Systemd detects containers based on whether they have
an environment variable starting with 'container=lxc';
using a longer name fits the expectations, while also
allowing detection of who created the container.

Requested by Lennart Poettering, in response to
https://bugs.freedesktop.org/show_bug.cgi?id=45175

* src/lxc/lxc_container.c (lxcContainerBuildInitCmd): Add another
env-var.

The current setup code for LXC is bind mounting /dev/pts/ptmx
on top of a character device /dev/ptmx. This is denied by SELinux
policy and is just wrong. The target of a bind mount should just
be a plain file

* src/lxc/lxc_container.c: Don't bind /dev/pts/ptmx onto
  a char device

Reusing common code makes things smaller; it also buys us some
additional safety, such as now rejecting duplicate parameters
during a set operation.

* src/qemu/qemu_driver.c (qemuDomainSetBlkioParameters)
(qemuDomainSetMemoryParameters, qemuDomainSetNumaParameters)
(qemuSetSchedulerParametersFlags)
(qemuDomainSetInterfaceParameters, qemuDomainSetBlockIoTune)
(qemuDomainGetBlkioParameters, qemuDomainGetMemoryParameters)
(qemuDomainGetNumaParameters, qemuGetSchedulerParametersFlags)
(qemuDomainBlockStatsFlags, qemuDomainGetInterfaceParameters)
(qemuDomainGetBlockIoTune): Use new helpers.
* src/esx/esx_driver.c (esxDomainSetSchedulerParametersFlags)
(esxDomainSetMemoryParameters)
(esxDomainGetSchedulerParametersFlags)
(esxDomainGetMemoryParameters): Likewise.
* src/libxl/libxl_driver.c
(libxlDomainSetSchedulerParametersFlags)
(libxlDomainGetSchedulerParametersFlags): Likewise.
* src/lxc/lxc_driver.c (lxcDomainSetMemoryParameters)
(lxcSetSchedulerParametersFlags, lxcDomainSetBlkioParameters)
(lxcDomainGetMemoryParameters, lxcGetSchedulerParametersFlags)
(lxcDomainGetBlkioParameters): Likewise.
* src/test/test_driver.c (testDomainSetSchedulerParamsFlags)
(testDomainGetSchedulerParamsFlags): Likewise.
* src/xen/xen_hypervisor.c (xenHypervisorSetSchedulerParameters)
(xenHypervisorGetSchedulerParameters): Likewise.

Based on qemu changes made in commits ae523427 and 659ded58.

* src/lxc/lxc_driver.c (lxcSetSchedulerParametersFlags)
(lxcGetSchedulerParametersFlags, lxcDomainSetBlkioParameters)
(lxcDomainGetBlkioParameters): Use helpers.
(lxcDomainSetBlkioParameters): Allow setting live and config at
once.

Given an LXC guest with a root filesystem path of

  /export/lxc/roots/helloworld/root

During startup, we will pivot the root filesystem to end up
at

  /.oldroot/export/lxc/roots/helloworld/root

We then try to open

  /.oldroot/export/lxc/roots/helloworld/root/dev/pts

Now consider if '/export/lxc' is an absolute symlink pointing
to '/media/lxc'. The kernel will try to open

  /media/lxc/roots/helloworld/root/dev/pts

whereas it should be trying to open

  /.oldroot//media/lxc/roots/helloworld/root/dev/pts

To deal with the fact that the root filesystem can be moved,
we need to resolve symlinks in *any* part of the filesystem
source path.

* src/libvirt_private.syms, src/util/util.c,
  src/util/util.h: Add virFileResolveAllLinks to resolve
  all symlinks in a path
* src/lxc/lxc_container.c: Resolve all symlinks in filesystem
  paths during startup

Currently the LXC controller attempts to deal with EOF on a
tty by spawning a thread to do an edge triggered epoll_wait().
This avoids the normal event loop spinning on POLLHUP. There
is a subtle mistake though - even after seeing POLLHUP on a
master PTY, it is still perfectly possible & valid to write
data to the PTY. There is a buffer that can be filled with
data, even when no client is present.

