It turns out that when cgroups are enabled, the use of a block device
for a snapshot target was failing with EPERM due to libvirt failing
to add the block device to the cgroup whitelist.  See also
https://bugzilla.redhat.com/show_bug.cgi?id=810200

* src/qemu/qemu_driver.c
(qemuDomainSnapshotCreateSingleDiskActive)
(qemuDomainSnapshotUndoSingleDiskActive): Account for cgroup.
(qemuDomainSnapshotCreateDiskActive): Update caller.

qemu's behavior in this case is to change the spice server behavior to
require secure connection to any channel not otherwise specified as
being in plaintext mode. libvirt doesn't currently allow requesting this
(via plaintext-channel=<channel name>).

RHBZ: 819499
Signed-off-by: NAlon Levy <alevy@redhat.com>

src/qemu/qemu_hostdev.c:
refactor qemuPrepareHostdevUSBDevices function, make it focus on
adding usb device to activeUsbHostdevs after check. After that,
the usb hotplug function qemuDomainAttachHostDevice also could use
it.
expand qemuPrepareHostUSBDevices to perform the usb search,
rollback on failure.

src/qemu/qemu_hotplug.c:
If there are multiple usb devices available with same vendorID and productID,
but with different value of "bus, device", we give an error to let user
use <address> to specify the desired one.

usbFindDevice():get usb device according to
                idVendor, idProduct, bus, device
                it is the exact match of the four parameters

usbFindDeviceByBus():get usb device according to bus, device
                  it returns only one usb device same as usbFindDevice

usbFindDeviceByVendor():get usb device according to idVendor,idProduct
                     it probably returns multiple usb devices.

usbDeviceSearch(): a helper function to do the actual search

When we added the default USB controller into domain XML, we efficiently
broke migration to older versions of libvirt that didn't support USB
controllers at all (0.9.4 and earlier) even for domains that don't use
anything that the older libvirt can't provide. We still want to present
the default USB controller in any XML seen by a user/app but we can
safely remove it from the domain XML used during migration. If we are
migrating to a new enough libvirt, it will add the controller XML back,
while older libvirt won't be confused with it although it will still
tell qemu to create the controller.

Similar approach can be used in the future whenever we find out we
always enabled some kind of device without properly advertising it in
domain XML.

Always use appropriate qemuDomain{,Def}Format wrapper since it may do
some additional magic based on the flags.

Commit 4c82f09e added a capability check for qemu per-device io
throttling, but only applied it to domain startup.  As mentioned
in the previous commit (98cec052), the user can still get an 'internal
error' message during a hotplug attempt, when the monitor command
doesn't exist.  It is confusing to allow tuning on inactive domains
only to then be rejected when starting the domain.

* src/qemu/qemu_driver.c (qemuDomainSetBlockIoTune): Reject
offline tuning if online can't match it.

If you have a qemu build that lacks the blockio tune monitor command,
then this command:

$ virsh blkdeviotune rhel6u2 hda --total_bytes_sec 1000
error: Unable to change block I/O throttle
error: internal error Unexpected error

fails as expected (well, the error message is lousy), but the next
dumpxml shows that the domain was modified anyway.  Worse, that means
if you save the domain then restore it, the restore will likely fail
due to throttling being unsupported, even though no throttling should
even be active because the monitor command failed in the first place.

* src/qemu/qemu_driver.c (qemuDomainSetBlockIoTune): Check for
error before making modification permanent.

Error: RESOURCE_LEAK:
/libvirt/src/qemu/qemu_driver.c:6968:
alloc_fn: Calling allocation function "calloc".
/libvirt/src/qemu/qemu_driver.c:6968:
var_assign: Assigning: "nodeset" =  storage returned from "calloc(1UL, 1UL)".
/libvirt/src/qemu/qemu_driver.c:6977:
noescape: Variable "nodeset" is not freed or pointed-to in function "virTypedParameterAssign".
/libvirt/src/qemu/qemu_driver.c:6997:
leaked_storage: Variable "nodeset" going out of scope leaks the storage it points to.

On 32-bit platforms, gcc warns that the comparison between a long
and (ULLONG_MAX/1024/1024) is always false; throwing in a type
conversion shuts up the warning.

