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 reverts commit 226094fb.

A deprecation is a warning to something that use of a feature is
being discouraged. By definition it is not an error condition to
continue to use a deprecated feature.

A VIR_ERR_DEPRECATED constant thus makes no conceptual sense. For
features which are entirely absent we already document that the
VIR_ERR_NO_SUPPORT code will be used. There is no need to distinguish
between a feature which never existed and a feature which previously
existed and was since removed.
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

When detecting available controllers on host we can be limited by list
of controllers from qemu.conf file.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NPeter Krempa <pkrempa@redhat.com>

Currently CPU controller cannot be enabled if there is any real-time
task running and is assigned to non-root cgroup which is the case on
several distributions with graphical environment.

Instead of erroring out treat it as the controller is not available.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NPeter Krempa <pkrempa@redhat.com>

In order to skip controllers that we are not able to activate we need
to return different return value so the caller can decide what to do.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NPeter Krempa <pkrempa@redhat.com>

It might happen that we are not able to enable CPU controller so we
can enable it for thread sub-cgroups only if it's available in parent
cgroup.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The assumption that CPU controller would be always enabled is wrong, we
should use any available controller to create a new sub-cgroup.
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>

virStorageSourceGetActualType would return VIR_STORAGE_TYPE_NONE in case
when a virStorageSource of (top level) type VIR_STORAGE_TYPE_VOLUME was
not prepared to use by the vm by calling
virDomainDiskTranslateSourcePool.

Fix this issue by returning VIR_STORAGE_TYPE_VOLUME in case when the
volume was not translated yet.

Additionally also add documentation for the function describing the
quirk.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Allow a simple programatic check that a given feature is no longer
supported by introducing a separate error code for this scenario.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Trivial change. Adding the name of the device that has an
unknown PCI header type in that function helps when debugging
PCI code.
Signed-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>

In the virStorageSourceChainHasManagedPR() function we iterate
over whole backing chain trying to determine if one of the layers
has managed PR configured. But due to a typo we in fact check the
top layer only.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

In kernel 4.12 there was introduced new BFQ scheduler and in kernel
5.0 the old CFQ scheduler was removed.  This has an implication on
the cgroups file names.

If the CFQ controller is enabled we use one file:

    io.weight

The new BFQ controller expose one file with different name:

    io.bfq.weight

Except for different name they have different syntax.

io.weight:

    default $val
    major:minor $val

io.bfq.weight:

    $val

The difference is that BFQ doesn't support per-device weight.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

In kernel 4.12 there was introduced new BFQ scheduler and in kernel
5.0 the old CFQ scheduler was removed.  This has an implication on
the cgroups file names.

If the CFQ controller is enabled we use these two files:

    blkio.weight
    blkio.weight_device

The new BFQ controller expose only one file with different name:

    blkio.bfq.weight

The reason is that BFQ controller doesn't support per-device weight.
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>

In some cases we report a low level error message which does not have
enough information to see what the problem is. To allow improving on
this add an API which will prefix the error message with another error
message string which can be used to describe where the error comes from.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
ACKed-by: NMichal Privoznik <mprivozn@redhat.com>

There are couple of functions which get shorter after the
treatment.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Couple of things happening in this patch:

1) We can mark the device we're adding onto active list as used
   way before - when adding it onto temporary list.

2) When actually moving device from a temporary helper list onto
   the list of active devices we check if the device isn't
   already there. The same check is performed by
   virSCSIVHostDeviceListAdd() later. Drop this duplicity.

3) The 'error' label is renamed to 'rollback' to reflect what it
   is actually doing. While in the rest of the code we don't
   allow random label names, this source file is different.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

When looking up a USB device by vendor the
virUSBDeviceFindByVendor() is used. The function returns number
of items found. But the logic in caller to process it is
needlessly complicated.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

There are couple of functions which get shorter after the
treatment.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

There's no need to translate virDomainHostdevDef-s into
virPCIDevice-s with locked list of PCI devices.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

There's no need to translate virDomainHostdevDef-s into
virPCIDevice-s with locked list of PCI devices.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

This function is a good candidate for VIR_AUTOPTR() conversion.
But this conversion will be easier if we only add @pci device
onto @pcidevs list after it was all set up.

This is no functional change.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>