This is in response to:

   https://bugzilla.redhat.com/show_bug.cgi?id=629662

Explanation

qemu's virtio-net-pci driver allows setting the algorithm used for tx
packets to either "bh" or "timer". This is done by adding ",tx=bh" or
",tx=timer" to the "-device virtio-net-pci" commandline option.

'bh' stands for 'bottom half'; when this is set, packet tx is all done
in an iothread in the bottom half of the driver. (In libvirt, this
option is called the more descriptive "iothread".)

'timer' means that tx work is done in qemu, and if there is more tx
data than can be sent at the present time, a timer is set before qemu
moves on to do other things; when the timer fires, another attempt is
made to send more data. (libvirt retains the name "timer" for this
option.)

The resulting difference, according to the qemu developer who added
the option is:

    bh makes tx more asynchronous and reduces latency, but potentially
    causes more processor bandwidth contention since the cpu doing the
    tx isn't necessarily the cpu where the guest generated the
    packets.

Solution

This patch provides a libvirt domain xml knob to change the option on
the qemu commandline, by adding a new attribute "txmode" to the
<driver> element that can be placed inside any <interface> element in
a domain definition. It's use would be something like this:

    <interface ...>
      ...
      <model type='virtio'/>
      <driver txmode='iothread'/>
      ...
    </interface>

I chose to put this setting as an attribute to <driver> rather than as
a sub-element to <tune> because it is specific to the virtio-net
driver, not something that is generally usable by all network drivers.
(note that this is the same placement as the "driver name=..."
attribute used to choose kernel vs. userland backend for the
virtio-net driver.)

Actually adding the tx=xxx option to the qemu commandline is only done
if the version of qemu being used advertises it in the output of

    qemu -device virtio-net-pci,?

If a particular txmode is requested in the XML, and the option isn't
listed in that help output, an UNSUPPORTED_CONFIG error is logged, and
the domain fails to start.

When the <driver> element (and its "name" attribute) was added to the
domain XML's interface element, a "backend" enum was simply added to
the toplevel of the virDomainNetDef struct.

Ignoring the naming inconsistency ("name" vs. "backend"), this is fine
when there's only a single item contained in the driver element of the
XML, but doesn't scale well as we add more attributes that apply to
the backend of the virtio-net driver, or add attributes applicable to
other drivers.

This patch changes virDomainNetDef in two ways:

1) Rename the item in the struct from "backend" to "name", so that
   it's the same in the XML and in the struct, hopefully avoiding
   confusion for someone unfamiliar with the function of the
   attribute.

2) Create a "driver" union within virDomainNetDef, and a "virtio"
   struct in that struct, which contains the "name" enum value.

3) Move around the virDomainNetParse and virDomainNetFormat functions
   to allow for simple plugin of new attributes without disturbing
   existing code. (you'll note that this results in a seemingly
   redundant if() in the format function, but that will no longer be
   the case as soon as a 2nd attribute is added).

In the future, new attributes for the virtio driver backend can be
added to the "virtio" struct, and any other network device backend that
needs an attribute will have its own struct added to the "driver"
union.

When formatting XML for smartcard device with mode=host, libvirt
generates invalid XML if the device has address info associated:

<smartcard mode='host' <address type='ccid' controller='0' slot='1'/>

When run non-root the nwfilter driver logs error messages about
being unable to find iptables/ebtables commands (they are in
/sbin which isn't in $PATH). The nwfilter driver can't ever work
as non-root, so simply skip it entirely thus avoiding the error
messages

* src/conf/nwfilter_conf.h, src/nwfilter/nwfilter_driver.c,
  src/nwfilter/nwfilter_gentech_driver.c,
  src/nwfilter/nwfilter_gentech_driver.h: Pass 'bool privileged'
  flag down to final driver impl
* src/nwfilter/nwfilter_ebiptables_driver.c: Skip initialization
  if not privileged

A typo s/spice/vnc/ caused parsing of the spice 'auth' data
to write into the wrong part of the struct, blowing away
other unrelated data.

* src/conf/domain_conf.c: s/vnc/spice/ in parsing spice auth

* src/util/sysinfo.h (virSysinfoFormat): New prototype.
* src/conf/domain_conf.c (virDomainSysinfoDefFormat): Move guts...
* src/util/sysinfo.c (virSysinfoFormat): ...into new function.
* src/libvirt_private.syms: Export it.

Implement blkio tunable XML configuration and parsing.
Reviewed-by: N"Nikunj A. Dadhania" <nikunj@linux.vnet.ibm.com>
Signed-off-by: NGui Jianfeng <guijianfeng@cn.fujitsu.com>

Adds <smartcard mode='passthrough' type='spicevmc'/>, which uses the
new <channel name='smartcard'/> of <graphics type='spice'>.

