Traditionally, macvtap devices are supported using <interface
type='direct'>, but that type requires specifying a source device name
and macvtap mode which can't be altered after the initial device
creation (and may not even be available to the management software
that's creating the XML config to feed to libvirt).

But the attributes in the <source> are essentially describing how the
device will be connected to the network, and if libvirt is to be
supplied with the name of a macvtap device that has already been
created, that device will also already be connected to the network
(and the connection can't be changed). Thus it seems more appropriate
to use type='ethernet', which was created explicitly for this purpose
- for devices that have already been (or will be) connected to the
external network by someone/something outside of libvirt. The fact
that it is a *macv*tap rather than a contentional tap device is just a
detail.

This patch supports using an existing macvtap device with <interface
type='ethernet'> by checking the supplied target dev name to see if it
is a macvtap device and, when this is the case, calling
virNetDevMacVLanTapOpen() instead of virNetDevTapCreate(). For
consistency, this is only done when target managed='no'.

Resolves: https://bugzilla.redhat.com/1723367 (partially)
Signed-off-by: NLaine Stump <laine@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

If managed='no', then the tap device must already exist, and setting
of MAC address and online status (IFF_UP) is skipped.

NB: we still set IFF_VNET_HDR and IFF_MULTI_QUEUE as appropriate,
because those bits must be properly set in the TUNSETIFF we use to set
the tap device name of the handle we've opened - if IFF_VNET_HDR has
not been set and we set it the request will be honored even when
running libvirtd unprivileged; if IFF_MULTI_QUEUE is requested to be
different than how it was created, that will result in an error from
the kernel. This means that you don't need to pay attention to
IFF_VNET_HDR when creating the tap devices, but you *do* need to set
IFF_MULTI_QUEUE if you're going to use multiple queues for your tap
device.

NB2: /dev/vhost-net normally has permissions 600, so it can't be
opened by an unprivileged process. This would normally cause a warning
message when using a virtio net device from an unprivileged
libvirtd. I've found that setting the permissions for /dev/vhost-net
permits unprivileged libvirtd to use vhost-net for virtio devices, but
have no idea what sort of security implications that has. I haven't
changed libvrit's code to avoid *attempting* to open /dev/vhost-net -
if you are concerned about the security of opening up permissions of
/dev/vhost-net (probably a good idea at least until we ask someone who
knows about the code) then add <driver name='qemu'/> to the interface
definition and you'll avoid the warning message.

Note that virNetDevTapCreate() is the correct function to call in the
case of an existing device, because the same ioctl() that creates a
new tap device will also open an existing tap device.

Resolves: https://bugzilla.redhat.com/1723367 (partially)
Signed-off-by: NLaine Stump <laine@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

This just moves around a few things in qemuInterfaceConnect() with no
functional difference (except that a few failures that would have
previously resulted in a "success" audit log will now properly produce
a "fail" audit). The change is so that adding support for unmanaged
tap/macvtap devices will be more easily reviewable.
Signed-off-by: NLaine Stump <laine@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

When the network interface is of "user" type, and QEMU has the "-net
socket,fd=" datagram support, call qemuInterfacePrepareSlirp() to
probe and associate a slirp-helper with the interface.

The usage of automated slirp-helper can be prevented with
disableSlirp (in particular when resuming a
VM that didn't start with slirp-helper before).
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Back in July 2010, commit 6ea90b84 (meant to resolve
https://bugzilla.redhat.com/571991 ) added code to set the MAC address
of any tap device to the associated guest interface's MAC, but with
the first byte replaced with 0xFE. This was done in order to assure
that

1) the tap MAC and guest interface MAC were different (otherwise L2
   forwarding through the tap would not work, and the kernel would
   repeatedly issue a warning stating as much).

