Match the fact that we have virAsprintf and virVasprintf.

* src/util/buf.h (virBufferVasprintf): New prototype.
* src/util/buf.c (virBufferAsprintf): Move guts...
(virBufferVasprintf): ...to new function.
* src/libvirt_private.syms (buf.h): Export it.
* bootstrap.conf (gnulib_modules): Add stdarg, for va_copy.

We already have virAsprintf, so picking a similar name helps for
seeing a similar purpose.  Furthermore, the prefix V before printf
generally implies 'va_list', even though this variant was '...', and
the old name got in the way of adding a new va_list version.

global rename performed with:

$ git grep -l virBufferVSprintf \
  | xargs -L1 sed -i 's/virBufferVSprintf/virBufferAsprintf/g'

then revert the changes in ChangeLog-old.

The qemuMigrationToFile method was accidentally annotated for
the 'compressor' parameter to be non-null, instead of the
'path' parameter. Thus GCC with -O2, unhelpfully deleted the
entire 'if (compressor == NULL)' block of code during
optimization. Thus NULL was passed to virCommandNew() with
predictably bad results.

* src/qemu/qemu_migration.h: Fix non-null annotation to be
  against path instead of compressor

* src/qemu/qemu_migration.c, src/qemu/qemu_migration.h: Remove
  qemuCaps parameters & use cached data
* src/qemu/qemu_driver.c: Don't create & pass qemuCaps to
  migration methods

* src/qemu/qemu_hotplug.h, src/qemu/qemu_hotplug.c: Remove
  qemuCaps parameters from all methods
* src/qemu/qemu_driver.c: Don't create & pass qemuCaps to
  hotplug methods

To cope with the QEMU binary being changed while a VM is running,
it is neccessary to persist the original qemu capabilities at the
time the VM is booted.

* src/qemu/qemu_capabilities.c, src/qemu/qemu_capabilities.h: Add
  an enum for a string rep of every capability
* src/qemu/qemu_domain.c, src/qemu/qemu_domain.h: Support for
  storing capabilities in the domain status XML
* src/qemu/qemu_process.c: Populate & free QEMU capabilities at
  domain startup

Detected by clang.  NULL deref added in commit 343a27af (Mar 11),
but leak of voldef present since commit 2cd9b2d8 (Apr 09).

* src/storage/storage_driver.c (storageVolumeCreateXML): Don't
leak voldef or dereference null volobj.

The queried values aren't used yet.

Add missing early exits and convert error logging to proper API level
error reporting.

Centralize cleanup code for the PerfQuerySpec object.

Reported by Eric Blake, detected by clang.

The ++ on preliminaryFileName was a left over from a previous version
of this function that explicitly returned the filename and did a strdup
on preliminaryFileName afterwards.

As the filename isn't returned explicitly anymore remove the preliminary
variable for it and reuse the tmp variable instead.

Reported by Eric Blake, detected by clang.

Clang warned about a dead assignment.  In the process, I noticed
that we are only using the function for a bool value.  I audited
all other callers in qemu_{migration,cgroup,driver,hotplug), and
all were making the call in a bool context.

Also, do bounds checking on the argument.

* src/qemu/qemu_cgroup.c (qemuSetupCgroup): Delete dead
assignment.
(qemuCgroupControllerActive): Change return type to bool.
* src/qemu/qemu_cgroup.h (qemuCgroupControllerActive): Likewise.

Clang complained about this, and it was easy enough to fix.

* src/util/util.c (virFileOpenAs): Drop dead assignment.

Clang noticed a dead assignment, which turned out to be the use
of the wrong variable.  rc starts life as -1, and is only ever
assigned to 0 just before a successful cleanup.

* src/lxc/lxc_driver.c (lxcSetupInterfaces): Don't call
virReportSystemError(-1).

Detected by gcc:

libxl/libxl_driver.c: In function 'libxlDomainDestroy':
libxl/libxl_drier.c:1351:30: error: variable 'priv' set but not used [-Werror=unused-but-set-variable]

* src/libxl/libxl_driver.c (libxlDomainDestroy): Delete unused
variable.

Detected by clang.

* src/qemu/qemu_migration.c (qemuMigrationToFile): Nothing later
uses is_reg.

clang didn't like the last increment to nargs.  But why even
track nargs ourselves, when virCommand does it for us?

