Let's change URI to parallels:///system. Parallels Server supports
creating VMs from non-privileged accounts, but it's not main usage
scenario and it may be forbidden in the future.
Also containers, which will be supported by the driver, can be managed
only by root, so /system path is more suitable for this driver.
Signed-off-by: Dmitry Guryanov <dguryanov@parallels.com>
Following commit added suport the CPU quota/period to the LXC driver.
Update the documentation to reflect that.
commit d9724a81b3
Author: Daniel P. Berrange <berrange@redhat.com>
Date: Thu Nov 10 12:16:26 2011 +0000
Add support for CPU quota/period to LXC driver
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
* tools/virsh.c: New macro vshStrcasecmp
* tools/virsh-domain-monitor.c: Use vshStrcasecmp instead of
strcasecmp
* tools/virsh-snapshot.c: Likewise
* cfg.mk: Only avoid doing strcase checking for virsh.c
Each interface has a single pointer to a filterref object. That
filterref can itself point to multiple other filterrefs, but at the
toplevel there is only one.
The parser had previously just silently overwritten earlier filterrefs
when a new one was encountered, so the interface was left with
whichever was the last filterref in the xml, ignoring all the
others. This patch logs an error when it sees more than one filterref.
Just as each physical device used by a network has a connections
counter, now each network has a connections counter which is
incremented once for each guest interface that connects using this
network.
The count is output in the live network XML, like this:
<network connections='20'>
...
</network>
It is read-only, and for informational purposes only - it isn't used
internally anywhere by libvirt.
A later patch will be adding a counter that will be
incremented/decremented each time an guest interface starts/stops
using a particular network. For this to work, all types of networks
need to go through a common return sequence rather than returning
early. To setup for this, a new success: label is added (when
necessary), a new error: label is added which does any cleanup
necessary only for error returns and then does goto cleanup, and early
returns are changed to goto error if it's a failure, or goto success
if it's successful. This way the intent of all the gotos is
unambiguous, and a successful return path never encounters the
"error:" label.
It may be useful for management applications to know which physical
network devices are in use by guests. This information is already
available in the network objects, but wasn't output in the XML. This
patch outputs it when the INACTIVE flag isn't set (and if it's non-0).
I want to include this count in the xml output of networks, but
calling it "connections" in the XML sounds better than "usageCount", and it
would be better if the name in the XML matched the variable name.
In a few places, usageCount was being initialized to 0, but this is
unnecessary, because VIR_ALLOC_N zero-fills everything anyway.
This array was originally defined using the existing
virNetworkForwardIfDef, but that struct has a UsageCount field that
isn't used in the case of PFs. This patch just copies that struct and
removes UsageCount. It ends up being a struct with a single field, but
I left it as a struct in case we need to add other fields to it in the
future.
Use of ldexp() requires -lm on some platforms; use gnulib to determine
this for our makefile. Also, optimize virRandomInt() for the case
of a power-of-two limit (actually rather common, given that Daniel
has a pending patch to replace virRandomBits(10) with code that will
default to virRandomInt(1024) on default SELinux settings).
* .gnulib: Update to latest, for ldexp.
* bootstrap.conf (gnulib_modules): Import ldexp.
* src/Makefile.am (libvirt_util_la_CFLAGS): Link with -lm when
needed.
* src/util/virrandom.c (virRandomInt): Optimize powers of 2.
One of the original ideas behind allowing a <virtualport> in an
interface definition as well as in the <network> definition *and*one
or more <portgroup>s within the network, was that guest-specific
parameteres (like instanceid and interfaceid) could be given in the
interface's virtualport, and more general things (portid, managerid,
etc) could be given in the network and/or portgroup, with all the bits
brought together at guest startup time and combined into a single
virtualport to be used by the guest. This was somehow overlooked in
the implementation, though - it simply picks the "most specific"
virtualport, and uses the entire thing, with no attempt to merge in
details from the others.
This patch uses virNetDevVPortProfileMerge3() to combine the three
possible virtualports into one, then uses
virNetDevVPortProfileCheck*() to verify that the resulting virtualport
type is appropriate for the type of network, and that all the required
attributes for that type are present.
An example of usage is this: assuming a <network> definitions on host
ABC of:
<network>
<name>testA</name>
...
