According to our recent changes (clarifications), we should be pinning
qemu's emulator processes using the <vcpu> 'cpuset' attribute in case
there is no <emulatorpin> specified. This however doesn't work
entirely as expected and this patch should resolve all the remaining
issues.
This patch resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=805071
to the extent that it can be resolved with current qemu functionality.
It attempts to detect as many situations as possible when the simple
operation of disconnecting an existing tap device from one bridge and
attaching it to another will satisfy the change requested in
virDomainUpdateDeviceFlags() for a network device. Before this patch,
that situation could only be detected if the pre-change interface
*and* the post-change interface definition were both "type='bridge'".
After this patch, it can also be detected if the before or after
interfaces are any combination of type='bridge' and type='network'
(the networks can be <forward mode='nat|route|bridge'>, as long as
they use a Linux host bridge and not macvtap connections).
This extra effort is especially useful since the recent discovery that
a netdev_del+netdev_add combo (to reconnect the network device with
completely different hostside configuration) doesn't work properly
with current qemu (1.2) unless it is accompanied by the matching
device_del+device_add - see this mailing list message for details:
http://lists.nongnu.org/archive/html/qemu-devel/2012-10/msg02355.html
(A slight modification of the patch referenced there has been prepared
to apply on top of this patch, but won't be pushed until qemu can be
made to work with it.)
* qemuDomainChangeNet needs access to the virDomainDeviceDef that
holds the new netdef (so that it can clear out the virDomainDeviceDef
if it ends up using the NetDef to replace the original), so the
virDomainNetDefPtr arg is replaced with a virDomainDeviceDefPtr.
* qemuDomainChangeNet previously checked for *some* changes to the
interface config, but this check was by no means complete. It was also
a bit disorganized.
This refactoring of the code is (I believe) complete in its check of
all NetDef attributes that might be changed, and either returns a
failure (for changes that are simply impossible), or sets one of three
flags:
needLinkStateChange - if the device link state needs to go up/down
needBridgeChange - if everything else is the same, but it needs
to be connected to a difference linux host
bridge
needReconnect - if the entire host side of the device needs
to be torn down and reconstructed (currently
non-working, as mentioned above)
Note that this function will refuse to make any change that requires
the *guest* side of the device to be detached (e.g. changing the PCI
address or mac address). Those would be disruptive enough to the guest
that it's reasonable to require an explicit detach/attach sequence
from the management application.
* As mentioned above, qemuDomainChangeNet also does its best to
understand when a simple change in attached bridge for the existing
tap device will work vs. the need to completely tear down/reconstruct
the host side of the device (including tap device).
This patch *does not* implement the "reconnect" code anyway - there is
a placeholder that turns that into an error. Rather, the purpose of
this patch is to replicate existing behavior with code that is ready
to have that functionality plugged in in a later patch.
* The expanded uses for qemuDomainChangeNetBridge meant that it needed
to be enhanced as well - it no longer replaces the original brname
string in olddev with the new brname; instead, it relies on the
caller to replace the *entire* olddev with newdev (since we've gone
to great lengths to assure they are functionally identical other
than the name of the bridge, this is now not only safe, but more
correct). Additionally, qemuDomainNetChangeBridge can now set the
bridge for type='network' interfaces as well as plain type='bridge'
interfaces. (Note that I had to make this change simultaneous to the
reorganization of qemuDomainChangeNet because the two are too
closely intertwined to separate).
The onlined vcpu pinning policy should inherit def->cpuset if
it's not specified explicitly, and the affinity should be set
in this case. Oppositely, the offlined vcpu pinning policy should
be free()'ed.
Various APIs use cgroup to either set or get the statistics of
host or guest. Hotplug or hot unplug new vcpus without creating
or removing the cgroup for the vcpus could cause problems for
those APIs. E.g.
