With the majority of fields in the virQEMUDriverPtr struct
now immutable or self-locking, there is no need for practically
any methods to be using the QEMU driver lock. Only a handful
of helper APIs in qemu_conf.c now need it
Currently the APIs for managing the shared disk list take
a virHashTablePtr as the primary argument. This is bad
because it requires the caller to deal with locking of
the QEMU driver. Switch the APIs to take the full
virQEMUDriverPtr instance
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
To enable locking to be introduced to the security manager
objects later, turn virSecurityManager into a virObjectLockable
class
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The 'driver->caps' pointer can be changed on the fly. Accessing
it currently requires the global driver lock. Isolate this
access in a single helper, so a future patch can relax the
locking constraints.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
To avoid confusion between 'virCapsPtr' and 'qemuCapsPtr'
do some renaming of various fucntions/variables. All
instances of 'qemuCapsPtr' are renamed to 'qemuCaps'. To
avoid that clashing with the 'qemuCaps' typedef though,
rename the latter to virQEMUCaps.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
To enable virCapabilities instances to be reference counted,
turn it into a virObject. All cases of virCapabilitiesFree
turn into virObjectUnref
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
We are requesting for stderr catching for all cases in
virFileWrapperFdNew(). There is no need to have a separate
function just to report an error, esp. when we can do it in
virFileWrapperFdClose().
Currently the activePciHostdevs, inactivePciHostdevsd and
activeUsbHostdevs lists are all implicitly protected by the
QEMU driver lock. Now that the lists all inherit from the
virObjectLockable, we can make the locking explicit, removing
the dependency on the QEMU driver lock for correctness.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
To allow modifications to the lists to be synchronized, convert
virPCIDeviceList and virUSBDeviceList into virObjectLockable
classes. The locking, however, will not be self-contained. The
users of these classes will have to call virObjectLock/Unlock
in the critical regions.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The QEMU driver struct has a 'qemuVersion' field that was previously
used to cache the version lookup from capabilities. With the recent
QEMU capabilities rewrite the caching happens at a lower level so
this field is pointless. Removing it avoids worries about locking
when updating it.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The duplicate VM checking should be done atomically with
virDomainObjListAdd, so shoud not be a separate function.
Instead just use flags to indicate what kind of checks are
required.
This pair, used in virDomainCreateXML:
if (virDomainObjListIsDuplicate(privconn->domains, def, 1) < 0)
goto cleanup;
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def, false)))
goto cleanup;
Changes to
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def,
VIR_DOMAIN_OBJ_LIST_ADD_CHECK_LIVE,
NULL)))
goto cleanup;
This pair, used in virDomainRestoreFlags:
if (virDomainObjListIsDuplicate(privconn->domains, def, 1) < 0)
goto cleanup;
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def, true)))
goto cleanup;
Changes to
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def,
VIR_DOMAIN_OBJ_LIST_ADD_LIVE |
VIR_DOMAIN_OBJ_LIST_ADD_CHECK_LIVE,
NULL)))
goto cleanup;
This pair, used in virDomainDefineXML:
if (virDomainObjListIsDuplicate(privconn->domains, def, 0) < 0)
goto cleanup;
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def, false)))
goto cleanup;
Changes to
if (!(dom = virDomainObjListAdd(privconn->domains,
privconn->caps,
def,
0, NULL)))
goto cleanup;
As a step towards making virDomainObjList thread-safe turn it
into an opaque virObject, preventing any direct access to its
internals.
As part of this a new method virDomainObjListForEach is
introduced to replace all existing usage of virHashForEach
Currently the virQEMUDriverPtr struct contains an wide variety
of data with varying access needs. Move all the static config
data into a dedicated virQEMUDriverConfigPtr object. The only
locking requirement is to hold the driver lock, while obtaining
an instance of virQEMUDriverConfigPtr. Once a reference is held
on the config object, it can be used completely lockless since
it is immutable.
NB, not all APIs correctly hold the driver lock while getting
a reference to the config object in this patch. This is safe
for now since the config is never updated on the fly. Later
patches will address this fully.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If a decompression binary prints something to stderr, currently
it is discarded. However, it can contain useful data from
debugging POV, so we should catch it.
https://bugzilla.redhat.com/show_bug.cgi?id=894723
Currently, if qemuProcessStart() succeeds, but it's decompression
binary that returns nonzero status, we don't kill the qemu process,
but remove it from internal domain list, leaving the qemu process
hanging around totally uncontrolled.
Currently QEMU capabilities are initialized before the QEMU driver
sets ownership on its various directories. The upshot is that if
you change the user/group in the qemu.conf file, libvirtd will fail
to probe QEMU the first time it is run after the config change.
