I am trying to use a qcow image with libvirt where the backing 'file' is a
qemu-nbd server. Unfortunately virDomainDiskDefForeachPath() assumes that
backingStore is always a real file so something like 'nbd:0:3333' is rejected
because a file with that name cannot be accessed. Note that I am not worried
about directly using nbd images. That would require a new disk type with XML
markup, etc. I only want it to be permitted as a backingStore
The following patch implements danpb's suggestion:
> I think I'm inclined to push the logic for skipping NBD one stage higher.
> I'd rather expect virStorageFileGetMetadata() to return all backing
> stores, even if not files. The virDomainDiskDefForeachPath() method
> should definitely ignore non-file backing stores though.
>
> So what I'm thinking is to extend the virStorageFileMetadata struct and
> just add a 'bool isFile' field to it. Default this field to true, unless
> you see the prefix of nbd: in which case set it to false. The
> virDomainDiskDefForeachPath() method can then skip over any backing
> store with isFile == false
Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: Daniel P. Berrange <berrange@redhat.com>
When adding domainMemoryStats API support for the qemu driver, I didn't
follow the locking rules exactly. The job condition must be held when
executing monitor commands. This corrects the segfaults I was seeing
when calling domainMemoryStats in a multi-threaded environment.
* src/qemu/qemu_driver.c: in qemudDomainMemoryStats() add missing
calls to qemuDomainObjBeginJob/qemuDomainObjEndJob
Fix a small problem with the qemu memory stats parsing algorithm. If qemu
reports a stat that libvirt does not recognize, skip past it so parsing can
continue. This corrects a potential infinite loop in the parsing code that can
only be triggered if new statistics are added to qemu.
* src/qemu/qemu_monitor_text.c: qemuMonitorParseExtraBalloonInfo add a
skip for extra ','
The behavior for the qemu balloon device has changed. Formerly, a virtio
balloon device was provided by default. Now, '-balloon virtio' must be
specified on the command line to enable it. This patch causes libvirt to
add '-balloon virtio' to the command line whenever the -balloon option is
available.
* src/qemu/qemu_conf.c src/qemu/qemu_conf.h: check for the new flag and
add "-baloon vitio" to qemu command when needed
* tests/qemuhelptest.c: add the new flag for detection
Enable virDomainMemoryStats in the python API. dom.memoryStats() will return a
dictionary containing the supported statistics. A dictionary is required
because the meaining of each quantity cannot be inferred from its index in a
list.
* python/generator.py: reenable bindings for this entry point
* python/libvirt-override-api.xml python/libvirt-override.c: the
generator can't handle this new function, add the new binding,
and the XML description
Define a new command 'dommemstats' to report domain memory statistics. The
output format is inspired by 'domblkstat' and 'domifstat' and consists of
tag/value pairs, one per line. The command can complete successfully and
print no output if virDomainMemoryStats is supported by the driver, but not
the guest operating system.
Sample output:
swap_in 0
swap_out 0
major_fault 54
minor_fault 58259
unused 487680
available 502472
All stats referring to a quantity of memory (eg. all above except major and
minor faults) represent the quantity in KBytes.
* tools/virsh.c: implements the new command
Use a dynamically sized xdr_array to pass memory stats on the wire. This
supports the addition of future memory stats and reduces the message size
since only supported statistics are returned.
* src/remote/remote_protocol.x: provide defines for the new entry point
* src/remote/remote_driver.c daemon/remote.c: implement the client and
server side
* daemon/remote_dispatch_args.h daemon/remote_dispatch_prototypes.h
daemon/remote_dispatch_ret.h daemon/remote_dispatch_table.h
src/remote/remote_protocol.c src/remote/remote_protocol.h: generated
stubs
Support for memory statistics reporting is accepted for qemu inclusion.
Statistics are reported via the monitor command 'info balloon' as a comma
seprated list:
(qemu) info balloon
balloon: actual=1024,mem_swapped_in=0,mem_swapped_out=0,major_page_faults=88,minor_page_faults=105535,free_mem=1017065472,total_mem=1045229568
Libvirt, qemu, and the guest operating system may support a subset of the
statistics defined by the virtio spec. Thus, only statistics recognized by
components will be reported.
* src/qemu/qemu_driver.c src/qemu/qemu_monitor_text.[ch]: implement the
new entry point by using info balloon monitor command
Set up the types for the domainMemoryStats function and insert it into the
virDriver structure definition. Because of static initializers, update
every driver and set the new field to NULL.
* include/libvirt/libvirt.h.in: new API
* src/driver.h src/*/*_driver.c src/vbox/vbox_tmpl.c: add the new
entry to the driver structure
* python/generator.py: fix compiler errors, the actual python binding is
implemented later
Adam Litke