*src/util/virstoragefile.c: Add a helper function to get
the first name of missing backing files, if the name is NULL,
it means the diskchain is not broken.
*src/qemu/qemu_domain.c: qemuDiskChainCheckBroken(disk) to
check if its chain is broken

There are some interesting escaping rules to consider when dealing
with systemd slice/scope names. Thus it is helpful to have APIs
for formatting names
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This function is needed for virt-login-shell.  Also modify virGirUserDirectory
to use the new function, to simplify the code.
Signed-off-by: NEric Blake <eblake@redhat.com>

The virCgroupIsValidMachine does not need to be called from
outside the cgroups file now, so make it static.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Instead of requiring drivers to use a combination of calls
to virCgroupNewDetect and virCgroupIsValidMachine, combine
the two into virCgroupNewDetectMachine
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Instead of requiring one API call to create a cgroup and
another to add a task to it, introduce a new API
virCgroupNewMachine which does both jobs at once. This
will facilitate the later code to talk to systemd to
achieve this job which is also atomic.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Otherwise libvirtd fails to load the lockd plugin.

Parsing 'user:group' is useful even outside the DAC security driver,
so expose the most abstract function which has no DAC security driver
bits in itself.

Since PCI bridges, PCIe bridges, PCIe switches, and PCIe root ports
all share the same namespace, they are all defined as controllers of
type='pci' in libvirt (but with a differing model attribute). Each of
these controllers has a certain connection type upstream, allows
certain connection types downstream, and each can either allow a
single downstream connection at slot 0, or connections from slot 1 -
31.

Right now, we only support the pci-root and pci-bridge devices, both
of which only allow PCI devices to connect, and both which have usable
slots 1 - 31. In preparation for adding other types of controllers
that have different capabilities, this patch 1) adds info to the
qemuDomainPCIAddressBus object to indicate the capabilities, 2) sets
those capabilities appropriately for pci-root and pci-bridge devices,
and 3) validates that the controller being connected to is the proper
type when allocating slots or validating that a user-selected slot is
appropriate for a device..

Having this infrastructure in place will make it much easier to add
support for the other PCI controller types.

While it would be possible to do all the necessary checking by just
storing the controller model in the qemyuDomainPCIAddressBus, it
greatly simplifies all the validation code to also keep a "flags",
"minSlot" and "maxSlot" for each - that way we can just check those
attributes rather than requiring a nearly identical switch statement
everywhere we need to validate compatibility.

You may notice many places where the flags are seemingly hard-coded to

  QEMU_PCI_CONNECT_HOTPLUGGABLE | QEMU_PCI_CONNECT_TYPE_PCI

This is currently the correct value for all PCI devices, and in the
future will be the default, with small bits of code added to change to
the flags for the few devices which are the exceptions to this rule.

Finally, there are a few places with "FIXME" comments. Note that these
aren't indicating places that are broken according to the currently
supported devices, they are places that will need fixing when support
for new PCI controller models is added.

To assure that there was no regression in the auto-allocation of PCI
addresses or auto-creation of integrated pci-root, ide, and usb
controllers, a new test case (pci-bridge-many-disks) has been added to
both the qemuxml2argv and qemuxml2xml tests. This new test defines a
domain with several dozen virtio disks but no pci-root or
pci-bridges. The .args file of the new test case was created using
libvirt sources from before this patch, and the test still passes
after this patch has been applied.

The virCgroupNewDomainDriver and virCgroupNewDriver methods
are obsolete now that we can auto-detect existing cgroup
placement. Delete them to reduce code bloat.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Add virCgroupIsValidMachine API to check whether an auto
detected cgroup is valid for a machine. This lets us
check if a VM has just been placed into some generic
shared cgroup, or worse, the root cgroup
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Add a virCgroupNewDetect API which is used to initialize a
cgroup object with the placement of an arbitrary process.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Introduce a new helper to check if the disk source is of block type

Instead of returning raw errno values, report full libvirt
errors in virCgroupNew* functions.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Add virErrorSetErrnoFromLastError and virLastErrorIsSystemErrno
to simplify code which wants to handle system errors in a more
graceful fashion.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

To register virtual machines and containers with systemd-machined,
and thus have cgroups auto-created, we need to talk over DBus.
This is somewhat tedious code, so introduce a dedicated function
to isolate the DBus call in one place.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Doing DBus method calls using libdbus.so is tedious in the
extreme. systemd developers came up with a nice high level
API for DBus method calls (sd_bus_call_method). While
systemd doesn't use libdbus.so, their API design can easily
be ported to libdbus.so.

This patch thus introduces methods virDBusCallMethod &
virDBusMessageRead, which are based on the code used for
sd_bus_call_method and sd_bus_message_read. This code in
systemd is under the LGPLv2+, so we're license compatible.