2) any bridge device that had one of these taps attached would *not*
   take on the MAC of the tap (leading to network instability as
   guests started and stopped)

A couple years later, https://bugzilla.redhat.com/798467 was filed,
complaining that a user could configure a tap-based guest interface to
have a MAC address that itself had a first byte of 0xFE, silently
(other than the kernel warning messages) resulting in a non-working
configuration. This was fixed by commit 5d571045, which logged an
error and failed the guest start / interface attach if the MAC's first
byte was 0xFE.

Although this restriction only reduces the potential pool of MAC
addresses from 2^46 (last two bits of byte 1 must be set to 10) by
2^32 (still 4 orders of magnitude larger than the entire IPv4 address
space), it also means that management software that autogenerates MAC
addresses must have special code to avoid an 0xFE prefix. Now after 7
years, someone has noticed this restriction and requested that we
remove it.

So instead of failing when 0xFE is found as the first byte, this patch
removes the restriction by just replacing the first byte in the tap
device MAC with 0xFA if the first byte in the guest interface is
0xFE. 0xFA is the next-highest value that still has 10 as the lowest
two bits, and still

2) meets the requirement of "tap MAC must be different from guest
   interface MAC", and

3) is high enough that there should never be an issue of the attached
   bridge device taking on the MAC of the tap.

The result is that *any* MAC can be chosen by management software
(although it would still not work correctly if a multicast MAC (lowest
bit of first byte set to 1) was chosen), but that's a different
issue).
Signed-off-by: NLaine Stump <laine@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com

This reverts commit 2f5e6502.
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

The call to resolve the actual network type will turn any NICs with
type=network into one of the other types. Thus there should be no need
to handle type=network in later switch() statements jumping off the
actual type.
Reviewed-by: NCole Robinson <crobinso@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Instead of repetitive:
  s ? s : ""
use NULLSTR_EMPTY.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>

This will be extended in the future, so let's simplify things by
centralizing the checks.
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>
Signed-off-by: NCole Robinson <crobinso@redhat.com>

The QEMU command line arguments are very long and currently all written
on a single line to /var/log/libvirt/qemu/$GUEST.log. This introduces
logic to add line breaks after every env variable and "-" optional
argument, and every positional argument. This will create a clearer log
file, which will in turn present better in bug reports when people cut +
paste from the log into a bug comment.

An example log file entry now looks like this:

  2018-12-14 12:57:03.677+0000: starting up libvirt version: 5.0.0, qemu version: 3.0.0qemu-3.0.0-1.fc29, kernel: 4.19.5-300.fc29.x86_64, hostname: localhost.localdomain
  LC_ALL=C \
  PATH=/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin \
  HOME=/home/berrange \
  USER=berrange \
  LOGNAME=berrange \
  QEMU_AUDIO_DRV=none \
  /usr/bin/qemu-system-ppc64 \
  -name guest=guest,debug-threads=on \
  -S \
  -object secret,id=masterKey0,format=raw,file=/home/berrange/.config/libvirt/qemu/lib/domain-33-guest/master-key.aes \
  -machine pseries-2.10,accel=tcg,usb=off,dump-guest-core=off \
  -m 1024 \
  -realtime mlock=off \
  -smp 1,sockets=1,cores=1,threads=1 \
  -uuid c8a74977-ab18-41d0-ae3b-4041c7fffbcd \
  -display none \
  -no-user-config \
  -nodefaults \
  -chardev socket,id=charmonitor,fd=23,server,nowait \
  -mon chardev=charmonitor,id=monitor,mode=control \
  -rtc base=utc \
  -no-shutdown \
  -boot strict=on \
  -device qemu-xhci,id=usb,bus=pci.0,addr=0x1 \
  -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x2 \
  -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
  -msg timestamp=on
  2018-12-14 12:57:03.730+0000: shutting down, reason=failed
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

In many files there are header comments that contain an Author:
statement, supposedly reflecting who originally wrote the code.
In a large collaborative project like libvirt, any non-trivial
file will have been modified by a large number of different
contributors. IOW, the Author: comments are quickly out of date,
omitting people who have made significant contribitions.

