Currently the virQEMUDriverPtr struct contains an wide variety
of data with varying access needs. Move all the static config
data into a dedicated virQEMUDriverConfigPtr object. The only
locking requirement is to hold the driver lock, while obtaining
an instance of virQEMUDriverConfigPtr. Once a reference is held
on the config object, it can be used completely lockless since
it is immutable.
NB, not all APIs correctly hold the driver lock while getting
a reference to the config object in this patch. This is safe
for now since the config is never updated on the fly. Later
patches will address this fully.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=892289
It seems like with new udev within guest OS, the tray is locked,
so we need to:
- 'eject'
- wait for tray to open
- 'change'
Moreover, even when doing bare 'eject', we should check for
'tray_open' as guest may have locked the tray. However, the
waiting phase shouldn't be unbounded, so I've chosen 10 retries
maximum, each per 500ms. This should give enough time for guest
to eject a media and open the tray.
This avoids "Event negative_returns: A negative constant "-1" is passed as
an argument to a parameter that cannot be negative.". The called function
uses -1 to determine whether it needs to traverse all the hostdevs.
When LXC labels USB devices during hotplug, it is running in
host context, so it needs to pass in a vroot path to the
container root.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When a network device's bridge connection is changed by
virDomainUpdateDevice, libvirt first removes the netdev's tap from its
old bridge, then adds it to the new bridge. Sometimes, due to a
network being destroyed while a guest device is still attached, the
tap may already be "removed" from the old bridge (or the old bridge
may not even exist any more); the existing code was needlessly failing
the update when this happened, making it impossible to recover from
the situation without completely detaching (i.e. removing) the netdev
from the guest and re-attaching.
Instead of failing the entire operation when removal of the tap from
the old bridge fails, this patch changes qemuDomainChangeNetBridge to
just log a warning and continue, allowing a reasonable recover from
the situation.
(you'll appreciate this change if you ever accidentally destroy a
network while your guests are still using it).
This fixes a problem that showed up during testing of:
https://bugzilla.redhat.com/show_bug.cgi?id=881480
Due to a logic error in the function that gets the name of the bridge
an interface connects to, any time a bridge was specified directly
(type='bridge') rather than indirectly (type='network'), An error
would be logged (although the operation would then complete
successfully):
Network type 6 is not supported
The final virReportError() in the function
qemuDomainNetGetBridgeName() was apparently avoided in the past with a
"goto cleanup" at the end of each case, but the case of bridge somehow
no longer has that final goto cleanup.
The proper solution is anyway to not rely on goto's, but put the error
log inside an else {} clause, so that it's executed only if the type
is neither bridge nor network (in reality, this function should only
ever be called for those two types, that's why this is an internal
error).
While making this change, the error message was also tuned to be more
correct (since it's not really the type of the network, but the type
of the interface, and it *is* otherwise supported, it's just that the
interface type in question doesn't *have* a bridge device associated
with it, or at least we don't know how to get it).
Since we can't (currently) rely on the ability to provide blanket
support for all possible network changes by calling the toplevel
netdev hostside disconnect/connect functions (due to qemu only
supporting a lockstep between initialization of host side and guest
side of devices), in order to support live change of an interface's
nwfilter we need to make a special purpose function to only call the
nwfilter teardown and setup functions if the filter for an interface
(or its parameters) changes. The pattern is nearly identical to that
used to change the bridge that an interface is connected to.
This patch was inspired by a request from Guido Winkelmann
<guido@sagersystems.de>, who tested an earlier version.
https://bugzilla.redhat.com/show_bug.cgi?id=876828
Commit 38c4a9cc introduced a regression in hot unplugging of disks
from qemu, where cgroup device ACLs were no longer being revoked
(thankfully not a security hole: cgroup ACLs only prevent open()
of the disk; so reverting the ACL prevents future abuse but doesn't
stop abuse from an fd that was already opened before the ACL change).
Commit 1b2ebf95 overlooked that there were two spots affected.
