libxl: convert libxl_device_disk_add to an async op

This patch converts libxl_device_disk_add to an ao operation that
waits for device backend to reach state XenbusStateInitWait and then
marks the operation as completed. This is not really useful now, but
will be used by later patches that will launch hotplug scripts after
we reached the desired xenbus state.

As usual, libxl_device_disk_add callers have been modified, and the
internal function libxl__device_disk_add has been used if the call was
inside an already running ao.

Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
[ ijc -- drop hunk modifying libxl_cdrom_insert which is not needed after
         25670:3666e9712eaf "libxl: make libxl_cdrom_insert async" ]
Committed-by: Ian Campbell <ian.campbell@citrix.com>

1 files changed, 53 insertions, 20 deletions

diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index 2c140b0086..8a731ae500 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -713,6 +713,9 @@ static void spawn_stubdom_pvqemu_cb(libxl__egc *egc,
                                 libxl__dm_spawn_state *stubdom_dmss,
                                 int rc);
 
+static void spawn_stub_launch_dm(libxl__egc *egc,
+                                 libxl__ao_devices *aodevs, int ret);
+
 static void spaw_stubdom_pvqemu_destroy_cb(libxl__egc *egc,
                                            libxl__destroy_domid_state *dis,
                                            int rc);
@@ -726,10 +729,9 @@ void libxl__spawn_stub_dm(libxl__egc *egc, libxl__stub_dm_spawn_state *sdss)
 {
     STATE_AO_GC(sdss->dm.spawn.ao);
     libxl_ctx *ctx = libxl__gc_owner(gc);
-    int i, num_console = STUBDOM_SPECIAL_CONSOLES, ret;
-    libxl__device_console *console;
-    libxl_device_vfb vfb;
-    libxl_device_vkb vkb;
+    int ret;
+    libxl_device_vfb *vfb;
+    libxl_device_vkb *vkb;
     char **args;
     struct xs_permissions perm[2];
     xs_transaction_t t;
@@ -784,10 +786,12 @@ void libxl__spawn_stub_dm(libxl__egc *egc, libxl__stub_dm_spawn_state *sdss)
     ret = libxl__domain_build_info_setdefault(gc, &dm_config->b_info);
     if (ret) goto out;
 
-    libxl__vfb_and_vkb_from_hvm_guest_config(gc, guest_config, &vfb, &vkb);
-    dm_config->vfbs = &vfb;
+    GCNEW(vfb);
+    GCNEW(vkb);
+    libxl__vfb_and_vkb_from_hvm_guest_config(gc, guest_config, vfb, vkb);
+    dm_config->vfbs = vfb;
     dm_config->num_vfbs = 1;
-    dm_config->vkbs = &vkb;
+    dm_config->vkbs = vkb;
     dm_config->num_vkbs = 1;
 
     stubdom_state->pv_kernel.path
@@ -845,22 +849,54 @@ retry_transaction:
         if (errno == EAGAIN)
             goto retry_transaction;
 
-    for (i = 0; i < dm_config->num_disks; i++) {
-        ret = libxl_device_disk_add(ctx, dm_domid, &dm_config->disks[i]);
-        if (ret)
-            goto out_free;
-    }
+    sdss->aodevs.size = dm_config->num_disks;
+    sdss->aodevs.callback = spawn_stub_launch_dm;
+    libxl__prepare_ao_devices(ao, &sdss->aodevs);
+    libxl__add_disks(egc, ao, dm_domid, 0, dm_config, &sdss->aodevs);
+
+    free(args);
+    return;
+
+out_free:
+    free(args);
+out:
+    assert(ret);
+    spawn_stubdom_pvqemu_cb(egc, &sdss->pvqemu, ret);
+}
+
+static void spawn_stub_launch_dm(libxl__egc *egc,
+                                 libxl__ao_devices *aodevs, int ret)
+{
+    libxl__stub_dm_spawn_state *sdss = CONTAINER_OF(aodevs, *sdss, aodevs);
+    STATE_AO_GC(sdss->dm.spawn.ao);
+    libxl_ctx *ctx = libxl__gc_owner(gc);
+    int i, num_console = STUBDOM_SPECIAL_CONSOLES;
+    libxl__device_console *console;
+
+    /* convenience aliases */
+    libxl_domain_config *const dm_config = &sdss->dm_config;
+    libxl_domain_config *const guest_config = sdss->dm.guest_config;
+    const int guest_domid = sdss->dm.guest_domid;
+    libxl__domain_build_state *const d_state = sdss->dm.build_state;
+    libxl__domain_build_state *const stubdom_state = &sdss->dm_state;
+    uint32_t dm_domid = sdss->pvqemu.guest_domid;
+
+    if (ret) {
+        LOG(ERROR, "error connecting disk devices");
+        goto out;
+     }
+
     for (i = 0; i < dm_config->num_nics; i++) {
         ret = libxl_device_nic_add(ctx, dm_domid, &dm_config->nics[i]);
         if (ret)
-            goto out_free;
+            goto out;
     }
     ret = libxl_device_vfb_add(ctx, dm_domid, &dm_config->vfbs[0]);
     if (ret)
-        goto out_free;
+        goto out;
     ret = libxl_device_vkb_add(ctx, dm_domid, &dm_config->vkbs[0]);
     if (ret)
-        goto out_free;
+        goto out;
 
     if (guest_config->b_info.u.hvm.serial)
         num_console++;
@@ -868,7 +904,7 @@ retry_transaction:
     console = libxl__calloc(gc, num_console, sizeof(libxl__device_console));
     if (!console) {
         ret = ERROR_NOMEM;
-        goto out_free;
+        goto out;
     }
 
     for (i = 0; i < num_console; i++) {
@@ -904,7 +940,7 @@ retry_transaction:
         ret = libxl__device_console_add(gc, dm_domid, &console[i],
                         i == STUBDOM_CONSOLE_LOGGING ? stubdom_state : NULL);
         if (ret)
-            goto out_free;
+            goto out;
     }
 
     sdss->pvqemu.spawn.ao = ao;
@@ -915,11 +951,8 @@ retry_transaction:
 
     libxl__spawn_local_dm(egc, &sdss->pvqemu);
 
-    free(args);
     return;
 
-out_free:
-    free(args);
 out:
     assert(ret);
     spawn_stubdom_pvqemu_cb(egc, &sdss->pvqemu, ret);