<virtualport type='openvswitch'/>
...
<portgroup name='engineering'>
<virtualport>
<parameters profileid='eng'/>
</virtualport>
</portgroup>
<portgroup name='sales'>
<virtualport>
<parameters profileid='sales'/>
</virtualport>
</portgroup>
</network>
and the same <network> on host DEF of:
<network>
<name>testA</name>
...
<virtualport type='802.1Qbg'>
<parameters typeid="1193047" typeidversion="2"/>
</virtualport>
...
<portgroup name='engineering'>
<virtualport>
<parameters managerid="11"/>
</virtualport>
</portgroup>
<portgroup name='sales'>
<virtualport>
<parameters managerid="55"/>
</virtualport>
</portgroup>
</network>
and a guest <interface> definition of:
<interface type='network'>
<source network='testA' portgroup='sales'/>
<virtualport>
<parameters instanceid="09b11c53-8b5c-4eeb-8f00-d84eaa0aaa4f"
interfaceid="09b11c53-8b5c-4eeb-8f00-d84eaa0aaa4f"\>
</virtualport>
...
</interface>
If the guest was started on host ABC, the <virtualport> used would be:
<virtualport type='openvswitch'>
<parameters interfaceid='09b11c53-8b5c-4eeb-8f00-d84eaa0aaa4f'
profileid='sales'/>
</virtualport>
but if that guest was started on host DEF, the <virtualport> would be:
<virtualport type='802.1Qbg'>
<parameters instanceid="09b11c53-8b5c-4eeb-8f00-d84eaa0aaa4f"
typeid="1193047" typeidversion="2"
managerid="55"/>
</virtualport>
Additionally, if none of the involved <virtualport>s had a specified type
(this includes cases where no virtualport is given at all),
Until now, all attributes in a <virtualport> parameter list that were
acceptable for a particular type, were also required. There were no
optional attributes.
One of the aims of supporting <virtualport> in libvirt's virtual
networks and portgroups is to allow specifying the group-wide
parameters in the network's virtualport, and merge that with the
interface's virtualport, which will have the instance-specific info
(i.e. the interfaceid or instanceid).
Additionally, the guest's interface XML shouldn't need to know what
type of network connection will be used prior to runtime - it could be
openvswitch, 802.1Qbh, 802.1Qbg, or none of the above - but should
still be able to specify instance-specific info just in case it turns
out to be applicable.
Finally, up to now, the parser for virtualport has always generated a
random instanceid/interfaceid when appropriate, making it impossible
to leave it blank (which is what's required for virtualports within a
network/portprofile definition).
This patch modifies the parser and formatter of the <virtualport>
element in the following ways:
* because most of the attributes in a virNetDevVPortProfile are fixed
size binary data with no reserved values, there is no way to embed a
"this value wasn't specified" sentinel into the existing data. To
solve this problem, the new *_specified fields in the
virNetDevVPortProfile object that were added in a previous patch of
this series are now set when the corresponding attribute is present
during the parse.
* allow parsing/formatting a <virtualport> that has no type set. In
this case, all fields are settable, but all are also optional.
* add a GENERATE_MISSING_DEFAULTS flag to the parser - if this flag is
set and an instanceid/interfaceid is expected but not provided, a
random one will be generated. This was previously the default
behavior, but is now done only for virtualports inside an
<interface> definition, not for those in <network> or <portgroup>.
* add a REQUIRE_ALL_ATTRIBUTES flag to the parser - if this flag is
set the parser will call the new
virNetDevVPortProfileCheckComplete() functions at the end of the
parser to check for any missing attributes (based on type), and
return failure if anything is missing. This used to be default
behavior. Now it is only used for the virtualport defined inside an
interface's <actual> element (by the time you've figured out the
contents of <actual>, you should have all the necessary data to fill
in the entire virtualport)
* add a REQUIRE_TYPE flag to the parser - if this flag is set, the
parser will return an error if the virtualport has no type
attribute. This also was previously the default behavior, but isn't
needed in the case of the virtualport for a type='network' interface
(i.e. the exact type isn't yet known), or the virtualport of a
portgroup (i.e. the portgroup just has modifiers for the network's
virtualport, which *does* require a type) - in those cases, the
check will be done at domain startup, once the final virtualport is
assembled (this is handled in the next patch).
