This patch adds XML definitions for guest NUMA specification and contains
routines to parse the same. The guest NUMA specification looks like this:
<cpu>
...
<topology sockets='2' cores='4' threads='2'/>
<numa>
<cell cpus='0-7' memory='512000'/>
<cell cpus='8-15' memory='512000'/>
</numa>
...
</cpu>
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
While Xen only has a single paravirt console, UML, and
QEMU both support multiple paravirt consoles. The LXC
driver can also be trivially made to support multiple
consoles. This patch extends the XML to allow multiple
<console> elements in the XML. It also makes the UML
and QEMU drivers support this config.
* src/conf/domain_conf.c, src/conf/domain_conf.h: Allow
multiple <console> devices
* src/lxc/lxc_driver.c, src/xen/xen_driver.c,
src/xenxs/xen_sxpr.c, src/xenxs/xen_xm.c: Update for
internal API changes
* src/security/security_selinux.c, src/security/virt-aa-helper.c:
Only label consoles that aren't a copy of the serial device
* src/qemu/qemu_command.c, src/qemu/qemu_driver.c,
src/qemu/qemu_process.c, src/uml/uml_conf.c,
src/uml/uml_driver.c: Support multiple console devices
* tests/qemuxml2xmltest.c, tests/qemuxml2argvtest.c: Extra
tests for multiple virtio consoles. Set QEMU_CAPS_CHARDEV
for all console /channel tests
* tests/qemuxml2argvdata/qemuxml2argv-channel-virtio-auto.args,
tests/qemuxml2argvdata/qemuxml2argv-channel-virtio.args
tests/qemuxml2argvdata/qemuxml2argv-console-virtio.args: Update
for correct chardev syntax
* tests/qemuxml2argvdata/qemuxml2argv-console-virtio-many.args,
tests/qemuxml2argvdata/qemuxml2argv-console-virtio-many.xml: New
test file
Allow the datacenter and compute resource parts of the path
to be prefixed with folders. Therefore, the way the path is
parsed has changed. Before, it was split in 2 or 3 items and
the items' meanings were determined by their positions. Now
the path can have 2 or more items and the the vCenter server
is asked whether a folder, datacenter of compute resource
with the specified name exists at the current hierarchy level.
Before the datacenter and compute resource lookup automatically
traversed folders during lookup. This is logic got removed
and folders have to be specified explicitly.
The proper datacenter path including folders is now used when
accessing a datastore over HTTPS. This makes virsh dumpxml
and define work for datacenters in folders.
https://bugzilla.redhat.com/show_bug.cgi?id=732676
The types used in domaincommon.rng and secret.rng should be the same.
Move genericName to basictypes.rng, then drop redundant types now
that secret.rng uses basictypes.rng.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Add additional fields to let you specify the how to authenticate with a disk.
The secret to use may be referenced by a usage string or a UUID, i.e.:
<auth username='myuser'>
<secret type='ceph' usage='secretname'/>
</auth>
or
<auth username='myuser'>
<secret type='ceph' uuid='0a81f5b2-8403-7b23-c8d6-21ccc2f80d6f'/>
</auth>
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Add a new secret type to store a Ceph authentication key. The name
is simply an identifier for easy human reference.
The xml looks like this:
<secret ephemeral='no' private='no'>
<uuid>0a81f5b2-8403-7b23-c8d6-21ccc2f80d6f</uuid>
<usage type='ceph'>
<name>mycluster_admin</name>
</usage>
</secret>
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.net>
Define two new RPC message types VIR_NET_CALL_WITH_FDS and
VIR_NET_REPLY_WITH_FDS. These message types are equivalent
to VIR_NET_CALL and VIR_NET_REPLY, except that between the
message header, and payload there is a 32-bit integer field
specifying how many file descriptors have been passed.
The actual file descriptors are sent/recv'd out of band.
* src/rpc/virnetmessage.c, src/rpc/virnetmessage.h,
src/libvirt_private.syms: Add support for handling
passed file descriptors
* src/rpc/virnetprotocol.x: Extend protocol for FD
passing
The 5th line of every xfig file has 'Letter ' which
annoys GITs trailing-whitespace commit hook. Hand edit
the files to remove that trailing whitespace
* docs/*.fig: Remove trailing whitespace
This adds a page documenting many aspects of migration:
- The types of migration (managed direct, p2p, unmanaged direct)
- Data transports (native, tunnelled)
- Migration URIs
- Config file handling
- Example scenarios
* libvirt.css: Rules for data tables and diagrams
* Makefile.am: Include extra png/fig files
* migration-managed-direct.fig, migration-managed-direct.png,
migration-managed-direct.png, migration-managed-p2p.png,
migration-native.fig, migration-native.png,
migration-tunnel.fig, migration-tunnel.png,
migration-unmanaged-direct.fig, migration-unmanaged-direct.png:
Diagrams of migration
* migration.html.in, sitemap.html.in: New migration doc
This attribute says what to do with cdrom (or floppy) if
the source is missing. It accepts:
- mandatory - fail if missing for any reason (the default)
- requisite - fail if missing on boot up, drop if missing on
migrate/restore/revert
- optional - drop if missing at any start attempt.
However, this patch introduces only XML part of this new
functionality.
In a recent expansion of the documentation on network forward modes, I
incorrectly stated that incoming sessions to guests on routed networks
were blocked. This is true for guests on NATed networks, but not
routed. This patch corrects that error, and adds a pointer to the
nwfilter page for those who do want to restrict incoming sessions to
hosts on routed networks.
Clarify some of the effects of managed passthrough <hostdev> devices;
with recent changes (commit d093547), a nodedev-reattach is only needed
to pair up to an explicit nodedev-dettach (but beware that older
virt-manager has a bug where it uses explicit nodedev-dettach under the
hood when using the gui to hotplug a hostdev device).
* docs/formatdomain.html.in: Mention reattach.
* tools/virsh.pod (nodedev): Mention managed mode.
This adds support for a libvirt client configuration file
either /etc/libvirt/libvirt.conf for privileged clients,
or $HOME/.libvirt/libvirt.conf for unprivileged clients.
It allows one parameter
uri_aliases = [
"hail=qemu+ssh://root@hail.cloud.example.com/system",
"sleet=qemu+ssh://root@sleet.cloud.example.com/system",
]
Any call to virConnectOpen with a non-NULL URI will first
attempt to match against the uri_aliases list. An application
can disable this by using VIR_CONNECT_NO_ALIASES
* docs/uri.html.in: Document URI aliases
* include/libvirt/libvirt.h.in: Add VIR_CONNECT_NO_ALIASES
* libvirt.spec.in, mingw32-libvirt.spec.in: Add /etc/libvirt/libvirt.conf
* src/Makefile.am: Install default config file
* src/libvirt.c: Add support for URI aliases
* src/remote/remote_driver.c: Don't try to handle URIs
with no scheme and which clearly are not paths
* src/util/conf.c: Don't raise error on virConfFree(NULL)
* src/xen/xen_driver.c: Don't raise error on URIs
with no scheme
A few people have attempted to use the new forwarding modes with older
versions of libvirt. The docs where the modes are described have
always stated the minimum required libvirt version, but the examples
at the end didn't, which I believe is what has caused the confusion.
Similarly, the section on portgroups now has a version tag added at
the beginning.
I also noticed that there was no example of defining a <dns> hostname,
so I added one, as well as making the domain name example more
recognizable (by adding ".com" to the domain).
VirtFS allows the user to choose between path/handle based fs driver.
As of now, libvirt hardcoded path based driver only. This patch provides
a solution to allow user to choose between path/handle based fs driver.
Sample:
<filesystem type='mount'>
<driver type='handle'/>
<source dir='/folder/to/share1'/>
<target dir='mount_tag1'/>
</filesystem>
<filesystem type='mount'>
<driver type='path'/>
<source dir='/folder/to/share2'/>
<target dir='mount_tag2'/>
</filesystem>
Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Previously libvirt's disk device XML only had a single attribute,
error_policy, to control both read and write error policy, but qemu
has separate options for controlling read and write. In one case
(enospc) a policy is allowed for write errors but not read errors.
This patch adds a separate attribute that sets only the read error
policy. If just error_policy is set, it will apply to both read and
write error policy (previous behavior), but if the new rerror_policy
attribute is set, it will override error_policy for read errors only.
Possible values for rerror_policy are "stop", "report", and "ignore"
("report" is the qemu-controlled default for rerror_policy when
error_policy isn't specified).
For consistency, the value "report" has been added to the possible
values for error_policy as well.
When booting a virtual machine with a kernel/initrd it is possible
to pass command line arguments using the <cmdline>...args...</cmdline>
element in the guest XML. These appear to the kernel / init process
in /proc/cmdline.