* docs/schemas/domain.rng: Support new XML.
* docs/formatdomain.html.in: Document it.
* src/conf/domain_conf.h (virDomainGraphicsSpiceChannelName): New
enum value.
(virDomainChrSpicevmcName): New enum.
(virDomainChrSourceDef): Distinguish spicevmc types.
* src/conf/domain_conf.c (virDomainGraphicsSpiceChannelName): Add
smartcard.
(virDomainSmartcardDefParseXML): Parse it.
(virDomainChrDefParseXML, virDomainSmartcardDefParseXML): Set
spicevmc name.
(virDomainChrSpicevmc): New enum conversion functions.
* src/libvirt_private.syms: Export new functions.
* src/qemu/qemu_command.c (qemuBuildChrChardevStr): Conditionalize
name.
* tests/qemuxml2argvtest.c (domain): New test.
* tests/qemuxml2argvdata/qemuxml2argv-smartcard-passthrough-spicevmc.args:
New file.
* tests/qemuxml2argvdata/qemuxml2argv-smartcard-passthrough-spicevmc.xml:
Likewise.

Inspired by https://bugzilla.redhat.com/show_bug.cgi?id=615757

Add a new character device backend for virtio serial channels that
activates the QEMU spice agent on the main channel using the vdagent
spicevmc connection.  The <target> must be type='virtio', and supports
an optional name that specifies how the guest will see the channel
(for now, name must be com.redhat.spice.0).

<channel type='spicevmc'>
  <target type='virtio'/>
  <address type='virtio-serial' controller='1' bus='0' port='3'/>
</channel>

* docs/schemas/domain.rng: Support new XML.
* docs/formatdomain.html.in: Document it.
* src/conf/domain_conf.h (virDomainChrType): New enum value.
* src/conf/domain_conf.c (virDomainChr): Add spicevmc.
(virDomainChrDefParseXML, virDomainChrSourceDefParseXML)
(virDomainChrDefParseTargetXML): Parse and enforce proper use.
(virDomainChrSourceDefFormat, virDomainChrDefFormat): Format.
* src/qemu/qemu_command.c (qemuBuildChrChardevStr)
(qemuBuildCommandLine): Add qemu support.
* tests/qemuxml2argvtest.c (domain): New test.
* tests/qemuxml2argvdata/qemuxml2argv-channel-spicevmc.xml: New
file.
* tests/qemuxml2argvdata/qemuxml2argv-channel-spicevmc.args:
Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

* src/conf/domain_conf.h (virDomainSmartcardType): New enum.
(virDomainSmartcardDef, virDomainDeviceCcidAddress): New structs.
(virDomainDef): Include smartcards.
(virDomainSmartcardDefIterator): New typedef.
(virDomainSmartcardDefFree, virDomainSmartcardDefForeach): New
prototypes.
(virDomainControllerType, virDomainDeviceAddressType): Add ccid
enum values.
(virDomainDeviceInfo): Add ccid address type.
* src/conf/domain_conf.c (virDomainSmartcard): Convert between
enum and string.
(virDomainSmartcardDefParseXML, virDomainSmartcardDefFormat)
(virDomainSmartcardDefFree, virDomainDeviceCcidAddressParseXML)
(virDomainDefMaybeAddSmartcardController): New functions.
(virDomainDefParseXML): Parse the new XML.
(virDomainDefFormat): Convert back to XML.
(virDomainDefFree): Clean up.
(virDomainDeviceInfoIterate): Iterate over passthrough aliases.
(virDomainController, virDomainDeviceAddress)
(virDomainDeviceInfoParseXML, virDomainDeviceInfoFormat)
(virDomainDefAddImplicitControllers): Support new values.
* src/libvirt_private.syms (domain_conf.h): New exports.
* cfg.mk (useless_free_options): List new function.

Pure cosmetic change.

Allows io={threads|native} as an optional attribute to <driver>.
Signed-off-by: NEric Blake <eblake@redhat.com>

Per the discussion in:

https://bugzilla.redhat.com/show_bug.cgi?id=670394

The port numbering should start from 1, not 0.  We assign maxport + 1,
so start maxport at 0.

In QEMU, the card itself is a PCI device, but it requires a codec
(either -device hda-output or -device hda-duplex) to actually output
sound. Specifying <sound model='ich6'/> gives us -device intel-hda
-device hda-duplex I think it's important that a simple <sound model='ich6'/>
sets up a useful codec, to have consistent behavior with all other sound cards.

This is basically Dan's proposal of

    <sound model='ich6'>
        <codec type='output' slot='0'/>
        <codec type='duplex' slot='3'/>
    </sound>

without the codec bits implemented.

