Support for this is included in qemu and seabios from upstream git.

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.

* src/conf/domain_conf.h (virDomainChrDeviceType): Drop monitor.
* src/conf/domain_conf.c (virDomainChrDevice)
(virDomainChrDefParseTargetXML, virDomainChrDefFormat): Drop
monitor support.
* src/qemu/qemu_command.h (qemuBuildCommandLine): Alter signature.
* src/qemu/qemu_monitor.h (qemuMonitorOpen): Likewise.
* src/qemu/qemu_domain.h (_qemuDomainObjPrivate): Change type of
monConfig.
* src/qemu/qemu_domain.c (qemuDomainObjPrivateFree)
(qemuDomainObjPrivateXMLFormat, qemuDomainObjPrivateXMLParse):
Adjust to type change.
* src/qemu/qemu_command.c (qemuBuildCommandLine): Likewise.
* src/qemu/qemu_driver.c (qemuPrepareMonitorChr)
(qemudStartVMDaemon, qemuDomainXMLToNative, qemuConnectMonitor)
(qemudShutdownVMDaemon): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainAttachNetDevice): Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorOpen): Likewise.
* tests/qemuxml2argvtest.c (testCompareXMLToArgvFiles): Likewise.

This opens up the possibility of reusing the smaller ChrSourceDef
for both qemu monitor and a passthrough smartcard device.

* src/conf/domain_conf.h (_virDomainChrDef): Factor host
details...
(_virDomainChrSourceDef): ...into new struct.
(virDomainChrSourceDefFree): New prototype.
* src/conf/domain_conf.c (virDomainChrDefFree)
(virDomainChrDefParseXML, virDomainChrDefFormat): Split...
(virDomainChrSourceDefClear, virDomainChrSourceDefFree)
(virDomainChrSourceDefParseXML, virDomainChrSourceDefFormat):
...into new functions.
(virDomainChrDefParseTargetXML): Update clients to reflect type
split.
* src/vmx/vmx.c (virVMXParseSerial, virVMXParseParallel)
(virVMXFormatSerial, virVMXFormatParallel): Likewise.
* src/xen/xen_driver.c (xenUnifiedDomainOpenConsole): Likewise.
* src/xen/xend_internal.c (xenDaemonParseSxprChar)
(xenDaemonFormatSxprChr): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainDumpXML, vboxAttachSerial)
(vboxAttachParallel): Likewise.
* src/security/security_dac.c (virSecurityDACSetChardevLabel)
(virSecurityDACSetChardevCallback)
(virSecurityDACRestoreChardevLabel)
(virSecurityDACRestoreChardevCallback): Likewise.
* src/security/security_selinux.c (SELinuxSetSecurityChardevLabel)
(SELinuxSetSecurityChardevCallback)
(SELinuxRestoreSecurityChardevLabel)
(SELinuxSetSecurityChardevCallback): Likewise.
* src/security/virt-aa-helper.c (get_files): Likewise.
* src/lxc/lxc_driver.c (lxcVmStart, lxcDomainOpenConsole):
Likewise.
* src/uml/uml_conf.c (umlBuildCommandLineChr): Likewise.
* src/uml/uml_driver.c (umlIdentifyOneChrPTY, umlIdentifyChrPTY)
(umlDomainOpenConsole): Likewise.
* src/qemu/qemu_command.c (qemuBuildChrChardevStr)
(qemuBuildChrArgStr, qemuBuildCommandLine)
(qemuParseCommandLineChr): Likewise.
* src/qemu/qemu_domain.c (qemuDomainObjPrivateXMLFormat)
(qemuDomainObjPrivateXMLParse): Likewise.
* src/qemu/qemu_cgroup.c (qemuSetupChardevCgroup): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainAttachNetDevice): Likewise.
* src/qemu/qemu_driver.c (qemudFindCharDevicePTYsMonitor)
(qemudFindCharDevicePTYs, qemuPrepareChardevDevice)
(qemuPrepareMonitorChr, qemudShutdownVMDaemon)
(qemuDomainOpenConsole): Likewise.
* src/qemu/qemu_command.h (qemuBuildChrChardevStr)
(qemuBuildChrArgStr): Delete, now that they are static.
* src/libvirt_private.syms (domain_conf.h): New exports.
* cfg.mk (useless_free_options): Update list.
* tests/qemuxml2argvtest.c (testCompareXMLToArgvFiles): Update
tests.