* src/qemu/qemu_hotplug.c (qemuDomainDetachDiskDevice):
Transfer backing chain before deletion.
* src/qemu/qemu_driver.c (qemuDomainDetachDeviceDiskLive): Fix
spacing (partly to ensure a different-looking patch).
Remove the obsolete 'qemud' naming prefix and underscore
based type name. Introduce virQEMUDriverPtr as the replacement,
in common with LXC driver naming style
https://bugzilla.redhat.com/show_bug.cgi?id=876828
Commit 38c4a9cc introduced a regression in hot unplugging of disks
from qemu, where cgroup device ACLs were no longer being revoked
(thankfully not a security hole: cgroup ACLs only prevent open()
of the disk; so reverting the ACL prevents future abuse but doesn't
stop abuse from an fd that was already opened before the ACL change).
The actual regression is due to a latent bug. The hot unplug code
was computing the set of files needing cgroup ACL revocation based
on the XML passed in by the user, rather than based on the domain's
details on which disk was being deleted. As long as the revoke
path was always recomputing the backing chain, this didn't really
matter; but now that we want to compute the chain exactly once and
remember that computation, we need to hang on to the backing chain
until after the revoke has happened.
* src/qemu/qemu_hotplug.c (qemuDomainDetachPciDiskDevice):
Transfer backing chain before deletion.
The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
For now, disk migration via block copy job is not implemented in
libvirt. But when we do implement it, we have to deal with the
fact that qemu does not yet provide an easy way to re-start a qemu
process with mirroring still intact. Paolo has proposed an idea
for a persistent dirty bitmap that might make this possible, but
until that design is complete, it's hard to say what changes
libvirt would need. Even something like 'virDomainSave' becomes
hairy, if you realize the implications that 'virDomainRestore'
would be stuck with recreating the same mirror layout.
But if we step back and look at the bigger picture, we realize that
the initial client of live storage migration via disk mirroring is
oVirt, which always uses transient domains, and that if a transient
domain is destroyed while a mirror exists, oVirt can easily restart
the storage migration by creating a new domain that visits just the
source storage, with no loss in data.
We can make life a lot easier by being cowards for now, forbidding
certain operations on a domain. This patch guarantees that we
never get in a state where we would have to restart a domain with
a mirroring block copy, by preventing saves, snapshots, migration,
hot unplug of a disk in use, and conversion to a persistent domain
(thankfully, it is still relatively easy to 'virsh undefine' a
running domain to temporarily make it transient, run tests on
'virsh blockcopy', then 'virsh define' to restore the persistence).
Later, if the qemu design is enhanced, we can relax our code.
The change to qemudDomainDefine looks a bit odd for undoing an
assignment, rather than probing up front to avoid the assignment,
but this is because of how virDomainAssignDef combines both a
lookup and assignment into a single function call.
* src/conf/domain_conf.h (virDomainHasDiskMirror): New prototype.
* src/conf/domain_conf.c (virDomainHasDiskMirror): New function.
* src/libvirt_private.syms (domain_conf.h): Export it.
* src/qemu/qemu_driver.c (qemuDomainSaveInternal)
(qemuDomainSnapshotCreateXML, qemuDomainRevertToSnapshot)
(qemuDomainBlockJobImpl, qemudDomainDefine): Prevent dangerous
actions while block copy is already in action.
* src/qemu/qemu_hotplug.c (qemuDomainDetachDiskDevice): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsAllowed): Likewise.
This resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=862515
which describes inconsistencies in dealing with duplicate mac
addresses on network devices in a domain.
(at any rate, it resolves *almost* everything, and prints out an
informative error message for the one problem that isn't solved, but
has a workaround.)
A synopsis of the problems:
1) you can't do a persistent attach-interface of a device with a mac
address that matches an existing device.
2) you *can* do a live attach-interface of such a device.
3) you *can* directly edit a domain and put in two devices with
matching mac addresses.