The second mistake is that the epoll_wait() thread was not
looking for the EPOLLOUT condition, so when a new client
connects to the LXC console, it had to explicitly send a
character before any queued output would appear.

Finally, there was in fact no need to spawn a new thread to
deal with epoll_wait(). The epoll file descriptor itself
can be poll()'d on normally.

This patch attempts to deal with all these problems.

 - The blocking epoll_wait() thread is replaced by a poll
   on the epoll file descriptor which then does a non-blocking
   epoll_wait() to handle events
 - Even if POLLHUP is seen, we continue trying to write
   any pending output until getting EAGAIN from write.
 - Once write returns EAGAIN, we modify the epoll event
   mask to also look for EPOLLOUT

* src/lxc/lxc_controller.c: Avoid stalled I/O upon
  connected to an LXC console

The lifetime of the virDomainEventState object is tied to
the lifetime of the driver, which in stateless drivers is
tied to the lifetime of the virConnectPtr.

If we add & remove a timer when allocating/freeing the
virDomainEventState object, we can get a situation where
the timer still triggers once after virDomainEventState
has been freed. The timeout callback can't keep a ref
on the event state though, since that would be a circular
reference.

The trick is to only register the timer when a callback
is registered with the event state & remove the timer
when the callback is unregistered.

The demo for the bug is to run

  while true ; do date ; ../tools/virsh -q -c test:///default 'shutdown test; undefine test; dominfo test' ; done

prior to this fix, it will frequently hang and / or
crash, or corrupt memory

Currently all drivers using domain events need to provide a callback
for handling a timer to dispatch events in a clean stack. There is
no technical reason for dispatch to go via driver specific code. It
could trivially be dispatched directly from the domain event code,
thus removing tedious boilerplate code from all drivers

Also fix the libxl & xen drivers to pass 'true' when creating the
virDomainEventState, since they run inside the daemon & thus always
expect events to be present.

* src/conf/domain_event.c, src/conf/domain_event.h: Internalize
  dispatch of events from timer callback
* src/libxl/libxl_driver.c, src/lxc/lxc_driver.c,
  src/qemu/qemu_domain.c, src/qemu/qemu_driver.c,
  src/remote/remote_driver.c, src/test/test_driver.c,
  src/uml/uml_driver.c, src/vbox/vbox_tmpl.c,
  src/xen/xen_driver.c: Remove all timer dispatch functions

* src/libxl/libxl_driver.c, src/lxc/lxc_driver.c,
  src/qemu/qemu_driver.c, src/remote/remote_driver.c,
  src/test/test_driver.c, src/uml/uml_driver.c,
  src/vbox/vbox_tmpl.c, src/xen/xen_driver.c: Convert
  to threadsafe APIs

When registering a callback for a particular event some callers
need to know how many callbacks already exist for that event.
While it is possible to ask for a count, this is not free from
race conditions when threaded. Thus the API for registering
callbacks should return the count of callbacks. Also rename
virDomainEventStateDeregisterAny to virDomainEventStateDeregisterID

* src/conf/domain_event.c, src/conf/domain_event.h,
  src/libvirt_private.syms: Return count of callbacks when
  registering callbacks
* src/libxl/libxl_driver.c, src/libxl/libxl_driver.c,
  src/qemu/qemu_driver.c, src/remote/remote_driver.c,
  src/remote/remote_driver.c, src/uml/uml_driver.c,
  src/vbox/vbox_tmpl.c, src/xen/xen_driver.c: Update
  for change in APIs

A preparatory patch for DHCP snooping where we want to be able to
differentiate between a VM's interface using the tuple of
<VM UUID, Interface MAC address>. We assume that MAC addresses could
possibly be re-used between different networks (VLANs) thus do not only
want to rely on the MAC address to identify an interface.