Move the code for handling the QEMU virDomainObjPtr private
data, and custom XML namespace into a separate file

* src/qemu/qemu_domain.c, src/qemu/qemu_domain.h: New file
  for private data & namespace code
* src/qemu/qemu_driver.c, src/qemu/qemu_driver.h: Remove
  private data & namespace code
* src/qemu/qemu_driver.h, src/qemu/qemu_command.h: Update
  includes
* src/Makefile.am: Add src/qemu/qemu_domain.c

The qemu_conf.c code is doing three jobs, driver config file
loading, QEMU capabilities management and QEMU command line
management. Move the command line code into its own file

* src/qemu/qemu_command.c, src/qemu/qemu_command.h: New
  command line management code
* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h: Delete command
  line code
* src/qemu/qemu_conf.h, src/qemu_conf.c: Adapt for API renames
* src/Makefile.am: add src/qemu/qemu_command.c
* src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_text.c: Add
  import of qemu_command.h

The qemu_conf.c code is doing three jobs, driver config file
loading, QEMU capabilities management and QEMU command line
management. Move the capabilities code into its own file

* src/qemu/qemu_capabilities.c, src/qemu/qemu_capabilities.h: New
  capabilities management code
* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h: Delete capabilities
  code
* src/qemu/qemu_conf.h: Adapt for API renames
* src/Makefile.am: add src/qemu/qemu_capabilities.c

`dump' watchdog action lets libvirtd to dump the guest when receives a
watchdog event (which probably means a guest crash)

Currently only qemu is supported.

Commit febc5916 introduced -vga none in
case no video card is included in domain XML. However, old qemu
versions do not support this and such domain cannot be successfully
started.

* src/qemu/qemu_conf.c (qemudExtractVersionInfo): Check for file
before executing it here, rather than in callers.
(qemudBuildCommandLine): Rewrite with virCommand.
* src/qemu/qemu_conf.h (qemudBuildCommandLine): Update signature.
* src/qemu/qemu_driver.c (qemuAssignPCIAddresses)
(qemudStartVMDaemon, qemuDomainXMLToNative): Adjust callers.

This patch introduces the usage of the pre-associate state of the IEEE 802.1Qbg standard on incoming VM migration on the target host. It is in response to bugzilla entry 632750.

https://bugzilla.redhat.com/show_bug.cgi?id=632750

For being able to differentiate the exact reason as to why a macvtap device is being created, either due to a VM creation or an incoming VM migration, I needed to pass that reason as a parameter from wherever qemudStartVMDaemon is being called in order to determine whether to send an ASSOCIATE (VM creation) or a PRE-ASSOCIATE (incoming VM migration) towards lldpad.

I am also fixing a problem with the virsh domainxml-to-native call on the way.

Gerhard successfully tested the patch with a recent blade network 802.1Qbg-compliant switch.

The patch should not have any side-effects on the 802.1Qbh support in libvirt, but Roopa (cc'ed) may want to verify this.

In common with VNC, the QEMU driver configuration file is used
specify the host level TLS certificate location and a default
password / listen address

* src/qemu/qemu.conf: Add spice_listen, spice_tls,
  spice_tls_x509_cert_dir & spice_password config params
* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h: Parsing of
  spice config parameters and updating -spice arg generation
  to use them
* tests/qemuxml2argvdata/qemuxml2argv-graphics-spice-rhel6.args,
  tests/qemuxml2argvtest.c: Expand test case to cover driver
  level configuration

This supports the -spice argument posted for review against
the latest upstream QEMU/KVM. This supports the bare minimum
config with port, TLS port & listen address. The x509 bits are
added in a later patch.

* src/qemu_conf.c, src/qemu_conf.h: Add SPICE flag. Check for
  -spice availability. Format -spice arg for command line
* qemuhelptest.c: Add SPICE flag
* qemuxml2argvdata/qemuxml2argv-graphics-spice.args: Add <graphics>
  for spice
* qemuxml2argvdata/qemuxml2argv-graphics-spice.xml: Add -spice arg
* qemuxml2argvtest.c: Add SPICE flag

This supports the '-vga qxl' parameter in upstream QEMU/KVM
which has SPICE support added. This isn't particularly useful
until you get the next patch for -spice support. Also note that
while the libvirt XML supports multiple video devices, this
patch only supports a single one. A later patch can add support
for 2nd, 3rd, etc PCI devices for QXL

* src/qemu/qemu_conf.h: Flag for QXL support
* src/qemu/qemu_conf.c: Probe for '-vga qxl' support and implement it
* tests/qemuxml2argvtest.c, tests/qemuxml2xmltest.c,
  tests/qemuxml2argvdata/qemuxml2argv-graphics-spice.args,
  tests/qemuxml2argvdata/qemuxml2argv-graphics-spice.xml: Test
  case for generating spice args with RHEL6 kvm

The patch is based on the possiblity in the QEmu command line to
add -smbios options allowing to override the default values picked
by QEmu. We need to detect this first from QEmu help output.
If the domain is defined with smbios to be inherited from host
then we pass the values coming from the Host own SMBIOS, but
if the domain is defined with smbios to come from sysinfo, we
use the ones coming from the domain definition.

