[PATCH v2 09/15] libxl: convert libxl_device_nic_add to an async operation

[Roger Pau Monne <roger.pau@citrix.com>]

This patch converts libxl_device_nic_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 latter patches that will launch hotplug scripts after
we reached the desired xenbus state.

Calls to libxl_device_nic_add have also been moved to occur after the
device model has been launched, so when hotplug scripts are called
from this functions the interfaces already exists.

As usual, libxl_device_nic_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.

Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
---
 tools/libxl/libxl.c          |   39 ++++++++++++++++++-----
 tools/libxl/libxl.h          |    3 +-
 tools/libxl/libxl_create.c   |   70 +++++++++++++++++++++++++++++++++++++-----
 tools/libxl/libxl_device.c   |   18 +++++++++++
 tools/libxl/libxl_dm.c       |   54 ++++++++++++++++++++++++++++++--
 tools/libxl/libxl_internal.h |   11 ++++++
 tools/libxl/xl_cmdimpl.c     |    2 +-
 7 files changed, 176 insertions(+), 21 deletions(-)

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 46d13a7..1a04f7a 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -2017,12 +2017,27 @@ static int libxl__device_from_nic(libxl__gc *gc, uint32_t domid,
     return 0;
 }
 
-int libxl_device_nic_add(libxl_ctx *ctx, uint32_t domid, libxl_device_nic *nic)
+int libxl_device_nic_add(libxl_ctx *ctx, uint32_t domid, libxl_device_nic *nic,
+                         const libxl_asyncop_how *ao_how)
 {
-    GC_INIT(ctx);
+    AO_CREATE(ctx, domid, ao_how);
+    libxl__ao_device *device;
+
+    GCNEW(device);
+    libxl__init_ao_device(device, ao, NULL);
+    device->callback = libxl__device_cb;
+    libxl__device_nic_add(egc, domid, nic, device);
+
+    return AO_INPROGRESS;
+}
+
+void libxl__device_nic_add(libxl__egc *egc, uint32_t domid,
+                           libxl_device_nic *nic, libxl__ao_device *aoadd)
+{
+    STATE_AO_GC(aoadd->ao);
     flexarray_t *front;
     flexarray_t *back;
-    libxl__device device;
+    libxl__device *device;
     char *dompath, **l;
     unsigned int nb, rc;
 
@@ -2053,7 +2068,8 @@ int libxl_device_nic_add(libxl_ctx *ctx, uint32_t domid, libxl_device_nic *nic)
         }
     }
 
-    rc = libxl__device_from_nic(gc, domid, nic, &device);
+    GCNEW(device);
+    rc = libxl__device_from_nic(gc, domid, nic, device);
     if ( rc != 0 ) goto out_free;
 
     flexarray_append(back, "frontend-id");
@@ -2094,6 +2110,9 @@ int libxl_device_nic_add(libxl_ctx *ctx, uint32_t domid, libxl_device_nic *nic)
     flexarray_append(back, libxl__strdup(gc, nic->bridge));
     flexarray_append(back, "handle");
     flexarray_append(back, libxl__sprintf(gc, "%d", nic->devid));
+    flexarray_append(back, "type");
+    flexarray_append(back, libxl__strdup(gc,
+                                     libxl_nic_type_to_string(nic->nictype)));
 
     flexarray_append(front, "backend-id");
     flexarray_append(front, libxl__sprintf(gc, "%d", nic->backend_domid));
@@ -2104,18 +2123,22 @@ int libxl_device_nic_add(libxl_ctx *ctx, uint32_t domid, libxl_device_nic *nic)
     flexarray_append(front, "mac");
     flexarray_append(front, libxl__sprintf(gc,
                                     LIBXL_MAC_FMT, LIBXL_MAC_BYTES(nic->mac)));
-    libxl__device_generic_add(gc, &device,
+    libxl__device_generic_add(gc, device,
                              libxl__xs_kvs_of_flexarray(gc, back, back->count),
                              libxl__xs_kvs_of_flexarray(gc, front, front->count));
 
-    /* FIXME: wait for plug */
+    aoadd->dev = device;
+    aoadd->action = DEVICE_CONNECT;
+    libxl__initiate_device_add(egc, aoadd);
+
     rc = 0;
 out_free:
     flexarray_free(back);
     flexarray_free(front);
 out:
-    GC_FREE;
-    return rc;
+    aoadd->rc = rc;
+    if (rc) aoadd->callback(egc, aoadd);
+    return;
 }
 
 int libxl_device_nic_remove(libxl_ctx *ctx, uint32_t domid,
diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index c14e832..0b15586 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -691,7 +691,8 @@ char * libxl_device_disk_local_attach(libxl_ctx *ctx, libxl_device_disk *disk);
 int libxl_device_disk_local_detach(libxl_ctx *ctx, libxl_device_disk *disk);
 
