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
When removing a VM from the virDomainObjListPtr, we must not
be holding the VM lock while acquiring the list lock. Re-order
code to ensure that we can release the VM lock early.
The hook scripts used by virCommand must be careful wrt
accessing any mutexes that may have been held by other
threads in the parent process. With the recent refactoring
there are 2 potential flaws lurking, which will become real
deadlock bugs once the global QEMU driver lock is removed.
Remove use of the QEMU driver lock from the hook function
by passing in the 'virQEMUDriverConfigPtr' instance directly.
Add functions to the virSecurityManager to be invoked before
and after fork, to ensure the mutex is held by the current
thread. This allows it to be safely used in the hook script
in the child process.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The security manager drivers are not allowed to call back
out to top level security manager APIs, since that results
in recursive mutex acquisition and thus deadlock. Remove
calls to virSecurityManagerGetModel from SELinux / AppArmor
drivers
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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>
Add locking to virSecurityManagerXXX APIs, so that use of the
security drivers is internally serialized. This avoids the need
to rely on the global driver locks to achieve serialization
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>
The virCgroupPtr instance APIs are safe to use without locking
in the QEMU driver, since all internal state they rely on is
immutable. Update the comment to reflect this.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The data files for testing QEMU command line generation are
hardcoded to use /etc/pki, so we should explicitly set that
in the test case, avoiding the dynamic SYSCONFDIR value.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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>
When iterating over USB host devices to setup cgroups, the
usbDevice object was leaked in both LXC and QEMU driers
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>
Switch virDomainObjList to inherit from virObjectLockable and
make all the APIs acquire/release the mutex when running. This
makes virDomainObjList completely self-locking and no longer
reliant on the hypervisor driver locks
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;
The virt-dbus.m4 check for DBus was preserving $LIBS before
modifying it. Except it wasn't. It was preserving another
copy of $CFLAGS. The result was that after the check completed,
$LIBS got polluted with $CFLAGS
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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>
The previous change to the generator, changed too much - only
the functions are in 'virerror.c', the constants remained in
'virerror.h' which could not be renamed for API compat reasons.
Add a test case to sanity check the generated python bindings
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
A logic bug meant we reported KVM was possible for every
architecture, merely based on whether the query-kvm command
exists. We should instead have been doing it based on whether
the query-kvm command returns 'present: 1'
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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>
This previous commit
commit 1a50ba2cb0
Author: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Date: Mon Nov 26 15:17:13 2012 +0100
qemu: Fix QMP Capabability Probing Failure
which attempted to make sure the QEMU process used for probing
ran as the right user id, caused serious performance regression
and unreliability in probing. The -daemonize switch in QEMU
guarantees that the monitor socket is present before the parent
process exits. This means libvirtd is guaranteed to be able to
connect immediately. By switching from -daemonize to the
virCommandDaemonize API libvirtd was no longer synchronized with
QEMU's startup process. The result was that the QEMU monitor
failed to open and went into its 200ms sleep loop. This happened
for all 25 binaries resulting in 5 seconds worth of sleeping
at libvirtd startup. In addition sometimes when libvirt connected,
QEMU would be partially initialized and crash causing total
failure to probe that binary.
This commit reverts the previous change, ensuring we do use the
-daemonize flag to QEMU. Startup delay is cut from 7 seconds
to 2 seconds on my machine, which is on a par with what it was
prior to the capabilities rewrite.
To deal with the fact that QEMU needs to be able to create the
pidfile, we switch pidfile location fron runDir to libDir, which
QEMU is guaranteed to be able to write to.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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>
The autodestroy callback code has the following function
called from a hash iterator
qemuDriverCloseCallbackRun(void *payload,
const void *name,
void *opaque)
{
...
char *uuidstr = name
...
dom = closeDef->cb(data->driver, dom, data->conn);
if (dom)
virObjectUnlock(dom);
virHashRemoveEntry(data->driver->closeCallbacks, uuidstr);
}
The closeDef->cb function may well cause the current callback
to be removed, if it shuts down 'dom'. As such the use of
'uuidstr' in virHashRemoveEntry is accessing free'd memory.
We must make a copy of the uuid str before invoking the
callback to be safe.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When linuxNodeInfoCPUPopulate() method triggered use of an
uninitialize value, since it did not initialize the 'sockets'
field in the virNodeInfoPtr struct:
==30020== Conditional jump or move depends on uninitialised value(s)
==30020== at 0x5125DBD: linuxNodeInfoCPUPopulate (nodeinfo.c:513)
==30020== by 0x51261A0: nodeGetInfo (nodeinfo.c:884)
==30020== by 0x149B9B10: qemuCapsInit (qemu_capabilities.c:846)
==30020== by 0x14A11B25: qemuCreateCapabilities (qemu_driver.c:424)
==30020== by 0x14A12426: qemuStartup (qemu_driver.c:874)
==30020== by 0x512A7AF: virStateInitialize (libvirt.c:822)
==30020== by 0x40DE04: daemonRunStateInit (libvirtd.c:877)
==30020== by 0x50ADCE5: virThreadHelper (virthreadpthread.c:161)
==30020== by 0x328CA07D14: start_thread (pthread_create.c:308)
==30020== by 0x328C6F246C: clone (clone.S:114)
(happened twice)
if (socks > nodeinfo->sockets) <--- here
nodeinfo->sockets = socks;
Rather than doing this for each field, just make the caller memset
the entire struct to zero.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Although the nwfilter driver skips startup when running in a
session libvirtd, it did not skip reload or shutdown. This
caused errors to be reported when sending SIGHUP to libvirtd,
and caused an abort() in libdbus on shutdown due to trying
to remove a dbus filter that was never added
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>
When creating the virClass object for virNetClient, we specified
virObject as the parent instead of virObjectLockable
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The QEMU driver default max port is 65535, but it then increments
this by 1 to 65536. This maps to 0 in an unsigned short :-( This
was apparently done so that for() loops could use "< max" instead
of "<= max". Remove this insanity and just make the loop do the
right thing.
