The current implementation requires users to configure the
preference as such:
-Dfirewall_backend_default_1=iptables
-Dfirewall_backend_default_2=nftables
In addition to being more verbose than one would hope, there
are several things that could go wrong.
First of all, meson performs no validation on the provided
values, so mistakes will only be caught by the compiler.
Additionally, it's entirely possible to provide nonsensical
combinations, such as repeating the same value twice.
Change things so that the preference can now be configured
as such:
-Dfirewall_backend_priority=iptables,nftables
Checks have been added to prevent invalid values from being
accepted.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Laine Stump <laine@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
The patch that added the nftables backend for virtual networks left
iptables as the default backend when both nftables and iptables are
installed.
The only functional difference between the two backends is that the
nftables backend doesn't add any rules to fix up the checksum of DHCP
packets, which will cause failures on guests with very old OSes
(e.g. RHEL5) that have a virtio-net network interface using vhost
packet processing (the default), connected to a libvirt virtual
network, and configured to acquire the interface IP using DHCP. Since
RHEL5 has been out of support for several years already, we might as
well start off nftables support right by making it the default.
Distros that aren't quite ready to default to nftables (e.g. maybe
they're rebasing libvirt within a release and don't want to surprise
anyone with an automatic switch from iptables to nftables) can simply
run meson with "-Dfirewall_backend=iptables" during their official
package build.
In the extremely unlikely case that this causes a problem for a user,
they can work around the failure by adding "<driver name='qemu'/> to
the guest <interface> element.
Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Support using nftables to setup the firewall for each virtual network,
rather than iptables. The initial implementation of the nftables
backend creates (almost) exactly the same ruleset as the iptables
backend, determined by running the following commands on a host that
has an active virtual network:
iptables-save >iptables.txt
iptables-restore-translate -f iptables.txt
(and the similar ip6tables-save/ip6tables-restore-translate for an
IPv6 network). Correctness of the new backend was checked by comparing
the output of:
nft list ruleset
when the backend is set to iptables and when it is set to nftables.
This page was used as a guide:
https://wiki.nftables.org/wiki-nftables/index.php/Moving_from_iptables_to_nftables
The only differences between the rules created by the nftables backed
vs. the iptables backend (aside from a few inconsequential changes in
display order of some chains/options) are:
1) When we add nftables rules, rather than adding them in the
system-created "filter" and "nat" tables, we add them in a private
table (ie only we should be using it) created by us called "libvirt"
(the system-created "filter" and "nat" tables can't be used because
adding any rules to those tables directly with nft will cause failure
of any legacy application attempting to use iptables when it tries to
list the iptables rules (e.g. "iptables -S").
(NB: in nftables only a single table is required for both nat and
filter rules - the chains for each are differentiated by specifying
different "hook" locations for the toplevel chain of each)
2) Since the rules that were added to allow tftp/dns/dhcp traffic from
the guests to the host are unnecessary in the context of nftables,
those rules aren't added.
(Longer explanation: In the case of iptables, all rules were in a
single table, and it was always assumed that there would be some
"catch-all" REJECT rule added by "someone else" in the case that a
packet didn't match any specific rules, so libvirt added these
specific rules to ensure that, no matter what other rules were added
by any other subsystem, the guests would still have functional
tftp/dns/dhcp. For nftables though, the rules added by each subsystem
are in a separate table, and in order for traffic to be accepted, it
must be accepted by *all* tables, so just adding the specific rules to
libvirt's table doesn't help anything (as the default for the libvirt
table is ACCEPT anyway) and it just isn't practical/possible for
libvirt to find *all* other tables and add rules in all of them to
make sure the traffic is accepted. libvirt does this for firewalld (it
creates a "libvirt" zone that allows tftp/dns/dhcp, and adds all
virtual network bridges to that zone), however, so in that case no
extra work is required of the sysadmin.)
3) nftables doesn't support the "checksum mangle" rule (or any
equivalent functionality) that we have historically added to our
iptables rules, so the nftables rules we add have nothing related to
checksum mangling.
