https://bugzilla.redhat.com/show_bug.cgi?id=871312

Recent fixes made almost all the right steps to make emulator pinned
to the cpuset of the whole domain in case <emulatorpin> isn't
specified, but qemudDomainGetEmulatorPinInfo still reports all the
CPUs even when cpuset is specified.  This patch fixes that.

There are multiple reasons canonicalize_file_name() used in
absolutePathFromBaseFile helper can fail. This patch enhances error
reporting from that helper.

When there is no 'qemu-kvm' binary and the emulator used for a machine
is, for example, 'qemu-system-x86_64' that, by default, runs without
kvm enabled, libvirt still supplies '-no-kvm' option to this process,
even though it does not recognize such option (making the start of a
domain fail in that case).

This patch fixes building a command-line for QEMU machines without KVM
acceleration and is based on following assumptions:

 - QEMU_CAPS_KVM flag means that QEMU is running KVM accelerated
   machines by default (without explicitly requesting that using a
   command-line option).  It is the closest to the truth according to
   the code with the only exception being the comment next to the
   flag, so it's fixed in this patch as well.

 - QEMU_CAPS_ENABLE_KVM flag means that QEMU is, by default, running
   without KVM acceleration and in case we need KVM acceleration it
   needs to be explicitly instructed to do so.  This is partially
   true for the past (this option essentially means that QEMU
   recognizes the '-enable-kvm' option, even though it's almost the
   same).

Three FORWARD chain rules are added and two INPUT chain rules
are added when a network is started but only the FORWARD chain
rules are removed when the network is destroyed.

I noticed this while answering a list question about Java bindings
of volume creation.  All other functions that take xml logged xmlDesc.

* src/libvirt.c (virStorageVolCreateXML)
(virStorageVolCreateXMLFrom): Use consistent spelling of xmlDesc,
and log the argument.

to avoid ENAMETOOLONG:

https://buildd.debian.org/status/fetch.php?pkg=libvirt&arch=amd64&ver=1.0.0~rc1-1&stamp=1351453521

This patch resolves: https://bugzilla.redhat.com/show_bug.cgi?id=871201

If libvirt is restarted after updating the dnsmasq or radvd packages,
a subsequent "virsh net-destroy" will fail to kill the dnsmasq/radvd
process.

The problem is that when libvirtd restarts, it re-reads the dnsmasq
and radvd pidfiles, then does a sanity check on each pid it finds,
including checking that the symbolic link in /proc/$pid/exe actually
points to the same file as the path used by libvirt to execute the
binary in the first place. If this fails, libvirt assumes that the
process is no longer alive.

But if the original binary has been replaced, the link in /proc is set
to "$binarypath (deleted)" (it literally has the string " (deleted)"
appended to the link text stored in the filesystem), so even if a new
binary exists in the same location, attempts to resolve the link will
fail.

In the end, not only is the old dnsmasq/radvd not terminated when the
network is stopped, but a new dnsmasq can't be started when the
network is later restarted (because the original process is still
listening on the ports that the new process wants).

The solution is, when the initial "use stat to check for identical
inodes" check for identity between /proc/$pid/exe and $binpath fails,
to check /proc/$pid/exe for a link ending with " (deleted)" and if so,
truncate that part of the link and compare what's left with the
original binarypath.

A twist to this problem is that on systems with "merged" /sbin and
/usr/sbin (i.e. /sbin is really just a symlink to /usr/sbin; Fedora
17+ is an example of this), libvirt may have started the process using
one path, but /proc/$pid/exe lists a different path (indeed, on F17
this is the case - libvirtd uses /sbin/dnsmasq, but /proc/$pid/exe
shows "/usr/sbin/dnsmasq"). The further bit of code to resolve this is
to call virFileResolveAllLinks() on both the original binarypath and
on the truncated link we read from /proc/$pid/exe, and compare the
results.

The resulting code still succeeds in all the same cases it did before,
but also succeeds if the binary was deleted or replaced after it was
started.

A mild case of dyslexia caused that commit
012f9b19 specifies wrong mask for the
smap cpu feature flag. This patch fixes that mistake.

The test data contained extra \0 bytes after newlines probably due to a
kernel off-by-one bug.

through which user set under what permissions does sanlock
daemon run so libvirt will set the same permissions for
files exposed to it.