In some places Author: lines have been added despite the person
merely being responsible for creating the file by moving existing
code out of another file. IOW, the Author: lines give an incorrect
record of authorship.

With this all in mind, the comments are useless as a means to identify
who to talk to about code in a particular file. Contributors will always
be better off using 'git log' and 'git blame' if they need to  find the
author of a particular bit of code.

This commit thus deletes all Author: comments from the source and adds
a rule to prevent them reappearing.

The Copyright headers are similarly misleading and inaccurate, however,
we cannot delete these as they have legal meaning, despite being largely
inaccurate. In addition only the copyright holder is permitted to change
their respective copyright statement.
Reviewed-by: NErik Skultety <eskultet@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Remove the callbacks that the nwfilter driver registers with the domain
object config layer. Instead make the current helper methods call into
the public API for creating/deleting nwfilter bindings.
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

The vm name is not needed for any functional requirement, but it will be
useful when debugging problems to identify which VM is associated with a
filter, since UUID is not human friendly.
Reviewed-by: NJiri Denemark <jdenemar@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Implied by QEMU >= 1.2.0.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>

Now that we assume QEMU_CAPS_NETDEV, the only thing left to check
is whether we need to use the legacy -net syntax because of
a non-conforming armchitecture.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>

This reverts commit 2841e675.

It turns out that adding the host_mtu field to the PCI capabilities in
the guest bumps the length of PCI capabilities beyond the 32 byte
boundary, so the virtio-net device gets 64 bytes of ioport space
instead of 32, which offsets the address of all the other following
devices. Migration doesn't work very well when the location and length
of PCI capabilities of devices is changed between source and
destination.

This means that we need to make sure that the absence/presence of
host_mtu on the qemu commandline always matches between source and
destination, which means that we need to make setting of host_mtu an
opt-in thing (it can't happen automatically when the bridge being used
has a non-default MTU, which is what commit 2841e675 implemented).

I do want to re-implement this feature with an <mtu auto='on'/>
setting, but probably won't backport that to any stable branches, so
I'm first reverting the original commit, and that revert can be pushed
to the few releases that have been made since the original (3.1.0 -
3.3.0)

Resolves: https://bugzilla.redhat.com/1449346

... with VIR_NET_GENERATED_MACV???_PREFIX, which is defined in
util/virnetdevmacvlan.h.

Since VIR_NET_GENERATED_PREFIX is used for plain tap devices, it is
renamed to VIR_NET_GENERATED_TAP_PREFIX and moved to virnetdev.h

This patch makes use of the virNetDevSetCoalesce() function to make
appropriate settings effective for devices that support them.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1414627Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

libvirt was able to set the host_mtu option when an MTU was explicitly
given in the interface config (with <mtu size='n'/>), set the MTU of a
libvirt network in the network config (with the same named
subelement), and would automatically set the MTU of any tap device to
the MTU of the network.

This patch ties that all together (for networks based on tap devices
and either Linux host bridges or OVS bridges) by learning the MTU of
the network (i.e. the bridge) during qemuInterfaceBridgeConnect(), and
returning that value so that it can then be passed to
qemuBuildNicDevStr(); qemuBuildNicDevStr() then sets host_mtu in the
interface's commandline options.

The result is that a higher MTU for all guests connecting to a
particular network will be plumbed top to bottom by simply changing
the MTU of the network (in libvirt's config for libvirt-managed
networks, or directly on the bridge device for simple host bridges or
OVS bridges managed outside of libvirt).

One question I have about this - it occurred to me that in the case of
migrating a guest from a host with an older libvirt to one with a
newer libvirt, the guest may have *not* had the host_mtu option on the
older machine, but *will* have it on the newer machine. I'm curious if
this could lead to incompatibilities between source and destination (I
guess it all depends on whether or not the setting of host_mtu has a
practical effect on a guest that is already running - Maxime?)