% virsh vcpucount dom
maximum config 10
maximum live 10
current config 1
current live 1
% virsh setvcpu dom 2
% virsh schedinfo dom --set vcpu_quota=1000
Scheduler : posix
error: Unable to find vcpu cgroup for rhel6.2(vcpu: 1): No such file or
directory
This patch fixes the problem by creating cgroups for each of the
onlined vcpus, and destroying cgroups for each of the offlined
vcpus.
Save/restore with passed through USB devices currently only works if the
USB device can be found at the same USB address where it used to be
before saving a domain. This makes sense in case a user explicitly
configure the USB address in domain XML. However, if the device was
found automatically by vendor/product identification, we should try to
search for that device when restoring the domain and use any device we
find as long as there is only one available. In other words, the USB
device can now be removed and plugged again or the host can be rebooted
between saving and restoring the domain.
Using VIR_DOMAIN_XML_MIGRATABLE flag, one can request domain's XML
configuration that is suitable for migration or save/restore. Such XML
may contain extra run-time stuff internal to libvirt and some default
configuration may be removed for better compatibility of the XML with
older libvirt releases.
This flag may serve as an easy way to get the XML that can be passed
(after desired modifications) to APIs that accept custom XMLs, such as
virDomainMigrate{,ToURI}2 or virDomainSaveFlags.
When adding variants of parameter setting APIs which accepted
flags, the existing APIs were all adapted internally to pass
VIR_DOMAIN_AFFECT_CURRENT to the new API. The QEMU impl
qemuSetSchedularParameters was an exception, which instead
used VIR_DOMAIN_AFFECT_LIVE. Change this to match other
compatibility scenarios, so that calling
virDomainSetSchedularParameters(dom, params, nparams);
Has the same semantics as
virDomainSetSchedularParametersFlags(dom, params, nparams, 0);
And
virDomainSetSchedularParametersFlags(dom, params, nparams, VIR_DOMAIN_AFFECT_CURRENT);
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Since libvirt switched to QMP capabilities probing recently, it starts
QEMU process used for this probing with -daemonize, which means
virCommandAbort can no longer reach these processes. As a result of
that, restarting libvirtd will leave several new QEMU processes behind.
Let's use QEMU's -pidfile and use it to kill the process when QMP caps
probing is done.
When doing snapshots, the filesystem freeze function used the agent
entering function that expects the qemud_driver unlocked. This might
cause a deadlock of the qemu driver if the agent does not respond.
The only call path of this function has the qemud_driver locked, so this
patch changes the entering functions to those expecting the driver
locked.
Start a QEMU process using
$QEMU -S -no-user-config -nodefaults \
-nographic -M none -qmp unix:/some/path,server,nowait
and talk QMP over stdio to discover what capabilities the
binary supports. This works for QEMU 1.2.0 or later and
for older QEMU automatically fallback to the old approach
of parsing -help and related command line args.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When XML for a new guest is received, the machine type is
immediately canonicalized into the version specific name.
This involves probing QEMU for supported machine types.
Replace this probing with a lookup of the machine types
in the (hopefully cached) qemuCapsPtr object
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Remove all use of the existing APIs for querying QEMU
capability flags. Instead obtain a qemuCapsPtr object
from the global cache. This avoids the execution of
'qemu -help' (and related commands) when launching new
guests.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When building up a virCapsPtr instance, the QEMU driver
was copying the list of machine types across from the
previous virCapsPtr instance, if the QEMU binary had not
changed. Replace this ad-hoc caching of data with use
of the new qemuCapsCache global cache.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
In the cgroups APIs we have a virCgroupKillPainfully function
which does the loop sending SIGTERM, then SIGKILL and waiting
for the process to exit. There is similar functionality for
simple processes in qemuProcessKill, but it is tangled with
the QEMU code. Untangle it to provide a virProcessKillPainfuly
function
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When calling qemuProcessKill from the virDomainDestroy impl
in QEMU, do not ignore the return value. This ensures that
if QEMU fails to respond to SIGKILL, the caller will know
about the failure.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
In most of the snapshot API's there's no need to hold the driver lock
the whole time.