* src/storage/storage_backend_iscsi.c
(virStorageBackendISCSIConnection): Switch to virCommand to avoid
a dead-store warning on nargs.

Clang detected a dead store to rc.  It turns out that in fixing this,
I also found a FILE* leak.

This is a subtle change in behavior, although unlikely to hit.  The
pidfile is a kernel file, so we've probably got more serious problems
under foot if we fail to parse one.  However, the previous behavior
was that even if one pid file failed to parse, we tried others,
whereas now we give up on the first failure.  Either way, though,
the function returns -1, so the caller will know that something is
going wrong, and that not all pids were necessarily reaped.  Besides,
there were other instances already in the code where failure in the
inner loop aborted the outer loop.

* src/util/cgroup.c (virCgroupKillInternal): Abort rather than
resuming loop on fscanf failure, and cleanup file on error.

Clang 2.8 wasn't quite able to follow that persistentDef was
assigned earlier if (flags & VIR_DOMAIN_MEM_CONFIG) is true.
Silence this false positive, to make clang analysis easier to use.

* src/qemu/qemu_driver.c (qemudDomainSetMemoryFlags): Add an
annotation to silence clang's claim of a NULL dereference.

Clang detected a null-pointer dereference regression, introduced
in commit 4e8969eb.  Without this patch, a device with
unbind_from_stub set to false would eventually try to call
virFileExists on uncomputed drvdir.

* src/util/pci.c (pciUnbindDeviceFromStub): Ensure drvdir is set
before use.

This code has had problems historically.  As originally
written, in commit 6bcf2501 (Jun 08), it could call unlink
on a random string, nuking an unrelated file.

Then commit 182a80b9 (Sep 09), the code was rewritten to
allocate tmp, with both a use-after-free bug and a chance to
call unlink(NULL).

Commit e206946d (Mar 11) fixed the use-after-free, but not the
NULL dereference.  Thanks to clang for catching this!

* src/qemu/qemu_driver.c (qemudDomainMemoryPeek): Don't call
unlink on NULL.

This reverts commit 0e7f7f85.

From the mailing list:

> So, AFAICT, this patch means we will never reconnect to any LXC
> VMs now.
>
> The correct solution, is to refactor LXC driver startup to work
> the same way as the QEMU driver startup.
>
>   - Load all the live state XML files (to pick up running VMs)
>   - Reconnect to all VMs
>   - Load all the persistent config XML files (to pick up any additional
>     inactive guets)

But that solution is invasive enough to be post-0.9.1.

The patch which moved libpciaccess initialization to one place caused
regression - we were not able to run on system with no PCI bus, like
s390(x).

Otherwise if there are inactive lxc domains, lxcStartup will
try to reconnect to sockets of these domains, which results in
errors in libvirtd log.

This commit fixes
qemu/qemu_driver.c: In function 'qemuDomainModifyDeviceFlags':
qemu/qemu_driver.c:4041:8: warning: 'ret' may be used uninitialized in this
function [-Wuninitialized]
qemu/qemu_driver.c:4013:9: note: 'ret' was declared here

The variable is set to -1 so that the error paths are taken when the code
to set it didn't get a chance to run. Without initializing it, we could
return some an undefined value from this function.

While I was at it, I made a trivial whitespace change in the same function
to improve readability.

Call shutdown functions for all subcomponents in nwfilterDriverShutdown.

Make sure that this shutdown functions can safely be called multiple times
and independent from the actual subcomponents state.

Commit e0d014f2 made binary potentially allocated on the heap.
It was freed in the parent in the error path, but not in the success path
that doesn't goto the cleanup label.

Found by 'make -C tests valgrind'.

Commit 1671d1dc introduced a memory leak in virHashFree, and
wholesale table corruption in virHashRemoveSet (elements not
requested to be freed are lost).

* src/util/hash.c (virHashFree): Free bucket array.
(virHashRemoveSet): Don't lose elements.
* tests/hashtest.c (testHashCheckForEachCount): New method.
(testHashCheckCount): Expose the bug.

Support update of disks by MODIFY_CONFIG

This patch includes changes for qemu's disk to support
virDomainUpdateDeviceFlags() with VIR_DOMAIN_DEVICE_MODIFY_CONFIG.

