When either "cpuset" of <vcpu> is specified, or the "placement" of
<vcpu> is "auto", only setting the cpuset.mems might cause the guest
starting to fail. E.g. ("placement" of both <vcpu> and <numatune> is
"auto"):

1) Related XMLs
  <vcpu placement='auto'>4</vcpu>
  <numatune>
    <memory mode='strict' placement='auto'/>
  </numatune>

2) Host NUMA topology
  % numactl --hardware
  available: 8 nodes (0-7)
  node 0 cpus: 0 4 8 12 16 20 24 28
  node 0 size: 16374 MB
  node 0 free: 11899 MB
  node 1 cpus: 32 36 40 44 48 52 56 60
  node 1 size: 16384 MB
  node 1 free: 15318 MB
  node 2 cpus: 2 6 10 14 18 22 26 30
  node 2 size: 16384 MB
  node 2 free: 15766 MB
  node 3 cpus: 34 38 42 46 50 54 58 62
  node 3 size: 16384 MB
  node 3 free: 15347 MB
  node 4 cpus: 3 7 11 15 19 23 27 31
  node 4 size: 16384 MB
  node 4 free: 15041 MB
  node 5 cpus: 35 39 43 47 51 55 59 63
  node 5 size: 16384 MB
  node 5 free: 15202 MB
  node 6 cpus: 1 5 9 13 17 21 25 29
  node 6 size: 16384 MB
  node 6 free: 15197 MB
  node 7 cpus: 33 37 41 45 49 53 57 61
  node 7 size: 16368 MB
  node 7 free: 15669 MB

4) cpuset.cpus will be set as: (from debug log)

2013-05-09 16:50:17.296+0000: 417: debug : virCgroupSetValueStr:331 :
Set value '/sys/fs/cgroup/cpuset/libvirt/qemu/toy/cpuset.cpus'
to '0-63'

5) The advisory nodeset got from querying numad (from debug log)

2013-05-09 16:50:17.295+0000: 417: debug : qemuProcessStart:3614 :
Nodeset returned from numad: 1

6) cpuset.mems will be set as: (from debug log)

2013-05-09 16:50:17.296+0000: 417: debug : virCgroupSetValueStr:331 :
Set value '/sys/fs/cgroup/cpuset/libvirt/qemu/toy/cpuset.mems'
to '0-7'

I.E, the domain process's memory is restricted on the first NUMA node,
however, it can use all of the CPUs, which will likely cause the domain
process to fail to start because of the kernel fails to allocate
memory with the the memory policy as "strict".

% tail -n 20 /var/log/libvirt/qemu/toy.log
...
2013-05-09 05:53:32.972+0000: 7318: debug : virCommandHandshakeChild:377 :
Handshake with parent is done
char device redirected to /dev/pts/2 (label charserial0)
kvm_init_vcpu failed: Cannot allocate memory
...
Signed-off-by: NPeter Krempa <pkrempa@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.

When user does not specify any model for scsi controller, or worse, no
controller at all, but libvirt automatically adds scsi controller with
no model, we are not searching for virtio-scsi and thus this can fail
for example on qemu which doesn't support lsi logic adapter.

This means that when qemu on x86 doesn't support lsi53c895a and the
user adds the following to an XML without any scsi controller:

<disk ...>
  ...
  <target dev='sda'>
</disk>

libvirt fails like this:
 # virsh define asdf.xml
 error: Failed to define domain from asdf.xml
 error: internal error Unable to determine model for scsi controller

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=974943

Similarly to qemu driver, we can use a helper function to
lookup a domain instead of copying multiple lines around.

With the majority of fields in the virLXCDriverPtr struct
now immutable or self-locking, there is no need for practically
any methods to be using the LXC driver lock. Only a handful
of helper APIs now need it.

The activeUsbHostdevs item in LXCDriver are lockable, but the lock has
to be called explicitly. Call the virObject(Un)Lock() in order to
achieve mutual exclusion once lxcDriverLock is removed.

The 'driver->caps' pointer can be changed on the fly. Accessing
it currently requires the global driver lock. Isolate this
access in a single helper, so a future patch can relax the
locking constraints.

Annotate the fields in virLXCDriverPtr to indicate the locking
rules for their use.

Currently the virLXCDriverPtr struct contains an wide variety
of data with varying access needs. Move all the static config
data into a dedicated virLXCDriverConfigPtr object. The only
locking requirement is to hold the driver lock, while obtaining
an instance of virLXCDriverConfigPtr. Once a reference is held
on the config object, it can be used completely lockless since
it is immutable.

NB, not all APIs correctly hold the driver lock while getting
a reference to the config object in this patch. This is safe
for now since the config is never updated on the fly. Later
patches will address this fully.

It is not used anywhere, so it makes no sense to have it there.

If testQemuHotplugAttach succeeds, the vm->def steals the dev pointer.
However, not the envelope, which needs to be freed. In addition,
driver.config is allocated, but never freed.

Moreover, since virAsprintf now does report OOM error, there's no need
to call virReportOOMError in error path.

When virAsprintf was changed from a function to a macro
reporting OOM error in dc6f2dad, it was documented as returning
0 on success. This is incorrect, it returns the number of bytes
written as asprintf does.

Some of the functions were converted to use virAsprintf's return
value directly, changing the return value on success from 0 to >= 0.

For most of these, this is not a problem, but the change in
virPCIDriverDir breaks PCI passthrough.

The return value check in virhashtest pre-dates virAsprintf OOM
conversion.

vmwareMakePath seems to be unused.

