The intent here is to allow the virt drivers to be run directly embedded
in an arbitrary process without interfering with libvirtd. To achieve
this they need to store all their configuration & state in a separate
directory tree from the main system or session libvirtd instances.

This can be useful for doing testing of the virt drivers in "make check"
without interfering with the user's own libvirtd instances.

It can also be used for applications using KVM/QEMU as a piece of
infrastructure to build an service, rather than for general purpose
OS hosting. A long standing example is libguestfs, which would prefer
if its temporary VMs did show up in the main libvirtd VM list, because
this confuses apps such as OpenStack Nova. A more recent example would
be Kata which is using KVM as a technology to build containers.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

The last_component() method is a GNULIB custom function
that returns a pointer to the base name in the path.
This is similar to g_path_get_basename() but without the
malloc. The extra malloc is no trouble for libvirt's
needs so we can use g_path_get_basename().
Reviewed-by: NFabiano Fidêncio <fidencio@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

virGetUserRuntimeDirectory() *never* *ever* returns NULL, making the
checks for it completely unnecessary.
Signed-off-by: NFabiano Fidêncio <fidencio@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

Signed-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

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

The function now does not return an error so we can drop it fully.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@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>

Replace:
  if (!s && VIR_STRDUP(s, str) < 0)
    goto;
with:
  if (!s)
    s = g_strdup(str);
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Replace all the occurrences of
  ignore_value(VIR_STRDUP(a, b));
with
  a = g_strdup(b);
Signed-off-by: NJán Tomko <jtomko@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>

Prefer the GLib version of the macro.
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>

All code using LOCALSTATEDIR "/run" is updated to use RUNSTATEDIR
instead. The exception is the remote driver client which still
uses LOCALSTATEDIR "/run". The client needs to connect to remote
machines which may not be using /run, so /var/run is more portable
due to the /var/run -> /run symlink.

Some duplicate paths in the apparmor code are also purged.

There's no functional change by default yet since both expressions
expand to the same value.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

When running in libvirtd, we are happy for any of the drivers to simply
skip their initialization in virStateInitialize, as other drivers are
still potentially useful.

When running in per-driver daemons though, we want the daemon to abort
startup if the driver cannot initialize itself, as the daemon will be
useless without it.
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

When the drivers acquire their pidfile lock we don't want to wait if the
lock is already held. We need the driver to immediately report error,
causing the daemon to exit.
Reviewed-by: NErik Skultety <eskultet@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

When we allow multiple instances of the driver for the same user
account, using a separate root directory, we need to ensure mutual
exclusion. Use a pidfile to guarantee this.

In privileged libvirtd this ends up locking

   /var/run/libvirt/nodedev/driver.pid

In unprivileged libvirtd this ends up locking

  /run/user/$UID/libvirt/nodedev/run/driver.pid

NB, the latter can vary depending on $XDG_RUNTIME_DIR
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

It has been exported by systemd commit
commit a571c23e954cb88cdd5faa28593b19bd7c340130
    libudev: export udev_monitor_set_receive_buffer_size()
released in v183.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NPavel Hrdina <phrdina@redhat.com>

The function was deprecated in udev 219 and all the supported OSes
don't have older version of udev or systemd.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Commit 3bd4ed46 introduced this element as required which
breaks backcompat for test driver. Let's make the element optional.
Reviewed-by: NErik Skultety <eskultet@redhat.com>
Signed-off-by: NNikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>

Vim treats *.h files as cpp ones with respect to syntax highlighting.
Thus "class" in _virNodeDevCapPCIDev highlighted mistakenly.
This can be fixed by filetype detection code tunables but it
is more convinient to skip this tuning by every project member.

Let's just use "klass" as field name instead of _class or class
and add syntax rule.
Signed-off-by: NNikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

Signal the udev thread the change of `priv->threadQuit` by using the
thread condition.
Signed-off-by: NMarc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

If the udev thread is stopped, it must be ensured that the watch
handle is also removed from the main loop.
Signed-off-by: NMarc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

Even if an error is reported by `udev_enumerate_scan_devices`,
e.g. because a driver of a device has an bug, we can still enumerate
all other devices. Additionally the documentation of
udev_enumerate_scan_devices says that on success an integer >= 0 is
returned (see man udev_enumerate_scan_devices(3)).
Reviewed-by: NBjoern Walk <bwalk@linux.ibm.com>
Signed-off-by: NMarc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

Missing semicolon at the end of macros can confuse some analyzers
(like cppcheck <filename>). VIR_ONCE_GLOBAL_INIT is almost
exclusively called without an ending semicolon, but let's
standardize on using one like the other macros.

Add a dummy struct definition at the end of the macro, so
the compiler will require callers to add a semicolon.
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>
Signed-off-by: NCole Robinson <crobinso@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>

Commit cdbe1332 neglected to document the API. So let's add some
details about the algorithm and why it was used to help future
readers understand the issues encountered.