4) When running virsh detach-device (live or config), only MAC address
is checked when matching the device to remove, so the first device
with the desired mac address will be removed. This isn't always the
one that's wanted.
5) when running virsh detach-interface (live or config), the only two
items that can be specified to match against are mac address and model
type (virtio, etc) - if multiple netdevs match both of those
attributes, it again just finds the first one added and assumes that
is the only match.
Since it is completely valid to have multiple network devices with the
same MAC address (although it can cause problems in many cases, there
*are* valid use cases), what is needed is:
1) remove the restriction that prohibits doing a persistent add of a
netdev with a duplicate mac address.
2) enhance the backend of virDomainDetachDeviceFlags to check for
something that *is* guaranteed unique (but still work with just mac
address, as long as it yields only a single results.
This patch does three things:
1) removes the check for duplicate mac address during a persistent
netdev attach.
2) unifies the searching for both live and config detach of netdevices
in the subordinate functions of qemuDomainModifyDeviceFlags() to use the
new function virDomainNetFindIdx (which matches mac address and PCI
address if available, checking for duplicates if only mac address was
specified). This function returns -2 if multiple matches are found,
allowing the callers to print out an appropriate message.
Steps 1 & 2 are enough to fully fix the problem when using virsh
attach-device and detach-device (which require an XML description of
the device rather than a bunch of commandline args)
3) modifies the virsh detach-interface command to check for multiple
matches of mac address and show an error message suggesting use of the
detach-device command in cases where there are multiple matching mac
addresses.
Later we should decide how we want to input a PCI address on the virsh
commandline, and enhance detach-interface to take a --address option,
eliminating the need to use detach-device
* src/conf/domain_conf.c
* src/conf/domain_conf.h
* src/libvirt_private.syms
* added new virDomainNetFindIdx function
* removed now unused virDomainNetIndexByMac and
virDomainNetRemoveByMac
* src/qemu/qemu_driver.c
* remove check for duplicate max from qemuDomainAttachDeviceConfig
* use virDomainNetFindIdx/virDomainNetRemove instead
of virDomainNetRemoveByMac in qemuDomainDetachDeviceConfig
* use virDomainNetFindIdx instead of virDomainIndexByMac
in qemuDomainUpdateDeviceConfig
* src/qemu/qemu_hotplug.c
* use virDomainNetFindIdx instead of a homespun loop in
qemuDomainDetachNetDevice.
* tools/virsh-domain.c: modified detach-interface command as described
above
This patch resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=805071
to the extent that it can be resolved with current qemu functionality.
It attempts to detect as many situations as possible when the simple
operation of disconnecting an existing tap device from one bridge and
attaching it to another will satisfy the change requested in
virDomainUpdateDeviceFlags() for a network device. Before this patch,
that situation could only be detected if the pre-change interface
*and* the post-change interface definition were both "type='bridge'".
After this patch, it can also be detected if the before or after
interfaces are any combination of type='bridge' and type='network'
(the networks can be <forward mode='nat|route|bridge'>, as long as
they use a Linux host bridge and not macvtap connections).
This extra effort is especially useful since the recent discovery that
a netdev_del+netdev_add combo (to reconnect the network device with
completely different hostside configuration) doesn't work properly
with current qemu (1.2) unless it is accompanied by the matching
device_del+device_add - see this mailing list message for details:
http://lists.nongnu.org/archive/html/qemu-devel/2012-10/msg02355.html
(A slight modification of the patch referenced there has been prepared
to apply on top of this patch, but won't be pushed until qemu can be
made to work with it.)
* qemuDomainChangeNet needs access to the virDomainDeviceDef that
holds the new netdef (so that it can clear out the virDomainDeviceDef
if it ends up using the NetDef to replace the original), so the
virDomainNetDefPtr arg is replaced with a virDomainDeviceDefPtr.
* qemuDomainChangeNet previously checked for *some* changes to the
interface config, but this check was by no means complete. It was also
a bit disorganized.