* src/qemu/qemu_conf.h: add the QEMUD_CMD_FLAG_SMBIOS_TYPE enum
  value
* src/qemu/qemu_conf.c: scan the help output for the smbios support,
  and if available add support based on the domain definitions,
  and host data
* tests/qemuhelptest.c: add the new enum in the outputs

Read and store the data when initializing the driver.

Add dump_image_format[] to qemu.conf and support compressed dump
at virsh dump. coredump compression is important for saving disk space
in an environment where multiple guests run.

In general, "disk space for dump" is specially allocated and will be
a dead space in the system. It's used only at emergency. So, it's better
to have both of save_image_format and dump_image_format. "save" is done
in scheduled manner with enough calculated disk space for it.

This code reuses some of save_image_format[] and supports the same format.

Changelog:
 - modified libvirtd_qemu.aug
 - modified test_libvirtd_qemu.aug
 - fixed error handling of qemudSaveCompressionTypeFromString()

So far, readonly=on option is used when qemu supports -device. However,
there are qemu versions which support readonly option with -drive
although they don't have support for -device.

This sets the process name to the same value as the Windows title,
but since the name is limited to 16 chars only this is kept as a
configuration option and turned off by default
* src/qemu/qemu.conf src/qemu/qemu_conf.[ch]: hceck for support in the
  QEmu help output, add the option in qemu conf file and augment
  qemudBuildCommandLine to add it if switched on
* src/qemu/libvirtd_qemu.aug src/qemu/test_libvirtd_qemu.aug: augment
  the augeas lenses accordingly
* tests/qemuhelptest.c: cope with the extra flag being detected now

This enables support for nested SVM using the regular CPU
model/features block. If the CPU model or features include
'svm', then the '-enable-nesting' flag will be added to the
QEMU command line. Latest out of tree patches for nested
'vmx', no longer require the '-enable-nesting' flag. They
instead just look at the cpu features. Several of the models
already include svm support, but QEMU was just masking out
the svm bit silently. So this will enable SVM on such
models

* src/qemu/qemu_conf.h: flag for -enable-nesting
* src/qemu/qemu_conf.c: Use -enable-nesting if VMX or SVM are in
  the CPUID
* src/cpu/cpu.h, src/cpu/cpu.c: API to check for a named feature
* src/cpu/cpu_x86.c: x86 impl of feature check
* src/libvirt_private.syms: Add cpuHasFeature
* src/qemuhelptest.c: Add nesting flag where required

Make use of the existing <filesystem> element to support plan9fs
filesystem passthrough in the QEMU driver

    <filesystem type='mount'>
      <source dir='/export/to/guest'/>
      <target dir='/import/from/host'/>
    </filesystem>

NB, the target is not actually a directory, it is merely a arbitrary
string tag that is exported to the guest as a hint for where to mount
it.

Previously QEMU enabled KQEMU by default and had -no-kqemu.
0.11.x switched to requiring -enable-kqemu. 0.12.x dropped
kqemu entirely. This patch adds support for -enable-kqemu
so 0.11.x works. It replaces a huge set of if() with a
switch() to make the code a bit more readable.

* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h: Support
  -enable-kqemu

Add a new element to the <os> block:

  <bootmenu enable="yes|no"/>

Which maps to -boot,menu=on|off on the QEMU command line.

I decided to use an explicit 'enable' attribute rather than just make the
bootmenu element boolean. This allows us to treat lack of a bootmenu element
as 'use hypervisor default'.

Implement the qemu hooks for XML namespace data.  This
allows us to specify a qemu XML namespace, and then
specify:

<qemu:commandline>
 <qemu:arg value='arg'/>
 <qemu:env name='name' value='value'/>
</qemu:commandline>

In the domain XML.