This function has several calls to increase the buffer indent by 6,
then decrease it again, then increase, then decrease. Additionally,
there were several printfs that had 6 spaces at the beginning of the
line.
virDomainActualNetDefFormat, which is called by virDomainNetDefFormat,
had similar ugliness.
This patch changes both functions to just increase the indent at the
beginning, decrease it at (well, just before*) the end, and remove all
of the occurences of 6/8 spaces at the beginning of lines.
*The indent had to be reset before the end of the function because
virDomainDeviceInfoFormat assumes a 0 indent and is called from many
other places, and I didn't want to do an overhaul of every caller of
that function. A separate patch to switch all of domain_conf.c would
be a useful exercise, but my current goal is unrelated to that, so
I'll leave it for another day.
There was an error: label that simply did "return ret", but ret was
defaulted to -1, and was never used other than setting it manually to
0 just before a non-error return. Aside from this, some of the error
return paths used "goto error" and others used "return ret".
This patch removes ret and the error: label, and makes all error
returns just consistently do "return -1".
virtPortProfile is now used by 4 different types of network devices
(NETWORK, BRIDGE, DIRECT, and HOSTDEV), and it's getting cumbersome to
replicate so much code in 4 different places just because each type
has the virtPortProfile in a slightly different place. This patch puts
a single virtPortProfile in a common place (outside the type-specific
union) in both virDomainNetDef and virDomainActualNetDef, and adjusts
the parse and format code (and the few other places where it is used)
accordingly.
Note that when a <virtualport> element is found, the parse functions
verify that the interface is of a type that supports one, otherwise an
error is generated (CONFIG_UNSUPPORTED in the case of <interface>, and
INTERNAL in the case of <actual>, since the contents of <actual> are
always generated by libvirt itself).
This patch adds three utility functions that operate on
virNetDevVPortProfile objects.
* virNetDevVPortProfileCheckComplete() - verifies that all attributes
required for the type of the given virtport are specified.
* virNetDevVPortProfileCheckNoExtras() - verifies that there are no
attributes specified which are inappropriate for the type of the
given virtport.
* virNetDevVPortProfileMerge3() - merges 3 virtports into a single,
newly allocated virtport. If any attributes are specified in
more than one of the three sources, and do not exactly match,
an error is logged and the function fails.
These new functions depend on new fields in the virNetDevVPortProfile
object that keep track of whether or not each attribute was
specified. Since the higher level parse function doesn't yet set those
fields, these functions are not actually usable yet (but that's okay,
because they also aren't yet used - all of that functionality comes in
a later patch.)
Note that these three functions return 0 on success and -1 on
failure. This may seem odd for the first two Check functions, since
they could also easily return true/false, but since they actually log
an error when the requested condition isn't met (and should result in
a failure of the calling function), I thought 0/-1 was more
appropriate.
virNetDevVPortProfile has (had) a type field that can be set to one of
several values, and a union of several structs, one for each
type. When a domain's interface object is of type "network", the
domain config may not know beforehand which type of virtualport is
going to be provided in the actual device handed down from the network
driver at runtime, but may want to set some values in the virtualport
that may or may not be used, depending on the type. To support this
usage, this patch replaces the union of structs with toplevel fields
in the struct, making it possible for all of the fields to be set at
the same time.
Both of these functions returned void, but it's convenient for them to
return a const char* of the char* that is passed in. This was you can
call the function and use the result in the same expression/arg.
Commit bb705e25 missed that the appArmor helper file also needs to
resolve the new symbols dragged in by domain_conf.c.
* src/Makefile.am (SECURITY_DRIVER_APPARMOR_HELPER_SOURCES): Pull
in datatypes.c.
openvzOpen fucntion must leave unlocked virDomainObj objects in
driver->domains.
Now even simple commands like list or domain lookup hang,
for example virsh -c openvz:///system list --all.