After separating 5.x and 5.1 versions of ESX, we forgot to add 5.1
into the list of allowed connections, so connections to 5.1 fail since
v1.0.0-rc1-5-g1e7cd395

Ever since commit eefb881d, ATTRIBUTE_NONNULL has normally been a
no-op under gcc (since it tends to cause more bugs than it cures
given gcc's current lame implementation of the attribute).  However,
the macro is still useful to Coverity and other static-analysis
tools, but only if we use it correctly.  Coverity follows gcc's lead
in accepting function declarations with attributes at the end, but
function bodies must attach attributes to the return type.  That is,
these are valid:

void foo(void *arg) ATTRIBUTE_NONNULL(1);
void ATTRIBUTE_NONNULL(1) foo(void *arg);
void ATTRIBUTE_NONNULL(1) foo(void *arg) {}

but this is not:

void foo(void *arg) ATTRIBUTE_NONNULL(1) {}

even though you don't get a compile failure until you do static
analysis.  Bug introduced in commit 80533ca2, with these symptoms:

nodeinfo.c:206: error: expected ',' or ';' before '{' token
cc1: warning: unrecognized command line option "-Wno-suggest-attribute=const"
cc1: warning: unrecognized command line option "-Wno-suggest-attribute=pure"
make[3]: *** [libvirt_driver_la-nodeinfo.lo] Error 1

* src/nodeinfo.c (virNodeParseNode): Fix syntax error when
non-null attribute is in use.

Commit 34e8f63a altered virfile.o to drag in additional symbols,
which in turn led to pulling in other .o files and eventually causing
a link failure when systemtap probes are enabled, such as:

./.libs/libvirt_util.a(libvirt_util_la-event_poll.o): In function `virEventPollRunOnce':
/home/dummy/libvirt/src/util/event_poll.c:614: undefined reference to `libvirt_event_poll_run_semaphore'
./.libs/libvirt_util.a(libvirt_util_la-event_poll.o):(.note.stapsdt+0x24): undefined reference to `libvirt_event_poll_add_handle_semaphore'

Even though libvirt_iohelper and libvirt_parthelper don't directly
use the portion of virfile.o that drags in probing, it was easier
to satisfy the linker and get the build back up, than to figure out
whether it is even possible or worth trying to disentangle the mess.

* src/Makefile.am (libvirt_iohelper_LDADD)
(libvirt_parthelper_LDADD): Use libvirt_probes.lo when needed.

Currently, we use iohelper when saving/restoring a domain.
However, if there's some kind of error (like I/O) it is not
propagated to libvirt. Since it is not qemu who is doing
the actual write() it will not get error. The iohelper does.
Therefore we should check for iohelper errors as it makes
libvirt more user friendly.

And drop a stray space at the end of the first line of the warning.

In the XML warning, we print a virsh command line that can be used to
edit that XML. This patch prints UUIDs if the entity name contains
special characters (like shell metacharacters, or "--" that would break
parsing of the XML comment). If the entity doesn't have a UUID, just
print the virsh command that can be used to edit it.

This reverts commit 8d75e47e.

Libvirt was never released with support for migration cookies without
hostuuid.

https://bugzilla.redhat.com/show_bug.cgi?id=636832

Introduced in commit 0039a32f.

* src/qemu/qemu_process.c (qemuPrepareCpumap): s/covert/convert/

When using block copy to pivot over to a new chain, the backing files
for the new chain might still need labeling (particularly if the user
passes --reuse-ext with a relative backing file name).  Relabeling a
file that is already labeled won't hurt, so this just labels the entire
chain at the point of the pivot.  Doing the relabel of the chain uses
the fact that we already safely probed the file type of an external
file at the start of the block copy.

* src/qemu/qemu_driver.c (qemuDomainBlockPivot): Relabel chain before
asking qemu to pivot.

Use the recent addition of qemuDomainPrepareDiskChainElement to
obtain locking manager lease, permit a block device through cgroups,
and set the SELinux label; then audit the fact that we hand a new
file over to qemu.  Alas, releasing the lease and label at the end
of the mirroring is a trickier prospect (we would have to trace the
backing chain of both source and destination, and be sure not to
revoke rights to any part of the chain that is shared), so for now,
virDomainBlockJobAbort still leaves things with additional access
granted (as block-pull and block-commit have the same problem of
not clamping access after completion, a future cleanup would cover
all three commands).

