To avoid backward compatibility issues, this patch suppresses
auto-generated DAC labels from XML. This change affects commands such as
dumpxml and save.
Signed-off-by: Marcelo Cerri <mhcerri@linux.vnet.ibm.com>
With this patch libvirt tries to assign a model to a single seclabel
when model is missing. Libvirt will look up at host's capabilities and
assign the first model to seclabel.
This patch fixes:
1. The problem with existing guests that have a seclabel defined in its XML.
2. A XML parse error when a guest is restored.
Signed-off-by: Marcelo Cerri <mhcerri@linux.vnet.ibm.com>
virDomainVcpuPinAdd does a realloc on vcpupin_list if the new vcpu pin
definition doesn't fit into the array. The list is an array of pointers
but the function definition didn't support returning the changed pointer
to the caller if it was realloced. This caused segfaults if realloc
would change the base pointer.
virDomainVcpuPinDefCopy when the control flow reaches out of memory
cleanup code, the flow would end in a infinite loop as the loop variable
wasn't decremented.
Also a dereference of NULL pointers was possible if allocation of the
Vcpu pinning definiton structure failed.
When checking for seclabels without security models, def->nseclabels is
already set to n. In the case of an error def->seclabels is freed but
nseclabels is left untouched. This leads to a segmentation fault when
def is freed in virDomainDefParseXML.
The name 'virDomainDiskSnapshot' didn't fit in with our normal
conventions of using a prefix hinting that it is related to a
virDomainSnapshotPtr. Also, a future patch will reuse the
enum for declaring where the VM memory is stored.
* src/conf/snapshot_conf.h (virDomainDiskSnapshot): Rename...
(virDomainSnapshotLocation): ...to this.
(_virDomainSnapshotDiskDef): Update clients.
* src/conf/domain_conf.h (_virDomainDiskDef): Likewise.
* src/libvirt_private.syms (domain_conf.h): Likewise.
* src/conf/domain_conf.c (virDomainDiskDefParseXML)
(virDomainDiskDefFormat): Likewise.
* src/conf/snapshot_conf.c: (virDomainSnapshotDiskDefParseXML)
(virDomainSnapshotAlignDisks, virDomainSnapshotDefFormat):
Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotDiskPrepare)
(qemuDomainSnapshotCreateSingleDiskActive)
(qemuDomainSnapshotCreateDiskActive, qemuDomainSnapshotCreateXML):
Likewise.
This has several benefits:
1. Future snapshot-related code has a definite place to go (and I
_will_ be adding some)
2. Snapshot errors now use the VIR_FROM_DOMAIN_SNAPSHOT error
classification, which has been underutilized (previously only in
libvirt.c)
* src/conf/domain_conf.h, domain_conf.c: Split...
* src/conf/snapshot_conf.h, snapshot_conf.c: ...into new files.
* src/Makefile.am (DOMAIN_CONF_SOURCES): Build new files.
* po/POTFILES.in: Mark new file for translation.
* src/vbox/vbox_tmpl.c: Update caller.
* src/esx/esx_driver.c: Likewise.
* src/qemu/qemu_command.c: Likewise.
* src/qemu/qemu_domain.h: Likewise.
We were failing to react to allocation failure when initializing
a snapshot object list. Changing things to store a pointer
instead of a complete object adds one more possible point of
allocation failure, but at the same time, will make it easier to
react to failure now, as well as making it easier for a future
patch to split all virDomainSnapshotPtr handling into a separate
file, as I continue to add even more snapshot code.
Luckily, there was only one client outside of domain_conf.c that
was actually peeking inside the object, and a new wrapper function
was easy.
* src/conf/domain_conf.h (_virDomainObj): Use a pointer.
(virDomainSnapshotObjListInit): Rename.
(virDomainSnapshotObjListFree, virDomainSnapshotForEach): New
declarations.
(_virDomainSnapshotObjList): Move definitions...
* src/conf/domain_conf.c: ...here.
(virDomainSnapshotObjListInit, virDomainSnapshotObjListDeinit):
Rename...
(virDomainSnapshotObjListNew, virDomainSnapshotObjListFree): ...to
these.
(virDomainSnapshotForEach): New function.
(virDomainObjDispose, virDomainListPopulate): Adjust callers.