The important thing is to keep a consistent API here, we don't want some
<sound> devs require tweaking codecs but not others. Steps I see to
accomplishing this:

    - every <sound> device has a <codec type='default'/> (unless codecs are
        manually specified)
    - <codec type='none'/> is required to specify 'no codecs'
    - new audio settings like mic=on|off could then be exposed in
        <sound> or <codec> in a consistent manner for all sound models

v2:
    Use model='ich6'

v3:
    Use feature detection, from eblake
    Set codec id, bus, and cad values

v4:
    intel-hda isn't supported if -device isn't available

v5:
    Comment spelling fixes

QEMU supports serving VNC over a unix domain socket rather than traditional
TCP host/port. This is specified with:

<graphics type='vnc' socket='/foo/bar/baz'/>

This provides better security access control than VNC listening on
127.0.0.1, but will cause issues with tools that rely on the lax security
(virt-manager in fedora runs as regular user by default, and wouldn't be
able to access a socket owned by 'qemu' or 'root').

Also not currently supported by any clients, though I have patches for
virt-manager, and virt-viewer should be simple to update.

v2:
    schema: Make listen vs. socket a <choice>

This will allow us to record transient runtime state in vm->def, like
default VNC parameters. Accomplish this by adding an extra 'live' parameter
to SetDefTransient, with similar semantics to the 'live' flag for
AssignDef.

VIR_ERR_INVALID_* is meant for invalid pointers only.

The public object is called NWFilter but the corresponding private
object is called NWFilterPool. I don't see compelling reasons for this
Pool suffix. One might argue that an NWFilter is a "pool" of rules, etc.

Remove the Pool suffix from NWFilterPool. No functional change included.

Currently, boot order can be specified per device class but there is no
way to specify exact disk/NIC device to boot from.

This patch adds <boot order='N'/> element which can be used inside
<disk/> and <interface/>. This is incompatible with the older os/boot
element. Since not all hypervisors support per-device boot
specification, new deviceboot flag is included in capabilities XML for
hypervisors which understand the new boot element. Presence of the flag
allows (but doesn't require) users to use the new style boot order
specification.

This is in response to a request in:

   https://bugzilla.redhat.com/show_bug.cgi?id=665293

In short, under heavy load, it's possible for qemu's networking to
lock up due to the tap device's default 1MB sndbuf being
inadequate. adding "sndbuf=0" to the qemu commandline -netdevice
option will alleviate this problem (sndbuf=0 actually sets it to
0xffffffff).

Because we must be able to explicitly specify "0" as a value, the
standard practice of "0 means not specified" won't work here. Instead,
virDomainNetDef also has a sndbuf_specified, which defaults to 0, but
is set to 1 if some value was given.

The sndbuf value is put inside a <tune> element of each <interface> in
the domain. The intent is that further tunable settings will also be
placed inside this element.

     <interface type='network'>
       ...
       <tune>
         <sndbuf>0</sndbuf>
       ...
       </tune>
     </interface>

This patch is in response to

  https://bugzilla.redhat.com/show_bug.cgi?id=643050

The existing libvirt support for the vhost-net backend to the virtio
network driver happens automatically - if the vhost-net device is
available, it is always enabled, otherwise the standard userland
virtio backend is used.

This patch makes it possible to force whether or not vhost-net is used
with a bit of XML. Adding a <driver> element to the interface XML, eg:

     <interface type="network">
       <model type="virtio"/>
       <driver name="vhost"/>

will force use of vhost-net (if it's not available, the domain will
fail to start). if driver name="qemu", vhost-net will not be used even
if it is available.

If there is no <driver name='xxx'/> in the config, libvirt will revert
to the pre-existing automatic behavior - use vhost-net if it's
available, and userland backend if vhost-net isn't available.

* 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.

Extend the virDomainFeature enumeration to include HAP (hardware
assisted paging) feature.

Hardware features such as Extended Page Table and Nested Page
Table augment hypervisor software techniques such as shadow
page table.  Adding HAP to the virDomainFeature enumeration
allows users to select between hardware and software memory
management mechanisms for their guests.

* src/conf/network_conf.c (virNetworkDefParseXML): Release ipNodes.

If invalid type is specified, e.g.
<serial type='foo'>
    <target port='0'/>
</serial>

We replace 'foo' with "null" type implicitly, without reporting an
error message to tell the user, and "start" or "edit" the domain
will be success.

It's not good to guess what the user wants, This patch is to fix
the problem.

* src/conf/domain_conf.c

This is partially in response to

  https://bugzilla.redhat.com/show_bug.cgi?id=653300

The crash in that report was coincidentally fixed when we switched
from using inet_pton() to using virSocketParseAddr(), but the absence
of an ip address in a dhcp static host definition was still silently
ignored (and that entry discarded from the saved XML). This patch
turns that into a logged failure; likewise if the entry has neither a
mac address nor a name attribute (the entry is useless without at
least one of those, plus an ip address).