Likewise, we could run into problems when migrating from a newer
libvirt to older libvirt - The guest would have been told of the
higher MTU on the newer libvirt, then migrated to a host that didn't
understand <mtu size='blah'/>. (If this really is a problem, it would
be a problem with or without the current patch).

virNetDevTapCreateInBridgePort() has always set the new tap device to
the current MTU of the bridge it's being attached to. There is one
case where we will want to set the new tap device to a different
(usually larger) MTU - if that's done with the very first device added
to the bridge, the bridge's MTU will be set to the device's MTU. This
patch allows for that possibility by adding "int mtu" to the arg list
for virNetDevTapCreateInBridgePort(), but all callers are sending -1,
so it doesn't yet have any effect.

Since the requested MTU isn't necessarily what is used in the end (for
example, if there is no MTU requested, the tap device will be set to
the current MTU of the bridge), and the hypervisor may want to know
the actual MTU used, we also return the actual MTU to the caller (if
actualMTU is non-NULL).

When support for auto-creating tap devices was added to <interface
type='ethernet'> in commit 9c17d6, the code assumed that
virNetDevTapCreate() would honor the VIR_NETDEV_TAP__CREATE_IFUP flag
that is supported by virNetDevTapCreateInBridgePort(). That isn't the
case - the latter function performs several operations, and one of
them is setting the tap device online. But virNetDevTapCreate() *only*
creates the tap device, and relies on the caller to do everything
else, so qemuInterfaceEthernetConnect() needs to call
virNetDevSetOnline() after the device is successfully created.

The call to virNetDevIPInfoAddToDev() that sets up tap device IP
addresses and routes was somehow incorrectly placed in
qemuInterfaceStopDevice() instead of qemuInterfaceStartDevice() in
commit fe8567f6.  This fixes that error by moving the call to
virNetDevIPInfoAddToDev() to qemuInterfaceStartDevice().
Signed-off-by: NVasiliy Tolstov <v.tolstov@selfip.ru>

For type='ethernet' interfaces only.

(This patch had been pushed earlier in
commit 0b4645a7, but was reverted in
commit 84d47a3c because it had been
accidentally pushed during the freeze for release 2.0.0)

This reverts commit 0b4645a7.

This feature was accidentally pushed in the feature freeze.

For type='ethernet' interfaces only.

SRIOV VFs used in macvtap passthrough mode can take advantage of the
SRIOV card's transparent vlan tagging. All the code was there to set
the vlan tag, and it has been used for SRIOV VFs used for hostdev
interfaces for several years, but for some reason, the vlan tag for
macvtap passthrough devices was stubbed out with a -1.

This patch moves a bit of common validation down to a lower level
(virNetDevReplaceNetConfig()) so it is shared by hostdev and macvtap
modes, and updates the macvtap caller to actually send the vlan config
instead of -1.

This reverts commit 6e244c65, which
added support to qemu for the "peer" attribute in domain interface <ip>
elements.

It's being removed temporarily for the release of libvirt 1.3.4
because the feature doesn't work, and there are concerns that it may
need to be modified in an externally visible manner which could create
backward compatibility problems.

 Conflicts:
   tests/qemuxml2argvmock.c - a mock of virNetDevSetOnline() was added
   which may be assumed by other tests added since the original commit,
   so it isn't being reverted.

This is just a wrapper for virCommand that takes two strings
and runs them.

Move it to virnetdev.c for easier mocking.

Signed-off-by: NVasiliy Tolstov <v.tolstov@selfip.ru>

If a user specify network type ethernet, then create it via libvirt and run
script if it provided. After this commit user does not need to
run external script to create tap device or add root permissions to qemu
process.
Signed-off-by: NVasiliy Tolstov <v.tolstov@selfip.ru>

Move function to qemu_interface.c and rename to qemuInterfaceOpenVhostNet
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Move the misplaced function from qemu_command.c to qemu_interface.c
since it's closer in functionality there and had less to do with building
the command line.

