The last Viktor's effort to fix the race and memory corruption unfortunately
wasn't complete in the case the close callback was not registered in an
connection. At that time, the trail of event's that I'll describe later could
still happen and corrupt the memory or cause a crash of the client (including
the daemon in case of a p2p migration).
Consider the following prerequisities and trail of events:
Let's have a remote connection to a hypervisor that doesn't have a close
callback registered and the client is using the event loop. The crash happens in
cooperation of 2 threads. Thread E is the event loop and thread W is the worker
that does some stuff. R denotes the remote client.
1.) W - The client finishes everything and sheds the last reference on the client
2.) W - The virObject stuff invokes virConnectDispose that invokes doRemoteClose
3.) W - the remote close method invokes the REMOTE_PROC_CLOSE RPC method.
4.) W - The thread is preempted at this point.
5.) R - The remote side receives the close and closes the socket.
6.) E - poll() wakes up due to the closed socket and invokes the close callback
7.) E - The event loop is preempted right before remoteClientCloseFunc is called
8.) W - The worker now finishes, and frees the conn object.
9.) E - The remoteClientCloseFunc accesses the now-freed conn object in the
attempt to retrieve pointer for the real close callback.
10.) Kaboom, corrupted memory/segfault.
This patch tries to fix this by introducing a new object that survives the
freeing of the connection object. We can't increase the reference count on the
connection object itself or the connection would never be closed, as the
connection is closed only when the reference count reaches zero.
The new object - virConnectCloseCallbackData - is a lockable object that keeps
the pointers to the real user registered callback and ensures that the
connection callback is either not called if the connection was already freed or
that the connection isn't freed while this is being called.
By adjusting the reference count of the connection object we
prevent races between callback function and virConnectClose.
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
virConnectOpenAuth didn't require 'name' to be specified (VIR_DEBUG
used NULLSTR() for the output) and by default, if name == NULL, the
default connection uri is used. This was not indicated in the
documentation and wasn't checked for in other API's VIR_DEBUG outputs.
VIR_CONNECT_LIST_NODE_DEVICES_CAP_FC_HOST to filter the FC HBA,
and VIR_CONNECT_LIST_NODE_DEVICES_CAP_VPORTS to filter the FC HBA
which supports vport.
These two flags in fact are mutually exclusive. Requesting them both
doesn't make any sense regardless of hypervisor driver. Hence, we have
to make it within libvirt.c file instead of fixing it in each driver.
Eugene Marcotte reported that if gcrypt-devel (a prereq of
gnutls-devel) is not present, then compilation fails due to
an unconditional use of <gcrypt.h>.
* src/libvirt.c (includes): Properly guard use of gcrypt.h.
VIR_ERR_NO_CONNECT already contains "no connection driver available".
This patch changes:
no connection driver available for No connection for URI hello
to:
no connection driver available for hello
Bug: https://bugzilla.redhat.com/show_bug.cgi?id=851413
Since the name (like scsi_host10) is not stable for vHBA, (it can
be changed either after recreating or system rebooting), current
API virNodeDeviceLookupByName is not nice to use for management app
in this case. (E.g. one wants to destroy the vHBA whose name has
been changed after system rebooting, he has to find out current
name first).
Later patches will support the persistent vHBA via storage pool,
with which one can identify the vHBA stably by the wwnn && wwpn
pair.
So this new API comes.
https://bugzilla.redhat.com/show_bug.cgi?id=895882
virDomainSnapshot.getDomain() and virDomainSnapshot.getConnect()
wrappers around virDomainSnapshotGet{Domain,Connect} were not supposed
to be ever implemented. The class should contain proper domain() and
connect() accessors that fetch python objects stored internally within
the class. While domain() was already provided, connect() was missing.
This patch adds connect() method to virDomainSnapshot class and
reimplements getDomain() and getConnect() methods as aliases to domain()
and connect() for backward compatibility.
This patch adds a new API, virDomainOpenChannel, that uses streams to
connect to a virtio channel on a guest. This creates a secure
communication channel between a guest and a libvirt client.
This behaves the same as virDomainOpenConsole, except on channels
instead of console/serial/parallel devices.
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).
Add VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA flag to virStorageVolCreateXML
and virStorageVolCreateXMLFrom. This flag requests metadata
preallocation when creating/cloning qcow2 images, resulting in creating
a sparse file with qcow2 metadata. It has only slightly larger disk usage
compared to new image with no allocation, but offers higher performance.
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>
Commit a21f5112 fixed one API, but missed two others that also
failed to log their 'flags' argument.
* src/libvirt.c (virNodeSuspendForDuration, virDomainGetHostname):
Log flags parameter.