When booting a container we do not have a custom /proc/cmdline,
but we can easily set an environment variable for it. Ideally
we could pass individual arguments to the init process as a
regular set of 'char *argv[]' parameters, but that would involve
libvirt parsing the <cmdline> XML text. This can easily be added
later, even if we add the env variable now
* docs/drvlxc.html.in: Document env variables passed to LXC
* src/conf/domain_conf.c: Add <cmdline> to be parsed for
guests of type='exe'
* src/lxc/lxc_container.c: Set LIBVIRT_LXC_CMDLINE env var
When support for was added for PCI multifunction cards (in commit
9f8baf, first included in libvirt 0.9.3), it was done by always
turning on the multifunction bit for all PCI devices. Since that time
it has been realized that this is not an ideal solution, and that the
multifunction bit must be selectively turned on. For example, see
https://bugzilla.redhat.com/show_bug.cgi?id=728174
and the discussion before and after
https://www.redhat.com/archives/libvir-list/2011-September/msg01036.html
This patch modifies multifunction support so that the multifunction=on
option is only added to the qemu commandline for a device if its PCI
<address> definition has the attribute "multifunction='on'", e.g.:
<address type='pci' domain='0x0000' bus='0x00'
slot='0x04' function='0x0' multifunction='on'/>
In practice, the multifunction bit should only be turned on if
function='0' AND other functions will be used in the same slot - it
usually isn't needed for functions 1-7 (although there are apparently
some exceptions, e.g. the Intel X53 according to the QEMU source
code), and should never be set if only function 0 will be used in the
slot. The test cases have been changed accordingly to illustrate.
With this patch in place, if a user attempts to assign multiple
functions in a slot without setting the multifunction bit for function
0, libvirt will issue an error when the domain is defined, and the
define operation will fail. In the future, we may decide to detect
this situation and automatically add multifunction=on to avoid the
error; even then it will still be useful to have a manual method of
turning on multifunction since, as stated above, there are some
devices that excpect it to be turned on for all functions in a slot.
A side effect of this patch is that attempts to use the same PCI
address for two different devices will now log an error (previously
this would cause the domain define operation to fail, but there would
be no log message generated). Because the function doing this log was
almost completely rewritten, I didn't think it worthwhile to make a
separate patch for that fix (the entire patch would immediately be
obsoleted).
there is no option "none":
>From libvirt/src/conf/domain_conf.c
<snip>
VIR_ENUM_IMPL(virDomainTimerTickpolicy,
VIR_DOMAIN_TIMER_TICKPOLICY_LAST,
"delay",
"catchup",
"merge",
"discard");
</snip>
Replacing with delay.
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Coupled with the recent virsh nodedev-* doc patch, this should now
give a better picture of libvirt node device handling.
* docs/formatnode.html.in: Fill in page.
This patch was made in response to:
https://bugzilla.redhat.com/show_bug.cgi?id=738095
In short, qemu's default for the rombar setting (which makes the
firmware ROM of a PCI device visible/not on the guest) was previously
0 (not visible), but they recently changed the default to 1
(visible). Unfortunately, there are some PCI devices that fail in the
guest when rombar is 1, so the setting must be exposed in libvirt to
prevent a regression in behavior (it will still require explicitly
setting <rom bar='off'/> in the guest XML).
rombar is forced on/off by adding:
<rom bar='on|off'/>
inside a <hostdev> element that defines a PCI device. It is currently
ignored for all other types of devices.
At the moment there is no clean method to determine whether or not the
rombar option is supported by QEMU - this patch uses the advice of a
QEMU developer to assume support for qemu-0.12+. There is currently a
patch in the works to put this information in the output of "qemu-kvm
-device pci-assign,?", but of course if we switch to keying off that,
we would lose support for setting rombar on all the versions of qemu
between 0.12 and whatever version gets that patch.
QEMU 0.13 introduced cache=unsafe for -drive, this patch exposes
it in the libvirt layer.
* Introduced a new QEMU capability flag ($prefix_CACHE_UNSAFE),
as even if $prefix_CACHE_V2 is set, we can't know if unsafe
is supported.
* Improved the reliability of qemu cache type detection.
A new element is introduced to XML that allows to control
state of virtual network interfaces in hypervisors.
Live modification of the link state allows networking tools
propagate topology changes to guest OS or testing of
scenarios in complex (virtual) networks.
This patch adds elements to XML grammars and parsing and generating
code.
It is important to be able to attach USB redirected devices to a
particular controller (one that supports USB2 for instance).
Without this patch, only the default bus was used.
<redirdev bus='usb' type='spicevmc'>
<address type='usb' bus='0' port='4'/>
</redirdev>
I got confused when 'virsh domblkinfo dom disk' required the
path to a disk (which can be ambiguous, since a single file
can back multiple disks), rather than the unambiguous target
device name that I was using in disk snapshots. So, in true
developer fashion, I went for the best of both worlds - all
interfaces that operate on a disk (aka block) now accept
either the target name or the unambiguous path to the backing
file used by the disk.
* src/conf/domain_conf.h (virDomainDiskIndexByName): Add
parameter.
(virDomainDiskPathByName): New prototype.
* src/libvirt_private.syms (domain_conf.h): Export it.
* src/conf/domain_conf.c (virDomainDiskIndexByName): Also allow
searching by path, and decide whether ambiguity is okay.
(virDomainDiskPathByName): New function.
(virDomainDiskRemoveByName, virDomainSnapshotAlignDisks): Update
callers.
* src/qemu/qemu_driver.c (qemudDomainBlockPeek)
(qemuDomainAttachDeviceConfig, qemuDomainUpdateDeviceConfig)
(qemuDomainGetBlockInfo, qemuDiskPathToAlias): Likewise.
* src/qemu/qemu_process.c (qemuProcessFindDomainDiskByPath):
Likewise.
* src/libxl/libxl_driver.c (libxlDomainAttachDeviceDiskLive)
(libxlDomainDetachDeviceDiskLive, libxlDomainAttachDeviceConfig)
(libxlDomainUpdateDeviceConfig): Likewise.
* src/uml/uml_driver.c (umlDomainBlockPeek): Likewise.
* src/xen/xend_internal.c (xenDaemonDomainBlockPeek): Likewise.
* docs/formatsnapshot.html.in: Update documentation.
* tools/virsh.pod (domblkstat, domblkinfo): Likewise.
* docs/schemas/domaincommon.rng (diskTarget): Tighten pattern on
disk targets.
* docs/schemas/domainsnapshot.rng (disksnapshot): Update to match.
* tests/domainsnapshotxml2xmlin/disk_snapshot.xml: Update test.
Adds an optional element to <domainsnapshot>, which will be used
to give user control over external snapshot filenames on input,
and specify generated filenames on output.
For now, no driver accepts this element; that will come later.
<domainsnapshot>
...
<disks>
<disk name='vda' snapshot='no'/>
<disk name='vdb' snapshot='internal'/>
<disk name='vdc' snapshot='external'>
<driver type='qcow2'/>
<source file='/path/to/new'/>
</disk>
</disks>
<domain>
...
<devices>
<disk ...>
<driver name='qemu' type='raw'/>
<target dev='vdc'/>
<source file='/path/to/old'/>
</disk>
</devices>
</domain>
</domainsnapshot>
* src/conf/domain_conf.h (_virDomainSnapshotDiskDef): New type.
(_virDomainSnapshotDef): Add new elements.
(virDomainSnapshotAlignDisks): New prototype.
* src/conf/domain_conf.c (virDomainSnapshotDiskDefClear)
(virDomainSnapshotDiskDefParseXML, disksorter)
(virDomainSnapshotAlignDisks): New functions.
(virDomainSnapshotDefParseString): Parse new fields.
(virDomainSnapshotDefFree): Clean them up.
(virDomainSnapshotDefFormat): Output them.
* src/libvirt_private.syms (domain_conf.h): Export new function.
* docs/schemas/domainsnapshot.rng (domainsnapshot, disksnapshot):
Add more xml.
* docs/formatsnapshot.html.in: Document it.
* tests/domainsnapshotxml2xmlin/disk_snapshot.xml: New test.
* tests/domainsnapshotxml2xmlout/disk_snapshot.xml: Update.
In order to distinguish disk snapshots from system checkpoints, a
new state value that is only valid for snapshots is helpful.
* include/libvirt/libvirt.h.in (VIR_DOMAIN_LAST): New placeholder.
* src/conf/domain_conf.h (virDomainSnapshotState): New enum mapping.
(VIR_DOMAIN_DISK_SNAPSHOT): New internal enum value.
* src/conf/domain_conf.c (virDomainState): Use placeholder.
(virDomainSnapshotState): Extend mapping by one for use in snapshot.
(virDomainSnapshotDefParseString, virDomainSnapshotDefFormat):
Handle new state.
(virDomainObjSetState, virDomainStateReasonToString)
(virDomainStateReasonFromString): Avoid compiler warnings.
* tools/virsh.c (vshDomainState, vshDomainStateReasonToString):
Likewise.
* src/libvirt_private.syms (domain_conf.h): Export new functions.
* docs/schemas/domainsnapshot.rng: Tighten state definition.
* docs/formatsnapshot.html.in: Document it.
* tests/domainsnapshotxml2xmlout/disk_snapshot.xml: New test.
As discussed here:
https://www.redhat.com/archives/libvir-list/2011-August/msg00361.htmlhttps://www.redhat.com/archives/libvir-list/2011-August/msg00552.html
Adds snapshot attribute and transient sub-element:
<devices>
<disk type=... snapshot='no|internal|external'>
...
<transient/>
</disk>
</devices>
* docs/schemas/domaincommon.rng (snapshot): New define.
(disk): Add snapshot and persistent attributes.
* docs/formatdomain.html.in: Document them.
* src/conf/domain_conf.h (virDomainDiskSnapshot): New enum.
(_virDomainDiskDef): New fields.
* tests/qemuxml2argvdata/qemuxml2argv-disk-transient.xml: New
test of rng, no args counterpart until qemu support is complete.
* tests/qemuxml2argvdata/qemuxml2argv-disk-snapshot.args: New
file, snapshot attribute does not affect args.
