It doesn't make sense to reattach a device to host while it's
still in use, e.g, by a domain.

pciTrySecondaryBusReset checks if there is active device on the
same bus, however, qemu driver doesn't maintain an effective
list for the inactive devices, and it passes meaningless argument
for parameter "inactiveDevs". e.g. (qemuPrepareHostdevPCIDevices)

if (!(pcidevs = qemuGetPciHostDeviceList(hostdevs, nhostdevs)))
    return -1;

..skipped...

if (pciResetDevice(dev, driver->activePciHostdevs, pcidevs) < 0)
    goto reattachdevs;

NB, the "pcidevs" used above are extracted from domain def, and
thus one won't be able to attach a device of which bus has other
device even detached from host (nodedev-detach). To see more
details of the problem:

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=773667

This patch is to resolve the problem by introducing an inactive
PCI device list (just like qemu_driver->activePciHostdevs), and
the whole logic is:

  * Add the device to inactive list during nodedev-dettach
  * Remove the device from inactive list during nodedev-reattach
  * Remove the device from inactive list during attach-device
    (for non-managed device)
  * Add the device to inactive list after detach-device, only
    if the device is not managed

With the above, we have a sufficient inactive PCI device list, and thus
we can use it for pciResetDevice. e.g.(qemuPrepareHostdevPCIDevices)

if (pciResetDevice(dev, driver->activePciHostdevs,
                   driver->inactivePciHostdevs) < 0)
    goto reattachdevs;

This introduces new attribute wrpolicy with only supported
value as immediate. This will be an optional
attribute with no defaults. This helps specify whether
to skip the host page cache.

When wrpolicy is specified, meaning when wrpolicy=immediate
a writeback is explicitly initiated for the dirty pages in
the host page cache as part of the guest file write operation.

Usage:
<filesystem type='mount' accessmode='passthrough'>
  <driver type='path' wrpolicy='immediate'/>
  <source dir='/export/to/guest'/>
  <target dir='mount_tag'/>
</filesystem>

Currently this only works with type='mount' for the QEMU/KVM driver.
Signed-off-by: NDeepak C Shetty <deepakcs@linux.vnet.ibm.com>

In the past we didn't reserve 0:0:2.0 PCI address if there was no video
device assigned to a domain, which made it impossible to add a video
device later on. So we fixed it (commit v0.9.0-37-g7b2cac12) by always
reserving that address. However, that breaks existing domains without
video devices that already have another device assigned to the
problematic address.

This patch reserves address 0:0:2.0 only in case it was not explicitly
assigned to another device, which means libvirt will try to keep this
address free and will not automatically assign it new devices. But
existing domains for which older libvirt already assigned the address to
a non-video device will keep working as they used to work before 0.9.1.
Moreover, users who want to create a domain without a video device and
use its address for another device may do so by explicitly configuring
the PCI address in domain XML.

The output of dumpxml for <iotune> settings was misformatted, this
patch just adds missing newlines.

This adds support for host-model and host-passthrough CPU modes to qemu
driver. The host-passthrough mode is mapped to -cpu host.

There are several reasons for doing this:

- the CPU specification is out of libvirt's control so we cannot
  guarantee stable guest ABI
- not every feature of a CPU may actually work as expected when
  advertised directly to a guest
- migration between two machines with exactly the same CPU may work but
  no guarantees can be made
- this mode is not supported and its use is at one's own risk

VIR_DOMAIN_XML_UPDATE_CPU flag for virDomainGetXMLDesc may be used to
get updated custom mode guest CPU definition in case it depends on host
CPU. This patch implements the same behavior for host-model and
host-passthrough CPU modes.

The mode can be either of "custom" (default), "host-model",
"host-passthrough". The semantics of each mode is described in the
following examples:

- guest CPU is a default model with specified topology:
    <cpu>
      <topology sockets='1' cores='2' threads='1'/>
    </cpu>

- guest CPU matches selected model:
    <cpu mode='custom' match='exact'>
      <model>core2duo</model>
    </cpu>

- guest CPU should be a copy of host CPU as advertised by capabilities
  XML (this is a short cut for manually copying host CPU specification
  from capabilities to domain XML):
    <cpu mode='host-model'/>

  In case a hypervisor does not support the exact host model, libvirt
  automatically falls back to a closest supported CPU model and
  removes/adds features to match host. This behavior can be disabled by
    <cpu mode='host-model'>
      <model fallback='forbid'/>
    </cpu>

