[PATCH v1 06/10] libxl: synchronise configuration when we remove/destroy a device

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

Xenstore is updated first, JSON is updated later, so that we maintain
the same invariant as previous commit: any device which is present in
xenstore has an entry in JSON.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxl/libxl.c          |   25 +++++++++++++++++++------
 tools/libxl/libxl_internal.h |    2 ++
 tools/libxl/libxl_pci.c      |   13 +++++++++++++
 3 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 5f9f94a..58f07d2 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -1822,7 +1822,7 @@ out:
     return;
 }
 
-#define DEFINE_DEVICE_RM_AOCOMPLETE(type)                               \
+#define DEFINE_DEVICE_RM_AOCOMPLETE(type, ptr, cnt, compare)            \
     static void device_##type##_rm_aocomplete(libxl__egc *egc,          \
                                               libxl__ao_device *aodev)  \
     {                                                                   \
@@ -1830,17 +1830,29 @@ out:
         if (aodev->rc) {                                                \
             DEVICE_AO_FAILED_MSG;                                       \
             goto out;                                                   \
+        } else {                                                        \
+            int lock = -1;                                              \
+                                                                        \
+            LOCK_DOMAIN_JSON_CONFIG(gc, aodev->dev->domid,              \
+                                    lock, aodev->rc);                   \
+            if (aodev->rc)                                              \
+                goto out;                                               \
+                                                                        \
+            DEVICE_REMOVE_JSON(type, ptr, cnt, aodev->dev->domid,       \
+                               aodev->pdev, compare, aodev->rc);        \
+                                                                        \
+            UNLOCK_DOMAIN_JSON_CONFIG(gc, aodev->dev->domid, lock);     \
         }                                                               \
                                                                         \
     out:                                                                \
         libxl__ao_complete(egc, ao, aodev->rc);                         \
     }
 
-DEFINE_DEVICE_RM_AOCOMPLETE(vtpm);
-DEFINE_DEVICE_RM_AOCOMPLETE(nic);
-DEFINE_DEVICE_RM_AOCOMPLETE(disk);
-DEFINE_DEVICE_RM_AOCOMPLETE(vfb);
-DEFINE_DEVICE_RM_AOCOMPLETE(vkb);
+DEFINE_DEVICE_RM_AOCOMPLETE(vtpm, vtpms, num_vtpms, COMPARE_DEVID);
+DEFINE_DEVICE_RM_AOCOMPLETE(nic, nics, num_nics, COMPARE_DEVID);
+DEFINE_DEVICE_RM_AOCOMPLETE(disk, disks, num_disks, COMPARE_DISK);
+DEFINE_DEVICE_RM_AOCOMPLETE(vfb, vfbs, num_vfbs, COMPARE_DEVID);
+DEFINE_DEVICE_RM_AOCOMPLETE(vkb, vkbs, num_vkbs, COMPARE_DEVID);
 
 /* common function to get next device id */
 static int libxl__device_nextid(libxl__gc *gc, uint32_t domid, char *device)
@@ -3677,6 +3689,7 @@ out:
                                                                         \
         GCNEW(aodev);                                                   \
         libxl__prepare_ao_device(ao, aodev);                            \
+        aodev->pdev = type;                                             \
         aodev->action = LIBXL__DEVICE_ACTION_REMOVE;                    \
         aodev->dev = device;                                            \
         aodev->callback = device_##type##_rm_aocomplete;                \
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index f27a6e98..b4f518a 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -2131,6 +2131,8 @@ struct libxl__ao_device {
     int num_exec;
     /* for calling hotplug scripts */
     libxl__async_exec_state aes;
+    /* point to libxl_device_TYPE */
+    void *pdev;
 };
 
 /*
diff --git a/tools/libxl/libxl_pci.c b/tools/libxl/libxl_pci.c
index d0d8f90..cab3a1b 100644
--- a/tools/libxl/libxl_pci.c
+++ b/tools/libxl/libxl_pci.c
@@ -1349,6 +1349,19 @@ int libxl_device_pci_remove(libxl_ctx *ctx, uint32_t domid,
 
     rc = libxl__device_pci_remove_common(gc, domid, pcidev, 0);
 
+    if (!rc) {
+        int lock = -1;
+
+        LOCK_DOMAIN_JSON_CONFIG(gc, domid, lock, rc);
+        if (rc)
+            goto out;
+
+        DEVICE_REMOVE_JSON(pci, pcidevs, num_pcidevs, domid,
+                           pcidev, COMPARE_PCI, rc);
+
+        UNLOCK_DOMAIN_JSON_CONFIG(gc, domid, lock);
+    }
+out:
     libxl__ao_complete(egc, ao, rc);
     return AO_INPROGRESS;
 }
-- 
1.7.10.4