* src/qemu/qemu_domain.c (qemuDomainSnapshotDiscard)
(qemuDomainSnapshotDiscardAllMetadata): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsAllowed): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotLoad)
(qemuDomainUndefineFlags, qemuDomainSnapshotCreateXML)
(qemuDomainSnapshotListNames, qemuDomainSnapshotNum)
(qemuDomainListAllSnapshots)
(qemuDomainSnapshotListChildrenNames)
(qemuDomainSnapshotNumChildren)
(qemuDomainSnapshotListAllChildren)
(qemuDomainSnapshotLookupByName, qemuDomainSnapshotGetParent)
(qemuDomainSnapshotGetXMLDesc, qemuDomainSnapshotIsCurrent)
(qemuDomainSnapshotHasMetadata, qemuDomainRevertToSnapshot)
(qemuDomainSnapshotDelete): Likewise.
* src/libvirt_private.syms (domain_conf.h): Export new function.
This patch introduces support of setting emulator's period and
quota to limit cpu bandwidth when the vm starts. Also updates
XML Schema for new entries and docs.
Introduce 2 APIs to support emulator threads pin.
1) virDomainEmulatorPinAdd: setup emulator threads pin with a given cpumap string.
2) virDomainEmulatorPinDel: remove all emulator threads pin.
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
This patch adds a new xml element <emulatorpin>, which is a sibling
to the existing <vcpupin> element under the <cputune>, to pin emulator
threads to specified physical CPUs.
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
A hypervisor may allow to override the disk geometry of drives.
Qemu, as an example with cyls=,heads=,secs=[,trans=].
This patch extends the domain config to allow the specification of
disk geometry with libvirt.
Signed-off-by: J.B. Joret <jb@linux.vnet.ibm.com>
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Port allocations for SPICE and VNC behave almost the same (with
default ports), but there is some mess in the code. This patch clears
these inconsistencies and makes sure the same behavior will be used
when ports for remote displays are changed.
Changes:
- hard-coded number 5900 removed (handled elsewhere like with VNC)
- reservedVNCPorts renamed to reservedRemotePorts (it's not just for
VNC anymore)
- QEMU_VNC_PORT_{MIN,MAX} renamed to QEMU_REMOTE_PORT_{MIN,MAX}
- port allocation unified for VNC and SPICE
This patch updates the domain and capability XML parser and formatter to
support more than one "seclabel" element for each domain and device. The
RNG schema and the tests related to this are also updated by this patch.
Signed-off-by: Marcelo Cerri <mhcerri@linux.vnet.ibm.com>
This patch updates the structures that store information about each
domain and each hypervisor to support multiple security labels and
drivers. It also updates all the remaining code to use the new fields.
Signed-off-by: Marcelo Cerri <mhcerri@linux.vnet.ibm.com>
This function is needed by the network driver in a later commit.
It is useful in functions like networkNotifyActualDevice and
networkReleaseActualDevice
This patch introduces the new forward mode='hostdev' along with
attribute managed. Includes updates to the network RNG and new xml
parser/formatter code.
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Move the functions the parse/format, and validate PCI addresses to
their own file so they can be conveniently used in other places
besides device_conf.c
Refactoring existing code without causing any functional changes to
prepare for new code.
This patch makes the code reusable.
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Change device type of a virtio channel from/to spicevmc is not a user
visible change. However, spicevmc channels use different default target
name than other virtio channels. To maintain ABI stability during this
change target name must be explicitly specified (and equal) in both
configurations.
The following config elements now support a <vlan> subelements:
within a domain: <interface>, and the <actual> subelement of <interface>
within a network: the toplevel, as well as any <portgroup>
Each vlan element must have one or more <tag id='n'/> subelements. If
there is more than one tag, it is assumed that vlan trunking is being
requested. If trunking is required with only a single tag, the
attribute "trunk='yes'" should be added to the toplevel <vlan>
element.
Some examples:
<interface type='hostdev'/>
<vlan>
<tag id='42'/>
</vlan>
<mac address='52:54:00:12:34:56'/>
...
</interface>
<network>
<name>vlan-net</name>
<vlan trunk='yes'>
<tag id='30'/>
</vlan>
<virtualport type='openvswitch'/>
</network>
<interface type='network'/>
<source network='vlan-net'/>
...
