[libvirt] [PATCH] qemu: add two hook script events "prepare" and "release"

[Thibault VINCENT]

>From 827261dbe2ab8f1cfd8c84df14bb42fd04df2307 Mon Sep 17 00:00:00 2001
From: Thibault VINCENT <thibault.vincent at smartjog.com>
Date: Mon, 21 Mar 2011 10:18:06 +0100
Subject: [PATCH] qemu: add two hook script events "prepare" and "release"

 * Fix for bug #618970

 * The "prepare" hook is called very early in the VM statup process
before device labeling, so that it can allocate ressources not
managed by libvirt, such as DRBD, or for instance create missing
bridges and vlan interfaces.

 * To shutdown these devices, the "release" hook is also required at
the very end of the VM destruction.

Signed-off-by: Thibault VINCENT <thibault.vincent at smartjog.com>
---
 src/qemu/qemu_process.c |   26 ++++++++++++++++++++++++++
 src/util/hooks.c        |    4 +++-
 src/util/hooks.h        |    2 ++
 3 files changed, 31 insertions(+), 1 deletions(-)

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 793a43c..7831c3b 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -1927,6 +1927,22 @@ int qemuProcessStart(virConnectPtr conn,

     vm->def->id = driver->nextvmid++;

+    /* Run a early hook to set-up missing devices */
+    if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) {
+        char *xml = virDomainDefFormat(vm->def, 0);
+        int hookret;
+
+        hookret = virHookCall(VIR_HOOK_DRIVER_QEMU, vm->def->name,
+                    VIR_HOOK_QEMU_OP_PREPARE, VIR_HOOK_SUBOP_BEGIN,
NULL, xml);
+        VIR_FREE(xml);
+
+        /*
+         * If the script raised an error abort the launch
+         */
+        if (hookret < 0)
+            goto cleanup;
+    }
+
     /* Must be run before security labelling */
     VIR_DEBUG0("Preparing host devices");
     if (qemuPrepareHostDevices(driver, vm->def) < 0)
@@ -2419,6 +2435,16 @@ retry:
     VIR_FREE(priv->vcpupids);
     priv->nvcpupids = 0;

+    /* The "release" hook cleans up additional ressources */
+    if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) {
+        char *xml = virDomainDefFormat(vm->def, 0);
+
+        /* we can't stop the operation even if the script raised an
error */
+        virHookCall(VIR_HOOK_DRIVER_QEMU, vm->def->name,
+                    VIR_HOOK_QEMU_OP_RELEASE, VIR_HOOK_SUBOP_END, NULL,
xml);
+        VIR_FREE(xml);
+    }
+
     if (vm->newDef) {
         virDomainDefFree(vm->def);
         vm->def = vm->newDef;
diff --git a/src/util/hooks.c b/src/util/hooks.c
index 5ba2036..c258318 100644
--- a/src/util/hooks.c
+++ b/src/util/hooks.c
@@ -70,8 +70,10 @@ VIR_ENUM_IMPL(virHookSubop, VIR_HOOK_SUBOP_LAST,
               "end")

 VIR_ENUM_IMPL(virHookQemuOp, VIR_HOOK_QEMU_OP_LAST,
+              "prepare",
               "start",
-              "stopped")
+              "stopped",
+              "release")

 VIR_ENUM_IMPL(virHookLxcOp, VIR_HOOK_LXC_OP_LAST,
               "start",
diff --git a/src/util/hooks.h b/src/util/hooks.h
index f311ed1..66b378a 100644
--- a/src/util/hooks.h
+++ b/src/util/hooks.h
@@ -52,8 +52,10 @@ enum virHookSubopType {
 };

 enum virHookQemuOpType {
+    VIR_HOOK_QEMU_OP_PREPARE,          /* domain startup initiated */
     VIR_HOOK_QEMU_OP_START,            /* domain is about to start */
     VIR_HOOK_QEMU_OP_STOPPED,          /* domain has stopped */
+    VIR_HOOK_QEMU_OP_RELEASE,          /* domain destruction is over */

     VIR_HOOK_QEMU_OP_LAST,
 };
-- 
1.7.2.3