Signed-off-by: Dmitry Guryanov <dguryanov@parallels.com>
The code for picking a MCS label is about to get significantly
more complicated, so it deserves to be in a standlone method,
instead of a switch/case body.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When generating an SELinux context for a VM from the template
"system_u:system_r:svirt_t:s0", copy the role + user from the
current process instead of the template context. So if the
current process is
unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
then the VM context ends up as
unconfined_u:unconfined_r:svirt_t:s0:c386,c703
instead of
system_u:system_r:svirt_t:s0:c177,c424
Ideally the /etc/selinux/targeted/contexts/virtual_domain_context
file would have just shown the 'svirt_t' type, and not the full
context, but that can't be changed now for compatibility reasons.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virSecuritySELinuxGenNewContext method was not reporting any
errors, leaving it up to the caller to report a generic error.
In addition it could potentially trigger a strdup(NULL) in an
OOM scenario. Move all error reporting into the
virSecuritySELinuxGenNewContext method where accurate info
can be provided
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
There is currently no way to distinguish the case that a requested
security driver was disabled, from the case where no security driver
was available. Use VIR_ERR_CONFIG_UNSUPPORTED as the error when an
explicitly requested security driver was disabled
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The security_manager.h header is not self-contained because it
uses the virDomainDefPtr without first including domain_conf.h
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The current virRandomBits() API is only usable if the caller wants
a random number in the range [0, n-1) where n is a power of two.
This adds a virRandom() API which generates a double in the
range [0.0,1.0) with 48 bits of entropy. It then also adds a
virRandomInt(uint32_t max) API which generates an unsigned
in the range [0,@max)
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The way LIBVIRT_VERSION_INFO is calculated has a timebomb that
will cause us to accidentally break soname when we change the
major version number to a non-zero value !
Given CURRENT:REVISION:AGE, libtool will generate
libvirt.so.($CURRENT-$AGE).$AGE.$REVISION
We set CURRENT to be MAJOR+MINOR and AGE to $MINOR, so as
soon as MAJOR changes to non-zero, we get libvirt.so.1
as the soname, eg 1.3.9 would create libvirt.so.1.3.9
Looks natural but is not ABI compatible with libvirt.so.0.x.y
The fix is to set CURRENT to always be exactly the same
as AGE. We want to have the major version reflected in
the so symlinks though. So then we set AGE to MAJOR*1000+MINOR
eg, so 1.3.9 would create libvirt.so.0.1003.9 and libvirt
2.51.3 would create libvirt.so.0.2051.3
As the consensus in:
https://www.redhat.com/archives/libvir-list/2012-July/msg01692.html,
this patch is to destroy conf/virdomainlist.[ch], folding the
helpers into conf/domain_conf.[ch].
* src/Makefile.am:
- Various indention fixes incidentally
- Add macro DATATYPES_SOURCES (datatypes.[ch])
- Link datatypes.[ch] for libvirt_lxc
* src/conf/domain_conf.c:
- Move all the stuffs from virdomainlist.c into it
- Use virUnrefDomain and virUnrefDomainSnapshot instead of
virDomainFree and virDomainSnapshotFree, which are defined
in libvirt.c, and we don't want to link to it.
- Remove "if" before "free" the object, as virObjectUnref
is in the list "useless_free_options".
* src/conf/domain_conf.h:
- Move all the stuffs from virdomainlist.h into it
- s/LIST_FILTER/LIST_DOMAINS_FILTER/
* src/libxl/libxl_driver.c:
- s/LIST_FILTER/LIST_DOMAINS_FILTER/
- no (include "virdomainlist.h")
* src/libxl/libxl_driver.c: Likewise
* src/lxc/lxc_driver.c: Likewise
* src/openvz/openvz_driver.c: Likewise
* src/parallels/parallels_driver.c: Likewise
* src/qemu/qemu_driver.c: Likewise
* src/test/test_driver.c: Likewise
* src/uml/uml_driver.c: Likewise
* src/vbox/vbox_tmpl.c: Likewise
* src/vmware/vmware_driver.c: Likewise
* tools/virsh-domain-monitor.c: Likewise
* tools/virsh.c: Likewise
libvirt creates invalid commands if wrong locale is selected. For
example with locale that uses comma as a decimal point, JSON commands
created with decimal numbers are invalid because comma separates the
entries in JSON. Fortunately even when decimal point is affected,
thousands grouping is not, because for grouping to be enabled with
*printf, there has to be an apostrophe flag specified (and supported).
