We need to be able to restore a domain which we already locked and
started a job for it without undoing these steps. This patch factors
out internals of qemudDomainRestore into separate functions which work
for locked objects.

These changes avoid false-positive syntax-check failure,
and also make the resulting diagnostics more comprehensible.

Run this:
  git grep -l 'VIR_ERROR\s*("'|xargs perl -pi -e \
    's/(VIR_ERROR)\s*\((".*?"),/$1(_($2),/'

Run this:
  git grep -l 'VIR_ERROR0\s*("'|xargs perl -pi -e \
    's/(VIR_ERROR0)\s*\((".*?")\)/$1(_($2))/'

Change VIR_ERROR("%s", "..."
to     VIR_ERROR0("..."

and

Change VIR_ERROR("%s", _("...")
to     VIR_ERROR0(_("...")

Use this command:
  git grep -E -l 'VIR_ERROR\("%s", (_\()?"'|xargs perl -pi -e \
  's/VIR_ERROR\("%s", (_\()?"/VIR_ERROR0($1"/'

The current cleanup: in StartVMDaemon path is a poor duplication.
qemuShutdownVMDaemon can handle teardown for inactive VMs, so let's use it.

v2: Remove old abort: label, only use cleanup:

Clients that require this already seem to do so. Calling this function
with pid < 1 also should not cause problems.

This only exists for a certain cleanup path in StartVMDaemon, but is
unneeded since domain_conf.c handles this for us automatically.

Everything after hostdev setup needs to jump to cleanup on error.

There doesn't seem to be anything specific to tap devices for this
array of file descriptors which need to stay open of the guest to use.
Rename then for others to make use of.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NChris Lalancette <clalance@redhat.com>

* src/qemu/qemu_driver.c (qemudDomainMigrateFinish2): Don't ignore
virDomainSaveStatus failure.
* src/conf/domain_conf.h (virDomainSaveStatus): Use
ATTRIBUTE_RETURN_CHECK, so this doesn't happen again.

Do not require each caller of virStorageFileGetMetadata and
virStorageFileGetMetadataFromFD to first clear the storage of the
"meta" buffer.  Instead, initialize that storage in
virStorageFileGetMetadataFromFD.
* src/util/storage_file.c (virStorageFileGetMetadataFromFD): Clear
"meta" here, not before each of the following callers.
* src/qemu/qemu_driver.c (qemuSetupDiskCgroup): Don't clear "meta" here.
(qemuTeardownDiskCgroup): Likewise.
* src/qemu/qemu_security_dac.c (qemuSecurityDACSetSecurityImageLabel):
Likewise.
* src/security/security_selinux.c (SELinuxSetSecurityImageLabel):
Likewise.
* src/security/virt-aa-helper.c (get_files): Likewise.

* src/qemu/qemu_driver.c (qemuTeardownDiskCgroup): Remove
bogus empty-body while-loop.
(qemuSetupDiskCgroup): Likewise.

Approximately 60 messages were marked.  Since these diagnostics are
intended solely for developers and maintainers, encouraging translation
is deemed to be counterproductive:
http://thread.gmane.org/gmane.comp.emulators.libvirt/25050/focus=25052

Run this command:
  git grep -l VIR_WARN|xargs perl -pi -e \
    's/(VIR_WARN0?)\s*\(_\((".*?")\)/$1($2/'

There were three very similar uses of qemuMonitorAddDrive.
This change makes the three 17-line sequences identical.
* src/qemu/qemu_driver.c (qemudDomainAttachPciDiskDevice): Detect
failure.  Add VIR_WARN and braces.
(qemudDomainAttachSCSIDisk): Add VIR_WARN and braces.
(qemudDomainAttachUsbMassstorageDevice): Likewise.

* src/qemu/qemu_driver.c (qemudDomainRestore): Don't ignore
virDomainSaveStatus failure.

Any method which intends to invoke a monitor command must have
a check for virDomainObjIsActive() before using the monitor to
ensure that priv->mon != NULL.