Since the network name is now pulled into this function in order for
those error logs to be more informative, the other error messages in
the function have also been changed to take advantage.

Running an instance of the router advertisement daemon (radvd) allows
guests using the virtual network to automatically acquire an IPv6
address and default route. Note that acquiring an address only works
for networks with a prefix length of exactly 64 - radvd is still run
in other circumstances, and still advertises routes, but autoconf will
not work because it requires exactly 64 bits of address info from the
network prefix.

This patch avoids a race condition with the pidfile by manually
daemonizing radvd rather than allowing it to daemonize itself, then
creating our own pidfile (in addition to radvd's own file, which is
unnecessary, but there is no way to tell radvd to not create it). This
is accomplished by exec'ing it with "--debug 1" in the commandline,
and using virCommand's features to fork, create a pidfile, and detach
from the newly forked process.

This commit adds support for IPv6 parsing and formatting to the
virtual network XML parser, including moving around data definitions
to allow for multiple <ip> elements on a single network, but only
changes the consumers of this API to accommodate for the changes in
API/structure, not to add any actual IPv6 functionality. That will
come in a later patch - this patch attempts to maintain the same final
functionality in both drivers that use the network XML parser - vbox
and "bridge" (the Linux bridge-based driver used by the qemu
hypervisor driver).

* src/libvirt_private.syms: Add new private API functions.
* src/conf/network_conf.[ch]: Change C data structure and
  parsing/formatting.
* src/network/bridge_driver.c: Update to use new parser/formatter.
* src/vbox/vbox_tmpl.c: update to use new parser/formatter
* docs/schemas/network.rng: changes to the schema -
  * there can now be more than one <ip> element.
  * ip address is now an ip-addr (ipv4 or ipv6) rather than ipv4-addr
  * new optional "prefix" attribute that can be used in place of "netmask"
  * new optional "family" attribute - "ipv4" or "ipv6"
    (will default to ipv4)
  * define data types for the above
* tests/networkxml2xml(in|out)/nat-network.xml: add multiple <ip> elements
  (including IPv6) to a single network definition to verify they are being
  correctly parsed and formatted.

When a netmask isn't specified for an IPv4 address, one can be implied
based on what network class range the address is in. The
virNetworkDefPrefix function does this for us, so netmask isn't
required.

Later patches will add the possibility to define a network's netmask
as a prefix (0-32, or 0-128 in the case of IPv6). To make it easier to
deal with definition of both kinds (prefix or netmask), add two new
functions:

virNetworkDefNetmask: return a copy of the netmask into a
virSocketAddr. If no netmask was specified in the XML, create a
default netmask based on the network class of the virNetworkDef's IP
address.

virNetworkDefPrefix: return the netmask as numeric prefix (or the
default prefix for the network class of the virNetworkDef's IP
address, if no netmask was specified in the XML)

Network disks are accessed by qemu directly, and have no
associated file on the host, so checking for file ownership etc.
is unnecessary.
Signed-off-by: NJosh Durgin <joshd@hq.newdream.net>

* src/conf/domain_conf.c (virDomainGraphicsDefParseXML)
(virDomainDeviceVirtioSerialAddressParseXML)
(virDomainDiskDefFree): Free various leaks.

Changes common to all network disks:
-Make source name optional in the domain schema, since NBD doesn't use it
-Add a hostName type to the domain schema, and use it instead of genericName, which doesn't include .
-Don't leak host names or ports
-Set the source protocol in qemuParseCommandline
Signed-off-by: NJosh Durgin <joshd@hq.newdream.net>

This patch adds network disk support to libvirt/QEMU.  The currently
supported protocols are nbd, rbd, and sheepdog.  The XML syntax is like
this:

    <disk type="network" device="disk">
      <driver name="qemu" type="raw" />
      <source protocol='rbd|sheepdog|nbd' name="...some image identifier...">
        <host name="mon1.example.org" port="6000">
        <host name="mon2.example.org" port="6000">
        <host name="mon3.example.org" port="6000">
      </source>
      <target dev="vda" bus="virtio" />
    </disk>
Signed-off-by: NMORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>

`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.

The extra data isn't being free()'d for IO error events that have a reason.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

* src/conf/domain_conf.c (virDomainDefParseXML): Prefer sysinfo
uuid over generating one, and if both uuids are present, require
them to be identical.
* src/qemu/qemu_conf.c (qemuBuildSmbiosSystemStr): Allow skipping
the uuid.
(qemudBuildCommandLine): Adjust caller; <smbios mode=host/> must
not use host uuid in place of guest uuid.