* tests/qemuxml2argvdata/qemuxml2argv-disk-snapshot.xml: Likewise.
* tests/qemuxml2argvtest.c (mymain): Run new test.
This patch will probably cause merge conflicts to those trying
to do backports. The end goal is simple - domaincommon.rng
should be the state of domain.rng pre-patch, with a few lines
tweaked in the header, while domain.rng post-patch is now just
a shell that includes domaincommon.rng and sets the <start>.
* docs/schemas/domain.rng: Move guts...
* docs/schemas/domaincommon.rng: ...to new file.
* docs/schemas/domainsnapshot.rng: Allow new xml.
* docs/schemas/Makefile.am (schema_DATA): Distribute new file.
* tests/domainsnapshotxml2xmlout/full_domain.xml: New test.
* libvirt.spec.in (%files client): Ship new file. Sort lines.
* mingw32-libvirt.spec.in: Likewise.
Just like VM saved state images (virsh save), snapshots MUST
track the inactive domain xml to detect any ABI incompatibilities.
The indentation is not perfect, but functionality comes before form.
Later patches will actually supply a full domain; for now, this
wires up the storage to support one, but doesn't ever generate one
in dumpxml output.
Happily, libvirt.c was already rejecting use of VIR_DOMAIN_XML_SECURE
from read-only connections, even though before this patch, there was
no information to be secured by the use of that flag.
And while we're at it, mark the libvirt snapshot metadata files
as internal-use only.
* src/libvirt.c (virDomainSnapshotGetXMLDesc): Document flag.
* src/conf/domain_conf.h (_virDomainSnapshotDef): Add member.
(virDomainSnapshotDefParseString, virDomainSnapshotDefFormat):
Update signature.
* src/conf/domain_conf.c (virDomainSnapshotDefFree): Clean up.
(virDomainSnapshotDefParseString): Optionally parse domain.
(virDomainSnapshotDefFormat): Output full domain.
* src/esx/esx_driver.c (esxDomainSnapshotCreateXML)
(esxDomainSnapshotGetXMLDesc): Update callers.
* src/vbox/vbox_tmpl.c (vboxDomainSnapshotCreateXML)
(vboxDomainSnapshotGetXMLDesc): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML)
(qemuDomainSnapshotLoad, qemuDomainSnapshotGetXMLDesc)
(qemuDomainSnapshotWriteMetadata): Likewise.
* docs/formatsnapshot.html.in: Rework doc example.
Based on a patch by Philipp Hahn.
The first two flags are essential for being able to replicate
snapshot hierarchies across multiple hosts, which will come in
handy for supervised migrations. It also allows a management app
to take a snapshot of a transient domain, save the metadata, stop
the domain, recreate a new transient domain by the same name,
redefine the snapshot, then revert to it.
This is not quite as convenient as leaving the metadata behind
after a domain is no longer around, but doing that has a few
problems: 1. the libvirt API can only delete snapshot metadata
if there is a valid domain handle to use to get to that snapshot
object - if stale data is left behind without a domain, there is
no way to request that the data be cleaned up. 2. creating a new
domain with the same name but different uuid than the older
domain where a snapshot existed cannot use the older snapshot
data; this risks confusing libvirt, and forbidding the stale
data is similar to the recent patch to forbid stale managed save.
The first two flags might be useful on hypervisors with no metadata,
but only for modifying the notion of the current snapshot;
however, I don't know how to do that for ESX or VBox.
The third flag is a convenience option, to combine a creation with
a delete metadata into one step. It is trivial for hypervisors
with no metadata.
The qemu changes will be involved enough to warrant a separate patch.
* include/libvirt/libvirt.h.in
(VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE)
(VIR_DOMAIN_SNAPSHOT_CREATE_CURRENT)
(VIR_DOMAIN_SNAPSHOT_CREATE_NO_METADATA): New flags.
* src/libvirt.c (virDomainSnapshotCreateXML): Document them, and
enforce mutual exclusion.
* src/esx/esx_driver.c (esxDomainSnapshotCreateXML): Trivial
implementation.
* src/vbox/vbox_tmpl.c (vboxDomainSnapshotCreateXML): Likewise.
* docs/formatsnapshot.html.in: Document re-creation.
So that devices can be attached to hubs. Example, to attach to first
port of a usb-hub on port 1.
<hub type='usb'>
<address type='usb' bus='0' port='1'/>
</hub>
<input type='mouse' type='usb'>
<address type='usb' bus='0' port='1.1'/>
</hub>
also add a test entry
Newer QEMU introduced cache=directsync for -drive, this patchset
is to expose it in libvirt layer.
* Introduced a new QEMU capability flag ($prefix_CACHE_DIRECTSYNC),
As even $prefix_CACHE_V2 is set, we can't known if directsync
is supported.
Audit all changes to the qemu vm->current_snapshot, and make them
update the saved xml file for both the previous and the new
snapshot, so that there is always at most one snapshot with
<active>1</active> in the xml, and that snapshot is used as the
current snapshot even across libvirtd restarts.
This patch does not fix the case of virDomainSnapshotDelete(,CHILDREN)
where one of the children is the current snapshot; that will be later.
* src/conf/domain_conf.h (_virDomainSnapshotDef): Alter member
type and name.
* src/conf/domain_conf.c (virDomainSnapshotDefParseString)
(virDomainSnapshotDefFormat): Update clients.
* docs/schemas/domainsnapshot.rng: Tighten rng.
* src/qemu/qemu_driver.c (qemuDomainSnapshotLoad): Reload current
snapshot.
(qemuDomainSnapshotCreateXML, qemuDomainRevertToSnapshot)
(qemuDomainSnapshotDiscard): Track current snapshot.
In some versions of qemu, both virtio-blk-pci and virtio-net-pci
devices can have an event_idx setting that determines some details of
event processing. When it is enabled, it "reduces the number of
interrupts and exits for the guest". qemu will automatically enable
this feature when it is available, but there may be cases where this
new feature could actually make performance worse (NB: no such case
has been found so far).
As a safety switch in case such a situation is encountered in the
field, this patch adds a new attribute "event_idx" to the <driver>
element of both disk and interface devices. event_idx can be set to
"on" (to force event_idx on in case qemu has it disabled by default)
or "off" (for force event_idx off). In the case that event_idx support
isn't present in qemu, the attribute is ignored (this on the advice of
the qemu developer).
docs/formatdomain.html.in: document the new flag (marking it as
"don't mess with this!"
docs/schemas/domain.rng: add event_idx in appropriate places
src/conf/domain_conf.[ch]: add event_idx to parser and formatter
src/libvirt_private.syms: export
virDomainVirtioEventIdx(From|To)String
src/qemu/qemu_capabilities.[ch]: detect and report event_idx in
disk/net
src/qemu/qemu_command.c: add event_idx parameter to qemu commandline
when appropriate.
tests/qemuxml2argvdata/qemuxml2argv-event_idx.args,
tests/qemuxml2argvdata/qemuxml2argv-event_idx.xml,
tests/qemuxml2argvtest.c,
tests/qemuxml2xmltest.c: test cases for event_idx.
Currently only tabs and blanks are used for tokenizing the description,
which breaks when a term is at the end of a line or has () appended to
it.
1. Use also other white space characters such as new-lines and carriage
return for splitting.
2. Remove some common non-word characters from the token before lookup.
Signed-off-by: Philipp Hahn <hahn@univention.de>
* remote.html.in: Remove obsolete notes about internals of the
RPC protocol
* internals/rpc.html.in: Extensive docs on RPC protocol/API
* sitemap.html.in: Add new page
When the description of an entry is too long and needs multiple lines,
all other table cells of the same row are currently vertically aligned
on center. Without row borders or different background colors for
alternating rows this is hard to read.
Change the style-sheet to align the table cells of a row on top.
Signed-off-by: Philipp Hahn <hahn@univention.de>
Someone in an IRC channel or an email pointed out a few days ago that
the examples of IPv6 addresses in the libvirt documentation were not
in the officially reserved "documentation" range. This addresses their
concern.
This should have been done with the rest of the patch for virtual
switch / network device abstraction. If documents the new elements
(and new usage of existing elements) in the <network> XML to support
libvirt networks that use existing host bridges and macvtap direct
connections, as well as the new <portgroup> element.
* configure.ac docs/news.html.in libvirt.spec.in: updates for new
release
* po/*.po*: pulled translations from the transifex teams and regenerated
localizations
I went with the shorter license notice used by src/libvirt.c,
rather than spelling out the full LGPLv2+ clause into each of
these files.
* configure.ac: Declare copyright.
* all Makefile.am: Likewise.
Once it's plugged in, the <listen> element will be an optional
replacement for the "listen" attribute that graphics elements already
have. If the <listen> element is type='address', it will have an
attribute called 'address' which will contain an IP address or dns
name that the guest's display server should listen on. If, however,
type='network', the <listen> element should have an attribute called
'network' that will be set to the name of a network configuration to
get the IP address from.
* docs/schemas/domain.rng: updated to allow the <listen> element
* docs/formatdomain.html.in: document the <listen> element and its
attributes.
* src/conf/domain_conf.[hc]:
1) The domain parser, formatter, and data structure are modified to
support 0 or more <listen> subelements to each <graphics>
element. The old style "legacy" listen attribute is also still
accepted, and will be stored internally just as if it were a
separate <listen> element. On output (i.e. format), the address
attribute of the first <listen> element of type 'address' will be
duplicated in the legacy "listen" attribute of the <graphic>
element.
