[libvirt] [PATCH v3] Fix up basic migration.

[Chris Lalancette]

Basic live migration was broken by the commit that added
non-shared block support in two ways:

1)  It added a virCheckFlags() to doNativeMigrate().  Besides
the fact that typical usage of virCheckFlags() is in driver
entry points, and doNativeMigrate() is not an entry point,
it was missing important flags like VIR_MIGRATE_LIVE.  Move
the virCheckFlags to the top-level qemuDomainMigratePrepare2
and friends.

2)  It also added a memory leak in qemuMonitorTextMigrate()
by not freeing the memory used by virBufferContentAndReset().
This is fixed by storing the pointer in a temporary variable
and freeing it at the end.

With this patch in place, normal live migration works again.

v3: Instead of the churn for virCheckFlagsUI and UL, instead
always promote flags to an unsigned long and always use %lx
for the fprintf.
v2: Add back flags check, which required adding virCheckFlagsUI
and virCheckFlagsUL

Signed-off-by: Chris Lalancette <clalance at redhat.com>
---
 src/internal.h               |    7 ++++---
 src/qemu/qemu_driver.c       |   30 +++++++++++++++++++++++++++---
 src/qemu/qemu_monitor_text.c |   10 +++++++---
 3 files changed, 38 insertions(+), 9 deletions(-)

diff --git a/src/internal.h b/src/internal.h
index c3c5311..fab3e11 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -212,15 +212,16 @@
  */
 # define virCheckFlags(supported, retval)                               \
     do {                                                                \
-        if ((flags & ~(supported))) {                                   \
+        unsigned long __unsuppflags = flags & ~(supported);             \
+        if (__unsuppflags) {                                            \
             virReportErrorHelper(NULL,                                  \
                                  VIR_FROM_THIS,                         \
                                  VIR_ERR_INVALID_ARG,                   \
                                  __FILE__,                              \
                                  __FUNCTION__,                          \
                                  __LINE__,                              \
-                                 _("%s: unsupported flags (0x%x)"),     \
-                                 __FUNCTION__, flags & ~(supported));   \
+                                 _("%s: unsupported flags (0x%lx)"),    \
+                                 __FUNCTION__, __unsuppflags);          \
             return retval;                                              \
         }                                                               \
     } while (0)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 77e71cc..941b482 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -10175,6 +10175,15 @@ qemudDomainMigratePrepare2 (virConnectPtr dconn,
     int ret = -1;
     int internalret;
 
+    virCheckFlags(VIR_MIGRATE_LIVE |
+                  VIR_MIGRATE_PEER2PEER |
+                  VIR_MIGRATE_TUNNELLED |
+                  VIR_MIGRATE_PERSIST_DEST |
+                  VIR_MIGRATE_UNDEFINE_SOURCE |
+                  VIR_MIGRATE_PAUSED |
+                  VIR_MIGRATE_NON_SHARED_DISK |
+                  VIR_MIGRATE_NON_SHARED_INC, -1);
+
     *uri_out = NULL;
 
     qemuDriverLock(driver);
@@ -10356,9 +10365,6 @@ static int doNativeMigrate(struct qemud_driver *driver,
     qemuDomainObjPrivatePtr priv = vm->privateData;
     unsigned int background_flags = 0;
 
-    virCheckFlags(VIR_MIGRATE_NON_SHARED_DISK | VIR_MIGRATE_NON_SHARED_INC,
-                  -1);
-
     /* Issue the migrate command. */
     if (STRPREFIX(uri, "tcp:") && !STRPREFIX(uri, "tcp://")) {
         /* HACK: source host generates bogus URIs, so fix them up */
@@ -10779,6 +10785,15 @@ qemudDomainMigratePerform (virDomainPtr dom,
     int resume = 0;
     qemuDomainObjPrivatePtr priv;
 
+    virCheckFlags(VIR_MIGRATE_LIVE |
+                  VIR_MIGRATE_PEER2PEER |
+                  VIR_MIGRATE_TUNNELLED |
+                  VIR_MIGRATE_PERSIST_DEST |
+                  VIR_MIGRATE_UNDEFINE_SOURCE |
+                  VIR_MIGRATE_PAUSED |
+                  VIR_MIGRATE_NON_SHARED_DISK |
+                  VIR_MIGRATE_NON_SHARED_INC, -1);
+
     qemuDriverLock(driver);
     vm = virDomainFindByUUID(&driver->domains, dom->uuid);
     if (!vm) {
@@ -10882,6 +10897,15 @@ qemudDomainMigrateFinish2 (virConnectPtr dconn,
     virErrorPtr orig_err;
     int newVM = 1;
 
+    virCheckFlags(VIR_MIGRATE_LIVE |
+                  VIR_MIGRATE_PEER2PEER |
+                  VIR_MIGRATE_TUNNELLED |
+                  VIR_MIGRATE_PERSIST_DEST |
+                  VIR_MIGRATE_UNDEFINE_SOURCE |
+                  VIR_MIGRATE_PAUSED |
+                  VIR_MIGRATE_NON_SHARED_DISK |
+                  VIR_MIGRATE_NON_SHARED_INC, NULL);
+
     /* Migration failed. Save the current error so nothing squashes it */
     orig_err = virSaveLastError();
 
diff --git a/src/qemu/qemu_monitor_text.c b/src/qemu/qemu_monitor_text.c
index 5511550..4b1e2ec 100644
--- a/src/qemu/qemu_monitor_text.c
+++ b/src/qemu/qemu_monitor_text.c
@@ -1144,6 +1144,7 @@ static int qemuMonitorTextMigrate(qemuMonitorPtr mon,
     int ret = -1;
     char *safedest = qemuMonitorEscapeArg(dest);
     virBuffer extra = VIR_BUFFER_INITIALIZER;
+    char *extrastr = NULL;
 
     if (!safedest) {
         virReportOOMError();
@@ -1159,10 +1160,12 @@ static int qemuMonitorTextMigrate(qemuMonitorPtr mon,
     if (virBufferError(&extra)) {
         virBufferFreeAndReset(&extra);
         virReportOOMError();
-        free(safedest);
-        return -1;
+        goto cleanup;
     }
-    if (virAsprintf(&cmd, "migrate %s\"%s\"", virBufferContentAndReset(&extra), safedest) < 0) {
+
+    extrastr = virBufferContentAndReset(&extra);
+    if (virAsprintf(&cmd, "migrate %s\"%s\"", extrastr ? extrastr : "",
+                    safedest) < 0) {
         virReportOOMError();
         goto cleanup;
     }
@@ -1191,6 +1194,7 @@ static int qemuMonitorTextMigrate(qemuMonitorPtr mon,
     ret = 0;
 
 cleanup:
+    VIR_FREE(extrastr);
     VIR_FREE(safedest);
     VIR_FREE(info);
     VIR_FREE(cmd);
-- 
1.6.6.1