* src/qemu/qemu_monitor.c (qemuMonitorBlockJob): Shut gcc up.

qemuDomainNetsRestart indents with 3 spaces.

This patch is to correct it.
Signed-off-by: NLi Zhang <zhlcindy@linux.vnet.ibm.com>

Signed-off-by: NJosh Durgin <josh.durgin@dreamhost.com>

This works with newer qemu that doesn't allow escaping spaces.
It's backwards compatible as well.
Signed-off-by: NJosh Durgin <josh.durgin@dreamhost.com>

When libvirtd is started, we create "libvirt/qemu" directories under
hugetlbfs mount point. Only the "qemu" subdirectory is chowned to qemu
user and "libvirt" remains owned by root. If umask was too restrictive
when libvirtd started, qemu user may lose access to "qemu"
subdirectory. Let's explicitly grant search permissions to "libvirt"
directory for all users.

Currently, qemu GA is not providing 'desc' field for errors like
we are used to from qemu monitor. Therefore, we fall back to this
general 'unknown error' string. However, GA is reporting 'class' which
is not perfect, but much more helpful than generic error string.
Thus we should fall back to class firstly and if even no class
is presented, then we can fall back to that generic string.

Before this patch:
virsh # dompmsuspend --target mem f16
error: Domain f16 could not be suspended
error: internal error unable to execute QEMU command
'guest-suspend-ram': unknown QEMU command error

After this patch:
virsh # dompmsuspend --target mem f16
error: Domain f16 could not be suspended
error: internal error unable to execute QEMU command
'guest-suspend-ram': The command has not been found

More bug extermination in the category of:

Error: CHECKED_RETURN:

/libvirt/src/conf/network_conf.c:595:
check_return: Calling function "virAsprintf" without checking return value (as is done elsewhere 515 out of 543 times).

/libvirt/src/qemu/qemu_process.c:2780:
unchecked_value: No check of the return value of "virAsprintf(&msg, "was paused (%s)", virDomainPausedReasonTypeToString(reason))".

/libvirt/tests/commandtest.c:809:
check_return: Calling function "setsid" without checking return value (as is done elsewhere 4 out of 5 times).

/libvirt/tests/commandtest.c:830:
unchecked_value: No check of the return value of "virTestGetDebug()".

/libvirt/tests/commandtest.c:831:
check_return: Calling function "virTestGetVerbose" without checking return value (as is done elsewhere 41 out of 42 times).

/libvirt/tests/commandtest.c:833:
check_return: Calling function "virInitialize" without checking return value (as is done elsewhere 18 out of 21 times).


One note about the error in commandtest line 809: setsid() seems to fail when running the test -- could be removed ?

With RHEL 6.2, virDomainBlockPull(dom, dev, bandwidth, 0) has a race
with non-zero bandwidth: there is a window between the block_stream
and block_job_set_speed monitor commands where an unlimited amount
of data was let through, defeating the point of a throttle.

This race was first identified in commit a9d3495e, and libvirt was
able to reduce the size of the window for that race.  In the meantime,
the qemu developers decided to fix things properly; per this message:
https://lists.gnu.org/archive/html/qemu-devel/2012-04/msg03793.html
the fix will be in qemu 1.1, and changes block-job-set-speed to use
a different parameter name, as well as adding a new optional parameter
to block-stream, which eliminates the race altogether.

Since our documentation already mentioned that we can refuse a non-zero
bandwidth for some hypervisors, I think the best solution is to do
just that for RHEL 6.2 qemu, so that the race is obvious to the user
(anyone using stock RHEL 6.2 binaries won't have this patch, and anyone
building their own libvirt with this patch for RHEL can also rebuild
qemu to get the modern semantics, so it is no real loss in behavior).

Meanwhile the code must be fixed to honor actual qemu 1.1 naming.
Rename the parameter to 'modern', since the naming difference now
covers more than just 'async' block-job-cancel.  And while at it,
fix an unchecked integer overflow.

* src/qemu/qemu_monitor.h (enum BLOCK_JOB_CMD): Drop unused value,
rename enum to match conventions.
* src/qemu/qemu_monitor.c (qemuMonitorBlockJob): Reflect enum rename.
* src/qemu_qemu_monitor_json.h (qemuMonitorJSONBlockJob): Likewise.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONBlockJob): Likewise,
and support difference between RHEL 6.2 and qemu 1.1 block pull.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Reject
bandwidth during pull with too-old qemu.
* src/libvirt.c (virDomainBlockPull, virDomainBlockRebase):
Document this.