This patch adds helper functions that get the domain object in functions
that don't require the driver lock and simplifies call paths from
snapshot-related API's.
maxcpu and hostcpus are defined and calculated in qemudDomainPinVcpuFlags()
and qemudDomainPinEmulator(), but never used. So remove them including nodeinfo.
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.
* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/; If/. If/
Upstream qemu has raised a concern about whether dumping guest
memory by reading guest paging tables is a security hole:
https://lists.gnu.org/archive/html/qemu-devel/2012-09/msg02607.html
While auditing libvirt to see if we would be impacted, I noticed
that we had some dead code. It is simpler to nuke the dead code
and limit our monitor code to just the subset we make use of.
* src/qemu/qemu_monitor.h (QEMU_MONITOR_DUMP): Drop poorly named
and mostly-unused enum.
* src/qemu/qemu_monitor.c (qemuMonitorDumpToFd): Drop arguments.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDump): Likewise.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONDump): Likewise.
* src/qemu/qemu_driver.c (qemuDumpToFd): Update caller.
BZ:https://bugzilla.redhat.com/show_bug.cgi?id=843372
when qemu supports the 'transaction' monitor command,
and libvirt's --reuse-ext flag was not specified, libvirt created
a stub file with zero size in first place. After the failure of
QEMU transaction command performing qcow2 snapshots on more than
one drives, the stub file is left behind with non-empty
by the QEMU transaction command.
In order to unlink the file, the patch removes the file size checking.
Steps to reproduce the issue:
Steps:
1, Create a qemu instance with two drive images of qcow2 type (root user)
/usr/libexec/qemu-kvm -m 1024 -smp 1 -name "rhel6u1" \
-drive file=/var/lib/libvirt/images/firstqcow2,if=none,id=drive-virtio-disk0,format=qcow2,cache=none
-device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 \
-drive file=/var/lib/libvirt/images/secondqcow2,if=none,id=drive-virtio-disk1,format=qcow2,cache=none \
-device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x7,drive=drive-virtio-disk1,id=virtio-disk1 -qmp stdio
2, Initialize qemu qmp
{"execute":"qmp_capabilities"}
3, Remove the second drive image file
rm -f /var/lib/libvirt/images/secondqcow2
4, Run 'transaction' command with snapshot qemu commands in.
{"execute":"transaction","arguments":
{"actions":
[{"type":"blockdev-snapshot-sync","data":
{"device":"drive-virtio-disk0","snapshot-file":"/var/lib/libvirt/images/firstqcow2-snapshot.img","format":"qcow2"}
},
{"type":"blockdev-snapshot-sync","data":
{"device":"drive-virtio-disk1","snapshot-file":"/var/lib/libvirt/images/secondqcow2-snapshot.img","format":"qcow2"}
}]
},
"id":"libvirt-6"}
5, Got the error as follows:
{"id": "libvirt-6",
"error": {"class": "OpenFileFailed", "desc": "Could not open '/var/lib/libvirt/images/secondqcow2-snapshot.img'",
"data": {"filename": "/var/lib/libvirt/images/secondqcow2-snapshot.img"}
}
}
6, List first newly-created snapshot file:
-rw-r--r--. 1 root root 262144 Sep 13 11:43 firstqcow2-snapshot.img
The QEMU capabilities APIs used a misc of 'int' and
'unsigned int' for variables relating to array sizes.
Change all these to use 'size_t'
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The current qemu capabilities are stored in a virBitmapPtr
object, whose type is exposed to callers. We want to store
more data besides just the flags, so we need to move to a
struct type. This object will also need to be reference
counted, since we'll be maintaining a cache of data per
binary. This change introduces a 'qemuCapsPtr' virObject
class. Most of the change is just renaming types and
variables in all the callers
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
I got an off-list report about a bad diagnostic:
Target network card mac 52:54:00:49:07:ccdoes not match source 52:54:00:49:07:b8
True to form, I've added a syntax check rule to prevent it
from recurring, and found several other offenders.