This refactoring of the code is (I believe) complete in its check of
all NetDef attributes that might be changed, and either returns a
failure (for changes that are simply impossible), or sets one of three
flags:
needLinkStateChange - if the device link state needs to go up/down
needBridgeChange - if everything else is the same, but it needs
to be connected to a difference linux host
bridge
needReconnect - if the entire host side of the device needs
to be torn down and reconstructed (currently
non-working, as mentioned above)
Note that this function will refuse to make any change that requires
the *guest* side of the device to be detached (e.g. changing the PCI
address or mac address). Those would be disruptive enough to the guest
that it's reasonable to require an explicit detach/attach sequence
from the management application.
* As mentioned above, qemuDomainChangeNet also does its best to
understand when a simple change in attached bridge for the existing
tap device will work vs. the need to completely tear down/reconstruct
the host side of the device (including tap device).
This patch *does not* implement the "reconnect" code anyway - there is
a placeholder that turns that into an error. Rather, the purpose of
this patch is to replicate existing behavior with code that is ready
to have that functionality plugged in in a later patch.
* The expanded uses for qemuDomainChangeNetBridge meant that it needed
to be enhanced as well - it no longer replaces the original brname
string in olddev with the new brname; instead, it relies on the
caller to replace the *entire* olddev with newdev (since we've gone
to great lengths to assure they are functionally identical other
than the name of the bridge, this is now not only safe, but more
correct). Additionally, qemuDomainNetChangeBridge can now set the
bridge for type='network' interfaces as well as plain type='bridge'
interfaces. (Note that I had to make this change simultaneous to the
reorganization of qemuDomainChangeNet because the two are too
closely intertwined to separate).
All USB device lookup functions emit an error when they cannot find the
requested device. With this patch, their caller can choose if a missing
device is an error or normal condition.
The code which looks up a USB device specified by hostdev is duplicated
in two places. This patch creates a dedicated function that can be
called in both places.
Many parts of virDomainDefPtr were using 'int' variables as
array length counts. Replace all these with size_t and update
various format strings & API signatures to adapt
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Disk hotplug is a two phase action: qemuMonitorAddDrive followed by
qemuMonitorAddDevice. When the first part succeeds but the second one
fails, we need to rollback the drive addition.
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.
* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/; If/. If/
The current qemu capabilities are stored in a virBitmapPtr
object, whose type is exposed to callers. We want to store
more data besides just the flags, so we need to move to a
struct type. This object will also need to be reference
counted, since we'll be maintaining a cache of data per
binary. This change introduces a 'qemuCapsPtr' virObject
class. Most of the change is just renaming types and
variables in all the callers
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
I got an off-list report about a bad diagnostic:
Target network card mac 52:54:00:49:07:ccdoes not match source 52:54:00:49:07:b8
True to form, I've added a syntax check rule to prevent it
from recurring, and found several other offenders.
* cfg.mk (sc_require_whitespace_in_translation): New rule.
* src/conf/domain_conf.c (virDomainNetDefCheckABIStability): Add
space.
* src/esx/esx_util.c (esxUtil_ParseUri): Likewise.
* src/qemu/qemu_command.c (qemuCollectPCIAddress): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSetMetadata)
(qemuDomainGetMetadata): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainChangeNetBridge): Likewise.
* src/rpc/virnettlscontext.c
(virNetTLSContextCheckCertDNWhitelist): Likewise.
* src/vmware/vmware_driver.c (vmwareDomainResume): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainGetXMLDesc, vboxAttachDrives):
Avoid false negatives.
* tools/virsh-domain.c (info_save_image_dumpxml): Reword.
Based on a report by Luwen Su.
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>
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 the support to run the QEMU network helper
under unprivileged user. It also adds the support for
attach-interface option in virsh to run under unprivileged
user.
Signed-off-by: Richa Marwaha <rmarwah@linux.vnet.ibm.com>
Signed-off-by: Corey Bryant<coreyb@linux.vnet.ibm.com>
* 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.