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>
A great many virObject instances require a mutex, so introduce
a convenient class for this which provides a mutex. This avoids
repeating the tedious init/destroy code
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently all classes must directly inherit from virObject.
This allows for arbitrarily deep hierarchy. There's not much
to this aside from chaining up the 'dispose' handlers from
each class & providing APIs to check types.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Add a 'lxc-enter-namespace' command which accepts a domain name
and then a command + args to run, attached to the container
eg
virsh -c lxc:/// lxc-enter-namespace demo -- /bin/ps -auxf
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virDomainLxcOpenNamespace method needs to open every file
in /proc/$INITPID/ns and return the open file descriptor to the
client application.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Some places missed the conversion from LIBCURL_{CFLAGS,LIBS} to
CURL_{CFLAGS,LIBS}, and a part of curl check was left in
configure.ac instead of m4/virt-curl.m4 by mistake
This patch introduces support for LXC specific public APIs. In
common with what was done for QEMU, this creates a libvirt_lxc.so
library and libvirt/libvirt-lxc.h header file.
The actual APIs are
int virDomainLxcOpenNamespace(virDomainPtr domain,
int **fdlist,
unsigned int flags);
int virDomainLxcEnterNamespace(virDomainPtr domain,
unsigned int nfdlist,
int *fdlist,
unsigned int *noldfdlist,
int **oldfdlist,
unsigned int flags);
which provide a way to use the setns() system call to move the
calling process into the container's namespace. It is not
practical to write in a generically applicable manner. The
nearest that we could get to such an API would be an API which
allows to pass a command + argv to be executed inside a
container. Even if we had such a generic API, this LXC specific
API is still useful, because it allows the caller to maintain
the current process context, in particular any I/O streams they
have open.
NB the virDomainLxcEnterNamespace() API is special in that it
runs client side, so does not involve the internal driver API.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
There are many aspects of the guest XML which result in the
SELinux driver applying file labelling. With the increasing
configuration options it is desirable to test this behaviour.
It is not possible to assume that the test suite has the
ability to set SELinux labels. Most filesystems though will
support extended attributes. Thus for the purpose of testing,
it is possible to extend the existing LD_PRELOAD hack to
override setfilecon() and getfilecon() to simply use the
'user.libvirt.selinux' attribute for the sake of testing.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This converts the libssh2 configure check to use LIBVIRT_CHECK_PKG.
Previously it would check version 1.0 and 1.3, but this simplifies
things to just require version 1.3
Most checks for libraries take the same format
* --with-libFOO=yes|no|check|/some/path argument
* check for a function NNN in libFOO.so
* check for a header file DDD/HHH.h
* Define a WITH_FOO config.h symbol
* Define a WITH_FOO make conditional
* Substitute FOO_CFLAGS and FOO_LIBS make variables
* Print CFLAGS & LIBS summary at the end
Doing all this correctly is rather difficult, typically
done by copy+paste of a previous usage. Further small
improvements people make are not applied to all previous
usages.
Improve this by creating some helper macros to apply
good practice. First, to perform the actual checks:
LIBVIRT_CHECK_LIB([SELINUX], [selinux],
[getfilecon], [selinux/selinux.h])
This checks for 'getfilecon' in -lselinux, and the
existence of 'selinux/selinux.h' header file. If successful
it sets SELINUX_CFLAGS and SELINUX_LIBS. The WITH_SELINUX
config.h macro and WITH_SELINUX make conditional are also
defined.
In some cases we need to check two variants of the same
library
LIBVIRT_CHECK_LIB_ALT([SASL], [sasl2],
[sasl_client_init], [sasl/sasl.h],
[SASL1], [sasl],
[sasl_client_init], [sasl/sasl.h])
This checks for sasl_client_init in libsasl2, and if that
is not found, checks sasl_client_init in libsasl. If the
first check succeeds WITH_SASL is set, while if the second
check succeeds *both* WITH_SASL and WITH_SASL1 are set.
If the library supports pkg-config, then another variant
is available
LIBVIRT_CHECK_PKG([AVAHI], [avahi-client], [0.6.0])
This checks for avahi-client >= 0.6.0 via pkg-config
and sets WITH_AVAHI if found.
Finally to print a summary of CFLAGS & LIBs found (if any):
LIBVIRT_RESULT_LIB([SELINUX])
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
To avoid confusion between the LXC driver <-> controller
monitor RPC protocol and the libvirt-lxc.so <-> libvirtd public
RPC protocol, rename the former to lxc_monitor_protocol.x
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently the libvirt client can pass FDs to the server, but the
dispatch mechanism provides no way to return FDs back from the
server to the client. Tweak the dispatch code, such that if a
dispatcher returns '1', this indicates that it populated the
virNetMessagePtr with FDs to return
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
A number of bugs handling file descriptors received from the
server caused the FDs to be lost and leaked.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The QEMU specific APIs all operate on domains, not the host,
so should be in the virsh-domain.c file / group
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Daniel P. Berrange