This code is probably pretty unintelligible unless you are
familiar with the DBus type system. So I added some API
docs trying to explain how to use them, as well as test
cases to validate that I didn't screw up the adaptation
from the original systemd code.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

These helpers use the remembered host capabilities to retrieve the cpu
map rather than query the host again. The intended usage for this
helpers is to fix automatic NUMA placement with strict memory alloc. The
code doing the prepare needs to pin the emulator process only to cpus
belonging to a subset of NUMA nodes of the host.

Merge the virCommandPreserveFD / virCommandTransferFD methods
into a single virCommandPasFD method, and use a new
VIR_COMMAND_PASS_FD_CLOSE_PARENT to indicate their difference
in behaviour
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

There are two levels on which a device may be hotplugged: config
and live. The config level requires just an insert or remove from
internal domain definition structure, which is exactly what this
patch does. There is currently no implementation for a chardev
update action, as there's not much to be updated. But more
importantly, the only thing that can be updated is path or socket
address by which chardevs are distinguished. So the update action
is currently not supported.

This new function updates or adds a feature to a existing cpu model
definition. This function will be helpful to allow tuning of
"host-model" features in later patches.

For now, only these three helpers are needed:
virDomainChrFind - to find a duplicate chardev within VM def
virDomainChrInsert - wrapper for inserting a new chardev into VM def
virDomainChrRemove - wrapper for removing chardev from VM def

There is, however, one internal helper as well:
virDomainChrGetDomainPtrs which sets given pointers to one of
vmdef->{parallels,serials,consoles,channels} based on passed
chardev type.

Since neither getpwuid_r() nor initgroups() are safe to call in
between fork and exec (they obtain a mutex, but if some other
thread in the parent also held the mutex at the time of the fork,
the child will deadlock), we have to split out the functionality
that is unsafe.  At least glibc's initgroups() uses getgrouplist
under the hood, so the ideal split is to expose getgrouplist for
use before a fork.  Gnulib already gives us a nice wrapper via
mgetgroups; we wrap it once more to look up by uid instead of name.

* bootstrap.conf (gnulib_modules): Add mgetgroups.
* src/util/virutil.h (virGetGroupList): New declaration.
* src/util/virutil.c (virGetGroupList): New function.
* src/libvirt_private.syms (virutil.h): Export it.
Signed-off-by: NEric Blake <eblake@redhat.com>

Actually, I'm turning this function into a macro as filename,
function name and line number needs to be passed. The new
function virAsprintfInternal is introduced with the extended set
of arguments.

While iterating with virDomainObjListForEach it is safe to remove
current element. But while iterating, 'doms' lock is already taken, so
can't use standard virDomainObjListRemove. So introduce
virDomainObjListRemoveLocked for this purpose.
Signed-off-by: NMarek Marczykowski-Górecki <marmarek@invisiblethingslab.com>

Ensure that all APIs which list storage objects filter
them against the access control system.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Ensure that all APIs which list node device objects filter
them against the access control system.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Ensure that all APIs which list network objects filter
them against the access control system.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

iptablesContext holds only 4 pairs of iptables
(table, chain) and there's no need to pass
it around.

This is a first step towards separating bridge_driver.c
in platform-specific parts.

Any device which belongs to an "IOMMU group" (used by vfio) will
have links to all devices of its group listed in
/sys/bus/pci/$device/iommu_group/devices;
/sys/bus/pci/$device/iommu_group is actually a link to
/sys/kernel/iommu_groups/$n, where $n is the group number (there
will be a corresponding device node at /dev/vfio/$n once the
devices are bound to the vfio-pci driver)

The following functions are added:

virPCIDeviceGetIOMMUGroupList

  Gets a virPCIDeviceList with one virPCIDeviceList for each device
  in the same IOMMU group as the provided virPCIDevice (a copy of the
  original device object is included in the list.

virPCIDeviceAddressIOMMUGroupIterate

  Calls the function @actor once for each device in the group that
  contains the given virPCIDeviceAddress.

virPCIDeviceAddressGetIOMMUGroupAddresses

  Fills in a virPCIDeviceAddressPtr * with an array of
  virPCIDeviceAddress, one for each device in the iommu group of the
  provided virPCIDeviceAddress (including a copy of the original).

virPCIDeviceAddressGetIOMMUGroupNum

  Returns the group number as an int (a valid group number will always
  be 0 or greater).  If there is no iommu_group link in the device's
  directory (usually indicating that vfio isn't loaded), -2 will be
  returned. On any real error, -1 will be returned.

Make a copy of the device and add the copy to the
list. (virPCIDeviceListAdd() adds the original object to the list
instead).

This function has utility outside of virpci.c, so make it public.

Also the name didn't fit convention, so change it to
virPCIDeviceAddressParse.

I realized after the fact that it's probably better in the long run to
give this function a name that matches the name of the link used in
sysfs to hold the group (iommu_group).

I'm changing it now because I'm about to add several more functions
that deal with iommu groups.

This patch implements extensible variants of all internal migration APIs
used for v3 migration.