NB: Management of the processing udev device notification is a
delicate balance between the udev process, the scheduler, and when
exactly the data from/for the socket is received. The balance is
particularly important for environments when multiple devices are
added into the system more or less simultaneously such as is done
for mdev or SRIOV. In these cases old libudev blocking on the udev
recv() occurs more frequently. It's expected that future devices
will follow similar algorithms. Even though the algorithm does
present some challenges for older OS's (such as Centos 6), trying
to rewrite the algorithm to fit both models would be more complex
and involve pulling the monitor object out of the private data
lockable object and would need to be guarded by a separate lock.
Devising such an algorithm to work around issues with older OS's
at the expense of more modern OS algorithms in newer event processing
code may result in unexpected issues, so the choice is to encourage
use of newer OS's with newer udev event processing code.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>
Reviewed-by: NErik Skultety <eskultet@redhat.com>

And remove NULL checking from all callers.
Signed-off-by: NAnya Harter <aharter@redhat.com>

So far we are repeating the following lines over and over:

  if (!(virSomeObjectClass = virClassNew(virClassForObject(),
                             "virSomeObject",
                             sizeof(virSomeObject),
                             virSomeObjectDispose)))
      return -1;

While this works, it is impossible to do some checking. Firstly,
the class name (the 2nd argument) doesn't match the name in the
code in all cases (the 3rd argument). Secondly, the current style
is needlessly verbose. This commit turns example into following:

  if (!(VIR_CLASS_NEW(virSomeObject,
                      virClassForObject)))
      return -1;
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

Declare what URI schemes a driver supports in its virConnectDriver
struct. This allows us to skip trying to open the driver entirely
if the URI scheme doesn't match.
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Add a localOnly flag to the virConnectDriver struct which allows a
driver to indicate whether it is local-only, or permits remote
connections. Stateful drivers running inside libvirtd are generally
local only. This allows us to remote the check for uri->server != NULL
from most drivers.
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

Allow the possibility of opening a connection to only the nodedev
driver, by defining nodedev:///system and nodedev:///session URIs
and registering a fake hypervisor driver that supports them.

The hypervisor drivers can now directly open a nodedev driver
connection at time of need, instead of having to pass around a
virConnectPtr through many functions. This will facilitate the later
change to support separate daemons for each driver.
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

These are not necessary anymore, since these are going to be shadowed by
the helpers provided by util/virmdev.c module.
Signed-off-by: NErik Skultety <eskultet@redhat.com>

The capabilities are defined/parsed/formatted/queried from this module,
no reason for 'update' not being part of the module as well. This also
involves some module-specific prefix changes.
This patch also drops the node_device_linux_sysfs module from the repo
since:
a) it only contained the capability handlers we just moved
b) it's only linked with the driver (by design) and thus unreachable to
other modules
c) we touch sysfs across all the src/util modules so the module being
deleted hasn't been serving its original intention for some time already.
Signed-off-by: NErik Skultety <eskultet@redhat.com>

We can call directly the virNodeDeviceGetSCSIHostCaps helper instead.
Signed-off-by: NErik Skultety <eskultet@redhat.com>

Let's move the udevEnumerateDevices into a thread to "speed
up" the initialization process. If the enumeration fails we
can set the Quit flag to ensure that udevEventHandleCallback
will not run.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>
Reviewed-by: NErik Skultety <eskultet@redhat.com>

Commit id '36555364' removed the setting of the driver->privileged,
which the udevProcessPCI would need in order to read the PCI device
configs.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Right-aligning backslashes when defining macros or using complex
commands in Makefiles looks cute, but as soon as any changes is
required to the code you end up with either distractingly broken
alignment or unnecessarily big diffs where most of the changes
are just pushing all backslashes a few characters to one side.

Generated using

  $ git grep -El '[[:blank:]][[:blank:]]\\$' | \
    grep -E '*\.([chx]|am|mk)$$' | \
    while read f; do \
      sed -Ei 's/[[:blank:]]*[[:blank:]]\\$/ \\/g' "$f"; \
    done
Signed-off-by: NAndrea Bolognani <abologna@redhat.com>

If we find ourselves in the situation that the 'add' uevent has been
fired earlier than the sysfs tree for a device was created, we should
use the best-effort approach and give kernel some predetermined amount
of time, thus waiting for the attributes to be ready rather than
discarding the device from our device list forever. If those don't appear
in the given time frame, we need to move on, since libvirt can't wait
indefinitely.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1463285Signed-off-by: NErik Skultety <eskultet@redhat.com>

Adjust udevEventHandleThread to be a proper thread routine running in an
infinite loop handling devices. The handler thread pulls all available
data from the udev monitor and only then waits until a wakeup signal for
new incoming data has been emitted by udevEventHandleCallback.
Signed-off-by: NErik Skultety <eskultet@redhat.com>