2) The "listenAddr" attribute has been removed from the unions in
virDomainGRaphicsDef for graphics types vnc, rdp, and spice.
This attribute is now in the <listen> subelement (aka
virDomainGraphicsListenDef)
3) Helper functions were written to provide simple access
(both Get and Set) to the listen elements and their attributes.
* src/libvirt_private.syms: export the listen helper functions
* src/qemu/qemu_command.c, src/qemu/qemu_hotplug.c,
src/qemu/qemu_migration.c, src/vbox/vbox_tmpl.c,
src/vmx/vmx.c, src/xenxs/xen_sxpr.c, src/xenxs/xen_xm.c
Modify all these files to use the listen helper functions rather
than directly referencing the (now missing) listenAddr
attribute. There can be multiple <listen> elements to a single
<graphics>, but the drivers all currently only support one, so all
replacements of direct access with a helper function indicate index
"0".
* tests/* - only 3 of these are new files added explicitly to test the
new <listen> element. All the others have been modified to reflect
the fact that any legacy "listen" attributes passed in to the domain
parse will be saved in a <listen> element (i.e. one of the
virDomainGraphicsListenDefs), and during the domain format function,
both the <listen> element as well as the legacy attributes will be
output.
Every DomainNetDef has a bandwidth, as does every portgroup.
Whenever a DomainNetDef of type NETWORK is about to be used, a call is
made to networkAllocateActualDevice(). This function chooses the "best"
bandwidth object and places it in the DomainActualNetDef.
From that point on, whenever some code needs to use the bandwidth data
for the interface, it's retrieved with virDomainNetGetActualBandwidth(),
which will always return the "best" info as determined in the
previous step.
We had a bit too many elements crammed in there. Separate it into different
headings:
- CPU Allocation (<vcpus>)
- CPU Tuning (<cputune>)
- Memory allocation (<memory> and <currentMemory>)
- Memory backing (<memoryBacking>)
- Memory tuning (<memtune>)
- Numa tuning (<numatune>)
- Block I/O tuning (<blkiotune>)
Define new 'bandwidth' element with possible child element 'inbound'
and 'outbound' addressing incoming and outgoing traffic respectively:
<bandwidth>
<inbound average='1000' peak='2000' burst='5120'/>
<outbound average='500'/>
</bandwidth>
Leaving any element out means not to shape traffic in that
direction.
The units for average and peak (rate) are in kilobytes per second,
for burst (size) are just in kilobytes.
This element can be inserted into domain's 'interface' and
'network'.
Set up the types for the block pull functions and insert them into the
virDriver structure definition. Symbols are exported in this patch to
prevent
documentation compile failures.
* include/libvirt/libvirt.h.in: new API
* src/driver.h: add the new entry to the driver structure
* python/generator.py: fix compiler errors, the actual python bindings
* are
implemented later
* src/libvirt_public.syms: export symbols
* docs/apibuild.py: Extend 'unsigned long' parameter exception to this
* API
The network XML is updated in the following ways:
1) The <forward> element can now contain a list of forward interfaces:
<forward .... >
<interface dev='eth10'/>
<interface dev='eth11'/>
<interface dev='eth12'/>
<interface dev='eth13'/>
</forward>
The first of these takes the place of the dev attribute that is
normally in <forward> - when defining a network you can specify
either one, and on output both will be present. If you specify
both on input, they must match.
2) In addition to forward modes of 'nat' and 'route', these new modes
are supported:
private, passthrough, vepa - when this network is referenced by a
domain's interface, it will have the same effect as if the
interface had been defined as type='direct', e.g.:
<interface type='direct'>
<source mode='${mode}' dev='${dev}>
...
</interface>
where ${mode} is one of the three new modes, and ${dev} is an interface
selected from the list given in <forward>.
bridge - if a <forward> dev (or multiple devs) is defined, and
forward mode is 'bridge' this is just like the modes 'private',
'passthrough', and 'vepa' above. If there is no forward dev
specified but a bridge name is given (e.g. "<bridge
name='br0'/>"), then guest interfaces using this network will use
libvirt's "host bridge" mode, equivalent to this:
<interface type='bridge'>
<source bridge='${bridge-name}'/>
...
</interface>
3) A network can have multiple <portgroup> elements, which may be
selected by the guest interface definition (by adding
"portgroup='${name}'" in the <source> element along with the
network name). Currently a portgroup can only contain a
virtportprofile, but the intent is that other configuration items
may be put there int the future (e.g. bandwidth config). When
building a guest's interface, if the <interface> XML itself has no
virtportprofile, and if the requested network has a portgroup with
a name matching the name given in the <interface> (or if one of the
network's portgroups is marked with the "default='yes'" attribute),
the virtportprofile from that portgroup will be used by the
interface.
4) A network can have a virtportprofile defined at the top level,
which will be used by a guest interface when connecting in one of
the 'direct' modes if the guest interface XML itself hasn't
specified any virtportprofile, and if there are also no matching
portgroups on the network.
the domain XML <interface> element is updated in the following ways:
1) <virtualportprofile> can be specified when source type='network'
(previously it was only valid for source type='direct')
2) A new attribute "portgroup" has been added to the <source>
element. When source type='network' (the only time portgroup is
recognized), extra configuration information will be taken from the
<portgroup> element of the given name in the network definition.
3) Each virDomainNetDef now also potentially has a
virDomainActualNetDef which is a private object (never
exported/imported via the public API, and not defined in the RNG) that
is used to maintain information about the physical device that was
actually used for a NetDef of type VIR_DOMAIN_NET_TYPE_NETWORK.
The virDomainActualNetDef will only be parsed/formatted if the
parse/format function is called with the
VIR_DOMAIN_XML_INTERNAL_ACTUAL_NET flag set (which is only needed when
saving/loading a running domain's state info to the stateDir).
virtPortProfiles are currently only used in the domain XML, but will
soon also be used in the network XML. To prepare for that change, this
patch moves the structure definition into util/network.h and the parse
and format functions into util/network.c (I decided that this was a
better choice than macvtap.h/c for something that needed to always be
available on all platforms).
Commit 8665f85 introduced a slight regression in doc generation,
since make only quits a rule on the first failed command ending
with a newline rather than a semicolon.
* docs/Makefile.am (html/index.html): Don't use xmllint unless
xsltproc succeeded.
* .gitignore: Ignore recently updated stamp file name.
The current API build scripts will continue and exit with a zero
status even if they find problems. This has been the cause of many
build problems, or hidden build errors, in the past. Change the
scripts so they always exit with a non-zero status for any problems
they do not understand. Also turn off all debug output by default
so they respect $(AM_V_GEN)
* docs/Makefile.am: Use $(AM_V_GEN) for API/HTML scripts
* docs/apibuild.py, python/generator.py: Exit with non-zero status
if problems are found. Also be silent, not outputting any debug
messages.
* src/Makefile.am: Use $(AM_V_GEN) for ESX generator
* python/Makefile.am: Tweak rule
The "libvirt supports:" section on the main page of libvirt.org
contains a list of hypervisors with links that point to the sites of
the underlying virt technologies. The entry for KVM points to
http://www.linux-kvm.org/, for example. People coming to libvirt.org
for the first time are likely to know about those sites, and they're
probably interested in how libvirt manages those technologies. This
patch points those links to the libvirt driver pages instead. It also
consolidates KVM and QEMU as there is only one libvirt driver page for
them. Finally, it adds a line about networking support.
v2: incorporate Eric's feedback adding project links to driver pages.
website: Add project links to KVM/QEMU driver page
website: Add project links to Xen driver page
website: Add project links to LXC driver page
website: Add project links to OpenVZ driver page
website: Add project links to UML driver page
website: Add project links to Virtualbox driver page
website: Add project links to ESX driver page
website: Add project links to VMware driver page
When using virCommandRunAsync and saving the pid for later, it
is useful to be able to reap that pid in the same way that it
would have been auto-reaped by virCommand if we had passed
NULL for the pid argument in the first place.
* src/util/command.c (virPidWait, virPidAbort): New functions,
created from...
(virCommandWait, virCommandAbort): ...bodies of these.
(includes): Drop duplicate <stdlib.h>. Ensure that our pid_t
assumptions hold.
(virCommandRunAsync): Improve documentation.
* src/util/command.h (virPidWait, virPidAbort): New prototypes.
* src/libvirt_private.syms: Export them.
* docs/internals/command.html.in: Document them.
Without this patch, the make rule in a VPATH build was trying to
invoke ../../docs/../../docs/todo.pl, which didn't exist.
* docs/Makefile.am (todo.html.in): Using $< already implies
$(srcdir) in GNU make VPATH situations.
Set StrictHostKeyChecking=no to auto-accept new ssh host keys if the
no_verify extra parameter was specified. This won't disable host key
checking for already known hosts. Includes a test and documentation.
Kernel cmdline args can be passed to xen pv domains even when a
bootloader is specified. The current config-to-sxpr mapping
ignores cmdline when bootloader is present.
Since the xend sub-driver is used with many xen toolstack versions,
this patch takes conservative approach of adding an else block to
existing !def->os.bootloader, and only appends sxpr if def->os.cmdline
is non-NULL.