This patch adds support for CDROM/foppy disk types.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

* src/qemu/qemu_driver.c
(qemuDomainUpdateDeviceConfig): support cdrom/floppy.

V2: Use virAsprintf instead of snprintf/strdup

The xend driver will generate a virDomainNetDef ifname if one is not
specified in xend sexpr, even if domain is inactive.  The result is
network interface XML containing 'vif-1.Y' on dev attribute of target
element, e.g.

  <interface type='bridge'>
    <target dev='vif-1.0'/>
    ...

This patch changes the behavior to only generate the ifname if not
specified in xend sexpr *and* domain is not inactive (id != -1).

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=664059

Reattaching pci device back to host without destroying guest or
detaching device from guest would cause host to crash. This patch adds
a check before doing device reattach. If the device is being assigned
to guest, libvirt refuses to reattach device to host. The patch only
works for Xen, for it just checks xenstore to get pci device
information.
Signed-off-by: NYufang Zhang <yuzhang@redhat.com>

The lone caller to hostsFileWrite (and the callers for at least 3
levels up the return stack) assume that the return value will be < 0
on failure. However, hostsFileWrite returns 0 on success, and a
positive errno on failure. This patch changes hostsFileWrite to return
-errno on failure.

* src/esx/esx_driver.c: Fix spelling of 'relative'.
* src/util/util.c: Likewise.

We support to initialize the hooks at daemon reload if there is no
hooks script is defined, we should also support initialize the hooks
at daemon shutdown if no hooks is defined.

To address bz: https://bugzilla.redhat.com/show_bug.cgi?id=688859

Support changes of disks by MODIFY_CONFIG for qemu.

This patch includes patches for qemu's disk to support
virDomainAt(De)tachDeviceFlags with VIR_DOMAIN_DEVICE_MODIFY_CONFIG.

Other devices can be added incrementally.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

* /src/conf/domain_conf.c
(virDomainDiskIndexByName): returns array index of disk in vmdef.
(virDomainDiskRemoveByName): removes a disk which has the name in vmdef.
* src/qemu/qemu_driver.c
(qemuDomainAttachDeviceConfig): add support for Disks.
(qemuDomainDetachDeviceConfig): add support for Disks.

This patch adds functions for modify domain's persistent definition.
To do error recovery in easy way, we use a copy of vmdef and update it.

The whole sequence will be:

  make a copy of domain definition.

  if (flags & MODIFY_CONFIG)
      update copied domain definition
  if (flags & MODIF_LIVE)
      do hotplug.
  if (no error)
      save copied one to the file and update cached definition.
  else
      discard copied definition.

This patch is mixuture of Eric Blake's work and mine.
From: Eric Blake <eblake@redhat.com>
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

(virDomainObjCopyPersistentDef): make a copy of persistent vm definition
(qemuDomainAttach/Detach/UpdateDeviceConfig) : callbacks. now empty
(qemuDomainModifyDeviceFlags): add support for MODIFY_CONFIG and MODIFY_CURRENT

So far first entries for each hash key are stored directly in the hash
table while other entries mapped to the same key are linked through
pointers. As a result of that, the code is cluttered with special
handling for the first items.

This patch makes all entries (even the first ones) linked through
pointers, which significantly simplifies the code and makes it more
maintainable.

This adds several tests for remaining hash APIs (custom
hasher/comparator functions are not covered yet, though).

All tests pass both before and after the "Simplify hash implementation".

Steps to reproduce this bug:
1. # cat net.xml # 00:03.0 has been used
    <interface type='network'>
      <mac address='52:54:00:04:72:f3'/>
      <source network='default'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>

2. # virsh attach-device vm1 net.xml
   error: Failed to attach device from net.xml
   error: internal error unable to reserve PCI address 0:0:3

3. # virsh attach-device vm1 net.xml
   error: Failed to attach device from net.xml
   error: internal error unable to execute QEMU command 'device_add': Device 'rtl8139' could not be initialized

The reason of this bug is that: we can not reserve PCI address 0:0:3 because it has
been used, but we release PCI address when we reserve it failed.

When buf->error is 1, we do not return buf->content in the function
virBufferContentAndReset(). So we should free buf->content when
vsnprintf() failed.