This patch reduces the complexity of the filtering algorithm in
virCgroupDetect by first correcting the controller mask and then
checking for potential co-mounts without any correlating
controller mask modifications.
If you agree that this patch removes complexity and improves
readability it could simply be squashed into the first patch
of this series.
Signed-off-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
The cgroup controller filtering in virCgroupDetect does not work
properly if the following conditions are met:
1) the host system does not have a cgroup controller which
libvirt requests (unavailable controller) and
2) libvirt is configured to disable a controller (disabled controller) and
3) the disabled controller is located before the unavailable controller
in virCgroupController.
As an example: The memory controller is unavailable and the cpuset
controller is configured to be disabled.
In this scenario trying to start a domain results in the error
error: Controller 'cpuset' is not wanted, but 'memory' is co-mounted: Invalid argument
This error occurs when virCgroupDetect is called with a valid parent group.
The resulting group created by virCgroupCopyMounts holds for cpuset and
memory controller empty mount points. The filtering of disabled controllers
checks for co-mounts by comparing the mount points. The cpuset controller
causes the filtering to occur before the memory controller is marked as to be
ignored by modifying the controller mask since it is unavailable.
Therefore the co-mount detection logic compares the cpuset and memory controller
mount points and since both are empty the memory controller is regarded
erroneously as being co-mounted.
Signed-off-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
In the website reorg we accidentally lost all links to the nice
reformatted news.html file. Add a link on the front page, and
also extend the download page table so that it includes links
to API docs and news files for each module (where available)
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The github.com/rgbkrk/libvirt-go bindings were the most complete
bindings historically, but their API coverage stops at 1.2.4,
with exception of a couple of newer APIs.
The new bindings at http://libvirt.org/git/?p=libvirt-go.git;a=log
how have (almost[1]) 100% API coverage all the way to 2.5.0. They also
expose the APIs in a way that allows for much stronger go type
checking by the compiler, and expose typed parameters as explicit
structs. Finally the bindings are able to conditionally compile against
any libvirt version 1.2.0 -> 2.5.0 without use of go build tags.
Change the docs to point to these new bindings, since they'll be
a better bet for users long term.
[1] virEvent & virStream callbacks are still TODO to be fixed
real soon.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Similarly to localOnly DNS domain, localPtr attribute can be used to
tell the DNS server not to forward reverse lookups for unknown IPs which
belong to the virtual network.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The API creates PTR domain which corresponds to a given addr/prefix.
Both IPv4 and IPv6 addresses are supported, but the prefix must be
divisible by 8 for IPv4 and divisible by 4 for IPv6.
The generated PTR domain has the following format
IPv4: 1.2.3.4.in-addr.arpa
IPv6: 0.1.2.3.4.5.6.7.8.9.a.b.c.d.e.f.0.1.2.3.4.5.6.7.8.9.a.b.c.d.e.f.ip6.arpa
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Iterating over all child nodes when we only support one instance of each
child is pretty weird. And it would even cause memory leaks if more
than one <tftp> element was specified.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The PERF_COUNT_HW_REF_CPU_CYCLES constant is not available
on all Linux distros libvirt targets, so its use must be
made conditional. Other constant have existed long enough
that we can assume they exist, as we don't support very
old distros like RHEL-5 any more.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Documents in formatdomain.html that when migrating a guest
defined with the host-passthrough CPU model from a machine that
is running on a newer CPU model than the destination machine's
CPU model, it is very likely that the guest will crash upon
arrival.
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Finally, now that all APIs have been introduced, wire them up to virt-admin
and introduce daemon-log-outputs and daemon-log-filters commands.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Enable libvirt users to modify daemon's logging output settings from outside.
If either an empty string or NULL is passed, a default logging output will be
used the same way as it would be in case writing an empty string to the
libvirtd.conf
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Now that virLog{Get,Set}DefaultOutput routines are introduced we can wire them
up to the daemon's logging initialization code. Also, change the order of
operations a bit so that we still strictly honor our precedence of settings:
cmdline > env > config now that outputs and filters are not appended anymore.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Along with an empty string, it should also be possible for users to pass
NULL to the public APIs which in turn would trigger a routine(future
work) responsible for defining an appropriate default logging output
given the current circumstances.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
These helpers will manage the log destination defaults (fetch/set). The reason
for this is to stay consistent with the current daemon's behaviour with respect
to /etc/libvirt/<daemon>.conf file, since both assignment of an empty string
or not setting the log output variable at all trigger the daemon's decision on
the default log destination which depends on whether the daemon runs daemonized
or not.