V2: Fix existing testcase broken by this patch and add new testcases
This patch creates new <bios> element which, at this time has only the
attribute useserial='yes|no'. This attribute allow users to use
Serial Graphics Adapter and see BIOS messages from the very first moment
domain boots up. Therefore, users can choose boot medium, set PXE, etc.
This option accepts 3 values:
-keep, to keep current client connected (Spice+VNC)
-disconnect, to disconnect client (Spice)
-fail, to fail setting password if there is a client connected (Spice)
Add libvirt support for MicroBlaze architecture as a QEMU target. Based on mips/mipsel pattern.
Signed-off-by: John Williams <john.williams@petalogix.com>
No change in wording. One spacing change in a <pre>, noticed because
of odd XML formatting online; the rest is in free-flowing text to
make it easier to see nesting levels in the document.
* docs/formatdomain.html.in: Adjust spacing. Break long lines.
domain.rng, network.rng, and interface.rng already use a few of the
same types (or in some cases *should* but don't), and an upcoming code
change will have them sharing even more. To prepare for that, this
patch takes those common data type definitions and moves them into
basictypes.rng.
This may break some rule about the need to RNG files to be autonomous
or something, but I saw that storageencryption.rng is used in this
way, so I figured it must not be completely against the law...
Add a new attribute to the <seclabel> XML to allow resource
relabelling to be enabled with static label usage.
<seclabel model='selinux' type='static' relabel='yes'>
<label>system_u:system_r:svirt_t:s0:c392,c662</label>
</seclabel>
* docs/schemas/domain.rng: Add relabel attribute
* src/conf/domain_conf.c, src/conf/domain_conf.h: Parse
the 'relabel' attribute
* src/qemu/qemu_process.c: Unconditionally clear out the
'imagelabel' attribute
* src/security/security_apparmor.c: Skip based on 'relabel'
attribute instead of label type
* src/security/security_selinux.c: Skip based on 'relabel'
attribute instead of label type and fill in <imagelabel>
attribute if relabel is enabled.
Normally the dynamic labelling mode will always use a base
label of 'svirt_t' for VMs. Introduce a <baselabel> field
in the <seclabel> XML to allow this base label to be changed
eg
<seclabel type='dynamic' model='selinux'>
<baselabel>system_u:object_r:virt_t:s0</baselabel>
</seclabel>
* docs/schemas/domain.rng: Add <baselabel>
* src/conf/domain_conf.c, src/conf/domain_conf.h: Parsing
of base label
* src/qemu/qemu_process.c: Don't reset 'model' attribute if
a base label is specified
* src/security/security_apparmor.c: Refuse to support base label
* src/security/security_selinux.c: Use 'baselabel' when generating
label, if available
Add a page which documents how to configure lock managers,
focusing on use of sanlock with the QEMU/KVM driver
* docs/locking.html.in: Docs about lock managers
* docs/sitemap.html.in: Add lock manager config to
the deployment section
The sub-elements of <ip> had been placed at the same level of
indentation as ip itself, implying that they were really elements of
<network>. Within that, sub-elements of ip/dhcp were also at that same
level. These have been double-indented.
At the same time, I realized that the documentation for the new <dns>
element had been placed right in the middle of the description of the
sub-elements of <ip>. I moved it up out of the way.
This commit introduces names definition for the DNS hosts file using
the following syntax:
<dns>
<host ip="192.168.1.1">
<name>alias1</name>
<name>alias2</name>
</host>
</dns>
Some of the improvements and fixes were done by Laine Stump so
I'm putting him into the SOB clause again ;-)
Signed-off-by: Michal Novotny <minovotn@redhat.com>
Signed-off-by: Laine Stump <laine@laine.org>
This commit introduces the <dns> element and <txt> record for the
virtual DNS network. The DNS TXT record can be defined using following
syntax in the network XML file:
<dns>
<txt name="example" value="example value" />
</dns>
Also, the Relax-NG scheme has been altered to allow the texts without
spaces only for the name element and some nitpicks about memory
free'ing have been fixed by Laine so therefore I'm adding Laine to the
SOB clause ;-)
Signed-off-by: Michal Novotny <minovotn@redhat.com>
Signed-off-by: Laine Stump <laine@laine.org>
This patch adds documentation about the 802.1Qbh related parameters
of the virtualport element for 'direct' interfaces.
Signed-off-by: David S. Wang <dwang2@cisco.com>
Signed-off-by: Roopa Prabhu <roprabhu@cisco.com>
Signed-off-by: Christian Benvenuti <benve@cisco.com>
Signed-off-by: Vasanthy Kolluri <vkolluri@cisco.com>
This fixes a number of issues most of them raised by Eric Blake on the
generated documentation output:
- parsing of "long long int" and similar
- add parsing of unions within a struct
- remove spurious " * " fron comments on structure fields and enums
- fix concatenation of base type and name in arrays
- extend XSLT to cope with union in structs
* docs/apibuild.py: fix and extend API extraction tool
* docs/newapi.xsl: extend the stylesheets to cope with union in
public structures
For virtio disks and interfaces, qemu allows users to enable or disable
ioeventfd feature. This means, qemu can execute domain code, while
another thread waits for I/O event. Basically, in some cases it is win,
in some loss. This feature is available via 'ioeventfd' attribute in disk
and interface <driver> element. It accepts 'on' and 'off'. Leaving this
attribute out defaults to hypervisor decision.
From a security pov copy and paste between the guest and the client is not
always desirable. So we need to be able to enable/disable this. The best place
to do this from an administration pov is on the hypervisor, so the qemu cmdline
is getting a spice disable-copy-paste option, see bug 693645. Example qemu
invocation:
qemu -spice port=5932,disable-ticketing,disable-copy-paste
https://bugzilla.redhat.com/show_bug.cgi?id=693661
For backwards compatibility, if no <video> is set but there is a
<graphics> tag, then we add a default <video> according to the
guest type. Add docs to tell the user about this to not make
them confused. Especially if they remove the video (such as via
"virsh edit"), it will be surprised for them to see the video
element is still in domain XML.
Partial revert of commit c3c30d4de9.
* docs/Makefile.am (internals/%.html.tmp): Restore MKDIR_P; it is
needed for intermediate file after all.
Reported by Daniel P. Berrange.
A lock manager may operate in various modes. The direct mode of
operation is to obtain locks based on the resources associated
with devices in the XML. The indirect mode is where the app
creating the domain provides explicit leases for each resource
that needs to be locked. This XML extension allows for listing
resources in the XML
<devices>
...
<lease>
<lockspace>somearea</lockspace>
<key>thequickbrownfoxjumpsoverthelazydog</key>
<target path='/some/lease/path' offset='23432'/>
</lease>
...
</devices>
The 'lockspace' is a unique identifier for the lockspace which
the lease is associated
The 'key' is a unique identifier for the resource associated
with the lease.
The 'target' is the file on disk where the leases are held.
* docs/schemas/domain.rng: Add lease schema
* src/conf/domain_conf.c, src/conf/domain_conf.h: parsing and
formatting for leases
* tests/qemuxml2argvdata/qemuxml2argv-lease.args,
tests/qemuxml2argvdata/qemuxml2argv-lease.xml,
tests/qemuxml2xmltest.c: Test XML handling for leases
I noticed this while building from libvirt.git on RHEL 5.6:
Generating internals/command.html.tmp
mkdir: cannot create directory `/internals': Permission denied
If I had been building as root instead, this pollutes /.
Older autoconf lacks $(builddir), but it is rigorously equal to '.'
in newer autoconf, so we could use '$(MKDIR_P) internals' instead.
However, since internals/command.html is part of the tarball, we
_already_ build it in $(srcdir), not $(builddir) during VPATH
builds, so the mkdir is wasted effort!
* docs/Makefile.am (internals/%.html.tmp): Drop unused mkdir.
This fixes this three warnings from the parser by allowing the parser
to ignore some macros in the same way as it can ignore functions.
Parsing ./../include/libvirt/libvirt.h
Misformatted macro comment for _virSchedParameter
Expecting '* _virSchedParameter:' got '* virSchedParameter:'
Misformatted macro comment for _virBlkioParameter
Expecting '* _virBlkioParameter:' got '* virBlkioParameter:'
Misformatted macro comment for _virMemoryParameter
Expecting '* _virMemoryParameter:' got '* virMemoryParameter:'
Since -vnc uses ':' to separate the address from the port, raw
IPv6 addresses need to be escaped like [addr]:port
* src/qemu/qemu_command.c: Escape raw IPv6 addresses with []
* tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc.args,
tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc.xml: Tweak
to test Ipv6 escaping
* docs/schemas/domain.rng: Allow Ipv6 addresses, or hostnames
in <graphics> listen attributes
This adds a streaming-video=filter|all|off attribute. It is used to change
the behavior of video stream detection in spice, the default is filter (the
default for libvirt is not to specify it - the actual default is defined in
libspice-server.so).
Usage:
<graphics type='spice' autoport='yes'>
<streaming mode='off'/>
</graphics>
Tested with the above and with tests/qemuxml2argvtest.
Signed-off-by: Alon Levy <alevy@redhat.com>
This patch enables filtering of gratuitous ARP packets using the following XML:
<rule action='accept' direction='in' priority='425'>
<arp gratuitous='true'/>
</rule>
starting with kernel 2.6.38 macvtap supports a 'passthru' mode for
attaching virtual functions of a SRIOV capable network card directly to a VM.
This patch adds the capability to configure such a device.