QEMU binary is called several times when we probe different kinds of
capabilities the binary supports. This patch introduces new common
helper so that all probes use a consistent way of invoking qemu.

https://bugzilla.redhat.com/show_bug.cgi?id=816662 pointed out
that attempting 'virsh blockpull' on an offline domain gave a
misleading error message about qemu lacking support for the
operation, even when qemu was specifically updated to support it.
The real problem is that we have several capabilities that are
only determined when starting a domain, and therefore are still
clear when first working with an inactive domain (namely, any
capability set by qemuMonitorJSONCheckCommands).

While this patch was able to hoist an existing check in one of the
three culprits, it had to add redundant checks in the other two
places (because you always have to check for an active domain after
obtaining a VM job lock, but the capability bits were being checked
prior to obtaining the job lock).

Someday it would be nice to patch libvirt to cache the set of
capabilities per qemu binary (as determined by inode and timestamp),
rather than re-probing the binary every time a domain is started,
and to teach the cache how to query the monitor during the one
time the probe is made rather than having to wait until a guest
is started; then, a capability probe would succeed even for offline
guests because it just refers to the cache, and the single check for
an active domain after grabbing the job lock would be sufficient.
But since that will involve a lot more coding, I'm happy to go
with this simpler solution for an immediate solution.

* src/qemu/qemu_driver.c (qemuDomainPMSuspendForDuration)
(qemuDomainSnapshotCreateXML, qemuDomainBlockJobImpl): Check for
offline state before checking an online-only cap.

Once qemu monitor reports migration has completed, we just closed our
end of the pipe and let migration tunnel die. This generated bogus error
in case we did so before the thread saw EOF on the pipe and migration
was aborted even though it was in fact successful.

With this patch we first wake up the tunnel thread and once it has read
all data from the pipe and finished the stream we close the
filedescriptor.

A small additional bonus of this patch is that real errors reported
inside qemuMigrationIOFunc are not overwritten by virStreamAbort any
more.

When QEMU reported failed or canceled migration, we correctly detected
it but didn't really consider it as an error condition and migration
protocol just went on. Luckily, some of the subsequent steps eventually
failed end we reported an (unrelated and mostly random) error back to
the caller.

In some cases (spotted with broken connection during tunneled migration)
we were overwriting the original error with worse or even misleading
errors generated when we were cleaning up after failed migration.

This patch modifies the CPU comparrison function to report the
incompatibilities in more detail to ease identification of problems.

* src/cpu/cpu.h:
    cpuGuestData(): Add argument to return detailed error message.
* src/cpu/cpu.c:
    cpuGuestData(): Add passthrough for error argument.
* src/cpu/cpu_x86.c
    x86FeatureNames(): Add function to convert a CPU definition to flag
                       names.
    x86Compute(): - Add error message parameter
                  - Add macro for reporting detailed error messages.
                  - Improve error reporting.
                  - Simplify calculation of forbidden flags.
    x86DataIteratorInit():
    x86cpuidMatchAny(): Remove functions that are no longer needed.
* src/qemu/qemu_command.c:
    qemuBuildCpuArgStr(): - Modify for new function prototype
                          - Add detailed error reports
                          - Change error code on incompatible processors
                            to VIR_ERR_CONFIG_UNSUPPORTED instead of
                            internal error
* tests/cputest.c:
    cpuTestGuestData(): Modify for new function prototype

Most of our errors complaining about an inability to support a
particular action due to qemu limitations used CONFIG_UNSUPPORTED,
but we had a few outliers.  Reported by Jiri Denemark.

* src/qemu/qemu_command.c (qemuBuildDriveDevStr): Prefer
CONFIG_UNSUPPORTED.
* src/qemu/qemu_driver.c (qemuDomainReboot)
(qemuDomainBlockJobImpl): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainAttachPciControllerDevice):
Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorTransaction)
(qemuMonitorBlockJob, qemuMonitorSystemWakeup): Likewise.

A "ide-drive" device can be either a hard disk or a CD-ROM,
if there is ",media=cdrom" specified for the backend, it's
a CD-ROM, otherwise it's a hard disk.