(NB: The result of (3) is that if you a) have a very old guest (RHEL5
era or earlier) and b) that guest is using a virtio-net network
device, and c) the virtio-net device is using vhost packet processing
(the default) then DHCP on the guest will fail. You can work around
this by adding <driver name='qemu'/> to the <interface> XML for the
guest).
There are certainly much better nftables rulesets that could be used
instead of those implemented here, and everything is in place to make
future changes to the rules that are used simple and free of surprises
(e.g. the rules that are added have coresponding "removal" commands
added to the network status so that we will always remove exactly the
rules that were previously added rather than trying to remove the
rules that "the current build of libvirt would have added" (which will
be incorrect the first time we run a libvirt with a newly modified
ruleset). For this initial implementation though, I wanted the
nftables rules to be as identical to the iptables rules as possible,
just to make it easier to verify that everything is working.
The backend can be manually chosen using the firewall_backend setting
in /etc/libvirt/network.conf. libvirtd/virtnetworkd will read this
setting when it starts; if there is no explicit setting, it will check
for availability of FIREWALL_BACKEND_DEFAULT_1 and then
FIREWALL_BACKEND_DEFAULT_2 (which are set at build time in
meson_options.txt or by adding -Dfirewall_backend_default_n=blah to
the meson commandline), and use the first backend that is available
(ie, that has the necessary programs installed). The standard
meson_options.txt is set to check for nftables first, and then
iptables.
Although it should be very safe to change the default backend from
iptables to nftables, that change is left for a later patch, to show
how the change in default can be undone if someone really needs to do
that.
Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Tested-by: Daniel P. Berrangé <berrange@redhat.com>
It still can have only one useful value ("iptables"), but once a 2nd
value is supported, it will be selectable by setting
"firewall_backend=nftables" in /etc/libvirt/network.conf.
If firewall_backend isn't set in network.conf, then libvirt will check
to see if FIREWALL_BACKEND_DEFAULT_1 is available and, if so, set
that. (Since FIREWALL_BACKEND_DEFAULT_1 is currently "iptables", this
means checking to see it the iptables binary is present on the
system). If the default backend isn't available, that is considered a
fatal error (since no networks can be started anyway), so an error is
logged and startup of the network driver fails.
NB: network.conf is itself created from network.conf.in at build time,
and the advertised default setting of firewall_backend (in a commented
out line) is set from the meson_options.txt setting
"firewall_backend_default_1". This way the conf file will have correct
information no matter what ordering is chosen for default backend at
build time (as more backends are added, settings will be added for
"firewall_backend_default_n", and those will be settable in
meson_options.txt and on the meson commandline to change the ordering
of the auto-detection when no backend is set in network.conf).
virNetworkLoadDriverConfig() may look more complicated than necessary,
but as additional backends are added, it will be easier to add checks
for those backends (and to re-order the checks based on builders'
preferences).
Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
This allows users to SSH into a domain with a VSOCK device:
ssh user@qemu/machineName
So far, only QEMU domains are supported AND qemu:///system is
looked for the first for 'machineName' followed by
qemu:///session. I took an inspiration from Systemd's ssh proxy
[1] [2].
To just work out of the box, it requires (yet unreleased) systemd
to be running inside the guest to set up a socket activated SSHD
on the VSOCK. Alternatively, users can set up the socket
activation themselves, or just run a socat that'll forward vsock
<-> TCP communication.
1: https://github.com/systemd/systemd/blob/main/src/ssh-generator/ssh-proxy.c
2: https://github.com/systemd/systemd/blob/main/src/ssh-generator/20-systemd-ssh-proxy.conf.in
Resolves: https://gitlab.com/libvirt/libvirt/-/issues/579
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Several meson options cannot be enabled, without first enabling another
option. This adds a small comment prior to an option to record its
mandatory dependencies.
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This option controls whether the sysctl config for enabling unprivileged
userfaultfd will be installed.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Currently when we build with nbdkit support, libvirt will always try to
use nbdkit to access remote disk sources when it is available. But
without an up-to-date selinux policy allowing this, it will fail.
because the required selinux policies are not yet widely available, we
have disabled nbdkit support on rpm builds for all distributions before
Fedora 40.
Unfortunately, this makes it more difficult to test nbdkit support.