There is one subtle edge case in this though. If a method invokes
multiple monitor commands, and calls qemuDomainObjExitMonitor()
in between two of these commands then there is no guarentee that
priv->mon != NULL anymore. This is because the QEMU process may
exit or die at any time, and because qemuDomainObjEnterMonitor()
releases the lock on virDomainObj, it is possible for the background
thread to close the monitor handle and thus qemuDomainObjExitMonitor
will release the last reference allowing priv->mon to become NULL.

This affects several methods, most notably migration but also some
hotplug methods. This patch takes a variety of approaches to solve
the problem, depending on the particular usage scenario. Generally
though it suffices to add an extra virDomainObjIsActive() check
if qemuDomainObjExitMonitor() was called during the method.

* src/qemu/qemu_driver.c: Fix multiple potential NULL pointer flaws
  in usage of the monitor

* src/qemu/qemu_driver.c (qemudDomainSetVcpus): Upon look-up failure,
i.e., vm==NULL, goto cleanup, rather than to "endjob", superficially
since the latter would dereference vm, but more fundamentally because
we certainly don't want to call qemuDomainObjEndJob before we've
even attempted qemuDomainObjBeginJob.

A fedora translator filed:

https://bugzilla.redhat.com/show_bug.cgi?id=580816

Pointing out these two error messages as unclear: "write save" sounds
like a typo without context, and lack of a colon made the second message
difficult to parse.

qemuReadLogOutput early VM death detection is racy and won't always work.
Startup then errors when connecting to the VM monitor. This won't report
the emulator cmdline output which is typically the most useful diagnostic.

Check if the VM has died at the very end of the monitor connection step,
and if so, report the cmdline output.

See also: https://bugzilla.redhat.com/show_bug.cgi?id=581381

* src/qemu/qemu_driver.c (qemudDomainStart): After setting vm to NULL,
goto cleanup, rather than dereferencing the NULL pointer.

* src/qemu/qemu_driver.c: Remove debugging fprintf() calls
  accidentally left in code

* src/qemu/qemu_driver.c (qemudDomainSetVcpus): Avoid NULL-deref
upon unknown UUID.  Call qemuDomainObjBeginJob(vm) only after
ensuring that vm != NULL, not before.  This potential NULL-deref
was introduced by commit 2c555d87.

This adds a missing driver lock in the qemu driver to protect
the list of domains.

The code specifies driver->cacheDir as the format string,
but it usually doesn't contain '%s', so the subsequent
argument, "/qemu.mem.XXXXXX", is always ignored.

The patch fixes the misuse.

When QEMU runs with its disk on NFS, and as a non-root user, the
disk is chownd to that non-root user. When migration completes
the last step is shutting down the QEMU on the source host. THis
normally resets user/group/security label. This is bad when the
VM was just migrated because the file is still in use on the dest
host. It is thus neccessary to skip the reset step for any files
found to be on a shared filesystem

* src/libvirt_private.syms: Export virStorageFileIsSharedFS
* src/util/storage_file.c, src/util/storage_file.h: Add a new
  method virStorageFileIsSharedFS() to determine if a file is
  on a shared filesystem (NFS, GFS, OCFS2, etc)
* src/qemu/qemu_driver.c: Tell security driver not to reset
  disk labels on migration completion
* src/qemu/qemu_security_dac.c, src/qemu/qemu_security_stacked.c,
  src/security/security_selinux.c, src/security/security_driver.h,
  src/security/security_apparmor.c: Add ability to skip disk
  restore step for files on shared filesystems.

The cgroups ACL code was only allowing the primary disk image.
It is possible to chain images together, so we need to search
for backing stores and add them to the ACL too. Since the ACL
only handles block devices, we ignore the EINVAL we get from
plain files. In addition it was missing code to teardown the
cgroup when hot-unplugging a disk

* src/qemu/qemu_driver.c: Allow backing stores in cgroup ACLs
  and add missing teardown code in unplug path

QEMU is gaining a new monitor command netdev_add for hotplugging
NICs using the netdev backend code. We already support this on
the command this, though it is disabled. This adds support for
hotplug too, also to remain disabled until 0.13 QEMU is released

* src/qemu/qemu_driver.c: Support netdev hotplug for NICs
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
  src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h: Add
  support for netdev_add and netdev_remove commands

With the introduction of the generic qemu device model, unplugging
SCSI disks works like a charm, so support it in libvirt.