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>
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>
To allow actions to be performed in libvirtd when the host
shuts down, or user session exits, introduce a 'stop'
method to virDriverState. This will do things like saving
the VM state to a file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Add an API for sending signals to arbitrary processes in the
guest OS. This is primarily useful for container based virt,
but can be used for machine virt too, if there is a suitable
guest agent,
* include/libvirt/libvirt.h.in: Add virDomainSendProcessSignal
and virDomainProcessSignal enum
* src/driver.h: Driver entry point
* src/libvirt.c, src/libvirt_public.syms: Impl for new API
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The documentation to this API has some defects from
grammar and wording POV. These were raised after I've
pushed the patches, so they are in a separate commit.
It makes no sense to fail the whole getting command if there is
a parameter unsupported by the kernel. This patch fixes it by
omitting the unsupported parameter for getMemoryParameters.
And for setMemoryParameters, this checks if there is an unsupported
parameter up front of the setting, and just returns failure if not
all parameters are supported.
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.
This will call FITRIM within guest. The API has 4 arguments,
however, only 2 will be used for now (@dom and @minumum).
The rest two are there if in future qemu guest agent learns them.
As we enable more modes of snapshot creation, it becomes more important
to be able to quickly filter based on snapshot properties. This patch
introduces new filter flags; subsequent patches will introduce virsh
back-compat filtering, as well as actual libvirt filtering.
* include/libvirt/libvirt.h.in (virDomainSnapshotListFlags): Add
five new flags in two new groups.
* src/libvirt.c (virDomainSnapshotNum, virDomainSnapshotListNames)
(virDomainListAllSnapshots, virDomainSnapshotNumChildren)
(virDomainSnapshotListChildrenNames)
(virDomainSnapshotListAllChildren): Document them.
* src/conf/snapshot_conf.h (VIR_DOMAIN_SNAPSHOT_FILTERS_STATUS)
(VIR_DOMAIN_SNAPSHOT_FILTERS_LOCATION): Add new convenience filter
collection macros.
* tools/virsh-snapshot.c (cmdSnapshotList): Add 5 new flags.
* tools/virsh.pod (snapshot-list): Document them.
The default behavior while creating external checkpoints is to pause the
guest while the memory state is captured. We want the users to sacrifice
space saving for creating the memory save image while the guest is live
to minimize downtime.
This patch adds a flag that causes the guest not to be paused before
taking the snapshot.
*include/libvirt/libvirt.h.in:
- add new paused reason: VIR_DOMAIN_PAUSED_SNAPSHOT
- add new flag for taking snapshot: VIR_DOMAIN_SNAPSHOT_CREATE_LIVE
*tools/virsh-domain-monitor.c:
- add string representation for VIR_DOMAIN_PAUSED_SNAPSHOT
*tools/virsh-snapshot.c:
- add support for VIR_DOMAIN_SNAPSHOT_CREATE_LIVE
*tools/virsh.pod:
- add docs for --live option added to use
VIR_DOMAIN_SNAPSHOT_CREATE_LIVE flag
The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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.
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.
Adding a new API to obtain information about the
host node's present, online and offline CPUs.
int virNodeGetCPUMap(virConnectPtr conn,
unsigned char **cpumap,
unsigned int *online,
unsigned int flags);
The function will return the number of CPUs present on the host
or -1 on failure;
If cpumap is non-NULL virNodeGetCPUMap will allocate an array
containing a bit map representation of the online CPUs. It's
the callers responsibility to deallocate cpumap using free().
If online is non-NULL, the variable pointed to will contain
the number of online host node CPUs.
The variable flags has been added to support future extensions
and must be set to 0.
Extend the driver structure by nodeGetCPUMap entry in support of the
new API virNodeGetCPUMap.
Added implementation of virNodeGetCPUMap to libvirt.c
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
In v2 migration protocol, XML is obtained by calling domainGetXMLDesc.
This includes the default USB controller in XML, which breaks migration
to older libvirt (before 0.9.2).
Commit 409b5f5495
qemu: Emit compatible XML when migrating a domain
only fixed this for v3 migration.
This patch uses the new VIR_DOMAIN_XML_MIGRATABLE flag (detected by
VIR_DRV_FEATURE_XML_MIGRATABLE) to obtain XML without the default controller,
enabling backward v2 migration.
Now that we can crawl the chain of backing files, we can do
argument validation and implement the 'shallow' flag. In
testing this, I discovered that it can be handy to pass the
shallow flag and an explicit base, as a means of validating
that the base is indeed the file we expected.
* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Crawl through
chain to implement shallow flag.
* src/libvirt.c (virDomainBlockCommit): Relax API.
Currently there is a restriction that multi-threaded applications
must manually call virInitialize, before threads start using
libvirt, because it is not thread-safe. By switching it to use
a virOnceControl initializer we gain thread safety, and thus
applications no longer need to manually call it. They can rely
on virConnectOpen invoking it for them.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