Upstream qemu splitted "ide-drive" into "ide-hd" and "ide-cd"
since commit 1f56e32, and ",media=cdrom" is not required for
ide-cd anymore. "ide-drive" is still supported for backwards
compatibility, but no doubt we should go foward.

A "scsi-disk" device can be either a hard disk or a CD-ROM,
if there is ",media=cdrom" specified for the backend, it's
a CD-ROM, otherwise it's a hard disk.

But upstream qemu splitted "scsi-disk" into "scsi-hd" and
"scsi-cd" since commit b443ae, and ",media=cdrom" is not
required for scsi-cd anymore. "scsi-disk" is still supported
for backwards compatibility, but no doubt we should go
foward.

If console[0] is an alias for serial[0], do not enforce the former to
have a PTY source type. This breaks serial consoles on stdio and makes
no sense.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>

Currently, we have 3 boolean arguments we have to pass
to qemuProcessStart(). As libvirt grows it is harder and harder
to remember them and their position. Therefore we should
switch to flags instead.

Instead of returning a CPUs list, numad returns NUMA node
list instead, this patch is to convert the node list to
cpumap before affinity setting. Otherwise, the domain
processes will be pinned only to CPU[$numa_cell_num],
which will cause significiant performance losses.

Also because numad will balance the affinity dynamically,
reflecting the cpuset from numad back doesn't make much
sense then, and it may just could produce confusion for
the users. Thus the better way is not to reflect it back
to XML. And in this case, it's better to ignore the cpuset
when parsing XML.

The codes to update the cpuset is removed in this patch
incidentally, and there will be a follow up patch to ignore
the manually specified "cpuset" if "placement" is "auto",
and document will be updated too.

If placement mode is AUTO, on some return paths char *cpumap or
char *nodeset are leaked.

This patch adds a netlink callback when migrating a VEPA enabled
virtual machine.  It fixes a Bug where a VM would not request a port
association when it was cleared by lldpad.

This patch requires the latest git version of lldpad to work.
Signed-off-by: ND. Herrendoerfer <d.herrendoerfer@herrendoerfer.name>

If dynamic_ownership is off and we are creating a file on NFS
we force chown. This will fail as chown/chmod are not supported
on NFS. However, with no dynamic_ownership we are not required
to do any chown.

In my testing, I was able to provoke an odd block pull failure:

$ virsh blockpull dom vda --bandwidth 10000
error: Requested operation is not valid: No active operation on device: drive-virtio-disk0

merely by using gdb to artifically wait to do the block job set speed
until after the pull had already finished.  But in reality, that should
be a success, since the pull finished before we had a chance to set
speed.  Furthermore, using a double job lock is not only annoying, but
a bug in itself - if you do parallel virDomainBlockRebase, and hit
the race window just right, the first call grabs the VM job to start
a fast block job, then the second call grabs the VM job to start
a long-running job with unspecified speed, then the first call finally
regrabs the VM job and sets the speed, which ends up running the
second job under the speed from the first call.  By consolidating
things into a single job, we avoid opening that race, as well as reduce
the time between starting the job and changing the speed, for less
likelihood of the speed change happening after block job completion
in the first place.

* src/qemu/qemu_monitor.h (BLOCK_JOB_CMD): Add new mode.
* src/qemu/qemu_driver.c (qemuDomainBlockRebase): Move secondary
job call...
(qemuDomainBlockJobImpl): ...here, for fewer locks.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONBlockJob): Change
return value on new internal mode.

Without the VIR_DOMAIN_BLOCK_JOB_ABORT_ASYNC flag, libvirt will internally
poll using qemu's "query-block-jobs" API and will not return until the
operation has been completed.  API users are advised that this operation
is unbounded and further interaction with the domain during this period
may block.  Future patches may refactor things to allow other queries in
parallel with this polling.  For older qemu, we synthesize the cancellation
event, since qemu won't generate it.

The choice of polling duration copies from the code in qemu_migration.c.
Signed-off-by: NAdam Litke <agl@us.ibm.com>
Cc: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Probably in the noise, but this will let us scale more efficiently
as we learn to recognize even more qemu events.

* src/qemu/qemu_monitor_json.c (eventHandlers): Sort.
(qemuMonitorEventCompare): New helper function.
(qemuMonitorJSONIOProcessEvent): Optimize event lookup.