Rename function to qemuInterfaceBridgeConnect and modify callers.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Move the misplaced function from qemu_command.c to qemu_interface.c
since it's closer in functionality there and had less to do with building
the command line.

Rename function to qemuInterfaceDirectConnect and modify callers.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Adds a new interface type using UDP sockets, this seems only applicable
to QEMU but have edited tree-wide to support the new interface type.

The interface type required the addition of a "localaddr" (local
address), this then maps into the following xml and qemu call.

<interface type='udp'>
  <mac address='52:54:00:5c:67:56'/>
  <source address='127.0.0.1' port='11112'>
    <local address='127.0.0.1' port='22222'/>
  </source>
  <model type='virtio'/>
  <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
</interface>

QEMU call:
	-net socket,udp=127.0.0.1:11112,localaddr=127.0.0.1:22222

Notice the xml "local" entry becomes the "localaddr" for the qemu call.

reference:
http://lists.gnu.org/archive/html/qemu-devel/2011-11/msg00629.htmlSigned-off-by: NJonathan Toppins <jtoppins@cumulusnetworks.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

A further fix for:

  https://bugzilla.redhat.com/show_bug.cgi?id=1113474

Since there is no possibility that any type of macvtap will work if
the parent physdev it's attached to is offline, we should bring the
physdev online at the same time as the macvtap. When taking the
macvtap offline, it's also necessary to take the physdev offline for
macvtap passthrough mode (because the physdev has the same MAC address
as the macvtap device, so could potentially cause problems with
misdirected packets during migration, as outlined in commits 829770
and 879c13). We can't set the physdev offline for other macvtap modes
1) because there may be other macvtap devices attached to the same
physdev (and/or the host itself may be using the device) in the other
modes whereas passthrough mode is exclusive to one macvtap at a time,
and 2) there's no practical reason to do so anyway.

When libvirt is managing a bridge's forwarding database (FDB)
(macTableManager='libvirt'), if we add FDB entries for a new guest
interface even before the qemu process is created, then in the case of
a migration any other guest attached to the "destination" bridge will
have its traffic immediately sent to the destination of the migration
even while the source domain is still running (and the destination, of
course, isn't). To make sure that traffic from other guests on the new
host continues flowing to the old guest until the new one is ready, we
have to wait until the new guest CPUs are started to add the FDB
entries.

Conversely, we need to remove the FDB entries from the bridge any time
the guest CPUs are stopped; among other things, this will assure
proper operation during a post-copy migration (which is just the
opposite of the problem described in the previous paragraph).

We now have a qemuInterfaceStartDevices() which does the final
activation needed for the host-side tap/macvtap devices that are used
for qemu network connections. It will soon make sense to have the
converse qemuInterfaceStopDevices() which will undo whatever was done
during qemuInterfaceStartDevices().

A function to "stop" a single device has also been added, and is
called from the appropriate place in qemuDomainDetachNetDevice(),
although this is currently unnecessary - the device is going to
immediately be deleted anyway, so any extra "deactivation" will be for
naught. The call is included for completeness, though, in anticipation
that in the future there may be some required action that *isn't*
nullified by deleting the device.

This patch is a part of a more complete fix for:

  https://bugzilla.redhat.com/show_bug.cgi?id=1081461

Currently, MAC registration occurs during device creation, which is
early enough that, during live migration, you end up with duplicate
MAC addresses on still-running source and target devices, even though
the target device isn't actually being used yet.
This patch proposes to defer MAC registration until right before
the guest can actually use the device -- In other words, right
before starting guest CPUs.
Signed-off-by: NMatthew Rosato <mjrosato@linux.vnet.ibm.com>
Signed-off-by: NLaine Stump <laine@laine.org>