* src/qemu/qemu_driver.c (qemuDomainBlockCopy): Set up labeling.

Support the REUSE_EXT flag, in part by copying sanity checks from
snapshot code.  This code introduces a case of probing an external
file for its type; such an action would be a security risk if the
existing file is supposed to be raw but the contents resemble some
other format; however, since the virDomainBlockRebase API has a
flag to force treating the file as raw rather than probe, we can
assume that probing is safe in all other instances.  Besides, if
we don't probe or force raw, then qemu will.

* src/qemu/qemu_driver.c (qemuDomainBlockRebase): Allow REUSE_EXT
flag.
(qemuDomainBlockCopy): Wire up flag, and add some sanity checks.

Minimal patch to wire up all the pieces in the previous patches
to actually enable a block copy job.  By minimal, I mean that
qemu creates the file (that is, no REUSE_EXT flag support yet),
SELinux must be disabled, a lock manager is not informed, and the
audit logs aren't updated.  But those will be added as
improvements in future patches.

This patch is designed so that if we ever add a future API
virDomainBlockCopy with more bells and whistles (such as letting
the user specify a destination image format different than the
source), where virDomainBlockRebase is a wrapper around the
simpler portions of the new functionality, then the new API can
just reuse the new qemuDomainBlockCopy function and already
support _SHALLOW and _REUSE_EXT flags.  Also note that libvirt.c
already filtered the new flags if _COPY is not present, so that
we are not impacting the case of BlockRebase being a wrapper
around BlockPull.

* src/qemu/qemu_driver.c (qemuDomainBlockCopy): New function.
(qemuDomainBlockRebase): Call it when appropriate.

Since libvirt drops locks between issuing a monitor command and
getting a response, it is possible for libvirtd to be restarted
before getting a response on a block-job-complete command; worse, it
is also possible for the guest to shut itself down during the window
while libvirtd is down, ending the qemu process.  A management app
needs to know if the pivot happened (and the destination file
contains guest contents not in the source) or failed (and the source
file contains guest contents not in the destination), but since
the job is finished, 'query-block-jobs' no longer tracks the
status of the job, and if the qemu process itself has disappeared,
even 'query-block' cannot be checked to ask qemu its current state.

At the time of this patch, the design for persistent bitmap has not
been clarified, so a followup patch will be needed once qemu
actually figures out how to expose it, and we figure out how to use
it.  In the meantime, we have a solution that avoids the worst of
the problem.  [This problem was first analyzed with the RHEL 6.3
__com.redhat_drive-reopen command; which partly explains why
upstream qemu 1.3 ditched the drive-reopen idea and went with
block-job-complete plus persistent bitmap instead.]

If we surround 'drive-reopen' with a pause/resume pair, then we can
guarantee that the guest cannot modify either source or destination
files in the window of libvirtd uncertainty, and the management app
is guaranteed that either libvirt knows the outcome and reported it
correctly; or that on libvirtd restart, the guest will still be
paused and that the qemu process cannot have disappeared due to
guest shutdown; and use that as a clue that the management app must
implement recovery protocol, with both source and destination files
still being in sync and with 'query-block' still being an option as
part of that recovery.  My testing shows that the pause window will
typically be only a fraction of a second.

* src/qemu/qemu_driver.c (qemuDomainBlockPivot): Pause around
drive-reopen.
(qemuDomainBlockJobImpl): Update caller.

This is the bare minimum to end a copy job (of course, until a
later patch adds the ability to start a copy job, this patch
doesn't do much in isolation; I've just split the patches to
ease the review).

This patch intentionally avoids SELinux, lock manager, and audit
actions.  Also, if libvirtd restarts at the exact moment that a
'block-job-complete' is in flight, the proposed proper way to
detect the outcome of that would be with a persistent bitmap and
some additional query commands when libvirtd restarts.  This
patch is enough to test the common case of success when used
correctly, while saving the subtleties of proper cleanup for
worst-case errors for later.