RHEL 6.2 was released with an early version of block jobs, which only
worked on the qed file format, where the commands were spelled with
underscore (contrary to QMP style), and where 'block_job_cancel' was
synchronous and did not trigger an event.

The upcoming qemu 1.1 release has fixed these short-comings [1][2]:
the commands now work on multiple file types, are spelled with dash,
and 'block-job-cancel' is asynchronous and emits an event upon conclusion.

[1]qemu commit 370521a1d6f5537ea7271c119f3fbb7b0fa57063
[2]https://lists.gnu.org/archive/html/qemu-devel/2012-04/msg01248.html

This patch recognizes the new spellings, and fixes virDomainBlockRebase
to give a graceful error when talking to a too-old qemu on a partial
rebase attempt.  Fixes for the new semantics will come later.  This
patch also removes a bogus ATTRIBUTE_NONNULL mistakenly added in
commit 10ec36e2.

* src/qemu/qemu_capabilities.h (QEMU_CAPS_BLOCKJOB_SYNC)
(QEMU_CAPS_BLOCKJOB_ASYNC): New bits.
* src/qemu/qemu_capabilities.c (qemuCaps): Name them.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONCheckCommands): Set
them.
(qemuMonitorJSONBlockJob): Manage both command names.
(qemuMonitorJSONDiskSnapshot): Minor formatting fix.
* src/qemu/qemu_monitor.h (qemuMonitorBlockJob): Alter signature.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONBlockJob): Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorBlockJob): Pass through
capability bit.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Update callers.

The new safe console handling introduced a possibility to deadlock the
qemu driver when a new console connection forcibly disconnects a
previous console stream that belongs to an already closed connection.

The virStreamFree function calls subsequently a the virReleaseConnect
function that tries to lock the driver while discarding the connection,
but the driver was already locked in qemuDomainOpenConsole.

Backtrace of the deadlocked thread:
0  0x00007f66e5aa7f14 in __lll_lock_wait () from /lib64/libpthread.so.0
1  0x00007f66e5aa3411 in _L_lock_500 () from /lib64/libpthread.so.0
2  0x00007f66e5aa322a in pthread_mutex_lock () from/lib64/libpthread.so.0
3  0x0000000000462bbd in qemudClose ()
4  0x00007f66e6e178eb in virReleaseConnect () from/usr/lib64/libvirt.so.0
5  0x00007f66e6e19c8c in virUnrefStream () from /usr/lib64/libvirt.so.0
6  0x00007f66e6e3d1de in virStreamFree () from /usr/lib64/libvirt.so.0
7  0x00007f66e6e09a5d in virConsoleHashEntryFree () from/usr/lib64/libvirt.so.0
8  0x00007f66e6db7282 in virHashRemoveEntry () from/usr/lib64/libvirt.so.0
9  0x00007f66e6e09c4e in virConsoleOpen () from /usr/lib64/libvirt.so.0
10 0x00000000004526e9 in qemuDomainOpenConsole ()
11 0x00007f66e6e421f1 in virDomainOpenConsole () from/usr/lib64/libvirt.so.0
12 0x00000000004361e4 in remoteDispatchDomainOpenConsoleHelper ()
13 0x00007f66e6e80375 in virNetServerProgramDispatch () from/usr/lib64/libvirt.so.0
14 0x00007f66e6e7ae11 in virNetServerHandleJob () from/usr/lib64/libvirt.so.0
15 0x00007f66e6da897d in virThreadPoolWorker () from/usr/lib64/libvirt.so.0
16 0x00007f66e6da7ff6 in virThreadHelper () from/usr/lib64/libvirt.so.0
17 0x00007f66e5aa0c5c in start_thread () from /lib64/libpthread.so.0
18 0x00007f66e57e7fcd in clone () from /lib64/libc.so.6

* src/qemu/qemu_driver.c: qemuDomainOpenConsole()
        -- unlock the qemu driver right after acquiring the domain
        object

qemuDomainObjEnterMonitor{,WithDriver} should not be called from async
jobs, only EnterMonitorAsync variant is allowed.

In case an API fails with "cannot acquire state change lock", searching
for the API that possibly forgot to end its job is not always easy.
Let's keep track of the job owner and print it out for easier
identification.