This patch adds specific internal function for converting doubles to
strings with C locale.
This is a patch for bug 847848
If registering an existing lockspace with the sanlock daemon
returns an error, libvirt should not proceed to unlink the lockspace.
Signed-off-by: Asad Saeed <asad.saeed@acidseed.com>
Similar to the previous patch, prepending 'help' to a partial
command string doesn't cut us any slack.
$ virsh help pool-define-as --name foo --type dir
error: command 'help' doesn't support option --name
This patch adds a few hacks to make 'help' ignore everything after the
first data bit, so the above command shows help output for pool-define-as.
Often times I find myself halfway through typing a long command when
I want to see 'help' output. I instinctively append '--help' to the
command I'm typing, only to get an error:
$ virsh vol-create-as foo --help
error: command 'vol-create-as' doesn't support option --help
This patch makes --help work in a pretty hacky way. One missing piece
here is that --help isn't listed as an option in the actual 'help <cmd>'
output, but maybe this can be a starting point for someone.
For some reason I only get this after applying subsequent upcoming
patches that touch virsh, but don't seem to actually cause the warning.
virsh.c: In function ‘vshCommandParse’:
virsh.c:2014:46: error: ‘opt_index’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
cc1: all warnings being treated as errors
Otherwise distcheck can fail with:
GEN check-symfile
Can't open perl script "../../src/check-symfile.pl": No such file or directory
make[4]: *** [check-symfile] Error 2
This is a patch for bug 826704
All sanlock resources get released when hot-dettaching a disk from the domain
because virLockManagerSanlockRelease uses the wrong function parameters/flags.
With the patch only the resources that should be released are cleaned up.
Signed-off-by: Frido Roose <frido.roose@gmail.com>
This patch introduces a new error code VIR_ERR_OPERATION_UNSUPPORTED to
mark error messages regarding operations that failed due to lack of
support on the hypervisor or other than libvirt issues.
The code is first used in reporting error if qemu does not support block
IO tuning variables yielding error message:
error: Unable to get block I/O throttle parameters
error: Operation not supported: block_io_throttle field
'total_bytes_sec' missing in qemu's output
instead of:
error: Unable to get block I/O throttle parameters
error: internal error cannot read total_bytes_sec
libvirt_qemu_probes.stp stopped working after switching to a build
that used --with-driver-modules. This was because the symbols listed
int libvirt_qemu_probes.stp are no longer in $(bindir)/libvirtd, but
are now in $(libdir)/connection-driver/libvirt_driver_qemu.so.
This patch enhances dtrace2systemtap.pl (which generates the .stp
files from .d files) to look for a new "module" setting in the
comments of the .d file (similar to the existing "binary" setting),
and to look for a --with-modules option. If the --with-modules option
is set *and* a "module" setting is present in the .d file, the process
name for the stap line is set to
$libdir/$module
If either of these isn't true, it reverts to the old behavior.
src/Makefile.am was also modified to add the --with-modules option
when the build calls for it, and src/libvirt_qemu_probes.d has added a
"module" line pointing to the correct .so file for the qemu driver.
List:
- some old libvir/libvirt rename leftovers (the only problem can be
if somebody parses 'virsh version' output really badly)
- remove pointless tags specified in some pages that are not used
This patch makes search.php autogenerated from search.php.in, thus
removing hardcoded menus, footer etc. and the search.php is added to
.gitignore.
There is new rule added for *.php files (to make it bit less
hardcoded) that takes *.php.code.in and injects it inside the
generated *.php (xslt was not happy about php code in the source xml).
Error 404 page had relative paths specified for both the image and
stylesheets which caused a problem when requested URL included a
subfolder (e.g. http://libvirt.org/asdf/asdf ). This patch corrects
this behaviour by modifying href_base to '/' (for style-sheets) and
changing the src of the image (to be '/' always).
The meat of this patch is just moving the calls to
virNWFilterRegisterCallbackDriver from each hypervisor's "register"
function into its "initialize" function. The rest is just code
movement to allow that, and a new virNWFilterUnRegisterCallbackDriver
function to undo what the register function does.