 /* Network Interfaces */
-int libxl_device_nic_add(libxl_ctx *ctx, uint32_t domid, libxl_device_nic *nic);
+int libxl_device_nic_add(libxl_ctx *ctx, uint32_t domid, libxl_device_nic *nic,
+                         const libxl_asyncop_how *ao_how);
 int libxl_device_nic_remove(libxl_ctx *ctx, uint32_t domid,
                             libxl_device_nic *nic,
                             const libxl_asyncop_how *ao_how);
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 4378f48..076f755 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -577,6 +577,11 @@ static void domcreate_bootloader_done(libxl__egc *egc,
 
 static void domcreate_disk_connected(libxl__egc *egc, libxl__ao_device *aorm);
 
+static void domcreate_nic_connected(libxl__egc *egc, libxl__ao_device *aorm);
+
+static void domcreate_attach_pci(libxl__egc *egc,
+                                 libxl__domain_create_state *dcs);
+
 static void domcreate_console_available(libxl__egc *egc,
                                         libxl__domain_create_state *dcs);
 
@@ -737,13 +742,11 @@ static void domcreate_disk_connected(libxl__egc *egc, libxl__ao_device *aorm)
     }
 
     for (i = 0; i < d_config->num_vifs; i++) {
-        ret = libxl_device_nic_add(ctx, domid, &d_config->vifs[i]);
-        if (ret) {
-            LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
-                       "cannot add nic %d to domain: %d", i, ret);
-            ret = ERROR_FAIL;
-            goto error_out;
-        }
+        /* We have to init the nic here, because we still haven't
+         * called libxl_device_nic_add at this point, but qemu needs
+         * the nic information to be complete.
+         */
+        libxl__device_nic_setdefault(gc, &d_config->vifs[i]);
     }
     switch (d_config->c_info.type) {
     case LIBXL_DOMAIN_TYPE_HVM:
@@ -816,7 +819,6 @@ static void domcreate_devmodel_started(libxl__egc *egc,
 {
     libxl__domain_create_state *dcs = CONTAINER_OF(dmss, *dcs, dmss.dm);
     STATE_AO_GC(dmss->spawn.ao);
-    int i;
     libxl_ctx *ctx = CTX;
     int domid = dcs->guest_domid;
 
@@ -836,6 +838,58 @@ static void domcreate_devmodel_started(libxl__egc *egc,
         }
     }
 
+    /* Plug nic interfaces */
+    if (!ret && d_config->num_vifs > 0) {
+        /* Attach nics */
+        dcs->num_devices = d_config->num_vifs;
+        libxl__add_nics(egc, ao, domid, d_config, &dcs->devices,
+                        domcreate_nic_connected);
+        return;
+    }
+
+    domcreate_attach_pci(egc, dcs);
+    return;
+
+error_out:
+    assert(ret);
+    domcreate_complete(egc, dcs, ret);
+}
+
+static void domcreate_nic_connected(libxl__egc *egc, libxl__ao_device *aorm)
+{
+    STATE_AO_GC(aorm->ao);
+    libxl__domain_create_state *dcs = CONTAINER_OF(aorm->base, *dcs, devices);
+    int last, ret = 0;
+
+    ret = libxl__ao_device_check_last(gc, aorm, dcs->devices,
+                                      dcs->num_devices, &last);
+
+    if (!last) return;
+    if (ret) {
+        LOGE(ERROR, "error connecting nics devices");
+        goto error_out;
+    }
+
+    domcreate_attach_pci(egc, dcs);
+    return;
+
+error_out:
+    assert(ret);
+    domcreate_complete(egc, dcs, ret);
+}
+
+static void domcreate_attach_pci(libxl__egc *egc,
+                                 libxl__domain_create_state *dcs)
+{
+    STATE_AO_GC(dcs->ao);
+    int i, ret = 0;
+    libxl_ctx *ctx = CTX;
+    int domid = dcs->guest_domid;
+
+    /* convenience aliases */
+    libxl_domain_config *const d_config = dcs->guest_config;
+
+
     for (i = 0; i < d_config->num_pcidevs; i++)
         libxl__device_pci_add(gc, domid, &d_config->pcidevs[i], 1);
 
diff --git a/tools/libxl/libxl_device.c b/tools/libxl/libxl_device.c
index 8058afa..91ec69f 100644
--- a/tools/libxl/libxl_device.c
+++ b/tools/libxl/libxl_device.c
@@ -444,6 +444,24 @@ void libxl__add_disks(libxl__egc *egc, libxl__ao *ao, uint32_t domid,
     }
 }
 
+void libxl__add_nics(libxl__egc *egc, libxl__ao *ao, uint32_t domid,
+                     libxl_domain_config *d_config,
+                     libxl__ao_device **devices,
+                     libxl__device_callback callback)
+{
+    AO_GC;
+    GCNEW_ARRAY(*devices, d_config->num_vifs);
+    libxl__ao_device *aodev = *devices;
+    int i;
+
+    for (i = 0; i < d_config->num_vifs; i++) {
+        libxl__init_ao_device(&aodev[i], ao, devices);
+        aodev[i].callback = callback;
+        libxl__device_nic_add(egc, domid, &d_config->vifs[i],
+                               &aodev[i]);
+    }
+}
+
 int libxl__device_destroy(libxl__gc *gc, libxl__device *dev)
 {
     libxl_ctx *ctx = libxl__gc_owner(gc);
diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index 670d1dd..034ca8e 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -675,6 +675,12 @@ static void spawn_stubdom_pvqemu_cb(libxl__egc *egc,
 
 static void spawn_stub_disk_connected(libxl__egc *egc, libxl__ao_device *aorm);
 