- the same as previous returned by virDomainGetXMLDesc with
  VIR_DOMAIN_XML_UPDATE_CPU flag:
    <cpu mode='host-model' match='exact'>
      <model fallback='allow'>Penryn</model>       --+
      <vendor>Intel</vendor>                         |
      <topology sockets='2' cores='4' threads='1'/>  + copied from
      <feature policy='require' name='dca'/>         | capabilities XML
      <feature policy='require' name='xtpr'/>        |
      ...                                          --+
    </cpu>

- guest CPU should be exactly the same as host CPU even in the aspects
  libvirt doesn't model (such domain cannot be migrated unless both
  hosts contain exactly the same CPUs):
    <cpu mode='host-passthrough'/>

- the same as previous returned by virDomainGetXMLDesc with
  VIR_DOMAIN_XML_UPDATE_CPU flag:
    <cpu mode='host-passthrough' match='minimal'>
      <model>Penryn</model>                        --+ copied from caps
      <vendor>Intel</vendor>                         | XML but doesn't
      <topology sockets='2' cores='4' threads='1'/>  | describe all
      <feature policy='require' name='dca'/>         | aspects of the
      <feature policy='require' name='xtpr'/>        | actual guest CPU
      ...                                          --+
    </cpu>

In case a hypervisor doesn't support the exact CPU model requested by a
domain XML, we automatically fallback to a closest CPU model the
hypervisor supports (and make sure we add/remove any additional features
if needed). This patch adds 'fallback' attribute to model element, which
can be used to disable this automatic fallback.

Commit 5d784bd6 was a nice attempt to
clarify the semantics by requiring domain name from dxml to either match
original name or dname. However, setting dxml domain name to dname
doesn't really work since destination host needs to know the original
domain name to be able to use it in migration cookies. This patch
requires domain name in dxml to match the original domain name. The
change should be safe and backward compatible since migration would fail
just a bit later in the process.

There are three address validation routines that do nothing:
  virDomainDeviceDriveAddressIsValid()
  virDomainDeviceUSBAddressIsValid()
  virDomainDeviceVirtioSerialAddressIsValid()

Remove them, and replace their call sites with "1" which is what they
currently return. In some cases this means we can remove an entire
if block.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>

We can't call qemuCapsExtractVersionInfo() from test code, because it
expects to be able to call the emulator, and for testing we have fake
emulators that can't be executed. For that reason qemuxml2argvtest.c
doesn't call qemuDomainAssignPCIAddresses(), instead it open codes its
own version.

That means we can't call qemuDomainAssignAddresses() from the test code,
instead we need to manually call qemuDomainAssignSpaprVioAddresses().

Also add logic to cope with qemuDomainAssignSpaprVioAddresses() failing,
so that we can write a test that checks for a known failure in there.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>

Adding a new model for virtio-scsi roughly follows the same scheme
as the previous patch.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

KVM will be able to use a PCI SCSI controller even on POWER.  Let
the user specify the vSCSI controller by other means than a default.

After this patch, the QEMU driver will actually look at the model
and reject anything but auto, lsilogic and ibmvscsi.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Commit d09f6ba5 introduced a regression in event
registration.  virDomainEventCallbackListAddID() will only return a positive
integer if the type of event being registered is VIR_DOMAIN_EVENT_ID_LIFECYCLE.
For other event types, 0 is always returned on success.  This has the
unfortunate side effect of not enabling remote event callbacks because
remoteDomainEventRegisterAny() uses the return value from the local call to
determine if an event callback needs to be registered on the remote end.

Make sure virDomainEventCallbackListAddID() returns the callback count for the
eventID being registered.
Signed-off-by: NAdam Litke <agl@us.ibm.com>

This avoids a linking error.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The new introduced optional attribute "copy_on_read</code> controls
whether to copy read backing file into the image file. The value can
be either "on" or "off". Copy-on-read avoids accessing the same backing
file sectors repeatedly and is useful when the backing file is over a
slow network. By default copy-on-read is off.

Earlier, when the number of vcpus was greater than the topology allowed,
libvirt didn't raise an error and continued, resulting in running qemu
with parameters making no sense. Even though qemu did not report any
error itself, the number of vcpus was set to maximum allowed by the
topology.

Detected by Coverity.  Although unlikely, if we are ever started
with stdin closed, we could reach a situation where we open a
uuid file but then fail to close it, making that file the new
stdin for the rest of the process.

* src/util/uuid.c (getDMISystemUUID): Allow for stdin.

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

If client stream does not have any data to sink and neither received
EOF, a dummy packet is sent to the daemon signalising client is ready to
sink some data. However, after we added event loop to client a race may
occur:

Thread 1 calls virNetClientStreamRecvPacket and since no data are cached
nor stream has EOF, it decides to send dummy packet to server which will
sent some data in turn. However, during this decision and actual message
exchange with server -

Thread 2 receives last stream data from server. Therefore an EOF is set
on stream and if there is a call waiting (which is not yet) it is woken
up. However, Thread 1 haven't sent anything so far, so there is no call
to be woken up. So this thread sent dummy packet to daemon, which
ignores that as no stream is associated with such packet and therefore
no reply will ever come.