* cfg.mk (sc_require_whitespace_in_translation): New rule.
* src/conf/domain_conf.c (virDomainNetDefCheckABIStability): Add
space.
* src/esx/esx_util.c (esxUtil_ParseUri): Likewise.
* src/qemu/qemu_command.c (qemuCollectPCIAddress): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSetMetadata)
(qemuDomainGetMetadata): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainChangeNetBridge): Likewise.
* src/rpc/virnettlscontext.c
(virNetTLSContextCheckCertDNWhitelist): Likewise.
* src/vmware/vmware_driver.c (vmwareDomainResume): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainGetXMLDesc, vboxAttachDrives):
Avoid false negatives.
* tools/virsh-domain.c (info_save_image_dumpxml): Reword.
Based on a report by Luwen Su.
The quota and period tunables for cpu scheduler accept only a certain
range of values. When changing the live configuration invalid values get
rejected. This check is not performed when changing persistent config.
This patch adds a separate range check, that improves error messages
when changing live config and adds the check for persistent config.
This check is done only when using the API. It is still possible to
specify invalid values in the XML.
This patch tries to clean the code up a little bit and shorten very long
lines.
The apparent semantic change from moving the condition before calling
the setter function is a non-issue here as the setter function is a
no-op when called with both arguments zero.
This patch adds support for running qemu guests with the required
parameters to forcefully enable or disable BIOS advertising of S3 and
S4 states. The support for this is added to capabilities and there is
also a qemu command parameter parsing implemented.
The variable max_id is initialized again in the step of
getting cpu mapping variable map2. But in the next for loop
we still expect original value of max_id, the bug will
crash libvirtd when using on NUMA machine with big number
of cpus.
virDomainVcpuPinAdd does a realloc on vcpupin_list if the new vcpu pin
definition doesn't fit into the array. The list is an array of pointers
but the function definition didn't support returning the changed pointer
to the caller if it was realloced. This caused segfaults if realloc
would change the base pointer.
Commit d0c0e79ac6 left behind some dead
code (hasDAC can't be efectively set to true, because
virSecurityManagerNew fails to load the "dac" driver).
This patch also enhances the condition for adding the default
auto-detected security manager if the manager array is allocated but
empty.
Also the configuration file for qemu driver still contains reference to
the DAC driver that can't be enabled manualy.
If no 'security_driver' config option was set, then the code
just loaded the 'dac' security driver. This is a regression
on previous behaviour, where we would probe for a possible
security driver. ie default to SELinux if available.
This changes things so that it 'security_driver' is not set,
we once again do probing. For simplicity we also always
create the stack driver, even if there is only one driver
active.
The desired semantics are:
- security_driver not set
-> probe for selinux/apparmour/nop
-> auto-add DAC driver
- security_driver set to a string
-> add that one driver
-> auto-add DAC driver
- security_driver set to a list
-> add all drivers in list
-> auto-add DAC driver
It is not allowed, or possible to specify 'dac' in the
security_driver config param, since that is always
enabled.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The security driver loading code in qemu has a flaw that causes it to
register the DAC security driver twice. This causes problems (machines
unable to start) as the two DAC drivers clash together.
This patch refactors the code to allow loading the DAC driver even if
its specified in configuration (it can't be registered as a common
security driver), and does not add the driver twice.
With current flow in qemudDomainDefine we might lose data
when updating an existing domain. We parse given XML and
overwrite the configuration. Then we try to save the new
config. However, this step may fail and we don't perform any
roll back. In fact, we remove the domain from the list of
domains held up by qemu driver. This is okay as long as the
domain was brand new one.
