_parse(char *cpu, libxl_bitmap *cpumap)
     return rc;
 }
 
+static void parse_top_level_vnc_options(XLU_Config *config,
+                                        libxl_defbool *enable,
+                                        char **listen,
+                                        char **passwd,
+                                        int *display,
+                                        libxl_defbool *unused)
+{
+    long l;
+    xlu_cfg_get_defbool(config, "vnc", enable, 0);
+    xlu_cfg_replace_string (config, "vnclisten", listen, 0);
+    xlu_cfg_replace_string (config, "vncpasswd", passwd, 0);
+    if (!xlu_cfg_get_long (config, "vncdisplay", &l, 0))
+        *display = l;
+    xlu_cfg_get_defbool(config, "vncunused", unused, 0);
+}
+
 static void parse_config_data(const char *config_source,
                               const char *config_data,
                               int config_len,
@@ -1357,11 +1380,12 @@ skip_nic:
         fprintf(stderr, "WARNING: vif2: netchannel2 is deprecated and not supported by xl\n");
     }
 
+    d_config->num_vfbs = 0;
+    d_config->num_vkbs = 0;
+    d_config->vfbs = NULL;
+    d_config->vkbs = NULL;
+
     if (!xlu_cfg_get_list (config, "vfb", &cvfbs, 0, 0)) {
-        d_config->num_vfbs = 0;
-        d_config->num_vkbs = 0;
-        d_config->vfbs = NULL;
-        d_config->vkbs = NULL;
         while ((buf = xlu_cfg_get_listitem (cvfbs, d_config->num_vfbs)) != NULL) {
             libxl_device_vfb *vfb;
             libxl_device_vkb *vkb;
@@ -1369,13 +1393,13 @@ skip_nic:
             char *buf2 = strdup(buf);
             char *p, *p2;
 
-            d_config->vfbs = (libxl_device_vfb *) realloc(d_config->vfbs, sizeof(libxl_device_vfb) * (d_config->num_vfbs + 1));
-            vfb = d_config->vfbs + d_config->num_vfbs;
+            ARRAY_EXTEND(d_config->vfbs, d_config->num_vfbs);
+            vfb = d_config->vfbs + (d_config->num_vfbs - 1);
             libxl_device_vfb_init(vfb);
             vfb->devid = d_config->num_vfbs;
 
-            d_config->vkbs = (libxl_device_vkb *) realloc(d_config->vkbs, sizeof(libxl_device_vkb) * (d_config->num_vkbs + 1));
-            vkb = d_config->vkbs + d_config->num_vkbs;
+            ARRAY_EXTEND(d_config->vkbs, d_config->num_vkbs);
+            vkb = d_config->vkbs + (d_config->num_vkbs - 1);
             libxl_device_vkb_init(vkb);
             vkb->devid = d_config->num_vkbs;
 
@@ -1418,8 +1442,6 @@ skip_nic:
 
 skip_vfb:
             free(buf2);
-            d_config->num_vfbs++;
-            d_config->num_vkbs++;
         }
     }
 
@@ -1608,6 +1630,44 @@ skip_vfb:
 
 #undef parse_extra_args
 
+    /* If we've already got vfb=[] for PV guestthen ignore top level
+     * VNC config. */
+    if (c_info->type == LIBXL_DOMAIN_TYPE_PV && !d_config->num_vfbs) {
+        long vnc_enabled = 0;
+
+        if (!xlu_cfg_get_long (config, "vnc", &l, 0))
+            vnc_enabled = l;
+
+        if (vnc_enabled) {
+            libxl_device_vfb *vfb;
+            libxl_device_vkb *vkb;
+
+            ARRAY_EXTEND(d_config->vfbs, d_config->num_vfbs);
+            vfb = d_config->vfbs + (d_config->num_vfbs - 1);
+            libxl_device_vfb_init(vfb);
+            vfb->devid = d_config->num_vfbs;
+
+            ARRAY_EXTEND(d_config->vkbs, d_config->num_vkbs);
+            vkb = d_config->vkbs + (d_config->num_vkbs - 1);
+            libxl_device_vkb_init(vkb);
+            vkb->devid = d_config->num_vkbs;
+
+            parse_top_level_vnc_options(config,
+                                        &vfb->vnc.enable,
+                                        &vfb->vnc.listen,
+                                        &vfb->vnc.passwd,
+                                        &vfb->vnc.display,
+                                        &vfb->vnc.findunused);
+        }
+    } else {
+        parse_top_level_vnc_options(config,
+                                    &b_info->u.hvm.vnc.enable,
+                                    &b_info->u.hvm.vnc.listen,
+                                    &b_info->u.hvm.vnc.passwd,
+                                    &b_info->u.hvm.vnc.display,
+                                    &b_info->u.hvm.vnc.findunused);
+    }
+
     if (c_info->type == LIBXL_DOMAIN_TYPE_HVM) {
         if (!xlu_cfg_get_string (config, "vga", &buf, 0)) {
             if (!strcmp(buf, "stdvga")) {
@@ -1622,15 +1682,6 @@ skip_vfb:
             b_info->u.hvm.vga.kind = l ? LIBXL_VGA_INTERFACE_TYPE_STD :
                                          LIBXL_VGA_INTERFACE_TYPE_CIRRUS;
 
-        xlu_cfg_get_defbool(config, "vnc", &b_info->u.hvm.vnc.enable, 0);
-        xlu_cfg_replace_string (config, "vnclisten",
-                                &b_info->u.hvm.vnc.listen, 0);
-        xlu_cfg_replace_string (config, "vncpasswd",
-                                &b_info->u.hvm.vnc.passwd, 0);
-        if (!xlu_cfg_get_long (config, "vncdisplay", &l, 0))
-            b_info->u.hvm.vnc.display = l;
-        xlu_cfg_get_defbool(config, "vncunused",
-                            &b_info->u.hvm.vnc.findunused, 0);
         xlu_cfg_replace_string (config, "keymap", &b_info->u.hvm.keymap, 0);
         xlu_cfg_get_defbool(config, "sdl", &b_info->u.hvm.sdl.enable, 0);
         xlu_cfg_get_defbool(config, "opengl", &b_info->u.hvm.sdl.opengl, 0);
-- 
1.7.10.4