The long explanation:
There is an array in nwfilter called callbackDrvArray that has
pointers to a table of functions for each hypervisor driver that are
called by nwfilter. One of those function pointers is to a function
that will lock the hypervisor driver. Entries are added to the table
by calling each driver's "register" function, which happens quite
early in libvirtd's startup.
Sometime later, each driver's "initialize" function is called. This
function allocates a driver object and stores a pointer to it in a
static variable that was previously initialized to NULL. (and here's
the important part...) If the "initialize" function fails, the driver
object is freed, and that pointer set back to NULL (but the entry in
nwfilter's callbackDrvArray is still there).
When the "lock the driver" function mentioned above is called, it
assumes that the driver was successfully loaded, so it blindly tries
to call virMutexLock on "driver->lock".
BUT, if the initialize never happened, or if it failed, "driver" is
NULL. And it just happens that "lock" is always the first field in
driver so it is also NULL.
Boom.
To fix this, the call to virNWFilterRegisterCallbackDriver for each
driver shouldn't be called until the end of its (*already guaranteed
successful*) "initialize" function, not during its "register" function
(which is currently the case). This implies that there should also be
a virNWFilterUnregisterCallbackDriver() function that is called in a
driver's "shutdown" function (although in practice, that function is
currently never called).
Otherwise, in locations like virobject.c where PROBE is used,
for certain configure options, the compiler warns:
util/virobject.c:110:1: error: 'intptr_t' undeclared (first use in this function)
As long as we are making this header always available, we can
clean up several other files.
* src/internal.h (includes): Pull in <stdint.h>.
* src/conf/nwfilter_conf.h: Rely on internal.h.
* src/storage/storage_backend.c: Likewise.
* src/storage/storage_backend.h: Likewise.
* src/util/cgroup.c: Likewise.
* src/util/sexpr.h: Likewise.
* src/util/virhashcode.h: Likewise.
* src/util/virnetdevvportprofile.h: Likewise.
* src/util/virnetlink.h: Likewise.
* src/util/virrandom.h: Likewise.
* src/vbox/vbox_driver.c: Likewise.
* src/xenapi/xenapi_driver.c: Likewise.
* src/xenapi/xenapi_utils.c: Likewise.
* src/xenapi/xenapi_utils.h: Likewise.
* src/xenxs/xenxs_private.h: Likewise.
* tests/storagebackendsheepdogtest.c: Likewise.
An ESX server has one or more PhysicalNics that represent the actual
hardware NICs. Those can be listed via the interface driver.
A libvirt virtual network is mapped to a HostVirtualSwitch. On the
physical side a HostVirtualSwitch can be connected to PhysicalNics.
On the virtual side a HostVirtualSwitch has HostPortGroups that are
mapped to libvirt virtual network's portgroups. Typically there is
HostPortGroups named 'VM Network' that is used to connect virtual
machines to a HostVirtualSwitch. A second HostPortGroup typically
named 'Management Network' is used to connect the hypervisor itself
to the HostVirtualSwitch. This one is not mapped to a libvirt virtual
network's portgroup. There can be more HostPortGroups than those
typical two on a HostVirtualSwitch.
+---------------+-------------------+
...---| | | +-------------+
| HostPortGroup | |---| PhysicalNic |
| VM Network | | | vmnic0 |
...---| | | +-------------+
+---------------+ HostVirtualSwitch |
| vSwitch0 |
+---------------+ |
| HostPortGroup | |
...---| Management | |
| Network | |
+---------------+-------------------+
The virtual counterparts of the PhysicalNic is the HostVirtualNic for
the hypervisor and the VirtualEthernetCard for the virtual machines
that are grouped into HostPortGroups.
+---------------------+ +---------------+---...
| VirtualEthernetCard |---| |
+---------------------+ | HostPortGroup |
+---------------------+ | VM Network |
| VirtualEthernetCard |---| |
+---------------------+ +---------------+
|
+---------------+
+---------------------+ | HostPortGroup |
| HostVirtualNic |---| Management |
+---------------------+ | Network |
+---------------+---...
The currently implemented network driver can list, define and undefine
HostVirtualSwitches including HostPortGroups for virtual machines.
Existing HostVirtualSwitches cannot be edited yet. This will be added
in a followup patch.