Moving QEMU capabilities initialization to after the chown() calls
fixes this
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently, there is no reason to hold qemu driver locked
throughout whole API execution. Moreover, we can use the
new qemuDomObjFromDomain() internal API to lookup domain then.
https://bugzilla.redhat.com/show_bug.cgi?id=876829 complains that
if a guest is put into S3 state (such as via virsh dompmsuspend)
and then an external snapshot is taken, qemu forcefully transitions
the domain to paused, but libvirt doesn't reflect that change
internally. Thus, a user has to use 'virsh suspend' to get libvirt
back in sync with qemu state, and if the user doesn't know this
trick, then the guest appears hung.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateActiveExternal):
Track fact that qemu wakes up a suspended domain on migration.
The previous fix to avoid leaking securityDriverNames forgot to
handle the case of securityDriverNames being NULL, leading to
a crash
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Should have been done in commit 56fd513 already, but was missed
due to oversight: qemuDomainSendKey didn't release the driver lock
in its cleanup section. This fixes an issue introduced by commit
8c5d2ba.
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
The snapshot name is used to create path to the definition save file.
When the name contains slashes the creation of the file fails. Reject
such names.
When the snapshot definition can't be saved, the
qemuDomainSnapshotCreate function succeeded without filling some of the
fields in the internal definition.
This patch removes the snapshot and returns failure if the XML file
cannot be written.
When running virDomainDestroy, we need to make sure that no other
background thread cleans up the domain while we're doing our work.
This can happen if we release the domain object while in the
middle of work, because the monitor might detect EOF in this window.
For this reason we have a 'beingDestroyed' flag to stop the monitor
from doing its normal cleanup. Unfortunately this flag was only
being used to protect qemuDomainBeginJob, and not qemuProcessKill
This left open a race condition where either libvirtd could crash,
or alternatively report bogus error messages about the domain already
having been destroyed to the caller
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The driver mutex was unlocked in qemuDomainModifyDeviceFlags before
entering qemuDomainObjBeginJobWithDriver where it will be unlocked once
more leaving it in an undefined state. The result was that two
threads were simultaneously looking up the domain hash table during
multiple parallel device attach/detach operations.
Luckily this triggered a virHashIterationError.
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
The virDomainObj, qemuAgent, qemuMonitor, lxcMonitor classes
all require a mutex, so can be switched to use virObjectLockable
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
After live change of cpu counts, the number of processor threads is
verified. This patch makes use of this approach to check if qemu ignored
the request for cpu hot-unplug and report an appropriate message.
Pass stub driver name directly to pciDettachDevice and pciReAttachDevice to fit
for different libvirt drivers. For example, qemu driver prefers pci-stub, but
Xen prefers pciback.
Signed-off-by: Chunyan Liu <cyliu@suse.com>
The current code is initializing capabilities before setting
directory permissions. Thus the QEMU binaries being run may
not have the ability to create the UNIX monitor socket on
the first run of libvirtd.
This prevents domain starting and disk attaching if the shared disk's
setting conflicts with other active domain(s), E.g. A domain with
"sgio" set as "filtered", however, another active domain is using
it set as "unfiltered".
This introduces a hash table for qemu driver, to store the shared
disk's info as (@major:minor, @ref_count). @ref_count is the number
of domains which shares the disk.
Since we only care about if the disk support unprivileged SG_IO
commands, and the SG_IO commands only make sense for block disk,
this patch only manages (add/remove hash entry) the shared disk for
block disk.
* src/qemu/qemu_conf.h: (Add member 'sharedDisks' of type
virHashTablePtr; Declare helpers
qemuGetSharedDiskKey, qemuAddSharedDisk
and qemuRemoveSharedDisk)
* src/qemu/qemu_conf.c (Implement the 3 helpers)
* src/qemu/qemu_process.c (Update 'sharedDisks' when domain
starting and shutdown)
* src/qemu/qemu_driver.c (Update 'sharedDisks' when attaching
or detaching disk).
When the disk alignment check done while redefining an existing snapshot
failed, the qemu driver attempted to free the existing snapshot. As in
the cleanup path the definition of the snapshot wasn't assigned, the
cleanup code dereferenced a NULL pointer.
This patch changes the behavior on error paths while redefining snapshot
in two ways:
1) On failure, modifications done on the snapshot definition object are
rolled back.
2) The previous definition of the data isn't freed until it's certain it
won't be needed any more.
This change avoids the segfault and additionally the snapshot doesn't
vanish if redefinition fails for some reason.
This also changes the function signature to take a
virDomainChrSourceDefPtr instead of just a path, since it needs to
differentiate behavior based on source->type.