Signed-off-by: Dirk Herrendoerfer <d.herrendoerfer@herrendoerfer.name>
Migration just seems to go from bad to worse. We already had to
introduce a second migration protocol when adding the QEMU driver,
since the one from Xen was insufficiently flexible to cope with
passing the data the QEMU driver required.
It turns out that this protocol still has some flaws that we
need to address. The current sequence is
* Src: DumpXML
- Generate XML to pass to dst
* Dst: Prepare
- Get ready to accept incoming VM
- Generate optional cookie to pass to src
* Src: Perform
- Start migration and wait for send completion
- Kill off VM if successful, resume if failed
* Dst: Finish
- Wait for recv completion and check status
- Kill off VM if unsuccessful
The problems with this are:
- Since the first step is a generic 'DumpXML' call, we can't
add in other migration specific data. eg, we can't include
any VM lease data from lock manager plugins
- Since the first step is a generic 'DumpXML' call, we can't
emit any 'migration begin' event on the source, or have
any hook that runs right at the start of the process
- Since there is no final step on the source, if the Finish
method fails to receive all migration data & has to kill
the VM, then there's no way to resume the original VM
on the source
This patch attempts to introduce a version 3 that uses the
improved 5 step sequence
* Src: Begin
- Generate XML to pass to dst
- Generate optional cookie to pass to dst
* Dst: Prepare
- Get ready to accept incoming VM
- Generate optional cookie to pass to src
* Src: Perform
- Start migration and wait for send completion
- Generate optional cookie to pass to dst
* Dst: Finish
- Wait for recv completion and check status
- Kill off VM if failed, resume if success
- Generate optional cookie to pass to src
* Src: Confirm
- Kill off VM if success, resume if failed
The API is designed to allow both input and output cookies
in all methods where applicable. This lets us pass around
arbitrary extra driver specific data between src & dst during
migration. Combined with the extra 'Begin' method this lets
us pass lease information from source to dst at the start of
migration
Moving the killing of the source VM out of Perform and
into Confirm, means we can now recover if the dst host
can't successfully Finish receiving migration data.
The hvsupport.html.in file is forever out of date. By annotating
the driver struct tables in each driver with version information,
we can auto-generate the hvsupport.html.in file. Annotating the
drivers will be mandatory for new patches, ensuring hvsupport.html.in
is never out of date again.
* docs/hvsupport.html.in: Delete
* hvsupport.pl: Script to generate hvsupport.html.in
* Makefile.am: Autogenerate hvsupport.html.in
This re-adds the example section originally written by Osier Yang,
and indicates the version in which the cputune parameters became
available in libvirt.
Signed-off-by: Igor Serebryany <igor47@moomers.org>
Update the documentation to mention that the CA certificate and the
client cert/key pair can come from the user's location or the global
location independent of each other.
Signed-off-by: Doug Goldstein <cardoe@gentoo.org>
We already have virAsprintf, so picking a similar name helps for
seeing a similar purpose. Furthermore, the prefix V before printf
generally implies 'va_list', even though this variant was '...', and
the old name got in the way of adding a new va_list version.
global rename performed with:
$ git grep -l virBufferVSprintf \
| xargs -L1 sed -i 's/virBufferVSprintf/virBufferAsprintf/g'
then revert the changes in ChangeLog-old.
* configure.ac libvirt.spec.in docs/news.html.in: update and document
the release
* po/*.po*: update localizations for german, polish, spanish, ukrainian
and vietnamese coming from transifex, regenerate
For IEEE 802.1Qbg, it is necessary to use a VLAN interface.
vepa itself does not require a VLAN interface.
Signed-off-by: Gerhard Stenzel <stenzel at de.ibm.com>
Tried to dredge through old changelogs and commits to come up with it, so
may not be completely accurate.
v2:
Drop ambiguous 'containers'
Use same mail archive for all links
This extends the SPICE XML to allow variable compression settings for audio,
images and streaming:
<graphics type='spice' port='5901' tlsPort='-1' autoport='yes'>
<image compression='auto_glz'/>
<jpeg compression='auto'/>
<zlib compression='auto'/>
<playback compression='on'/>
</graphics>
All new elements are optional.
This patch adds support for the evaluation of TCP flags in nwfilters.
It adds documentation to the web page and extends the tests as well.
Also, the nwfilter schema is extended.
The following are some example for rules using the tcp flags:
<rule action='accept' direction='in'>
<tcp state='NONE' flags='SYN/ALL' dsptportstart='80'/>
</rule>
<rule action='drop' direction='in'>
<tcp state='NONE' flags='SYN/ALL'/>
</rule>
It was just pointed out that, although I added documentation for the
IPv6 additions to the network XML, I neglected to use those additions
in the examples. This patch adds an IPv6 address to each of the
examples except for the "default" network, since that is a faithful
reproduction of the default network config that's automatically
installed, which doesn't include any IPv6 address (for good reason -
because there is no such thing as IPv6 NAT, there is no one IPv6
address that would work for all installations).
Commit 78ba748ef1 claims to fix
documentation for swap_hard_limit virsh memtune option but it only fixes
documentation in formatdomain.html and libvirt.h. This patch completes
the task by fixing "virsh help memtune" output and memtune section of
virsh man page.
The Open Nebula driver has been unmaintained since it was first
introduced. The only commits have been for tree-wide cleanups.
It also has a major design flaw, in that it only knows about guests
that it has created itself, which makes it of very limited use.
Discussions wrt evolution of the VMWare ESX driver, concluded that
it should limit itself to single-node ESX operation and not try to
manage the multi-node architecture of VirtualCenter. Open Nebula
is a cluster like Virtual Center, not a single node system, so
the same reasoning applies.
The DeltaCloud project includes an Open Nebula driver and is a much
better fit architecturally, since it is explicitly targetting the
distributed multihost cluster scenario.
Thus this patch deletes the libvirt Open Nebula driver with the
recommendation that people use DeltaCloud for managing it instead.
* configure.ac: Remove probe for xmlrpc & --with-one arg
* daemon/Makefile.am, daemon/libvirtd.c, src/Makefile.am: Remove
ONE driver build
* src/opennebula/one_client.c, src/opennebula/one_client.h,
src/opennebula/one_conf.c, src/opennebula/one_conf.h,
src/opennebula/one_driver.c, src/opennebula/one_driver.c: Delete
files
* autobuild.sh, libvirt.spec.in, mingw32-libvirt.spec.in: Remove
build rules for Open Nebula
* docs/drivers.html.in, docs/sitemap.html.in: Remove reference
to OpenNebula
* docs/drvone.html.in: Delete file
Some things to note in this patch:
- we do extend libvirt scope beyond purely managing domains, there is
already a number of blocks which are here as helpr functions to
manage the resources on the host.
- we are expanding in the direction of libvirt being sufficient to do
most of the management on the Host (but within the limits of the need
for virtualization, e.g. managing users on the host is out of scope)
- we don't require anymore APIs to be supported by multiple
hypervisors to get in, it's already the case in practice, but we
should still make sure the semantic of those APIs are clear. We
added quite a bit for QEmu, but for example I saw on IRC that VBox
could emulate a network unplug/replug on a domain interface, and
that would be a good addition even if a priori no other hypervisor
supports it.
- Make clear that all libvirt APIs are available remotely, which is
key to use libvirt for building management tools.
- link the goal page from the project main page
As for libvirt project directions, I think it just reflects the natural
evolution in the last couple of years. We are less hypervisor agnostic
and extending in the Host management. Clearly there is interest in
making sure libvirt is complete in term of features for the hypervisors
supported, especially the ones like KVM or LXC which don't really have
integrated management library.
* docs/goals.html.in: update the goals page
* docs/index.html.in: link it from the top page
<imagelable> is not generated by running domain, actually we parse
it in src/conf/domain_conf.c, this patch is to fix it, otherwise any
validation (virt-xml-validate) on the domain xml dumped from shutoff
domain containing <imagelable> will fail.
* docs/schemas/domain.rng
* docs/logging.html.in: document the fact that starting from
0.9.0 the server logs goes to libvirtd.log instead of syslog
by default, describe the debug buffer, restructure the page
and add a couple more examples
* Correct the documentation for cgroup: the swap_hard_limit indicates
mem+swap_hard_limit.
* Change cgroup private apis to: virCgroupGet/SetMemSwapHardLimit
Signed-off-by: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com>
The current LXC I/O controller looks for HUP to detect
when a guest has quit. This isn't reliable as during
initial bootup it is possible that 'init' will close
the console and let mingetty re-open it. The shutdown
of containers was also flakey because it only killed
the libvirt I/O controller and expected container
processes to gracefully follow.
Change the I/O controller such that when it see HUP
or an I/O error, it uses kill($PID, 0) to see if the
process has really quit.
Change the container shutdown sequence to use the
virCgroupKillPainfully function to ensure every
really goes away
This change makes the use of the 'cpu', 'devices'
and 'memory' cgroups controllers compulsory with
LXC
* docs/drvlxc.html.in: Document that certain cgroups
controllers are now mandatory
* src/lxc/lxc_controller.c: Check if PID is still
alive before quitting on I/O error/HUP
* src/lxc/lxc_driver.c: Use virCgroupKillPainfully
The Relax-NG schema for domains regarding <hostdev> doesn't match what's
implemented in src/conf/domain_conf.c#virDomainHostdevDefFormat(): The
implementation only requires @type, but the schema currently either
required none or all three attributes (@mode, @type, and @managed) to be
defined together, because they are declared in the same
<optional)-section. (@managed is currently even undocumented on
<http://libvirt.org/formatdomain.html#elementsUSB>).