After someone updates to the necessary selinux policies, they would also
need to rebuild libvirt to enable nbdkit support. By introducing a
configure option (nbdkit_config_default), we can build packages with
nbdkit support but have it disabled by default.
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Suggested-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Given that this variable now controls not just whether C tests
are built, but also whether any test at all is executed, the new
name is more appropriate.
Update the description for the corresponding meson option
accordingly.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Currently, nbdkit support will automatically be enabled as long as
the pidfd_open(2) syscall is available. Optionally, libnbd is used
to generate more user-friendly error messages.
In theory this is all good, since use of nbdkit is supposed to be
transparent to the user. In practice, however, there is a problem:
if support for it is enabled at build time and the necessary
runtime components are installed, nbdkit will always be preferred,
with no way for the user to opt out.
This will arguably be fine in the long run, but right now none of
the platforms that we target ships with a SELinux policy that
allows libvirt to launch nbdkit, and the AppArmor policy that we
maintain ourselves hasn't been updated either.
So, in practice, as of today having nbdkit installed on the host
makes network disks completely unusable unless you're willing to
compromise the overall security of the system by disabling
SELinux/AppArmor.
In order to make the transition smoother, provide a convenient
way for users and distro packagers to disable nbdkit support at
compile time until SELinux and AppArmor are ready.
In the process, detection is completely overhauled. libnbd is
made mandatory when nbdkit support is enabled, since availability
across operating systems is comparable and offering users the
option to make error messages worse doesn't make a lot of sense;
we also make sure that an explicit request from the user to
enable/disable nbdkit support is either complied with, or results
in a build failure when that's not possible. Last but not least,
we avoid linking against libnbd when nbdkit support is disabled.
At the RPM level, we disable the feature when building against
anything older than Fedora 40, which still doesn't have the
necessary SELinux bits but will hopefully gain them by the time
it's released. We also allow nbdkit support to be disabled at
build time the same way as other optional features, that is, by
passing "--define '_without_nbdkit 1'" to rpmbuild. Finally, if
nbdkit support has been disabled, installing libvirt will no
longer drag it in as a (weak) dependency.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Jonathon Jongsma <jjongsma@redhat.com>
When using nbdkit to serve a network disk source, the nbdkit process
will start and wait for an nbd connection before actually attempting to
connect to the (remote) disk location. Because of this, nbdkit will not
report an error until after qemu is launched and tries to read from the
disk. This results in a fairly user-unfriendly error saying that qemu
was unable to start because "Requested export not available".
Ideally we'd like to be able to tell the user *why* the export is not
available, but this sort of information is only available to nbdkit, not
qemu. It could be because the url was incorrect, or because of an
authentication failure, or one of many other possibilities.
To make this friendlier for users and easier to detect
misconfigurations, try to connect to nbdkit immediately after starting
nbdkit and before we try to start qemu. This requires adding a
dependency on libnbd. If an error occurs when connecting to nbdkit, read
back from the nbdkit error log and provide that information in the error
report from qemuNbdkitProcessStart().
User-visible change demonstrated below:
Previous error:
$ virsh start nbdkit-test
2023-01-18 19:47:45.778+0000: 30895: error : virNetClientProgramDispatchError:172 : internal
error: process exited while connecting to monitor: 2023-01-18T19:47:45.704658Z
qemu-system-x86_64: -blockdev {"driver":"nbd","server":{"type":"unix",
"path":"/var/lib/libvirt/qemu/domain-1-nbdkit-test/nbdkit-libvirt-1-storage.socket"},
"node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}: Requested export not
available
error: Failed to start domain 'nbdkit-test'
error: internal error: process exited while connecting to monitor: 2023-01-18T19:47:45.704658Z
qemu-system-x86_64: -blockdev {"driver":"nbd","server":{"type":"unix",
"path":"/var/lib/libvirt/qemu/domain-1-nbdkit-test/nbdkit-libvirt-1-storage.socket"},
"node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}: Requested export not
available
After this change:
$ virsh start nbdkit-test
2023-01-18 19:44:36.242+0000: 30895: error : virNetClientProgramDispatchError:172 : internal
error: Failed to connect to nbdkit for 'http://localhost:8888/nonexistent.iso': nbdkit: curl[1]:
error: problem doing HEAD request to fetch size of URL [http://localhost:8888/nonexistent.iso]:
HTTP response code said error: The requested URL returned error: 404
error: Failed to start domain 'nbdkit-test'
error: internal error: Failed to connect to nbdkit for 'http://localhost:8888/nonexistent.iso]:
error: problem doing HEAD request to fetch size of URL [http://localhost:8888/nonexistent.iso]:
HTTP response code said error: The requested URL returned error: 404
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Right now we expect the configuration files for init scripts
to live in /etc/sysconfig, but that location is only used by
RHEL- and SUSE-derived distros.