Currently, when guest agent is configured but not responsive
(e.g. due to appropriate service not running in the guest)
we return VIR_ERR_INTERNAL_ERROR. Both are wrong. Therefore
we need to introduce new error code to reflect this case.
With the latest patches libvirt supports qemu agent monitor
passthrough. However, function in qemu driver is called
qemuDrvDomainAgentCommand. s/Drv// as used in all other names.
The name 'virDomainDiskSnapshot' didn't fit in with our normal
conventions of using a prefix hinting that it is related to a
virDomainSnapshotPtr. Also, a future patch will reuse the
enum for declaring where the VM memory is stored.
* src/conf/snapshot_conf.h (virDomainDiskSnapshot): Rename...
(virDomainSnapshotLocation): ...to this.
(_virDomainSnapshotDiskDef): Update clients.
* src/conf/domain_conf.h (_virDomainDiskDef): Likewise.
* src/libvirt_private.syms (domain_conf.h): Likewise.
* src/conf/domain_conf.c (virDomainDiskDefParseXML)
(virDomainDiskDefFormat): Likewise.
* src/conf/snapshot_conf.c: (virDomainSnapshotDiskDefParseXML)
(virDomainSnapshotAlignDisks, virDomainSnapshotDefFormat):
Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotDiskPrepare)
(qemuDomainSnapshotCreateSingleDiskActive)
(qemuDomainSnapshotCreateDiskActive, qemuDomainSnapshotCreateXML):
Likewise.
We were failing to react to allocation failure when initializing
a snapshot object list. Changing things to store a pointer
instead of a complete object adds one more possible point of
allocation failure, but at the same time, will make it easier to
react to failure now, as well as making it easier for a future
patch to split all virDomainSnapshotPtr handling into a separate
file, as I continue to add even more snapshot code.
Luckily, there was only one client outside of domain_conf.c that
was actually peeking inside the object, and a new wrapper function
was easy.
* src/conf/domain_conf.h (_virDomainObj): Use a pointer.
(virDomainSnapshotObjListInit): Rename.
(virDomainSnapshotObjListFree, virDomainSnapshotForEach): New
declarations.
(_virDomainSnapshotObjList): Move definitions...
* src/conf/domain_conf.c: ...here.
(virDomainSnapshotObjListInit, virDomainSnapshotObjListDeinit):
Rename...
(virDomainSnapshotObjListNew, virDomainSnapshotObjListFree): ...to
these.
(virDomainSnapshotForEach): New function.
(virDomainObjDispose, virDomainListPopulate): Adjust callers.
* src/qemu/qemu_domain.c (qemuDomainSnapshotDiscard)
(qemuDomainSnapshotDiscardAllMetadata): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsAllowed): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotLoad)
(qemuDomainUndefineFlags, qemuDomainSnapshotCreateXML)
(qemuDomainSnapshotListNames, qemuDomainSnapshotNum)
(qemuDomainListAllSnapshots)
(qemuDomainSnapshotListChildrenNames)
(qemuDomainSnapshotNumChildren)
(qemuDomainSnapshotListAllChildren)
(qemuDomainSnapshotLookupByName, qemuDomainSnapshotGetParent)
(qemuDomainSnapshotGetXMLDesc, qemuDomainSnapshotIsCurrent)
(qemuDomainSnapshotHasMetadata, qemuDomainRevertToSnapshot)
(qemuDomainSnapshotDelete): Likewise.
* src/libvirt_private.syms (domain_conf.h): Export new function.
The recent virDomainQemuAgentCommand addition is part of 0.10.0;
also, grouping all libvirt-qemu.so callbacks together makes them
easier to identify.
* src/libvirt_qemu.syms: Fix release symbol.
* src/qemu/qemu_driver.c (qemuDriver): Likewise.
* src/remote/remote_driver.c (remote_driver): Likewise.
* src/driver.h (_virDriver): Group qemu-specific callbacks.