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>

Add a "--pass-fds N,M,..." arg to the virsh start/create
methods. This allows pre-opened file descriptors from the
shell to be passed on into the guest
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Wire up the new virDomainCreate{XML}WithFiles methods in the
LXC driver, so that FDs get passed down to the init process.

The lxc_container code needs to do a little dance in order
to renumber the file descriptors it receives into linear
order, starting from STDERR_FILENO + 1.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

In the following commit:

  commit 03d813bb
  Author: Marek Marczykowski <marmarek@invisiblethingslab.com>
  Date:   Thu May 23 02:01:30 2013 +0200

    remote: fix dom->id after virDomainCreateWithFlags

The virDomainCreateWithFlags remote client helper was made to
invoke REMOTE_PROC_DOMAIN_LOOKUP_BY_UUID to refresh the 'id'
of the domain, following the pattern used in the previous
virDomainCreate method impl.

The remote protocol for virDomainCreateWithFlags though did
actually fix the design flaw in virDomainCreate, by directly
returning the new domain info. For some reason, this data was
never used. So we can just use that data now instead.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Since they make use of file descriptor passing, the remote protocol
methods for virDomainCreate{XML}WithFiles must be written by hand.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

With container based virt, it is useful to be able to pass
pre-opened file descriptors to the container init process.
This allows for containers to be auto-activated from incoming
socket connections, passing the active socket into the container.

To do this, introduce a pair of new APIs, virDomainCreateXMLWithFiles
and virDomainCreateWithFiles, which accept an array of file
descriptors. For the LXC driver, UNIX file descriptor passing
will be used to send them to libvirtd, which will them pass
them down to libvirt_lxc, which will then pass them to the container
init process.

This will only be implemented for LXC right now, but the design
is generic enough it could work with other hypervisors, hence
I suggest adding this to libvirt.so, rather than libvirt-lxc.so
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The .ctags file specifies default options for ctags so that it does not
ignore libvirt.h.in and ignores uninteresting files. As a result, you
can just run "ctags" and navigating to a public API won't get you to a
useless entry in api.html.

Add support for creating disk-only (no memory) snapshots in esx, and
for quiescing the VM before taking the snapshot. The VMware API
supports these operations directly, so adding support to libvirt is
just a matter of setting the flags correctly when calling
VMware. VIR_DOMAIN_SNAPSHOT_CREATE_DISK_ONLY and
VIR_DOMAIN_SNAPSHOT_CREATE_QUIESCE are now valid flags for esx.
Signed-off-by: NEric Blake <eblake@redhat.com>

Although, having it depending on Xen >= 4.3 (by using the proper
libxl feature flag).

Xen currently implements a NUMA placement policy which is basically
the same as the 'interleaved' policy of `numactl', although it can
be applied on a subset of the available nodes. We therefore hardcode
"interleave" as 'numa_mode', and we use the newly introduced libxl
interface to figure out what nodes a domain spans ('numa_nodeset').

With this change, it is now possible to query the NUMA node
affinity of a running domain:

[raistlin@Zhaman ~]$ sudo virsh --connect xen:/// list
 Id    Name                           State
----------------------------------------------------
 23    F18_x64                        running

[raistlin@Zhaman ~]$ sudo virsh --connect xen:/// numatune 23
numa_mode      : interleave
numa_nodeset   : 1
Signed-off-by: NDario Faggioli <dario.faggioli@citrix.com>

domainGetNumaParameters has a string typed parameter, hence it
is necessary for the libxl driver to support this.

This change implements the connectSupportsFeature hook for the
libxl driver, advertising that VIR_DRV_FEATURE_TYPED_PARAM_STRING
is supported.
Signed-off-by: NDario Faggioli <dario.faggioli@citrix.com>
Cc: Eric Blake <eblake@redhat.com>

Xen 4.3 changes sysctl version to 10 and domctl version to 9. Update
the hypervisor driver to work with those.
Signed-off-by: NStefan Bader <stefan.bader@canonical.com>

Commit 75c12564 states that virGetGroupList must not be called
between fork and exec, then commit ee777e99 promptly violated
that for lxc.

Patch originally posted by Eric Blake <eblake@redhat.com>.

Reuse the buffer for getline and track buffer allocation
separately from the string length to prevent unlikely
out-of-bounds memory access.

This fixes the following leak that happened when zero bytes were read:

==404== 120 bytes in 1 blocks are definitely lost in loss record 1,344 of 1,671
==404==    at 0x4C2C71B: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==404==    by 0x906F862: getdelim (iogetdelim.c:68)
==404==    by 0x52A48FB: virCgroupPartitionNeedsEscaping (vircgroup.c:1136)
==404==    by 0x52A0FB4: virCgroupPartitionEscape (vircgroup.c:1171)
==404==    by 0x52A0EA4: virCgroupNewDomainPartition (vircgroup.c:1450)

In all qemu APIs we tend to prefer qemuDomObjFromDomain over
virDomainObjListFindByUUID. But somehow the
qemuDomainGetSchedulerType left unattended.

While generating seclabels, we check the seclabel stack if required
driver is in the stack. If not, an error is returned. However, it is
possible for a seclabel to not have any model set (happens with LXC
domains that have just <seclabel type='none'>). If that's the case,
we should just skip the iteration instead of calling STREQ(NULL, ...)
and SIGSEGV-ing subsequently.

Currently, if the primary security driver is 'none', we skip
initializing caps->host.secModels. This means, later, when LXC domain
XML is parsed and <seclabel type='none'/> is found (see
virSecurityLabelDefsParseXML), the model name is not copied to the
seclabel. This leads to subsequent crash in virSecurityManagerGenLabel
where we call STREQ() over the model (note, that we are expecting model
to be !NULL).