The functionality provided in virchrdev.c (previously virconsole.c) is
applicable to other types of character devices besides consoles, such
as channels. This patch is just code motion, renaming things such as
"console" or "pty", instead using more general terms such as
"character device" or "device path".
Many internal qemu APIs must find domain object from passed
virDomainPtr. And with function Peter's introduced, we can use it
instead of copying multiple lines among code.
https://bugzilla.redhat.com/show_bug.cgi?id=888426
The code for doing a block-copy was supposed to track the destination
file in drive->mirror, but was set up to do all mallocs prior to
starting the copy so that OOM wouldn't leave things partially started.
However, the wrong variable was being written; later in the code we
silently did 'disk->mirror = mirror' which was still NULL, and thus
leaking memory and leaving libvirt to think that the mirror job was
never started, which prevented a pivot operation after a copy.
Problem introduced in commit 35c7701c6.
* src/qemu/qemu_driver.c (qemuDomainBlockCopy): Initialize correct
variable.
Convert the host capabilities and domain config structs to
use the virArch datatype. Update the parsers and all drivers
to take account of datatype change
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Noticed these while building on FreeBSD.
* src/qemu/qemu_monitor.c (qemuMonitorBlockInfoLookup): Rename
variable to avoid 'devname' collision.
* src/qemu/qemu_driver.c (qemuDomainInterfaceStats): Mark unused
variable.
Refactor virLockManagerPluginNew() so that the caller does
not need to pass in the config file path itself - just the
config directory and driver name.
Fix QEMU to actually pass in a config file when creating the
default lock manager plugin, rather than NULL.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This patch adds a new domain lookup helper qemuDomObjFromDomainDriver
that lookups the domain and leaves the driver locked. The driver is
returned as the second argument of that function. If the lookup fails
the driver is unlocked to help avoid cleanup codepaths.
This patch also improves docs for the helpers.
These classes can borrow unused bandwidth. Basically,
only egress qdsics can have classes, therefore we can
do this kind of traffic shaping only on host's outgoing,
that is domain's incoming traffic.
When the disk snapshot part of an external system checkpoint fails the
memory image is retained. This patch adds code to remove the image in
such case.
In case the snapshot code isn't able to restart CPUs after an external
checkpoint we would leak a copy of the domains XML definition. This
patch fixes the cleanup path.
When restarting CPUs after an external snapshot, the restarting function
was called without the appropriate async job type. This caused that a
new sync job wasn't created and allowed races in the monitor.
Offline migration transfers inactive definition of a domain (which may
or may not be active). After successful completion, the domain remains
in its current state on source host and is defined but inactive on
destination host. It's a bit more clever than virDomainGetXMLDesc() on
source host followed by virDomainDefineXML() on destination host, as
offline migration will run pre-migration hook to update the domain XML
on destination host. Currently, copying non-shared storage is not
supported during offline migration.
Offline migration can be requested with a new migration flag called
VIR_MIGRATE_OFFLINE (which has to be combined with
VIR_MIGRATE_PERSIST_DEST flag).
An attempt to attach device that is already attached to a domain results
in the following error:
virsh # attach-device rhel6 pci2 --persistent
error: Failed to attach device from pci2
error: invalid argument: device is already in the domain configuration
The "invalid argument" error code looks wrong, we usually use "operation
invalid" when the action cannot be done in current state.
Without this patch, attempts to create a disk snapshot when qemu
is too old results in a cryptic message:
virsh # snapshot-create 23 --disk-only
error: operation failed: Failed to take snapshot: unknown command: 'snapshot_blkdev'
Now it reports:
virsh # snapshot-create 23 --disk-only
error: unsupported configuration: live disk snapshot not supported with this QEMU binary
All versions of qemu that support live disk snapshot also support
QMP (basically upstream qemu 1.1 and later, and backports to RHEL 6.2).
* src/qemu/qemu_capabilities.h (QEMU_CAPS_DISK_SNAPSHOT): New
capability.
* src/qemu/qemu_capabilities.c (qemuCaps): Track it.
(qemuCapsProbeQMPCommands): Set it.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateDiskActive): Use
it.
* src/qemu/qemu_monitor.c (qemuMonitorDiskSnapshot): Simplify.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONDiskSnapshot):
Likewise.
* src/qemu/qemu_monitor_text.h (qemuMonitorTextDiskSnapshot):
Delete.
* src/qemu/qemu_monitor_text.c (qemuMonitorTextDiskSnapshot):
Likewise.