Thus the following minimal <hostdev>-example fails to validate:
<domain type='test'>
<name>N</name>
<memory>4096</memory>
<bootloader>/bin/false</bootloader>
<os>
<type arch='x86_64' machine='xenpv'>linux</type>
</os>
<devices>
<hostdev type='pci'>
<source>
<address bus='0x06' slot='0x00' function='0x0'/>
</source>
</hostdev>
</devices>
</domain>
The schema is changed to match the current implementation:
1. @mode is optional (which defaults to 'subsystem')
2. @type is required
3. @managed is optional (which defaults to 'no')
The documentation is updated to mention @managed.
Signed-off-by: Philipp Hahn <hahn@univention.de>
This patchs adds documentation about the 802.1Qbg related parameters
of the virtualport element in a 'direct' interface definition.
Signed-off-by: Gerhard Stenzel <gerhard.stenzel@de.ibm.com>
A diff of 'make dist' from in-tree vs. a VPATH build showed
that we were missing docs/api_extension/*.patch files, but
shipping other files that we didn't need.
* bootstrap.conf (gnulib_extra_files): Don't distribute files we
don't care about.
* docs/Makefile.am (patches): Perform wildcard correctly.
Done mechanically with:
$ git grep -l '\bDEBUG0\? *(' | xargs -L1 sed -i 's/\bDEBUG0\? *(/VIR_&/'
followed by manual deletion of qemudDebug in daemon/libvirtd.c, along
with a single 'make syntax-check' fallout in the same file, and the
actual deletion in src/util/logging.h.
* src/util/logging.h (DEBUG, DEBUG0): Delete.
* daemon/libvirtd.h (qemudDebug): Likewise.
* global: Change remaining clients over to VIR_DEBUG counterpart.
XSLT allows for two ways of generating the output of transformation.
Either implicit, which xsltproc prints to stdout and can be redirected
to a file using -o file. Or explicit, which means the stylesheet
contains <xsl:document> element which specifies where the output should
be saved. This can be used for generating more files by a single run of
xsltproc and -o directory/ can change the directory where the output
files will be stored.
devhelp.xsl is special in that it combines both options in one
stylesheet, which doesn't work well with -o:
xsltproc --nonet -o ./devhelp/ ./devhelp/devhelp.xsl ./libvirt-api.xml
Outputs 4 *.html files into ./devhelp but then tries to write to
./devhelp/ as a file (hence the I/O error) rather than writing output to
the fifth file devhelp/libvirt.devhelp.
This patch modifies devhelp.xsl so that all files are generated using
<xsl:document> element and -o directory/ can be used to override output
directory where those files are saved.
This patch adds the possibility to not just drop packets, but to also have them rejected where iptables at least sends an ICMP msg back to the originator. On ebtables this again maps into dropping packets since rejecting is not supported.
I am adding 'since 0.8.9' to the docs assuming this will be the next version of libvirt.
This still doesn't fix {html,devhelp}/libvirt-{libvirt-virterror}.html,
but it's progress in the right direction.
* docs/Makefile.am (%.html): Build into srcdir.
This fixes https://bugzilla.redhat.com/show_bug.cgi?id=609463
The problem was that, since a bridge always acquires the MAC address
of the connected interface with the numerically lowest MAC, as guests
are started and stopped, it was possible for the MAC address to change
over time, and this change in the network was being detected by
Windows 7 (it sees the MAC of the default route change), so on each
reboot it would bring up a dialog box asking about this "new network".
The solution is to create a dummy tap interface with a MAC guaranteed
to be lower than any guest interface's MAC, and attach that tap to the
bridge as soon as it's created. Since all guest MAC addresses start
with 0xFE, we can just generate a MAC with the standard "0x52, 0x54,
0" prefix, and it's guaranteed to always win (physical interfaces are
never connected to these bridges, so we don't need to worry about
competing numerically with them).
Note that the dummy tap is never set to IFF_UP state - that's not
necessary in order for the bridge to take its MAC, and not setting it
to UP eliminates the clutter of having an (eg) "virbr0-nic" displayed
in the output of the ifconfig command.
I chose to not auto-generate the MAC address in the network XML
parser, as there are likely to be consumers of that API that don't
need or want to have a MAC address associated with the
bridge.
Instead, in bridge_driver.c when the network is being defined, if
there is no MAC, one is generated. To account for virtual network
configs that already exist when upgrading from an older version of
libvirt, I've added a %post script to the specfile that searches for
all network definitions in both the config directory
(/etc/libvirt/qemu/networks) and the state directory
(/var/lib/libvirt/network) that are missing a mac address, generates a
random address, and adds it to the config (and a matching address to
the state file, if there is one).
docs/formatnetwork.html.in: document <mac address.../>
docs/schemas/network.rng: add nac address to schema
libvirt.spec.in: %post script to update existing networks
src/conf/network_conf.[ch]: parse and format <mac address.../>
src/libvirt_private.syms: export a couple private symbols we need
src/network/bridge_driver.c:
auto-generate mac address when needed,
create dummy interface if mac address is present.
tests/networkxml2xmlin/isolated-network.xml
tests/networkxml2xmlin/routed-network.xml
tests/networkxml2xmlout/isolated-network.xml
tests/networkxml2xmlout/routed-network.xml: add mac address to some tests
This is in response to:
https://bugzilla.redhat.com/show_bug.cgi?id=629662
Explanation
qemu's virtio-net-pci driver allows setting the algorithm used for tx
packets to either "bh" or "timer". This is done by adding ",tx=bh" or
",tx=timer" to the "-device virtio-net-pci" commandline option.
'bh' stands for 'bottom half'; when this is set, packet tx is all done
in an iothread in the bottom half of the driver. (In libvirt, this
option is called the more descriptive "iothread".)
'timer' means that tx work is done in qemu, and if there is more tx
data than can be sent at the present time, a timer is set before qemu
moves on to do other things; when the timer fires, another attempt is
made to send more data. (libvirt retains the name "timer" for this
option.)
The resulting difference, according to the qemu developer who added
the option is:
bh makes tx more asynchronous and reduces latency, but potentially
causes more processor bandwidth contention since the cpu doing the
tx isn't necessarily the cpu where the guest generated the
packets.
Solution
This patch provides a libvirt domain xml knob to change the option on
the qemu commandline, by adding a new attribute "txmode" to the
<driver> element that can be placed inside any <interface> element in
a domain definition. It's use would be something like this:
<interface ...>
...
<model type='virtio'/>
<driver txmode='iothread'/>
...
</interface>
I chose to put this setting as an attribute to <driver> rather than as
a sub-element to <tune> because it is specific to the virtio-net
driver, not something that is generally usable by all network drivers.
(note that this is the same placement as the "driver name=..."
attribute used to choose kernel vs. userland backend for the
virtio-net driver.)
Actually adding the tx=xxx option to the qemu commandline is only done
if the version of qemu being used advertises it in the output of
qemu -device virtio-net-pci,?
If a particular txmode is requested in the XML, and the option isn't
listed in that help output, an UNSUPPORTED_CONFIG error is logged, and
the domain fails to start.
* configure.ac docs/news.html.in libvirt.spec.in: bump version and add docs
* po/*.po*: updated Gujarati, Polish and Dutch localisations and regenerated
Libxml2-Logo-90x34.gif was removed from the repository in Sep 2009
(commit d6d528c) because our docs no longer reference it.
* docs/Makefile.am (install-data-local): Don't install missing file.
Adds <smartcard mode='passthrough' type='spicevmc'/>, which uses the
new <channel name='smartcard'/> of <graphics type='spice'>.
* docs/schemas/domain.rng: Support new XML.
* docs/formatdomain.html.in: Document it.
* src/conf/domain_conf.h (virDomainGraphicsSpiceChannelName): New
enum value.
(virDomainChrSpicevmcName): New enum.
(virDomainChrSourceDef): Distinguish spicevmc types.
* src/conf/domain_conf.c (virDomainGraphicsSpiceChannelName): Add
smartcard.
(virDomainSmartcardDefParseXML): Parse it.
(virDomainChrDefParseXML, virDomainSmartcardDefParseXML): Set
spicevmc name.
(virDomainChrSpicevmc): New enum conversion functions.
* src/libvirt_private.syms: Export new functions.
* src/qemu/qemu_command.c (qemuBuildChrChardevStr): Conditionalize
name.
* tests/qemuxml2argvtest.c (domain): New test.
* tests/qemuxml2argvdata/qemuxml2argv-smartcard-passthrough-spicevmc.args:
New file.
* tests/qemuxml2argvdata/qemuxml2argv-smartcard-passthrough-spicevmc.xml:
Likewise.
Inspired by https://bugzilla.redhat.com/show_bug.cgi?id=615757
Add a new character device backend for virtio serial channels that
activates the QEMU spice agent on the main channel using the vdagent
spicevmc connection. The <target> must be type='virtio', and supports
an optional name that specifies how the guest will see the channel
(for now, name must be com.redhat.spice.0).
<channel type='spicevmc'>
<target type='virtio'/>
<address type='virtio-serial' controller='1' bus='0' port='3'/>
</channel>
* docs/schemas/domain.rng: Support new XML.
* docs/formatdomain.html.in: Document it.
* src/conf/domain_conf.h (virDomainChrType): New enum value.