* src/qemu/qemu_driver.c: Add qemudDomainDetachSCSIDiskDevice() to do the
  unplugging, extend qemudDomainDetachDeviceAdd().
Signed-off-by: NWolfgang Mauerer <wolfgang.mauerer@siemens.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

* src/qemu/qemu_driver.c (qemudFindDisk): Mark parameter const.
(qemudShrinkDisks): Mark parameter unsigned.

We can reuse some of the code for other purposes.
Signed-off-by: NWolfgang Mauerer <wolfgang.mauerer@siemens.com>

81 patches to gnulib, picks up several new syntax checks.

* .gnulib: Update to latest.
* .x-sc_prohibit_always_true_header_tests: New file.
* bootstrap.conf (gnulib_modules): Add sched.
* src/util/processinfo.c (includes): <sched.h> is now guaranteed.
* src/network/bridge_driver.c (includes): Drop useless
<strings.h>.
* src/openvz/openvz_conf.c (includes): Likewise.
* src/openvz/openvz_driver.c (includes): Likewise.
* src/phyp/phyp_driver.c (includes): Likewise.
* src/qemu/qemu_driver.c (includes): Likewise.
* src/uml/uml_driver.c (includes): Likewise.

Support for live migration between hosts that do not share storage was
added to qemu-kvm release 0.12.1.
It supports two flags:
-b migration without shared storage with full disk copy
-i migration without shared storage with incremental copy (same base image
shared between source and destination).

I tested the live migration without shared storage (both flags) for native
and p2p with and without tunnelling.  I also verified that the fix doesn't
affect normal migration with shared storage.

WIN32 is always defined when __MINGW32__ is defined, but the
converse is not true.  WIN32 is more generic, if someone were
to ever attempt porting to a microsoft compiler.  This does
not affect Cygwin, which intentionally does not define WIN32.

* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo): Use more
generic flag macro.
* src/storage/storage_backend.c
(virStorageBackendUpdateVolTargetInfoFD)
(virStorageBackendRunProgRegex): Likewise.
* tools/console.h (vshRunConsole): Likewise.

This introduces a new event type

   VIR_DOMAIN_EVENT_ID_IO_ERROR_REASON

This event is the same as the previous VIR_DOMAIN_ID_IO_ERROR
event, but also includes a string describing the cause of
the event.

Thus there is a new callback definition for this event type

typedef void (*virConnectDomainEventIOErrorReasonCallback)(virConnectPtr conn,
                                                           virDomainPtr dom,
                                                           const char *srcPath,
                                                           const char *devAlias,
                                                           int action,
                                                           const char *reason,
                                                           void *opaque);

This is currently wired up to the QEMU block IO error events

* daemon/remote.c: Dispatch IO error events to client
* examples/domain-events/events-c/event-test.c: Watch for
  IO error events
* include/libvirt/libvirt.h.in: Define new IO error event ID
  and callback signature
* src/conf/domain_event.c, src/conf/domain_event.h,
  src/libvirt_private.syms: Extend API to handle IO error events
* src/qemu/qemu_driver.c: Connect to the QEMU monitor event
  for block IO errors and emit a libvirt IO error event
* src/remote/remote_driver.c: Receive and dispatch IO error
  events to application
* src/remote/remote_protocol.x: Wire protocol definition for
  IO error events
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c: Watch for BLOCK_IO_ERROR event
  from QEMU monitor

* src/qemu/qemu_driver.c (qemudDomainSaveFlag): Remove dead store to "rc".

When using -device syntax, the IO event will have a different
prefix, 'drive-' that needs to be skipped over before matching
against the libvirt disk alias

* src/qemu/qemu_driver.c: Skip QEMU_DRIVE_HOST_PREFIX in IO event

* src/qemu/qemu_driver.c: Implementation of virDomainGetBlockInfo
* src/util/storage_file.h: Add DEV_BSIZE
* src/storage/storage_backend.c: Remove DEV_BSIZE