This race causes client to hang indefinitely.

QEMU does not support security_model for anything but 'path' fs driver type.
Currently in libvirt, when security_model ( accessmode attribute) is not
specified it auto-generates it irrespective of the fs driver type, which
can result in a qemu error for drivers other than path. This patch ensures
that the qemu cmdline is correctly generated by taking into account the
fs driver type.
Signed-off-by: NDeepak C Shetty <deepakcs@linux.vnet.ibm.com>

The above option helps to differentiate between implicit and explicit
interface pools.

If a system has 64 or more VF's, it is quite tedious to mention each VF
in the interface pool.
The following modification will implicitly create an interface pool from
the SR-IOV PF.

This element will help the user to just specify the SR-IOV physical
function in order to access all the Virtual functions attached to it.

This functions enables us to get the Virtual Functions attached to
a Physical function given the name of a SR-IOV physical functio.

In order to accomplish the task, added a getter function pciGetDeviceAddrString
to get the BDF of the Virtual Function in a char array.

The autobuilder pointed out an odd failure on mingw:
../../src/interface/netcf_driver.c:644:5: error: unknown field 'close_used_without_including_unistd_h' specified in initializer
cc1: warnings being treated as errors

This is because the gnulib headers #define close to different strings,
according to which headers are included, in order to work around some
odd mingw problems with close(), and these defines happen to also
affect field members declared with a name of struct foo.close. As long
as all headers are included before both the definition and use of the
struct, the various #define doesn't matter, but the netcf file hit
an instance where things were included in a different order.  Fix this
for all clients that use a struct member named 'close'.

* src/driver.h: Include <unistd.h> before using 'close'.

For some weird reason, i686-pc-mingw32-gcc version 4.6.1 at -O2 complained:
../../src/conf/nwfilter_params.c: In function 'virNWFilterVarCombIterCreate':
../../src/conf/nwfilter_params.c:346:23: error: 'minValue' may be used uninitialized in this function [-Werror=uninitialized]
../../src/conf/nwfilter_params.c:319:28: note: 'minValue' was declared here
../../src/conf/nwfilter_params.c:344:23: error: 'maxValue' may be used uninitialized in this function [-Werror=uninitialized]
../../src/conf/nwfilter_params.c:319:18: note: 'maxValue' was declared here
cc1: all warnings being treated as errors

even though all paths of the preceding switch statement either
assign the variables or return.

* src/conf/nwfilter_params.c (virNWFilterVarCombIterAddVariable):
Initialize variables.

Address side effect of accessing a variable via an index: Filters
accessing a variable where an element is accessed that is beyond the
size of the list (for example $TEST[10] and only 2 elements are available)
cannot instantiate that filter. Test for this and report proper error
to user.

This patch adds access to single elements of variables via index. Example:

  <rule action='accept' direction='in' priority='500'>
    <tcp srcipaddr='$ADDR[1]' srcportstart='$B[2]'/>
  </rule>

This patch introduces the capability to use a different iterator per
variable.

The currently supported notation of variables in a filtering rule like

  <rule action='accept' direction='out'>
     <tcp  srcipaddr='$A' srcportstart='$B'/>
  </rule>

processes the two lists 'A' and 'B' in parallel. This means that A and B
must have the same number of 'N' elements and that 'N' rules will be 
instantiated (assuming all tuples from A and B are unique).

In this patch we now introduce the assignment of variables to different
iterators. Therefore a rule like

  <rule action='accept' direction='out'>
     <tcp  srcipaddr='$A[@1]' srcportstart='$B[@2]'/>
  </rule>

will now create every combination of elements in A with elements in B since
A has been assigned to an iterator with Id '1' and B has been assigned to an
iterator with Id '2', thus processing their value independently.

The first rule has an equivalent notation of

  <rule action='accept' direction='out'>
     <tcp  srcipaddr='$A[@0]' srcportstart='$B[@0]'/>
  </rule>

In this patch we introduce testing whether the iterator points to a
unique set of entries that have not been seen before at one of the previous
iterations. The point is to eliminate duplicates and with that unnecessary
filtering rules by preventing identical filtering rules from being
instantiated.
Example with two lists:

list1 = [1,2,1]
list2 = [1,3,1]

The 1st iteration would take the 1st items of each list -> 1,1
The 2nd iteration would take the 2nd items of each list -> 2,3
The 3rd iteration would take the 3rd items of each list -> 1,1 but
skip them since this same pair has already been encountered in the 1st
iteration

Implementation-wise this is solved by taking the n-th element of list1 and
comparing it against elements 1..n-1. If no equivalent is found, then there
is no possibility of this being a duplicate. In case an equivalent element
is found at position i, then the n-th element in the 2nd list is compared
against the i-th element in the 2nd list and if that is not the same, then
this is a unique pair, otherwise it is not unique and we may need to do
the same comparison on the 3rd list.