Changes since v1:
 - Change the <qemu:arg>arg</qemu:arg> XML to <qemu:arg value='arg'/> XML
 - Fix up some memory leaks in qemuDomainDefNamespaceParse
 - Rename num_extra and extra to num_args and args, respectively
 - Fixed up some error messages
 - Make sure to escape user-provided data in qemuDomainDefNamespaceFormatXML

Changes since v2:
 - Add checking to ensure environment variable names are valid
 - Invert the logic in qemuDomainDefNamespaceFormatXML to return early

Changes since v3:
 - Change strspn() to c_isalpha() check of first letter of environment variable
Signed-off-by: NChris Lalancette <clalance@redhat.com>

To allow compatibility with older QEMU PCI device slot assignment
it is necessary to explicitly track the balloon device in the
XML. This introduces a new device

   <memballoon model='virtio|xen'/>

It can also have a PCI address, auto-assigned if necessary.

The memballoon will be automatically added to all Xen and QEMU
guests by default.

* docs/schemas/domain.rng: Add <memballoon> element
* src/conf/domain_conf.c, src/conf/domain_conf.h: parsing
  and formatting for memballoon device. Always add a memory
  balloon device to Xen/QEMU if none exists in XML
* src/libvirt_private.syms: Export memballoon model APIs
* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h: Honour the
  PCI device address in memory balloon device
* tests/*: Update to test new functionality

Disk format probing is now disabled by default. A new config
option in /etc/qemu/qemu.conf will re-enable it for existing
deployments where this causes trouble

In case qemu supports -nodefconfig, libvirt adds uses it when launching
new guests. Since this option may affect CPU models supported by qemu,
we need to use it when probing for available models.

We previously assumed that if the -device option existed in qemu, that
-nodefconfig would also exist. It turns out that isn't the case, as
demonstrated by qemu-kvm-0.12.3 in Fedora 13.

*/src/qemu/qemu_conf.[hc] - add a new QEMUD_CMD_FLAG, set it via the
                            help output, and check it before adding
                            -nodefconfig to the qemu commandline.

Currently there is no way to opt out of libvirt dropping POSIX
capabilities for qemu. This at least is a useful debugging tool, but
is also wanted by users (and distributors):

https://bugzilla.redhat.com/show_bug.cgi?id=559154
https://bugzilla.redhat.com/show_bug.cgi?id=573850

v2: Clarify qemu.conf comment, warn about security implications

v3: Add .aug changes

This allows libvirt to open the PCI device sysfs config file prior
to dropping privileges so qemu can access the full config space.
Without this, a de-privileged qemu can only access the first 64
bytes of config space.

* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h: Detect support
  for pci-assign.configfd option. Use this option when formatting
  PCI device string if possible
* src/qemu/qemu_driver.c: Pre-open PCI sysfs config file and pass
  to QEMU

This patch parses the following two XML descriptions, one for
802.1Qbg and one for 802.1Qbh, and stores the data internally.
The actual triggering of the switch setup protocol has not been
implemented here but the relevant code to do that should go into
the functions associatePortProfileId() and disassociatePortProfileId().

   <interface type='direct'>
      <source dev='eth0.100' mode='vepa'/>
      <model type='virtio'/>
      <virtualport type='802.1Qbg'>
        <parameters managerid='12' typeid='0x123456' typeidversion='1'
         instanceid='fa9b7fff-b0a0-4893-8e0e-beef4ff18f8f'/>
      </virtualport>
      <filterref filter='clean-traffic'/>
    </interface>

    <interface type='direct'>
      <source dev='eth0.100' mode='vepa'/>
      <model type='virtio'/>
      <virtualport type='802.1Qbh'>
        <parameters profileid='my_profile'/>
      </virtualport>
    </interface>

I'd suggest to use this patch as a base for triggering the setup
protocol with the 802.1Qb{g|h} switch.

Several rounds of changes were made to this patch. The
following is a list of these changes.
- Renamed structure virVirtualPortProfileDef to virVirtualPortProfileParams
  as per Daniel Berrange's request
- Addressing Daniel Berrange's comments:
 - removing macvtap.h's dependency on domain_conf.h by
   moving the virVirtualPortProfileDef structure into macvtap.h
   and not passing virtDomainNetDefPtr to any functions in
   macvtap.c
- Addressed most of Chris Wright's comments:
  - indicating error in case virtualport XML node cannot be parsed
    properly
  - parsing hex and decimal numbers using virStrToLong_ui() with
    parameter '0' for base
  - tgifname (target interface name) variable wasn't necessary
    to pass to openMacvtapTap function anymore
- assigning the virtual port data structure to the virDomainNetDef
  only if it was previously parsed
- make sure that the error code returned by openMacvtapTap() is a negative n
  in case the associatePortProfileId() function failed.
- renaming vsi in the XML to virtualport
- replace all occurrences of vsi in the source as well
- removing mode and MAC address parameters from the functions that
  will communicate with the hareware diretctly or indirectly
- moving the associate and disassociate functions to the end of the
  file for subsequent patches to easier make them generally available
  for export
- passing the macvtap interface name rather than the link device since
  this otherwise gives funny side effects when using netlink messages
  where IFLA_IFNAME and IFLA_ADDRESS are specified and the link dev
  all of a sudden gets the MAC address of the macvtap interface.
- Removing rc = -1 error indications in the case of 802.1Qbg|h setup in case
  we wanted to use hook scripts for the setup and so the setup doesn't fail
  here.
- if instance ID UUID is not supplied it will automatically be generated
  - adapted schema to make instance ID UUID optional
  - added test case
- parser and XML generator have been separated into their own
  functions so they can be re-used elsewhere (passthrough case
  for example)
- Adapted XML parser and generator support the above shown type
  (802.1Qbg, 802.1Qbh).
- Adapted schema to above XML
- Adapted test XML to above XML
- Passing through the VM's UUID which seems to be necessary for
  802.1Qbh -- sorry no host UUID
- adding virtual function ID to association function, in case it's
  necessary to use (for SR-IOV)