At the current 'final destination' in virNWFilterInstantiate I am leaving
the vmuuid parameter as ATTRIBUTE_UNUSED until the DHCP snooping patches arrive.
(we may not post the DHCP snooping patches for 0.9.9, though)

Mostly this is a pretty trivial patch. On the lowest layers, in lxc_driver
and uml_conf, I am passing the virDomainDefPtr around until I am passing
only the VM's uuid into the NWFilter calls.

* src/lxc/lxc_controller.c: Fix check for tty count

The virTimestamp and virTimeMs functions in src/util/util.h
duplicate functionality from virtime.h, in a non-async signal
safe manner. Remove them, and convert all code over to the new
APIs.

* src/util/util.c, src/util/util.h: Delete virTimeMs and virTimestamp
* src/lxc/lxc_driver.c, src/qemu/qemu_domain.c,
  src/qemu/qemu_driver.c, src/qemu/qemu_migration.c,
  src/qemu/qemu_process.c, src/util/event_poll.c: Convert to use
  virtime APIs

* src/lxc/lxc_conf.c, src/uml/uml_conf.c,
  src/xen/xen_hypervisor.c: Initialize suspend capabilities
* tests/xencapsdata/*xml: Add empty powermgmt capabilities

After the previous patch, there are now some redundant checks.

* src/qemu/qemu_driver.c (qemudDomainGetVcpuPinInfo)
(qemuGetSchedulerParametersFlags): Drop checks now guaranteed by
libvirt.c.
* src/lxc/lxc_driver.c (lxcGetSchedulerParametersFlags):
Likewise.

Add the core functions that implement the functionality of the API.
Suspend is done by using an asynchronous mechanism so that we can return
the status to the caller before the host gets suspended. This asynchronous
operation is achieved by suspending the host in a separate thread of
execution. However, returning the status to the caller is only best-effort,
but not guaranteed.

To resume the host, an RTC alarm is set up (based on how long we want to
suspend) before suspending the host. When this alarm fires, the host
gets woken up.

Suspend-to-RAM operation on a host running Linux can take upto more than 20
seconds, depending on the load of the system. (Freezing of tasks, an operation
preceding any suspend operation, is given up after a 20 second timeout).
And Suspend-to-Disk can take even more time, considering the time required
for compaction, creating the memory image and writing it to disk etc.
So, we do not allow the user to specify a suspend duration of less than 60
seconds, to be on the safer side, since we don't want to prematurely declare
failure when we only had to wait for some more time.

To make lxcSetContainerResources smaller, pull the mem tune
and device ACL setup code out into separate methods

* src/lxc/lxc_controller.c: Introduce lxcSetContainerMemTune
  and lxcSetContainerDeviceACL

* src/lxc/lxc_controller.c: Refactor setting of initial blkio
  tuning parameters
* src/lxc/lxc_driver.c: Enable live change of blkio tuning

* src/lxc/lxc_driver.c: Support changing quota/period for LXC
  containers
* src/lxc/lxc_controller.c: Set initial quota/period at startup

While LXC does not have the concept of VCPUS, so we can't do
per-VCPU pCPU placement, we can support the VM level CPU
placement. Todo this simply set the CPU affinity of the LXC
controller at startup. All child processes will inherit this
affinity.

* src/lxc/lxc_controller.c: Set process affinity

Use numactl to set NUMA memory placement for LXC containers

* src/lxc/lxc_controller.c: Support NUMA memory placement

Support creation of macvlan devices for LXC containers. Do not
allow setting of bandwidth controls or vport profiles due to the
complication that there is no host side visible device to work
with.

* src/lxc/lxc_driver.c: Support type=direct interfaces

The current lxcSetupInterfaces() method directly performs setup
of the bridge devices. Since it will shortly need to also create
macvlan devices, move the bridge related code into a separate
method

* src/lxc/lxc_driver.c: Split lxcSetupInterfaces() to create a
  new lxcSetupInterfaceBridge()

Move the virNetDevSetName and virNetDevSetNamespace APIs out
of LXC's veth.c and into virnetdev.c.

