QEMU monitor commands may sleep for a prolonged period of time.
If the virDomainObjPtr or qemu driver lock is held this will
needlessly block execution of many other API calls. it also
prevents asynchronous monitor events from being dispatched
while a monitor command is executing, because deadlock will
ensure.
To resolve this, it is neccessary to release all locks while
executing a monitor command. This change introduces a flag
indicating that a monitor job is active, and a condition
variable to synchronize access to this flag. This ensures that
only a single thread can be making a state change or executing
a monitor command at a time, while still allowing other API
calls to be completed without blocking
* src/qemu/qemu_driver.c: Release driver and domain lock when
running monitor commands. Re-add locking to disk passphrase
callback
* src/qemu/THREADS.txt: Document threading rules
Change the QEMU monitor file handle watch to poll for both
read & write events, as well as EOF. All I/O to/from the
QEMU monitor FD is now done in the event callback thread.
When the QEMU driver needs to send a command, it puts the
data to be sent into a qemuMonitorMessagePtr object instance,
queues it for dispatch, and then goes to sleep on a condition
variable. The event thread sends all the data, and then waits
for the reply to arrive, putting the response / error data
back into the qemuMonitorMessagePtr and notifying the condition
variable.
There is a temporary hack in the disk passphrase callback to
avoid acquiring the domain lock. This avoids a deadlock in
the command processing, since the domain lock is still held
when running monitor commands. The next commit will remove
the locking when running commands & thus allow re-introduction
of locking the disk passphrase callback
* src/qemu/qemu_driver.c: Temporarily don't acquire lock in
disk passphrase callback. To be reverted in next commit
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h: Remove
raw I/O functions, and a generic qemuMonitorSend() for
invoking a command
* src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h:
Remove all low level I/O, and use the new qemuMonitorSend()
API. Provide a qemuMonitorTextIOProcess() method for detecting
command/reply/prompt boundaries in the monitor data stream
Use ssh keyfiles from the current user's home directory instead of trying
to use keyfiles from a hardcoded /home/user directory. Fallback to
username/password authentication if keyfiles are not available or keyfile
authentication failed.
Add reference counting on the virDomainObjPtr objects. With the
forthcoming asynchronous QEMU monitor, it will be neccessary to
release the lock on virDomainObjPtr while waiting for a monitor
command response. It is neccessary to ensure one thread can't
delete a virDomainObjPtr while another is waiting. By introducing
reference counting threads can make sure objects they are using
are not accidentally deleted while unlocked.
* src/conf/domain_conf.h, src/conf/domain_conf.c: Add
virDomainObjRef/Unref APIs, remove virDomainObjFree
* src/openvz/openvz_conf.c: replace call to virDomainObjFree
with virDomainObjUnref
In preparation of the monitor I/O process becoming fully asynchronous,
it is neccessary to ensure all access to internals of the qemuMonitorPtr
object is protected by a mutex lock.
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h: Add mutex for locking
monitor.
* src/qemu/qemu_driver.c: Add locking around all monitor commands
Change the QEMU driver to not directly invoke the text mode monitor
APIs. Instead add a generic wrapper layer, which will eventually
invoke either the text or JSON protocol code as needed. Pass an
qemuMonitorPtr object into the monitor APIs instead of virDomainObjPtr
to complete the de-coupling of the monitor impl from virDomainObj
data structures
* src/qemu/qemu_conf.h: Remove qemuDomainObjPrivate definition
* src/qemu/qemu_driver.c: Add qemuDomainObjPrivate definition.
Pass qemuMonitorPtr into all monitor APIs instead of the
virDomainObjPtr instance.
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h: Add thin
wrappers for all qemuMonitorXXX command APIs, calling into
qemu_monitor_text.c/h
* src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h:
Rename qemuMonitor -> qemuMonitorText & update to accept
qemuMonitorPtr instead of virDomainObjPtr
Decouple the monitor code from the virDomainDefPtr structure
by moving the disk encryption lookup code back into the
qemu_driver.c file. Instead provide a function callback to
the monitor code which can be invoked to retrieve encryption
data as required.
* src/qemu/qemu_driver.c: Add findDomainDiskEncryption,
and findVolumeQcowPassphrase. Pass address of the method
findVolumeQcowPassphrase into qemuMonitorOpen()
* src/qemu/qemu_monitor.c: Associate a disk
encryption function callback with the qemuMonitorPtr
object.
* src/qemu/qemu_monitor_text.c: Remove findDomainDiskEncryption
and findVolumeQcowPassphrase.
Introduce a new qemuDomainObjPrivate object which is used to store
the private QEMU specific data associated with each virDomainObjPtr
instance. This contains a single member, an instance of the new
qemuMonitorPtr object which encapsulates the QEMU monitor state.
The internals of the latter are private to the qemu_monitor* files,
not to be shown to qemu_driver.c
* src/qemu/qemu_conf.h: Definition of qemuDomainObjPrivate.
* src/qemu/qemu_driver.c: Register a functions for creating
and freeing qemuDomainObjPrivate instances with the domain
capabilities. Remove the qemudDispatchVMEvent() watch since
I/O watches are now handled by the monitor code itself. Pass
a new qemuHandleMonitorEOF() callback into qemuMonitorOpen
to allow notification when the monitor quits.
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h: Introduce
the 'qemuMonitor' object. Temporarily add new APIs
qemuMonitorWrite, qemuMonitorRead, qemuMonitorWaitForInput
to allow text based monitor impl to perform I/O.
* src/qemu/qemu_monitor_text.c: Call APIs for reading/writing
to monitor instead of accessing the file handle directly.