* src/conf/domain_conf.c (virDomainChr): Add spicevmc.
(virDomainChrDefParseXML, virDomainChrSourceDefParseXML)
(virDomainChrDefParseTargetXML): Parse and enforce proper use.
(virDomainChrSourceDefFormat, virDomainChrDefFormat): Format.
* src/qemu/qemu_command.c (qemuBuildChrChardevStr)
(qemuBuildCommandLine): Add qemu support.
* tests/qemuxml2argvtest.c (domain): New test.
* tests/qemuxml2argvdata/qemuxml2argv-channel-spicevmc.xml: New
file.
* tests/qemuxml2argvdata/qemuxml2argv-channel-spicevmc.args:
Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Assuming a hypervisor that supports multiple smartcard devices in the
guest, this would be a valid XML description:
<devices>
<smartcard mode='host'/>
<smartcard mode='host-certificates'>
<certificate>/path/to/cert1</certificate>
<certificate>/path/to/cert2</certificate>
<certificate>/path/to/cert3</certificate>
</smartcard>
<smartcard mode='passthrough' type='tcp'>
<source mode='bind' host='127.0.0.1' service='2001'/>
<protocol type='raw'/>
</smartcard>
</devices>
(As of this commit, the qemu hypervisor will be the first
implementation, but it only supports one smartcard.)
* docs/formatdomain.html.in (Smartcard devices): New section.
* docs/schemas/domain.rng (smartcard): New define, used in
devices.
* tests/qemuxml2argvdata/qemuxml2argv-smartcard-host.xml: New file
to test schema.
* tests/qemuxml2argvdata/qemuxml2argv-smartcard-host-certificates.xml:
Likewise.
* tests/qemuxml2argvdata/qemuxml2argv-smartcard-passthrough-tcp.xml:
Likewise.
* tests/qemuxml2argvdata/qemuxml2argv-smartcard-controller.xml:
Likewise.
In QEMU, the card itself is a PCI device, but it requires a codec
(either -device hda-output or -device hda-duplex) to actually output
sound. Specifying <sound model='ich6'/> gives us -device intel-hda
-device hda-duplex I think it's important that a simple <sound model='ich6'/>
sets up a useful codec, to have consistent behavior with all other sound cards.
This is basically Dan's proposal of
<sound model='ich6'>
<codec type='output' slot='0'/>
<codec type='duplex' slot='3'/>
</sound>
without the codec bits implemented.
The important thing is to keep a consistent API here, we don't want some
<sound> devs require tweaking codecs but not others. Steps I see to
accomplishing this:
- every <sound> device has a <codec type='default'/> (unless codecs are
manually specified)
- <codec type='none'/> is required to specify 'no codecs'
- new audio settings like mic=on|off could then be exposed in
<sound> or <codec> in a consistent manner for all sound models
v2:
Use model='ich6'
v3:
Use feature detection, from eblake
Set codec id, bus, and cad values
v4:
intel-hda isn't supported if -device isn't available
v5:
Comment spelling fixes
QEMU supports serving VNC over a unix domain socket rather than traditional
TCP host/port. This is specified with:
<graphics type='vnc' socket='/foo/bar/baz'/>
This provides better security access control than VNC listening on
127.0.0.1, but will cause issues with tools that rely on the lax security
(virt-manager in fedora runs as regular user by default, and wouldn't be
able to access a socket owned by 'qemu' or 'root').
Also not currently supported by any clients, though I have patches for
virt-manager, and virt-viewer should be simple to update.
v2:
schema: Make listen vs. socket a <choice>
Currently, boot order can be specified per device class but there is no
way to specify exact disk/NIC device to boot from.
This patch adds <boot order='N'/> element which can be used inside
<disk/> and <interface/>. This is incompatible with the older os/boot
element. Since not all hypervisors support per-device boot
specification, new deviceboot flag is included in capabilities XML for
hypervisors which understand the new boot element. Presence of the flag
allows (but doesn't require) users to use the new style boot order
specification.
This is in response to a request in:
https://bugzilla.redhat.com/show_bug.cgi?id=665293
In short, under heavy load, it's possible for qemu's networking to
lock up due to the tap device's default 1MB sndbuf being
inadequate. adding "sndbuf=0" to the qemu commandline -netdevice
option will alleviate this problem (sndbuf=0 actually sets it to
0xffffffff).
Because we must be able to explicitly specify "0" as a value, the
standard practice of "0 means not specified" won't work here. Instead,
virDomainNetDef also has a sndbuf_specified, which defaults to 0, but
is set to 1 if some value was given.
The sndbuf value is put inside a <tune> element of each <interface> in
the domain. The intent is that further tunable settings will also be
placed inside this element.
<interface type='network'>
...
<tune>
<sndbuf>0</sndbuf>
...
</tune>
</interface>
This patch is in response to
https://bugzilla.redhat.com/show_bug.cgi?id=643050
The existing libvirt support for the vhost-net backend to the virtio
network driver happens automatically - if the vhost-net device is
available, it is always enabled, otherwise the standard userland
virtio backend is used.
This patch makes it possible to force whether or not vhost-net is used
with a bit of XML. Adding a <driver> element to the interface XML, eg:
<interface type="network">
<model type="virtio"/>
<driver name="vhost"/>
will force use of vhost-net (if it's not available, the domain will
fail to start). if driver name="qemu", vhost-net will not be used even
if it is available.
If there is no <driver name='xxx'/> in the config, libvirt will revert
to the pre-existing automatic behavior - use vhost-net if it's
available, and userland backend if vhost-net isn't available.
* docs/hacking.html.in (Curly braces): Tighten recommendations to
disallow if (cond) one-line; else { block; }.
* HACKING: Regenerate.
Suggested by Daniel P. Berrange.
At this point everything is already in place to make IPv6 happen, we just
need to add a few rules, remove some checks for IPv4-only, and document
the changes to the XML on the website.
This commit adds support for IPv6 parsing and formatting to the
virtual network XML parser, including moving around data definitions
to allow for multiple <ip> elements on a single network, but only
changes the consumers of this API to accommodate for the changes in
API/structure, not to add any actual IPv6 functionality. That will
come in a later patch - this patch attempts to maintain the same final
functionality in both drivers that use the network XML parser - vbox
and "bridge" (the Linux bridge-based driver used by the qemu
hypervisor driver).
* src/libvirt_private.syms: Add new private API functions.
* src/conf/network_conf.[ch]: Change C data structure and
parsing/formatting.
* src/network/bridge_driver.c: Update to use new parser/formatter.
* src/vbox/vbox_tmpl.c: update to use new parser/formatter
* docs/schemas/network.rng: changes to the schema -
* there can now be more than one <ip> element.
* ip address is now an ip-addr (ipv4 or ipv6) rather than ipv4-addr
* new optional "prefix" attribute that can be used in place of "netmask"
* new optional "family" attribute - "ipv4" or "ipv6"
(will default to ipv4)
* define data types for the above
* tests/networkxml2xml(in|out)/nat-network.xml: add multiple <ip> elements
(including IPv6) to a single network definition to verify they are being
correctly parsed and formatted.
In practice this has always been optional, but the RNG has shown it as
mandatory, and since all the examples for make check had it, it was
never noticed. One of the existing test cases has been changed to
check for this.
I also noticed that the dhcp/host/ip was still defined as <text/>,
but should really be <ref name='ipv4-addr'/>
formatnetwork.html has a menu item at level 3. libvirt.css
doesn't have a explicit rule for level 3 and level 3 and
level 2 items end up at the same indentation level.
Add an additional 1em indentation to level 3 menu items.
The xml watchdog dump option is converted to qemu watchdog pause arg
but it is not reasonable to convert it back from qemu watchdog pause
arg since there already is a xml watchdog pause option, so a test for
the dump option to convert it from arg to xml is not added.
Changes common to all network disks:
-Make source name optional in the domain schema, since NBD doesn't use it
-Add a hostName type to the domain schema, and use it instead of genericName, which doesn't include .
-Don't leak host names or ports
-Set the source protocol in qemuParseCommandline
Signed-off-by: Josh Durgin <joshd@hq.newdream.net>
This patch adds network disk support to libvirt/QEMU. The currently
supported protocols are nbd, rbd, and sheepdog. The XML syntax is like
this:
<disk type="network" device="disk">
<driver name="qemu" type="raw" />
<source protocol='rbd|sheepdog|nbd' name="...some image identifier...">
<host name="mon1.example.org" port="6000">
<host name="mon2.example.org" port="6000">
<host name="mon3.example.org" port="6000">
</source>
<target dev="vda" bus="virtio" />
</disk>
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Guarantee that outbuf/errbuf are allocated on success, even if to the
empty string. Caller always has to free the result, and empty output
check requires checking if *outbuf=='\0'. Makes the API easier to use
safely. Failure is best effort allocation (some paths, like
out-of-memory, cannot allocate a buffer, but most do), so caller must
free buffer on failure.
* docs/internals/command.html.in: Update documentation.
* src/util/command.c (virCommandSetOutputBuffer)
(virCommandSetErrorBuffer, virCommandProcessIO) Guarantee empty
string on no output.
* tests/commandtest.c (test17): New test.
* docs/internals/command.html.in: Better documentation of buffer
vs. fd considerations.
* src/util/command.c (virCommandRunAsync): Reject raw execution
with string io.
(virCommandRun): Reject execution with user-specified fds not
visiting a regular file.