When a mirror job is started, cancelling the job safely reverts back
to the source disk, regardless of whether the destination is in
phase 1 (streaming, in which case the destination is worthless) or
phase 2 (mirroring, in which case the destination is synced up to
the source at the time of the cancel).  Our existing code does just
fine in either phase, other than some bookkeeping cleanup; this
implements live block copy.

Ideas for future enhancements via new flags:

Depending on when persistent bitmap support is added, it may be
worth adding a VIR_DOMAIN_REBASE_COPY_ATOMIC flag that fails up
front if we detect an older qemu with risky pivot operation.

Interesting side note: while snapshot-create --disk-only creates a
copy of the disk at a point in time by moving the domain on to a
new file (the copy is the file now in the just-extended backing
chain), blockjob --abort of a copy job creates a copy of the disk
while keeping the domain on the original file.  There may be
potential improvements to the snapshot code to exploit block copy
over multiple disks all at one point in time.  And, if
'block-job-cancel' were made part of 'transaction', you could
copy multiple disks at the same point in time without pausing
the domain.  This also implies we may want to add a --quiesce flag
to virDomainBlockJobAbort, so that when breaking a mirror (whether
by cancel or pivot), the side of the mirror that we are abandoning
is at least in a stable state with regards to guest I/O.

* src/qemu/qemu_driver.c (qemuDomainBlockJobAbort): Accept new flag.
(qemuDomainBlockPivot): New helper function.
(qemuDomainBlockJobImpl): Implement it.

Handle the new type of block copy event and info.  Of course,
this patch does nothing until a later patch actually allows the
creation/abort of a block copy job.

* include/libvirt/libvirt.h.in (VIR_DOMAIN_BLOCK_JOB_READY): New
block job status.
* src/libvirt.c (virDomainBlockRebase): Document the event.
* src/qemu/qemu_monitor_json.c (eventHandlers): New event.
(qemuMonitorJSONHandleBlockJobReady): New function.
(qemuMonitorJSONGetBlockJobInfoOne): Translate new job type.
(qemuMonitorJSONHandleBlockJobImpl): Handle new event and job type.
* src/qemu/qemu_process.c (qemuProcessHandleBlockJob): Recognize
the event to minimize snooping.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Snoop a successful
info query to save effort on a pivot request.

For now, disk migration via block copy job is not implemented in
libvirt.  But when we do implement it, we have to deal with the
fact that qemu does not yet provide an easy way to re-start a qemu
process with mirroring still intact.  Paolo has proposed an idea
for a persistent dirty bitmap that might make this possible, but
until that design is complete, it's hard to say what changes
libvirt would need.  Even something like 'virDomainSave' becomes
hairy, if you realize the implications that 'virDomainRestore'
would be stuck with recreating the same mirror layout.

But if we step back and look at the bigger picture, we realize that
the initial client of live storage migration via disk mirroring is
oVirt, which always uses transient domains, and that if a transient
domain is destroyed while a mirror exists, oVirt can easily restart
the storage migration by creating a new domain that visits just the
source storage, with no loss in data.

We can make life a lot easier by being cowards for now, forbidding
certain operations on a domain.  This patch guarantees that we
never get in a state where we would have to restart a domain with
a mirroring block copy, by preventing saves, snapshots, migration,
hot unplug of a disk in use, and conversion to a persistent domain
(thankfully, it is still relatively easy to 'virsh undefine' a
running domain to temporarily make it transient, run tests on
'virsh blockcopy', then 'virsh define' to restore the persistence).
Later, if the qemu design is enhanced, we can relax our code.

The change to qemudDomainDefine looks a bit odd for undoing an
assignment, rather than probing up front to avoid the assignment,
but this is because of how virDomainAssignDef combines both a
lookup and assignment into a single function call.

* src/conf/domain_conf.h (virDomainHasDiskMirror): New prototype.
* src/conf/domain_conf.c (virDomainHasDiskMirror): New function.
* src/libvirt_private.syms (domain_conf.h): Export it.
* src/qemu/qemu_driver.c (qemuDomainSaveInternal)
(qemuDomainSnapshotCreateXML, qemuDomainRevertToSnapshot)
(qemuDomainBlockJobImpl, qemudDomainDefine): Prevent dangerous
actions while block copy is already in action.
* src/qemu/qemu_hotplug.c (qemuDomainDetachDiskDevice): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsAllowed): Likewise.