Move the remaining content of the file to src/util/virnetdevveth.c

* src/lxc/veth.c: Rename to src/util/virnetdevveth.c
* src/lxc/veth.h: Rename to src/util/virnetdevveth.h
* src/util/virnetdev.c, src/util/virnetdev.h: Add
  virNetDevSetName and virNetDevSetNamespace
* src/lxc/lxc_container.c, src/lxc/lxc_controller.c,
  src/lxc/lxc_driver.c: Update include paths

The src/lxc/veth.c file contains APIs for managing veth devices,
but some of the APIs duplicate stuff from src/util/virnetdev.h.
Delete thed duplicate APIs and rename the remaining ones to
follow virNetDevVethXXXX

* src/lxc/veth.c, src/lxc/veth.h: Rename APIs & delete duplicates
* src/lxc/lxc_container.c, src/lxc/lxc_controller.c,
  src/lxc/lxc_driver.c: Update for API renaming

* .gnulib: Update to latest, for improved syntax-check.
* src/lxc/lxc_container.c (includes): Drop unused include.
* src/network/bridge_driver.c: Likewise.
* src/node_device/node_device_linux_sysfs.c: Likewise.
* src/openvz/openvz_driver.c: Likewise.
* src/qemu/qemu_conf.c: Likewise.
* src/storage/storage_backend_iscsi.c: Likewise.
* src/storage/storage_backend_mpath.c: Likewise.
* src/uml/uml_conf.c: Likewise.
* src/uml/uml_driver.c: Likewise.

Rename virBandwidth to virNetDevBandwidth, and virRate to
virNetDevBandwidthRate.

* src/util/network.c, src/util/network.h: Rename bandwidth
  structs and APIs
* src/conf/domain_conf.c, src/conf/domain_conf.h,
  src/conf/network_conf.c, src/conf/network_conf.h,
  src/lxc/lxc_driver.c, src/network/bridge_driver.c,
  src/qemu/qemu_command.c, src/util/macvtap.c,
  src/util/macvtap.h, tools/virsh.c: Update for API changes.

Following the renaming of the bridge management APIs, we can now
split the source file into 3 corresponding pieces

 * src/util/virnetdev.c: APIs for any type of network interface
 * src/util/virnetdevbridge.c: APIs for bridge interfaces
 * src/util/virnetdevtap.c: APIs for TAP interfaces

* src/util/virnetdev.c, src/util/virnetdev.h,
  src/util/virnetdevbridge.c, src/util/virnetdevbridge.h,
  src/util/virnetdevtap.c, src/util/virnetdevtap.h: Copied
  from bridge.{c,h}
* src/util/bridge.c, src/util/bridge.h: Split into 3 pieces
* src/lxc/lxc_driver.c, src/network/bridge_driver.c,
  src/openvz/openvz_driver.c, src/qemu/qemu_command.c,
  src/qemu/qemu_conf.h, src/uml/uml_conf.c, src/uml/uml_conf.h,
  src/uml/uml_driver.c: Update #include directives

The existing brXXX APIs in src/util/bridge.h are renamed to
follow one of three different conventions

 - virNetDevXXX       - operations for any type of interface
 - virNetDevBridgeXXX - operations for bridge interfaces
 - virNetDevTapXXX    - operations for tap interfaces

* src/util/bridge.h, src/util/bridge.c: Rename all APIs
* src/lxc/lxc_driver.c, src/network/bridge_driver.c,
  src/qemu/qemu_command.c, src/uml/uml_conf.c,
  src/uml/uml_driver.c: Update for API renaming

Currently every caller of the brXXX APIs has to store the returned
errno value and then raise an error message. This results in
inconsistent error messages across drivers, additional burden on
the callers and makes the error reporting inaccurate since it is
hard to distinguish different scenarios from 1 errno value.

