Another vircgroup helper to avoid code repetition between
the LXC and QEMU driver.
Signed-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

qemuSetupCgroupVcpuBW() and lxcSetVcpuBWLive() shares the
same code to set CPU CFS period and quota. This code can be
moved to a new virCgroupSetupCpuPeriodQuota() helper to
avoid code repetition.

A similar code is also executed in virLXCCgroupSetupCpuTune(),
but without the rollback on error. Use the new helper in this
function as well since the 'period' rollback, if not a
straight improvement for virLXCCgroupSetupCpuTune(), is
benign. And we end up cutting more code repetition.
Signed-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The code that calls virCgroupSetCpuShares() and virCgroupGetCpuShares()
is repeated in 4 different places. Let's put it in a new
virCgroupSetupCpuShares() to avoid code repetition.

There's a reason of why we execute a Get in the same value we
just executed Set, explained in detail by commit 97814d8a.
Let's add a gist of the reasoning behind it as a comment in
this new function as well.
Signed-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The code from qemuSetupCgroupCpusetCpus() and virLXCCgroupSetupCpusetTune()
can be centralized in a new helper called virCgroupSetupCpusetCpus().
Signed-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Previous patch moved all duplicated code that were setting
and getting BlkioDevice parameters to vircgroup.c. We can
turn them into static and spare a few symbols in
libvirt_private.syms.
Signed-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The current use of the functions that set and get
BlkioDevice attributes is doing a set(), followed by
a get() of the same parameter right after. This is done
because there is no guarantee that the kernel will accept
the desired value given by the set() call, thus we need to
execute a get() right after to get the actual value.

This patch adds helpers inside vircgroup.c to execute these
operations. Next patch will use these helpers to reduce
code repetition in LXC and QEMU files.
Signed-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

All our supported Linux distros now have this header.
It has never existed on FreeBSD / macOS / Mingw.
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

The strchrnul function doesn't exist on Windows and rather
than attempt to implement it, it is simpler to just avoid
its usage, as any callers are easily adapted.
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

If we get a user reporting this error message being shown it's pretty
useless in terms of actually debugging it since we don't know which hash
and which key are actually subject to the error.

This patch adds a new hash table callback which formats the
user-readable version of the hash key and reports it in the new message
which will look like:

"Duplicate hash table key 'blah'"

That way we will at least have an anchor point where to start the
search.

There are two special implementations of keys which are numeric so we
add specific printer functions for them.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

This previous commit introduced a simpler free callback for
hash data with only 1 arg, the value to free:

  commit 49288fac
  Author: Peter Krempa <pkrempa@redhat.com>
  Date:   Wed Oct 9 15:26:37 2019 +0200

    util: hash: Add possibility to use simpler data free function in virHash

It missed two functions in the hash table code which need
to call the alternate data free function, virHashRemoveEntry
and virHashRemoveSet.

After the previous patch though, there is no code that
makes functional use of the 2nd key arg in the data
free function. There is merely one log message that can
be dropped.

We can thus purge the current virHashDataFree callback
entirely, and rename virHashDataFreeSimple to replace
it.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Call first virCgroupNew on the parent group virCgroupNewPartition if
it is available on before the creation of the child group.  This
ensures that the creation of a first level group on the unified
architecture, as the check at virCgroupV2ParseControllersFile as the
parent file is there.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1760233Signed-off-by: NMiguel Ángel Arruga Vivas <rosen644835@gmail.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

So the issue here is that you can end up with configuration where
you have cgroup v1 and v2 enabled at the same time and the devices
controllers is enabled for cgroup v1.

In cgroup v2 there is no devices controller, the device access is
controlled using BPF and since it is not a cgroup controller both
of them can exists at the same time and both of them are applied while
resolving access to devices.

In order to avoid configuring both BPF and cgroup v1 devices we will
use BPF if possible and otherwise fallback to cgroup v1 devices.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>

Introduce a new type virHashDataFreeSimple which has only a void * as
argument for cases when knowing the name of the entry when freeing the
hash entry is not required.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
ACKed-by: NEric Blake <eblake@redhat.com>

Replace all occurrences of
  if (VIR_STRDUP(a, b) < 0)
     /* effectively dead code */
with:
  a = g_strdup(b);
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Provide some consistency over error message variable name and usage
when saving error messages across possible other errors or possibility
of resetting of the last error.