Any time we have a string with no % passed through gettext, a
translator can inject a % to cause a stack overread. When there
is nothing to format, it's easier to ask for a string that cannot
be used as a formatter, by using a trivial "%s" format instead.
In the past, we have used --disable-nls to catch some of the
offenders, but that doesn't get run very often, and many more
uses have crept in. Syntax check to the rescue!
The syntax check can catch uses such as
virReportError(code,
_("split "
"string"));
by using a sed script to fold context lines into one pattern
space before checking for a string without %.
This patch is just mechanical insertion of %s; there are probably
several messages touched by this patch where we would be better
off giving the user more information than a fixed string.
* cfg.mk (sc_prohibit_diagnostic_without_format): New rule.
* src/datatypes.c (virUnrefConnect, virGetDomain)
(virUnrefDomain, virGetNetwork, virUnrefNetwork, virGetInterface)
(virUnrefInterface, virGetStoragePool, virUnrefStoragePool)
(virGetStorageVol, virUnrefStorageVol, virGetNodeDevice)
(virGetSecret, virUnrefSecret, virGetNWFilter, virUnrefNWFilter)
(virGetDomainSnapshot, virUnrefDomainSnapshot): Add %s wrapper.
* src/lxc/lxc_driver.c (lxcDomainSetBlkioParameters)
(lxcDomainGetBlkioParameters): Likewise.
* src/conf/domain_conf.c (virSecurityDeviceLabelDefParseXML)
(virDomainDiskDefParseXML, virDomainGraphicsDefParseXML):
Likewise.
* src/conf/network_conf.c (virNetworkDNSHostsDefParseXML)
(virNetworkDefParseXML): Likewise.
* src/conf/nwfilter_conf.c (virNWFilterIsValidChainName):
Likewise.
* src/conf/nwfilter_params.c (virNWFilterVarValueCreateSimple)
(virNWFilterVarAccessParse): Likewise.
* src/libvirt.c (virDomainSave, virDomainSaveFlags)
(virDomainRestore, virDomainRestoreFlags)
(virDomainSaveImageGetXMLDesc, virDomainSaveImageDefineXML)
(virDomainCoreDump, virDomainGetXMLDesc)
(virDomainMigrateVersion1, virDomainMigrateVersion2)
(virDomainMigrateVersion3, virDomainMigrate, virDomainMigrate2)
(virStreamSendAll, virStreamRecvAll)
(virDomainSnapshotGetXMLDesc): Likewise.
* src/nwfilter/nwfilter_dhcpsnoop.c (virNWFilterSnoopReqLeaseDel)
(virNWFilterDHCPSnoopReq): Likewise.
* src/openvz/openvz_driver.c (openvzUpdateDevice): Likewise.
* src/openvz/openvz_util.c (openvzKBPerPages): Likewise.
* src/qemu/qemu_cgroup.c (qemuSetupCgroup): Likewise.
* src/qemu/qemu_command.c (qemuBuildHubDevStr, qemuBuildChrChardevStr)
(qemuBuildCommandLine): Likewise.
* src/qemu/qemu_driver.c (qemuDomainGetPercpuStats): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainAttachNetDevice): Likewise.
* src/rpc/virnetsaslcontext.c (virNetSASLSessionGetIdentity):
Likewise.
* src/rpc/virnetsocket.c (virNetSocketNewConnectUNIX)
(virNetSocketSendFD, virNetSocketRecvFD): Likewise.
* src/storage/storage_backend_disk.c
(virStorageBackendDiskBuildPool): Likewise.
* src/storage/storage_backend_fs.c
(virStorageBackendFileSystemProbe)
(virStorageBackendFileSystemBuild): Likewise.
* src/storage/storage_backend_rbd.c
(virStorageBackendRBDOpenRADOSConn): Likewise.
* src/storage/storage_driver.c (storageVolumeResize): Likewise.