* src/util/bridge.c: Raise errors instead of returning errnos
* src/lxc/lxc_driver.c, src/network/bridge_driver.c,
  src/qemu/qemu_command.c, src/uml/uml_conf.c,
  src/uml/uml_driver.c: Remove error reporting code

The bridge management APIs in src/util/bridge.c require a brControl
object to be passed around. This holds the file descriptor for the
control socket. This extra object complicates use of the API for
only a minor efficiency gain, which is in turn entirely offset by
the need to fork/exec the brctl command for STP configuration.

This patch removes the 'brControl' object entirely, instead opening
the control socket & closing it again within the scope of each method.

The parameter names for the APIs are also made to consistently use
'brname' for bridge device name, and 'ifname' for an interface
device name. Finally annotations are added for non-NULL parameters
and return check validation

* src/util/bridge.c, src/util/bridge.h: Remove brControl object
  and update API parameter names & annotations.
* src/lxc/lxc_driver.c, src/network/bridge_driver.c,
  src/uml/uml_conf.h, src/uml/uml_conf.c, src/uml/uml_driver.c,
  src/qemu/qemu_command.c, src/qemu/qemu_conf.h,
  src/qemu/qemu_driver.c: Remove reference to 'brControl' object

Detected by Coverity. Leak introduced in commit 9d201a5c.

* src/lxc/lxc_driver.c: Clean up on failure.
Signed-off-by: NAlex Jia <ajia@redhat.com>

Detected by Coverity. Leak introduced in commit 0f31f7b7.

* src/lxc/lxc_driver.c: Clean up on failure.
Signed-off-by: NAlex Jia <ajia@redhat.com>

I got this weird failure:

error: Failed to start domain simple
error: internal error cannot mix caller fds with blocking execution

and tracked it down to a use-after-free - virCommandSetOutputFD
was storing the address of a stack-local variable, which then
went out of scope before the virCommandRun that dereferenced it.

Bug introduced in commit 451cfd05 (0.9.2).

* src/lxc/lxc_driver.c (lxcBuildControllerCmd): Move log fd
registration...
(lxcVmStart): ...to caller.

Based on a Coverity report - the return value of waitpid() should
always be checked, to avoid problems with leaking resources.

* src/lxc/lxc_controller.c (lxcControllerRun): Use simpler virPidAbort.

The default console type may vary based on the OS type. ie a Xen
paravirt guests wants a 'xen' console, while a fullvirt guests
wants a 'serial' console.

A plain integer default console type in the capabilities does
not suffice. Instead introduce a callback that is passed the
OS type.

* src/conf/capabilities.h: Use a callback for default console
  type
* src/conf/domain_conf.c, src/conf/domain_conf.h: Use callback
  for default console type. Add missing LXC/OpenVZ console types.
* src/esx/esx_driver.c, src/libxl/libxl_conf.c,
  src/lxc/lxc_conf.c, src/openvz/openvz_conf.c,
  src/phyp/phyp_driver.c, src/qemu/qemu_capabilities.c,
  src/uml/uml_conf.c, src/vbox/vbox_tmpl.c,
  src/vmware/vmware_conf.c, src/xen/xen_hypervisor.c,
  src/xenapi/xenapi_driver.c: Set default console type callback

To allow virDomainOpenConsole to access non-primary consoles,
device aliases are required to be set. Until now only the QEMU
driver has done this. Update LXC & UML to set aliases for any
console devices

* src/lxc/lxc_driver.c, src/uml/uml_driver.c: Set aliases
  for console devices

Currently the LXC controller only supports setup of a single
text console. This is wired up to the container init's stdio,
as well as /dev/console and /dev/tty1. Extending support for
multiple consoles, means wiring up additional PTYs to /dev/tty2,
/dev/tty3, etc, etc. The LXC controller is passed multiple open
file handles, one for each console requested.

* src/lxc/lxc_container.c, src/lxc/lxc_container.h: Wire up
  all the /dev/ttyN links required to symlink to /dev/pts/NN
* src/lxc/lxc_container.h: Open more container side /dev/pts/NN
  devices, and adapt event loop to handle I/O from all consoles
* src/lxc/lxc_driver.c: Setup multiple host side PTYs