Instead of virSaveLastError paired up with virSetError and virFreeError,
we should use the newer virErrorPreserveLast and virRestoreError.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Since commit 44e7f029
    util: rewrite auto cleanup macros to use glib's equivalent

VIR_AUTOFREE is just an alias for g_autofree. Use the GLib macros
directly instead of our custom aliases.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Use G_GNUC_UNUSED from GLib instead of ATTRIBUTE_UNUSED.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

The usleep function was missing on older mingw versions, but we can rely
on it existing everywhere these days. It may only support times upto 1
second in duration though, so we'll prefer to use g_usleep instead.

The commandhelper program is not changed since that can't link to glib.
Fortunately it doesn't need to build on Windows platforms either.
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

These helped with debugging
https://bugzilla.redhat.com/show_bug.cgi?id=1612383Reviewed-by: NPavel Hrdina <phrdina@redhat.com>
Signed-off-by: NCole Robinson <crobinso@redhat.com>

When creating new group for cgroups v2 the we cannot check
cgroups.controllers for that cgroup because the directory is created
later.  In that case we should check cgroups.subtree_control of parent
group to get list of controllers enabled for child cgroups.

In order to achieve that we will prefer the parent group if it exists,
the current group will be used only for root group.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Acked-by: NPeter Krempa <pkrempa@redhat.com>

Commit d5572f62 forgot to add maxthreads to the non-Linux definition
of the function, thus breaking the MinGW build.
Signed-off-by: NErik Skultety <eskultet@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Acked-by: NPeter Krempa <pkrempa@redhat.com>

Some VM configurations may result in a large number of threads created by
the associated qemu process which can exceed the system default limit. The
maximum number of threads allowed per process is controlled by the pids
cgroup controller and is set to 16k when creating VMs with systemd's
machined service. The maximum number of threads per process is recorded
in the pids.max file under the machine's pids controller cgroup hierarchy,
e.g.

$cgrp-mnt/pids/machine.slice/machine-qemu\\x2d1\\x2dtest.scope/pids.max

Maximum threads per process is controlled with the TasksMax property of
the systemd scope for the machine. This patch adds an option to qemu.conf
which can be used to override the maximum number of threads allowed per
qemu process. If the value of option is greater than zero, it will be set
in the TasksMax property of the machine's scope after creating the machine.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

virCgroupRemove return -1 when removing cgroup failed.
But there are retry code to remove cgroup in QemuProcessStop:

 retry:
    if ((ret = qemuRemoveCgroup(vm)) < 0) {
        if (ret == -EBUSY && (retries++ < 5)) {
            usleep(200*1000);
            goto retry;
        }
        VIR_WARN("Failed to remove cgroup for %s",
                 vm->def->name);
    }

The return value of qemuRemoveCgroup will never be equal to "-EBUSY",
so change the return value of virCgroupRemove if failed.
Signed-off-by: NWang Yechao <wang.yechao255@zte.com.cn>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Because of a systemd delegation policy [1] we should not write to any
cgroups files owned by systemd which in case of cgroups v2 includes
'cgroups.subtree_control'.

systemd will enable controllers automatically for us to have them
available for VM cgroups.

[1] <https://github.com/systemd/systemd/blob/master/docs/CGROUP_DELEGATION.md>
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

This reverts commit 7bca1c9b.

As it turns out it's not a good idea on systemd hosts.  The root
cgroup can have all controllers enabled but they don't have to be
enabled for sub-cgroups.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

This affects only cgroups v2 where enabled controllers are not based on
available mount points but on the list provided in cgroup.controllers
file.  However, moving it will fill in placement as well, so it needs
to be freed together with mount point if we don't need that controller.

Before this patch we were assuming that all controllers available in
root cgroup where available in all other sub-cgroups which was wrong.