The qemu_driver.c code should not contain any code that interacts
with the QEMU monitor at a low level. A previous commit moved all
the command invocations out. This change moves out the code which
actually opens the monitor device.
* src/qemu/qemu_driver.c: Remove qemudOpenMonitor & methods called
from it.
* src/Makefile.am: Add qemu_monitor.{c,h}
* src/qemu/qemu_monitor.h: Add qemuMonitorOpen()
* src/qemu/qemu_monitor.c: All code for opening the monitor
* src/util/threads-pthread.c: pthreads APIs do not set errno, instead
the return value is the positive errno. Set errno based on the return
value in the wrappers
* src/util/pci.c, src/util/pci.h: Make the pciDeviceList struct
opaque to callers of the API. Add accessor methods for managing
devices in the list
* src/qemu/qemu_driver.c: Update to use APIs instead of directly
accessing pciDeviceList fields
* docs/formatdomain.html.in: refactors the existing character device
documentation to make it explicit which directives configure the guest
interface, and which configure the host interface.
As it was basically unimplemented and more confusing than useful
at the moment.
* src/libvirt_private.syms: remove from internal symbols list
* src/qemu/qemu_bridge_filter.c src/util/ebtables.c: remove code and
one use of the unimplemented function
In case of an error the domains hash and the driver mutex may leak.
* src/opennebula/one_driver.c: free/destroy domains hash and driver
mutex in error cases
It also demonstrates how to use the libvirt.openAuth() method.
* examples/python/Makefile.am: add esxlist.py to EXTRA_DIST
* examples/python/README: add some notes about esxlist.py
* examples/python/esxlist.py: the new example
- Make reading ID from file working for IDs > 127
- Fix inverse error check for writing ID to file
- Use feof() to distinguish EOF from real error of fread()
- Don't interpret libssh2 error codes as number of bytes
phypNumDomainsGeneric() and phypListDomainsGeneric() return 0 in case
of an error. This makes it impossible to distinguish between an actual
error and no domains being defined on the hypervisor. It also turn the
no domains situation into an error. Return -1 in case of an error to
fix this problem.
* src/network/bridge_driver.c: when exec'ing dnsmaq, if there are
DHCP ranges defined, then compute and pass the --dhcp-lease-max
deriving the maximum number of leases
* src/conf/network_conf.h: extend the structure to store the range
* src/conf/network_conf.c: before adding a range parse the IP addresses
do some checking and keep the size
This patch is the result of running the following command in the docs
directory: sed -i 's/\t/ /g; s/\s*$//' *.html.in
* docs/*.html.in:convert tabs into 8 spaces and remove trailing whitespace
* src/internal.h (ATTRIBUTE_SENTINEL): New, it's a ggc feature and
protected as such
* src/util/buf.c (virBufferStrcat): Use it.
* src/util/ebtables.c (ebtablesAddRemoveRule): Use it.
* src/util/iptables.c (iptableAddRemoveRule: Use it.
* src/util/qparams.h (new_qparam_set, append_qparams): Use it.
* docs/apibuild.py: avoid breaking the API generator with that new
internal keyword macro
* include/libvirt/virterror.h src/util/virterror.c: add a new error
VIR_ERR_CONFIG_UNSUPPORTED for valid but unsupported configuration options
* src/conf/domain_conf.c: Throw an error if guestfwd address isn't IPv4
and cleanup a number of parsing return error values.
allows the following to be specified in a domain:
<channel type='pipe'>
<source path='/tmp/guestfwd'/>
<target type='guestfwd' address='10.0.2.1' port='4600'/>
</channel>
* proxy/Makefile.am: add network.c as dep of domain_conf.c
* docs/schemas/domain.rng src/conf/domain_conf.[ch]: extend the domain
schemas and the parsing/serialization side for the new construct
QEmu support will add the following on the qemu command line:
-chardev pipe,id=channel0,path=/tmp/guestfwd
-net user,guestfwd=tcp:10.0.2.1:4600-chardev:channel0
* src/qemu/qemu_conf.c: Add argument output for channel
* tests/qemuxml2(argv|xml)test.c: Add test for <channel> domain syntax
A character device's target (it's interface in the guest) had only a
single property: port. This patch is in preparation for adding targets
which require other properties.
Since this changes the conf type for character devices this affects
a number of drivers:
* src/conf/domain_conf.[ch] src/esx/esx_vmx.c src/qemu/qemu_conf.c
src/qemu/qemu_driver.c src/uml/uml_conf.c src/uml/uml_driver.c
src/vbox/vbox_tmpl.c src/xen/xend_internal.c src/xen/xm_internal.c:
target properties are moved into a union in virDomainChrDef, and a
targetType field is added to identify which union member should be
used. All current code which touches a virDomainChrDef is updated both
to use the new union field, and to populate targetType if necessary.
Current implementation of lxc driver creates vethN named
interface(s) in the host and passes as it is to a container.
The reason why it doesn't use ethN is due to the limitation
that one namespace cannot have multiple iterfaces that have
an identical name so that we give up creating ethN named
interface in the host for the container.
However, we should be able to allow the container to have
ethN by changing the name after clone(CLONE_NEWNET).
* src/lxc/lxc_container.c src/lxc/veth.c src/lxc/veth.h: do the clone
and then renames interfaces eth0 ... ethN to keep the interface names
familiar in the domain
* src/lxc/lxc_container.c src/lxc/lxc_controller.c src/lxc/lxc_driver.c
src/lxc/veth.c: most of cleanups are just capitalizing their messages
though, some fixes wrong error messages and awkward indentations, and
improves error messages.