This means that packagers for other distros have to patch
things as part of the build process, while people building
from source will get wonky integration.
This new option will provide a convenient way to override
the default location at build time that is usable by distro
packagers and people building from source alike.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
The sheepdog project is unmaintained, with last commit in 2018 and
numerous unanswered issues reported.
Remove the libvirt storage driver support for it to follow the removal
of the client support in qemu.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
There is no guarantee that QEMU and libvirt have been configured
with the same prefix.
In particular, Homebrew on macOS will pass a different, private
prefix for each package version and then use symlinks to make
the files for a specific version appear in the usual locations.
This works perfectly fine as long as one package doesn't try to
go poking around another package's data - which is exactly what
libvirt needs to do in order to read and parse the QEMU interop
data.
qemu_datadir can now be explicitly provided to make this and
other uncommon scenarios work. The common scenario, where QEMU
and libvirt both use the same prefix, is unaffected.
https://gitlab.com/libvirt/libvirt/-/issues/168
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
When determining what socket path to connect to for a given URI we will
- Connect to the driver specific daemon if its UNIX socket exists
- Connect to libvirtd if its UNIX socket exists
- If non-root, auto-spawn a daemon based on the default mode
Historically the last point would result in spawning libvirtd, but with
this change we now spawn a modular daemon. Remote client probing logic
will pick a specific hypervisor daemon to connect to when the URI is
NULL.
Tested-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Cloud-Hypervisor is a KVM virtualization using hypervisor. It
functions similarly to qemu and the libvirt Cloud-Hypervisor driver
uses a very similar structure to the libvirt driver.
The biggest difference from the libvirt perspective is that the
"monitor" socket is seperated into two sockets one that commands are
issued to and one that events are notified from. The current
implementation only uses the command socket (running over a REST API
with json encoded data) with future changes to add support for the
event socket (to better handle shutdowns from inside the VM).
This patch adds support for the following initial VM actions using the
Cloud-Hypervsior API:
* vm.create
* vm.delete
* vm.boot
* vm.shutdown
* vm.reboot
* vm.pause
* vm.resume
To use the Cloud-Hypervisor driver, the v15.0 release of
Cloud-Hypervisor is required to be installed.
Some additional notes:
* The curl handle is persistent but not useful to detect ch process
shutdown/crash (a future patch will address this shortcoming)
* On a 64-bit host Cloud-Hypervisor needs to support PVH and so can
emulate 32-bit mode but it isn't fully tested (a 64-bit kernel and
32-bit userspace is fine, a 32-bit kernel isn't validated)
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: William Douglas <william.douglas@intel.com>
Match the behavior of most other features.
This will result in a change in behavior, because profiles will
now be installed whenever AppArmor support is enabled; on the
other hand, this is probably the behavior users expected in the
first place.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Similar knobs, such as firewalld_zone and sysctl_config, are
already features, so convert this one as well to comply with
expectations.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Allow the directory to be chosen at installation time, to support local
conventions e.g. versioning.
Signed-off-by: Chris Mayo <aklhfex@gmail.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
These options don't check for any external libraries, they only enable
libvirt features.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
This flag was originally created to indicate that either 1) the build
platform wasn't linux, 2) the build platform was linux, but the kernel
was too old to have macvtap support. Since there was already a switch
there, the ability to also disable it when 3) the kernel supports
macvtap but the user doesn't want it, was added in. I don't think that
(3) was ever an intentional goal, just something that grew naturally
out of having the flag there in the first place (unless possibly the
original author wanted a way to quickly disable their new code in case
it caused regressions elsewhere).