In order to fix it we need to move the cgroup controllers detection
after cgroup placement was prepared in order to build correct path for
cgroup.controllers file.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NPeter Krempa <pkrempa@redhat.com>

In cgroups v2 we don't have to detect available controllers every single
time if we are creating a new cgroup based on parent cgroup.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

If we need to get a path of specific file and we need to check its
existence before we use it then we can reuse that path to get value
for specific device.  This way we will not build the path again in
virCgroupGetValueForBlkDev.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

If we need to get a path of specific file and we need to check its
existence before we use it then we can reuse that path to get/set
values instead of calling the existing get/set value functions which
would be building the path again.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

virCgroup struct is always defined and the free function is not calling
anything that would require OS supporting cgroups.

This fixes an issue if we try to start a VM with QEMU binary that
doesn't support QXL.  The start operation will fail in
qemuProcessStartValidateVideo() which will set correct error message,
but later in one of the cleanup paths we will call
qemuDomainObjPrivateDataClear() which always calls virCgroupFree()
and that will fail on OS that doesn't support cgroups and it will
set a new error which will be eventually reported to user.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

Standardize on putting the _LAST enum value on the second line
of VIR_ENUM_IMPL invocations. Later patches that add string labels
to VIR_ENUM_IMPL will push most of these to the second line anyways,
so this saves some noise.
Signed-off-by: NCole Robinson <crobinso@redhat.com>

Prior to rewrite of cgroup code we only had one backend to try.
After the rewrite the virCgroupBackendGetAll() returns both
backends (for v1 and v2). However, not both have to really be
present on the system which results in killRecursive callback
failing which in turn might mean we won't try the other backend.

At the same time, this function reports no error as it should.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NErik Skultety <eskultet@redhat.com>

Missing semicolon at the end of macros can confuse some analyzers
(like cppcheck <filename>), and we have a mix of semicolon and
non-semicolon usage through the code. Let's standardize on using
a semicolon for VIR_ENUM_IMPL calls.

Move the verify() statement to the end of the macro and drop
the semicolon, so the compiler will require callers to add a
semicolon.

While we are touching these call sites, standardize on putting
the closing parenth on its own line, as discussed here:
https://www.redhat.com/archives/libvir-list/2019-January/msg00750.htmlReviewed-by: NJohn Ferlan <jferlan@redhat.com>
Signed-off-by: NCole Robinson <crobinso@redhat.com>

Require that all headers are guarded by a symbol named

  LIBVIRT_$FILENAME

where $FILENAME is the uppercased filename, with all characters
outside a-z changed into '_'.

Note we do not use a leading __ because that is technically a
namespace reserved for the toolchain.
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

The rewrite to support cgroup v2 missed this function.  In cgroup v2
we have different files to track tasks.

We would fail to remove cgroup on non-systemd OSes if there is any
extra process assigned to guest cgroup because we would not kill any
process form the guest cgroup.
Signed-off-by: NPavel Hrdina <phrdina@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>

Signed-off-by: NYuri Chornoivan <yurchor@ukr.net>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

This enables to use both cgroup v1 and v2 at the same time together
with libvirt.  It is supported by kernel and there is valid use-case,
not all controllers are implemented in cgroup v2 so there might be
configurations where administrator would enable these missing
controllers in cgroup v1.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

When creating cgroup hierarchy we need to enable controllers in the
parent cgroup in order to be usable.  That means writing "+{controller}"
into cgroup.subtree_control file.  We can enable only controllers that
are enabled for parent cgroup, that means we need to do that for the
whole cgroup tree.

Cgroups for threads needs to be handled differently in cgroup v2.  There
are two types of controllers:

    - domain controllers: these cannot be enabled for threads
    - threaded controllers: these can be enabled for threads

In addition there are multiple types of cgroups:

    - domain: normal cgroup
    - domain threaded: a domain cgroup that serves as root for threaded
                       cgroups
    - domain invalid: invalid cgroup, can be changed into threaded, this
                      is the default state if you create subgroup inside
                      domain threaded group or threaded group
    - threaded: threaded cgroup which can have domain threaded or
                threaded as parent group

In order to create threaded cgroup it's sufficient to write "threaded"
into cgroup.type file, it will automatically make parent cgroup
"domain threaded" if it was only "domain".  In case the parent cgroup
is already "domain threaded" or "threaded" it will modify only the type
of current cgroup.  After that we can enable threaded controllers.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>