When sVirt is integrated with the LXC driver, it will be neccessary
to invoke the security driver APIs using only a virDomainDefPtr
since the lxc_container.c code has no virDomainObjPtr available.
Aside from two functions which want obj->pid, every bit of the
security driver code only touches obj->def. So we don't need to
pass a virDomainObjPtr into the security drivers, a virDomainDefPtr
is sufficient. Two functions also gain a 'pid_t pid' argument.

* src/qemu/qemu_driver.c, src/qemu/qemu_hotplug.c,
  src/qemu/qemu_migration.c, src/qemu/qemu_process.c,
  src/security/security_apparmor.c,
  src/security/security_dac.c,
  src/security/security_driver.h,
  src/security/security_manager.c,
  src/security/security_manager.h,
  src/security/security_nop.c,
  src/security/security_selinux.c,
  src/security/security_stack.c: Change all security APIs to use a
  virDomainDefPtr instead of virDomainObjPtr

When disk snapshots were first implemented, libvirt blindly refused
to allow an external snapshot destination that already exists, since
qemu will blindly overwrite the contents of that file during the
snapshot_blkdev monitor command, and we don't like a default of
data loss by default.  But VDSM has a scenario where NFS permissions
are intentionally set so that the destination file can only be
created by the management machine, and not the machine where the
guest is running, so that libvirt will necessarily see the destination
file already existing; adding a flag will allow VDSM to force the file
reuse without libvirt complaining of possible data loss.

https://bugzilla.redhat.com/show_bug.cgi?id=767104

* include/libvirt/libvirt.h.in (virDomainSnapshotCreateFlags): Add
VIR_DOMAIN_SNAPSHOT_CREATE_REUSE_EXT.
* src/libvirt.c (virDomainSnapshotCreateXML): Document it.  Add
note about partial failure.
* tools/virsh.c (cmdSnapshotCreate, cmdSnapshotCreateAs): Add new
flag.
* tools/virsh.pod (snapshot-create, snapshot-create-as): Document
it.
* src/qemu/qemu_driver.c (qemuDomainSnapshotDiskPrepare)
(qemuDomainSnapshotCreateXML): Implement the new flag.

We had loads of different styles in describing the @flags parameter
for various APIs, as well as several APIs that didn't list which
enums provided the bit values valid for the flags.

The end result is one of two formats:
@flags: bitwise-OR of vir...Flags
@flags: extra flags; not used yet, so callers should always pass 0

* src/libvirt.c: Use common sentences for flags.  Also,
(virDomainGetBlockIoTune): Mention virTypedParameterFlags.
(virConnectOpenAuth): Mention virConnectFlags.
(virDomainMigrate, virDomainMigrate2, virDomainMigrateToURI)
(virDomainMigrateToURI2): Mention virDomainMigrateFlags.
(virDomainMemoryPeek): Mention virDomainMemoryFlags.
(virStoragePoolBuild): Mention virStoragePoolBuildFlags.
(virStoragePoolDelete): Mention virStoragePoolDeleteFlags.
(virStreamNew): Mention virStreamFlags.
(virDomainOpenGraphics): Mention virDomainOpenGraphicsFlags.

This *kind of* addresses:

  https://bugzilla.redhat.com/show_bug.cgi?id=772395

(it doesn't eliminate the failure to start, but causes libvirt to give
a better idea about the cause of the failure).

If a guest uses a kvm emulator (e.g. /usr/bin/qemu-kvm) and the guest
is started when kvm isn't available (either because virtualization is
unavailable / has been disabled in the BIOS, or the kvm modules
haven't been loaded for some reason), a semi-cryptic error message is
logged:

  libvirtError: internal error Child process (LC_ALL=C
  PATH=/sbin:/usr/sbin:/bin:/usr/bin /usr/bin/qemu-kvm -device ? -device
  pci-assign,? -device virtio-blk-pci,? -device virtio-net-pci,?) status
  unexpected: exit status 1

This patch notices at process start that a guest needs kvm, and checks
for the presence of /dev/kvm (a reasonable indicator that kvm is
available) before trying to execute the qemu binary. If kvm isn't
available, a more useful (too verbose??) error is logged.