</interface>
<network>
<name>trunk-vlan</name>
<vlan>
<tag id='42'/>
<tag id='43'/>
</vlan>
...
</network>
<network>
<name>multi</name>
...
<portgroup name='production'/>
<vlan>
<tag id='42'/>
</vlan>
</portgroup>
<portgroup name='test'/>
<vlan>
<tag id='666'/>
</vlan>
</portgroup>
</network>
<interface type='network'/>
<source network='multi' portgroup='test'/>
...
</interface>
IMPORTANT NOTE: As of this patch there is no backend support for the
vlan element for *any* network device type. When support is added in
later patches, it will only be for those select network types that
support setting up a vlan on the host side, without the guest's
involvement. (For example, it will be possible to configure a vlan for
a guest connected to an openvswitch bridge, but it won't be possible
to do that for one that is connected to a standard Linux host bridge.)
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.
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.
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).
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.
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
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.
Switch virDomainObjPtr to use the virObject APIs for reference
counting. The main change is that virObjectUnref does not return
the reference count, merely a bool indicating whether the object
still has any refs left. Checking the return value is also not
mandatory.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This converts the following public API datatypes to use the
virObject infrastructure:
virConnectPtr
virDomainPtr
virDomainSnapshotPtr
virInterfacePtr
virNetworkPtr
virNodeDevicePtr
virNWFilterPtr
virSecretPtr
virStreamPtr
virStorageVolPtr
virStoragePoolPtr
The code is significantly simplified, since the mutex in the
virConnectPtr object now only needs to be held when accessing
the per-connection virError object instance. All other operations
are completely lock free.
* src/datatypes.c, src/datatypes.h, src/libvirt.c: Convert
public datatypes to use virObject
* src/conf/domain_event.c, src/phyp/phyp_driver.c,
src/qemu/qemu_command.c, src/qemu/qemu_migration.c,
src/qemu/qemu_process.c, src/storage/storage_driver.c,
src/vbox/vbox_tmpl.c, src/xen/xend_internal.c,
tests/qemuxml2argvtest.c, tests/qemuxmlnstest.c,
tests/sexpr2xmltest.c, tests/xmconfigtest.c: Convert
to use virObjectUnref/virObjectRef
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Commit ba226d334acbc49f6751b430e0c4e00f69eef6bf tried to fix crash of
the daemon when a domain with an open console was destroyed. The fix was
wrong as it tried to remove the callback also when the stream was
aborted, where at that point the fd stream driver was already freed and
removed.
This patch clears the callbacks with a helper right before the hash is
freed, so that it doesn't interfere with other codepaths where the
stream object is freed.
* src/conf/domain_conf.c:
- Add virDomainControllerFind to find controller device by type
and index.
- Add virDomainControllerRemove to remove the controller device
from maintained controler list.
* src/conf/domain_conf.h:
- Declare the two new helpers.
* src/libvirt_private.syms:
- Expose private symbols for the two new helpers.
* src/qemu/qemu_driver.c:
- Support attach/detach controller device persistently
* src/qemu/qemu_hotplug.c:
- Use the two helpers to simplify the codes.
The access, birth, modification and change times are added to
storage volumes and corresponding xml representations. This
shows up in the XML in this format:
<timestamps>
<atime>1341933637.027319099</atime>
<mtime>1341933637.027319099</mtime>
</timestamps>
Signed-off-by: Eric Blake <eblake@redhat.com>
capability.rng: Guest features can be in any order.
nodedev.rng: Added <driver> element, <capability> phys_function and
virt_functions for PCI devices.
storagepool.rng: Owner or group ID can be -1.
schema tests: New capabilities and nodedev files; changed owner and
group to -1 in pool-dir.xml.
storage_conf: Print uid_t and gid_t as signed to storage pool XML.
This patch adds helpers that validate domain's device configuration.
This will be needed later on to verify devices being hot-plugged to
guests. If the guest has no USB bus, then it's not valid to plug a USB
device to that guest.
Libvirt adds a USB controller to the guest even if the user does not
specify any in the XML. This is due to back-compat reasons.
To allow disabling USB for a guest this patch adds a new USB controller
type "none" that disables USB support for the guest.