Upstream qemu 1.3 is adding two new monitor commands, 'drive-mirror'
and 'block-job-complete'[1], which can drive live block copy and
storage migration.  [Additionally, RHEL 6.3 had backported an earlier
version of most of the same functionality, but under the names
'__com.redhat_drive-mirror' and '__com.redhat_drive-reopen' and with
slightly different JSON arguments, and has been using patches similar
to these upstream patches for several months now.]

The libvirt API virDomainBlockRebase as already committed for 0.9.12
is flexible enough to expose the basics of block copy, but some
additional features in the 'drive-mirror' qemu command, such as
setting error policy, setting granularity, or using a persistent
bitmap, may later require a new libvirt API virDomainBlockCopy.  I
will wait to add that API until we know more about what qemu 1.3
will finally provide.

This patch caters only to the upstream qemu 1.3 interface, although
I have proven that the changes for RHEL 6.3 can be isolated to
just qemu_monitor_json.c, and the rest of this series will
gracefully handle either interface once the JSON differences are
papered over in a downstream patch.

For consistency with other block job commands, libvirt must handle
the bandwidth argument as MiB/sec from the user, even though qemu
exposes the speed argument as bytes/sec; then again, qemu rounds
up to cluster size internally, so using MiB hides the worst effects
of that rounding if you pass small numbers.

[1]https://lists.gnu.org/archive/html/qemu-devel/2012-10/msg04123.html

* src/qemu/qemu_capabilities.h (QEMU_CAPS_DRIVE_MIRROR)
(QEMU_CAPS_DRIVE_REOPEN): New bits.
* src/qemu/qemu_capabilities.c (qemuCaps): Name them.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONCheckCommands): Set
them.
(qemuMonitorJSONDriveMirror, qemuMonitorDrivePivot): New functions.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDriveMirror)
(qemuMonitorDrivePivot): Declare them.
* src/qemu/qemu_monitor.c (qemuMonitorDriveMirror)
(qemuMonitorDrivePivot): New passthroughs.
* src/qemu/qemu_monitor.h (qemuMonitorDriveMirror)
(qemuMonitorDrivePivot): Declare them.

This resolves:

   https://bugzilla.redhat.com/show_bug.cgi?id=862515

which describes inconsistencies in dealing with duplicate mac
addresses on network devices in a domain.

(at any rate, it resolves *almost* everything, and prints out an
informative error message for the one problem that isn't solved, but
has a workaround.)

A synopsis of the problems:

1) you can't do a persistent attach-interface of a device with a mac
address that matches an existing device.

2) you *can* do a live attach-interface of such a device.

3) you *can* directly edit a domain and put in two devices with
matching mac addresses.

4) When running virsh detach-device (live or config), only MAC address
is checked when matching the device to remove, so the first device
with the desired mac address will be removed. This isn't always the
one that's wanted.

5) when running virsh detach-interface (live or config), the only two
items that can be specified to match against are mac address and model
type (virtio, etc) - if multiple netdevs match both of those
attributes, it again just finds the first one added and assumes that
is the only match.

Since it is completely valid to have multiple network devices with the
same MAC address (although it can cause problems in many cases, there
*are* valid use cases), what is needed is:

1) remove the restriction that prohibits doing a persistent add of a
netdev with a duplicate mac address.

2) enhance the backend of virDomainDetachDeviceFlags to check for
something that *is* guaranteed unique (but still work with just mac
address, as long as it yields only a single results.

This patch does three things:

1) removes the check for duplicate mac address during a persistent
netdev attach.

2) unifies the searching for both live and config detach of netdevices
in the subordinate functions of qemuDomainModifyDeviceFlags() to use the
new function virDomainNetFindIdx (which matches mac address and PCI
address if available, checking for duplicates if only mac address was
specified). This function returns -2 if multiple matches are found,
allowing the callers to print out an appropriate message.

Steps 1 & 2 are enough to fully fix the problem when using virsh
attach-device and detach-device (which require an XML description of
the device rather than a bunch of commandline args)

3) modifies the virsh detach-interface command to check for multiple
matches of mac address and show an error message suggesting use of the
detach-device command in cases where there are multiple matching mac
addresses.