Currently all host audio backends are disabled if a VM is using VNC, in
favor of the QEMU VNC audio extension. Unfortunately no released VNC
client supports this extension, so users have no way of getting audio
to work if using VNC.

Add a new config option in qemu.conf which allows changing libvirt's
behavior, but keep the default intact.

v2: Fix doc typos, change name to vnc_allow_host_audio

The qemu driver contains a subtle race in the logic to find next
available vnc port.  Currently it iterates through all available ports
and returns the first for which bind(2) succeeds.  However it is possible
that a previously issued port has not yet been bound by qemu, resulting
in the same port used for a subsequent domain.

This patch addresses the race by using a simple bitmap to "reserve" the
ports allocated by libvirt.

V2:
  - Put port bitmap in struct qemud_driver
  - Initialize bitmap in qemudStartup

V3:
  - Check for failure of virBitmapGetBit
  - Additional check for port != -1 before calling virbitmapClearBit

V4:
  - Check for failure of virBitmap{Set,Clear}Bit

There doesn't seem to be anything specific to tap devices for this
array of file descriptors which need to stay open of the guest to use.
Rename then for others to make use of.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NChris Lalancette <clalance@redhat.com>

(gdb) p/x QEMUD_CMD_FLAG_VNET_HOST
$7 = 0xffffffff80000000

Oops - that meant we were incorrectly setting QEMU_CMD_FLAG_RTC_TD_HACK
for qemu-kvm-0.12.3 (and probably botching a few other settings as well).

Fixes Red Hat BZ#592070

* src/qemu/qemu_conf.h (QEMUD_CMD_FLAG_VNET_HOST): Avoid sign
extension.
* tests/qemuhelpdata/qemu-kvm-0.12.3: New file.
* tests/qemuhelptest.c (mymain): Add another case.

Disk devices in QEMU have two parts, the guest device and the host
backend driver. Historically these two parts have had the same
"unique" name. With the switch to using -device though, they now
have separate names. Thus when changing CDROM media, for guests
using -device syntax, we need to prepend the QEMU_DRIVE_HOST_PREFIX
constant

* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h: Add helper function
  qemuDeviceDriveHostAlias() for building a host backend alias
* src/qemu/qemu_driver.c: Use qemuDeviceDriveHostAlias() to determine
  the host backend alias for performing eject/change commands in the
  monitor

The device_add command was added in JSON mode in a way I didn't
expect. Instead of passing the normal device string to the JSON
command:

    { "execute": "device_add", "arguments": { "device": "ne2k_pci,id=nic.1,netdev=net.1" } }

We need to split up the device string into a full JSON object

    { "execute": "device_add", "arguments": { "driver": "ne2k_pci", "id": "nic.1", "netdev": "net.1" } }

* src/qemu/qemu_conf.h, src/qemu/qemu_conf.c: Rename the
  qemuCommandLineParseKeywords method to qemuParseKeywords
  and export it to monitor
* src/qemu/qemu_monitor_json.c: Split up device string into
  a JSON object for device_add command

Signed-off-by: NChris Lalancette <clalance@redhat.com>

The images are saved in /var/lib/libvirt/qemu/save/
and named $domainname.save . The directory is created appropriately
at daemon startup. When a domain is started while a saved image is
available, libvirt will try to load this saved image, and start the
domain as usual in case of failure. In any case the saved image is
discarded once the domain is created.

* src/qemu/qemu_conf.h: adds an extra save path to the driver config
* src/qemu/qemu_driver.c: implement the 3 new operations and handling
  of the image directory