This patch also changes the logic of the selection of the default
logging output compared to how it is done now. The main difference though is
that we should only really care if we're running daemonized or not, disregarding
the fact of (not) having a TTY completely (introduced by commit eba36a3878) as
that should be of the libvirtd's parent concern (what FD it will pass to it).
Before:
if (godaemon || !hasTTY):
if (journald):
use journald
if (godaemon):
if (privileged):
use SYSCONFIG/libvirtd.log
else:
use XDG_CONFIG_HOME/libvirtd.log
else:
use stderr
After:
if (godaemon):
if (journald):
use journald
else:
if (privileged):
use SYSCONFIG/libvirtd.log
else:
use XDG_CONFIG_HOME/libvirtd.log
else:
use stderr
Signed-off-by: Erik Skultety <eskultet@redhat.com>
External disk-only snapshots with recent enough qemu don't require
libvirt to pause the VM. The logic determining when to resume cpus was
slightly flawed and attempted to resume them even if they were not
paused by the snapshot code. This normally was not a problem, but with
locking enabled the code would attempt to acquire the lock twice.
The fallout of this bug would be a error from the API, but the actual
snapshot being created. The bug was introduced with when adding support
for external snapshots with memory (checkpoints) in commit f569b87.
Resolves problems described by:
https://bugzilla.redhat.com/show_bug.cgi?id=1403691
After qemu delivers the resume event it's already running and thus it's
too late to enter lockspaces since it may already have modified the
disk. The code only creates false log entries in the case when locking
is enabled. The lockspace needs to be acquired prior to starting cpus.
Given how intrusive previous patches are, it might happen that
there's a bug or imperfection. Lets give users a way out: if they
set 'namespaces' to an empty array in qemu.conf the feature is
suppressed.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Instead of trying to fix our security drivers, we can use a
simple trick to relabel paths in both namespace and the host.
I mean, if we enter the namespace some paths are still shared
with the host so any change done to them is visible from the host
too.
Therefore, we can just enter the namespace and call
SetAllLabel()/RestoreAllLabel() from there. Yes, it has slight
overhead because we have to fork in order to enter the namespace.
But on the other hand, no complexity is added to our code.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Prime time. When it comes to spawning qemu process and
relabelling all the devices it's going to touch, there's inherent
race with other applications in the system (e.g. udev). Instead
of trying convincing udev to not touch libvirt managed devices,
we can create a separate mount namespace for the qemu, and mount
our own /dev there. Of course this puts more work onto us as we
have to maintain /dev files on each domain start and device
hot(un-)plug. On the other hand, this enhances security also.
From technical POV, on domain startup process the parent
(libvirtd) creates:
/var/lib/libvirt/qemu/$domain.dev
/var/lib/libvirt/qemu/$domain.devpts
The child (which is going to be qemu eventually) calls unshare()
to create new mount namespace. From now on anything that child
does is invisible to the parent. Child then mounts tmpfs on
$domain.dev (so that it still sees original /dev from the host)
and creates some devices (as explained in one of the previous
patches). The devices have to be created exactly as they are in
the host (including perms, seclabels, ACLs, ...). After that it
moves $domain.dev mount to /dev.
What's the $domain.devpts mount there for then you ask? QEMU can
create PTYs for some chardevs. And historically we exposed the
host ends in our domain XML allowing users to connect to them.
Therefore we must preserve devpts mount to be shared with the
host's one.
To make this patch as small as possible, creating of devices
configured for domain in question is implemented in next patches.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This is a list of devices that qemu needs for its run (apart from
what's configured for domain). The devices on the list are
enabled in the CGroups by default so they will be good candidates
for initial /dev for new qemu.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
We will need this function in near future so that we know what
/dev device corresponds to the SCSI device.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
We will need this function in near future so that we know what
/dev device corresponds to the SCSI device.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
We will need this function in near future so that we know what
/dev device corresponds to the USB device.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Namely, virFileGetACLs, virFileSetACLs, virFileFreeACLs and
virFileCopyACLs. These functions are going to be required when we
are creating /dev for qemu. We have copy anything that's in
host's /dev exactly as is. Including ACLs.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