Now that the check for (2) has been removed, WITH_MACVTAP is just
checking (1) and (3), but (3) is pointless (because the extra code in
libvirt itself is miniscule, and the only external library needed for
it is libnl, which is also required for other unrelated features (and
itself has no subordinate dependencies and takes up < 1MB on
disk)). We can therfore eliminate the WITH_MACVTAP flag, as it is
functionally equivalent to WITH_LIBNL (which implies __linux__).
Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
WITH_VIRTUALPORT just checks that we are building on Linux and that
IFLA_PORT_MAX is defined in linux/if_link.h. Back when 802.11Qb[gh]
support was added, the IFLA_* stuff was new (introduced in kernel
2.6.35, backported to RHEL6 2.6.32 kernel at some point), and so this
extra check was necessary, because libvirt was being built on Linux
distros that didn't yet have IFLA_* (e.g. older RHEL6, all
RHEL5). It's been in the kernel for a *very* long time now, so all
supported versions of all Linux platforms libvirt builds on have it.
Note that the above paragraph implies that the conditional compilation
should be changed to #if defined(__linux__). However, the astute
reader will notice that the code in question is sending and receiving
netlink messages, so it really should be conditional on WITH_LIBNL
(which implies __linux__) instead, so that's what this patch does.
Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Right now, the logic that takes care of deciding whether expensive
tests should be run or not is not working correctly: more
specifically, it's not possible to use something like
$ VIR_TEST_EXPENSIVE=1 ninja test
to override the default choice, because in meson.build we always
pass an explicit value that overrides whatever is present in the
environment.
We could implement logic to make this work properly, but that
would require some refactoring of our test infrastructure and is
arguably of little value given that running
$ meson build -Dexpensive_tests=enabled
is very fast, so let's just stop telling users about the variable
instead and call it a day.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
There was one attempt a year ago done by me to drop HAL [1] but it was
never resolved. There was another time when Dan suggested to drop HAL
driver [2] but it was decided to keep it around in case device
assignment will be implemented for FreeBSD and the fact that
virt-manager uses node device driver [3].
I checked git history and code and it doesn't look like bhyve supports
device assignment so from that POV it should not block removing HAL.
The argument about virt-manager is not strong as well because libvirt
installed from FreeBSD packages doesn't have HAL support so it will not
affect these users as well [4].
The only users affected by this change would be the ones compiling
libvirt from GIT on FreeBSD.
I looked into alternatives and there is libudev-devd package on FreeBSD
but unfortunately it doesn't work as it doesn't list any devices when
used with libvirt. It provides libudev APIs using devd.
I also looked into devd directly and it provides some APIs but there are
no APIs for device monitoring and events so that would have to be
somehow done by libvirt.
Main motivation for dropping HAL support is to replace libdbus with GLib
dbus implementation and it cannot be done with HAL driver present in
libvirt because HAL APIs heavily depends on symbols provided by libdbus.
[1] <https://www.redhat.com/archives/libvir-list/2019-May/msg00203.html>
[2] <https://www.redhat.com/archives/libvir-list/2016-April/msg00992.html>
[3] <https://www.redhat.com/archives/libvir-list/2016-April/msg00994.html>
[4] <https://svnweb.freebsd.org/ports/head/devel/libvirt/Makefile?view=markup>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Add a configuration option for specifying location of the qemu modules
directory, defaulting to /usr/lib64/qemu. Then use this location to
check for changes in the directory, indicating that a qemu module has
changed and capabilities need to be reprobed.
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Right now we're unconditionally adding RPATH information to the
installed binaries and libraries, but that's not always desired.
autotools seem to be smart enough to only include that information
when targeting a non-standard prefix, so most distro packages
don't actually contain it; moreover, both Debian and Fedora have
wiki pages encouraging packagers to avoid setting RPATH:
https://wiki.debian.org/RpathIssuehttps://fedoraproject.org/wiki/RPath_Packaging_Draft
Implement RPATH logic that Does The Right Thing™ in the most
common cases, while still offering users the ability to override
the default behavior if they have specific needs.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Reported-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Now that the rewrite is complete it is safe to drop this option and the
corresponding error message.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Neal Gompa <ngompa13@gmail.com>