Currently to deal with auto-shutdown libvirtd must periodically
poll all stateful drivers. Thus sucks because it requires
acquiring both the driver lock and locks on every single virtual
machine. Instead pass in a "inhibit" callback to virStateInitialize
which drivers can invoke whenever they want to inhibit shutdown
due to existance of active VMs.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The fact that only the guest agent, or ACPI flag can be used
when requesting reboot/shutdown is merely a limitation of the
QEMU driver impl at this time. Thus it should not be in
libvirt.c code
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=876828
Commit 38c4a9cc introduced a regression in hot unplugging of disks
from qemu, where cgroup device ACLs were no longer being revoked
(thankfully not a security hole: cgroup ACLs only prevent open()
of the disk; so reverting the ACL prevents future abuse but doesn't
stop abuse from an fd that was already opened before the ACL change).
Commit 1b2ebf95 overlooked that there were two spots affected.
* src/qemu/qemu_hotplug.c (qemuDomainDetachDiskDevice):
Transfer backing chain before deletion.
* src/qemu/qemu_driver.c (qemuDomainDetachDeviceDiskLive): Fix
spacing (partly to ensure a different-looking patch).
The virStateInitialize method and several cgroups methods were
using an 'int privileged' parameter or similar for dual-state
values. These are better represented with the bool type.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Replace the following names
* struct qemu_snap_remove with virQEMUSnapRemovePtr
* struct qemu_snap_reparent with virQEMUSnapReparentPtr
* struct qemu_save_header with virQEMUSaveHeaderPtr
* enum qemu_save_formats with virQEMUSaveFormat
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Remove the obsolete 'qemud' naming prefix and underscore
based type name. Introduce virQEMUDriverPtr as the replacement,
in common with LXC driver naming style
Throughout the code, we've always used VIR_DOMAIN_SHUTDOWN* flags
even for virDomainReboot() API and its implementation. Fortunately,
the appropriate macros has the same value. But if we want to keep
things consistent, we should be using the correct macros. This
patch doesn't break anything, luckily.
using qemu guest agent. As said in previous patch,
@mountPoint must be NULL and @flags zero because
qemu guest agent doesn't support these arguments
yet. If qemu learns them, we can start supporting
them as well.
QMP Capability probing will fail if QEMU cannot bind to the
QMP monitor socket in the qemu_driver->libDir directory.
That's because the child process is stripped of all
capabilities and this directory is chown'ed to the configured
QEMU user/group (normally qemu:qemu) by the QEMU driver.
To prevent this from happening, the driver startup will now pass
the QEMU uid and gid down to the capability probing code.
All capability probing invocations of QEMU will be run with
the configured QEMU uid instead of libvirtd's.
Furter, the pid file handling is moved to libvirt, as QEMU
cannot write to the qemu_driver->runDir (root:root). This also
means that the libvirt daemonizing must be used.
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Change some legacy function names to use 'qemu' as their
prefix instead of 'qemud' which was a hang over from when
the QEMU driver ran inside a separate daemon
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Upcoming patches for revert-and-clone branching of snapshots need
to be able to copy a domain definition; make this step reusable.
* src/conf/domain_conf.h (virDomainDefCopy): New prototype.
* src/conf/domain_conf.c (virDomainObjCopyPersistentDef): Split...
(virDomainDefCopy): ...into new function.
(virDomainObjSetDefTransient): Use it.
* src/libvirt_private.syms (domain_conf.h): Export it.
* src/qemu/qemu_driver.c (qemuDomainRevertToSnapshot): Use it.
This patch adds a helper to determine if snapshots are external and uses
the helper to fix detection of those in snapshot deletion code.
Snapshots are external if they have an external memory image or if the
disk locations are external. As mixed snapshots are forbidden for now
we need to check just one disk to know.
Currently, if user calls virDomainAbortJob we just issue
'migrate_cancel' and hope for the best. However, if user calls
the API in wrong phase when migration hasn't been started yet
(perform phase) the cancel request is just ignored. With this
patch, the request is remembered and as soon as perform phase
starts, migration is cancelled.
When the libvirt daemon is restarted it tries to reconnect to running
qemu domains. Since commit d38897a5d4 the
re-connection code runs in separate threads. In the original
implementation the maximum of domain ID's (that is used as an
initializer for numbering guests created next) while libvirt was
reconnecting to the guest.
With the threaded implementation this opens a possibility for race
conditions with the thread that is autostarting guests. When there's a
guest running with id 1 and the daemon is restarted. The autostart code
is reached first and spawns the first guest that should be autostarted
as id 1. This results into the following unwanted situation:
# virsh list
Id Name State
----------------------------------------------------
1 guest1 running
1 guest2 running
This patch extracts the detection code before the re-connection threads
are started so that the maximum id of the guests being reconnected to is
known.
The only semantic change created by this is if the guest with greatest ID
quits before we are able to reconnect it's ID is used anyway as the
greatest one as without this patch the greatest ID of a process we could
successfuly reconnect to would be used.