+static void stubdom_nics_connected(libxl__egc *egc, libxl__ao_device *aorm);
+
+static void stubdom_pvqemu_cb(libxl__egc *egc,
+                              libxl__dm_spawn_state *stubdom_dmss,
+                              int rc);
+
 static void spaw_stubdom_pvqemu_destroy_cb(libxl__egc *egc,
                                            libxl__destroy_domid_state *dis,
                                            int rc);
@@ -840,9 +846,11 @@ static void spawn_stub_disk_connected(libxl__egc *egc, libxl__ao_device *aorm)
      }
 
     for (i = 0; i < dm_config->num_vifs; i++) {
-        ret = libxl_device_nic_add(ctx, dm_domid, &dm_config->vifs[i]);
-        if (ret)
-            goto out;
+         /* We have to init the nic here, because we still haven't
+         * called libxl_device_nic_add at this point, but qemu needs
+         * the nic information to be complete.
+         */
+        libxl__device_nic_setdefault(gc, &dm_config->vifs[i]);
     }
     ret = libxl_device_vfb_add(ctx, dm_domid, &dm_config->vfbs[0]);
     if (ret)
@@ -918,9 +926,49 @@ static void spawn_stubdom_pvqemu_cb(libxl__egc *egc,
         CONTAINER_OF(stubdom_dmss, *sdss, pvqemu);
     STATE_AO_GC(sdss->dm.spawn.ao);
     uint32_t dm_domid = sdss->pvqemu.guest_domid;
+    libxl_domain_config *d_config = stubdom_dmss->guest_config;
 
     if (rc) goto out;
 
+    if (!rc && d_config->num_vifs > 0) {
+        sdss->num_devices = d_config->num_vifs;
+        libxl__add_nics(egc, ao, dm_domid, d_config, &sdss->devices,
+                        stubdom_nics_connected);
+        return;
+    }
+
+out:
+    stubdom_pvqemu_cb(egc, stubdom_dmss, rc);
+}
+
+static void stubdom_nics_connected(libxl__egc *egc, libxl__ao_device *aoadd)
+{
+    STATE_AO_GC(aoadd->ao);
+    libxl__stub_dm_spawn_state *sdss =
+        CONTAINER_OF(aoadd->base, *sdss, devices);
+    int last, ret = 0;
+
+    ret = libxl__ao_device_check_last(gc, aoadd, sdss->devices,
+                                      sdss->num_devices, &last);
+
+    if (!last) return;
+    if (ret)
+        LOGE(ERROR, "error connecting nics devices");
+
+    stubdom_pvqemu_cb(egc, &sdss->pvqemu, ret);
+    return;
+}
+
+static void stubdom_pvqemu_cb(libxl__egc *egc,
+                              libxl__dm_spawn_state *stubdom_dmss,
+                              int rc)
+{
+    libxl__stub_dm_spawn_state *sdss =
+        CONTAINER_OF(stubdom_dmss, *sdss, pvqemu);
+    STATE_AO_GC(sdss->dm.spawn.ao);
+    uint32_t dm_domid = sdss->pvqemu.guest_domid;
+
+
     rc = libxl_domain_unpause(CTX, dm_domid);
     if (rc) goto out;
 
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index a5fc092..d303123 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -1796,6 +1796,11 @@ _hidden void libxl__device_disk_add(libxl__egc *egc, uint32_t domid,
                                     libxl_device_disk *disk,
                                     libxl__ao_device *aorm);
 
+/* Internal AO operation to connect a nic device */
+_hidden void libxl__device_nic_add(libxl__egc *egc, uint32_t domid,
+                                   libxl_device_nic *nic,
+                                   libxl__ao_device *aorm);
+
 /* Arranges that dev will be added to the guest, and the
  * hotplug scripts will be executed (if necessary). When
  * this is done (or an error happens), the callback in
@@ -1900,6 +1905,12 @@ void libxl__add_disks(libxl__egc *egc, libxl__ao *ao, uint32_t domid,
                       libxl__ao_device **devices,
                       libxl__device_callback callback);
 
+/* Helper function to add a bunch of disks */
+void libxl__add_nics(libxl__egc *egc, libxl__ao *ao, uint32_t domid,
+                     libxl_domain_config *d_config,
+                     libxl__ao_device **devices,
+                     libxl__device_callback callback);
+
 /*----- device model creation -----*/
 
 /* First layer; wraps libxl__spawn_spawn. */
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index 69ce45a..46af9fb 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -4970,7 +4970,7 @@ int main_networkattach(int argc, char **argv)
         return 0;
     }
 
-    if (libxl_device_nic_add(ctx, domid, &nic)) {
+    if (libxl_device_nic_add(ctx, domid, &nic, 0)) {
         fprintf(stderr, "libxl_device_nic_add failed.\n");
         return 1;
     }
-- 
1.7.7.5 (Apple Git-26)