* src/test/test_driver.c (testInterfaceChangeBegin)
(testInterfaceChangeCommit, testInterfaceChangeRollback):
Likewise.
* src/vbox/vbox_tmpl.c (vboxListAllDomains): Likewise.
* src/xenxs/xen_sxpr.c (xenFormatSxprDisk, xenFormatSxpr):
Likewise.
* src/xenxs/xen_xm.c (xenXMConfigGetUUID, xenFormatXMDisk)
(xenFormatXM): Likewise.
Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)
You should have received a copy of the GNU General Public License
along with Foobar. If not, see <http://www.gnu.org/licenses/>.
This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').
Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:
src/security/security_selinux.h
src/security/security_driver.h
src/security/security_selinux.c
src/security/security_apparmor.h
src/security/security_apparmor.c
src/security/security_driver.c
Introduce new members in the virMacAddr 'class'
- virMacAddrSet: set virMacAddr from a virMacAddr
- virMacAddrSetRaw: setting virMacAddr from raw 6 byte MAC address buffer
- virMacAddrGetRaw: writing virMacAddr into raw 6 byte MAC address buffer
- virMacAddrCmp: comparing two virMacAddr
- virMacAddrCmpRaw: comparing a virMacAddr with a raw 6 byte MAC address buffer
then replace raw MAC addresses by replacing
- 'unsigned char *' with virMacAddrPtr
- 'unsigned char ... [VIR_MAC_BUFLEN]' with virMacAddr
and introduce usage of above functions where necessary.
Libvirt updates the configuration of SPICE server only when something
changes. This is unfortunate when the user wants to disconnect a
existing spice session when the connected attribute is already
"disconnect".
This patch modifies the conditions for calling the password updater to
be called when nothing changes, but the connected attribute is already
"disconnect".
The pciDevice structure corresponding to the device being hot-unplugged
was freed after it was "stolen" from activeList. The pointer was still
used for eg-inactive list. This patch removes the free of the structure
and frees it only if reset fails on the device.
If qemuPrepareHostdevUSBDevices fail it will roll back devices added
to the driver list of used devices. However, if it may fail because
the device is being used already. But then again - with roll back.
Therefore don't try to remove a usb device manually if the function
fail. Although, we want to remove the device if any operation
performed afterwards fail.
when failing to attach another usb device to a domain for some reason
which has one use device attached before, the libvirtd crashed.
The crash is caused by null-pointer dereference error in invoking
usbDeviceListSteal passed in NULL value usb variable.
commit 05abd1507d introduces the bug.
src/qemu/qemu_hostdev.c:
refactor qemuPrepareHostdevUSBDevices function, make it focus on
adding usb device to activeUsbHostdevs after check. After that,
the usb hotplug function qemuDomainAttachHostDevice also could use
it.
expand qemuPrepareHostUSBDevices to perform the usb search,
rollback on failure.
src/qemu/qemu_hotplug.c:
If there are multiple usb devices available with same vendorID and productID,
but with different value of "bus, device", we give an error to let user
use <address> to specify the desired one.
usbFindDevice():get usb device according to
idVendor, idProduct, bus, device
it is the exact match of the four parameters
usbFindDeviceByBus():get usb device according to bus, device
it returns only one usb device same as usbFindDevice
usbFindDeviceByVendor():get usb device according to idVendor,idProduct
it probably returns multiple usb devices.
usbDeviceSearch(): a helper function to do the actual search
Most of our errors complaining about an inability to support a
particular action due to qemu limitations used CONFIG_UNSUPPORTED,
but we had a few outliers. Reported by Jiri Denemark.
* src/qemu/qemu_command.c (qemuBuildDriveDevStr): Prefer
CONFIG_UNSUPPORTED.
* src/qemu/qemu_driver.c (qemuDomainReboot)
(qemuDomainBlockJobImpl): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainAttachPciControllerDevice):
Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorTransaction)
(qemuMonitorBlockJob, qemuMonitorSystemWakeup): Likewise.