Later we should decide how we want to input a PCI address on the virsh
commandline, and enhance detach-interface to take a --address option,
eliminating the need to use detach-device

* src/conf/domain_conf.c
* src/conf/domain_conf.h
* src/libvirt_private.syms
  * added new virDomainNetFindIdx function
  * removed now unused virDomainNetIndexByMac and
    virDomainNetRemoveByMac

* src/qemu/qemu_driver.c
  * remove check for duplicate max from qemuDomainAttachDeviceConfig
  * use virDomainNetFindIdx/virDomainNetRemove instead
    of virDomainNetRemoveByMac in qemuDomainDetachDeviceConfig
  * use virDomainNetFindIdx instead of virDomainIndexByMac
    in qemuDomainUpdateDeviceConfig

* src/qemu/qemu_hotplug.c
  * use virDomainNetFindIdx instead of a homespun loop in
    qemuDomainDetachNetDevice.

* tools/virsh-domain.c: modified detach-interface command as described
    above

It turns out that the cpuacct results properly account for offline
cpus, and always returns results for every possible cpu, not just
the online ones.  So there is no need to check the map of online
cpus in the first place, merely only a need to know the maximum
possible cpu.  Meanwhile, virNodeGetCPUBitmap had a subtle change
from returning the maximum id to instead returning the width of
the bitmap (one larger than the maximum id) in commit 2f4c5338,
which made this code encounter some off-by-one logic leading to
bad error messages when a cpu was offline:

$ virsh cpu-stats dom
error: Failed to virDomainGetCPUStats()

error: An error occurred, but the cause is unknown

Cleaning this up unraveled a chain of other unused variables.

* src/qemu/qemu_driver.c (qemuDomainGetPercpuStats): Drop
pointless check for cpumap changes, and use correct number of
cpus.  Simplify signature.
(qemuDomainGetCPUStats): Adjust caller.
* src/nodeinfo.h (nodeGetCPUCount): New prototype.
(nodeGetCPUBitmap): Drop unused parameter.
* src/nodeinfo.c (nodeGetCPUBitmap): Likewise.
(nodeGetCPUMap): Adjust caller.
(nodeGetCPUCount): New function.
* src/libvirt_private.syms (nodeinfo.h): Export it.

* tools/Makefile.am: Fix tab damage in previous patch.

Patch 61299a1c fixed a long-standing pod error in the man page.
But we should be preventing these up front.
See also https://bugzilla.redhat.com/show_bug.cgi?id=870273

* tools/Makefile.am (virt-xml-validate.1, virt-pki-validate.1)
(virt-host-validate.1, virt-sanlock-cleanup.8, virsh.1): Reject
pod conversion errors.
* daemon/Makefile.am ($(srcdir)/libvirtd.8.in): Likewise.

Commit 246143b6 fixed a warning on older gcc, but caused a warning
on newer gcc.

../../src/rpc/virnetserverservice.c: In function 'virNetServerServiceNewPostExecRestart':
../../src/rpc/virnetserverservice.c:277:41: error: pointer targets in passing argument 3 of 'virJSONValueObjectGetNumberUint' differ in signedness [-Werror=pointer-sign]

* src/rpc/virnetserverservice.c: Use correct types.

With older gcc and 64-bit size_t, the compiler issues a real warning:
rpc/virnetserverservice.c:277: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]

Introduced in commit 0cc79255.  Depending on machine endianness,
this warning represents a real bug that could mis-interpret the
value by a factor of 2^32.  I don't know why I couldn't get newer
gcc to report the same warning message.

* src/rpc/virnetserverservice.c
(virNetServerServiceNewPostExecRestart): Use temporary instead.

Found this when building on RHEL5:

parallels/parallels_storage.c: In function 'parallelsStorageOpen':
parallels/parallels_storage.c:180: error: 'for' loop initial declaration used outside C99 mode

(and similar error in parallels_driver.c). This was in spite of
configuring with "-Wno-error".

Replace '%' by '&' for correct escaping of '>' in Domain specification.
Signed-off-by: NPhilipp Hahn <hahn@univention.de>

Sorting of the .gitignore file was broken after the last addition. After
a clean build the scripts re-sort it making the working tree dirty.