Attempt to turn on vhost-net mode for devices of type NETWORK, BRIDGE,
and DIRECT (macvtap).

* src/qemu/qemu_conf.h: add vhostfd to qemuBuildHostNetStr prototype
  add qemudOpenVhostNet prototype new flag to set when :,vhost=" found in
  qemu help
* src/qemu/qemu_conf.c: * set QEMUD_CMD_FLAG_VNET_HOST is ",vhost=" found
  in qemu help
   - qemudOpenVhostNet - opens /dev/vhost-net to pass to qemu if everything
     is in place to use it.
   - qemuBuildHostNetStr - add vhostfd to commandline if it's not empty
     (higher levels decide whether or not to fill it in)
   - qemudBuildCommandLine - if /dev/vhost-net is successfully opened, add
     its fd to tapfds array so it isn't closed on qemu exec, and populate
     vhostfd_name to be passed in to commandline builder.
* src/qemu/qemu_driver.c: add filler 0 for new arg to qemuBuildHostNetStr,
  along with a note that this must be implemented in order for hot-plug of
  vhost-net virtio devices to work properly (once qemu "netdev_add" monitor
  command is implemented).

The logfile FD is dup2'ed in __virExec in the child. The FD needs to
be closed in the parent, otherwise it leaks.

Currently no command can be sent to a qemu process while another job is
active. This patch adds support for signaling long-running jobs (such as
migration) so that other threads may request predefined operations to be
done during such jobs. Two signals are defined so far:
    - QEMU_JOB_SIGNAL_CANCEL
    - QEMU_JOB_SIGNAL_SUSPEND

The first one is used by qemuDomainAbortJob.

The second one is used by qemudDomainSuspend for suspending a domain
during migration, which allows for changing live migration into offline
migration. However, there is a small issue in the way qemudDomainSuspend
is currently implemented for migrating domains. The API calls returns
immediately after signaling migration job which means it is asynchronous
in this specific case.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

* src/qemu/qemu_driver.c (qemudDomainAttachSCSIDisk): The ".controller"
member is an index, and *may* be 0.  As such, the commit that we're
reverting broke SCSI disk hot-plug on controller 0.
Reported by Wolfgang Mauerer.

We need to call PrepareHostdevs to determine the USB device path before
any security calls. PrepareHostUSBDevices was also incorrectly skipping
all USB devices.

Currently if you dump the core of a qemu guest with
qemudDomainCoreDump, subsequent commands will hang
up libvirtd.  This is because qemudDomainCoreDump
uses qemuDomainWaitForMigrationComplete, which expects
the qemuDriverLock to be held when it's called.  This
patch does the simple thing and moves the qemuDriveUnlock
to the end of the qemudDomainCoreDump so that the driver
lock is held for the entirety of the call (as it is done
in qemudDomainSave).  We will probably want to make the
lock more fine-grained than that in the future, but
we can fix both qemudDomainCoreDump and qemudDomainSave
at the same time.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

The code to add job support into libvirtd caused a problem
in qemudDomainSetVcpus.  In particular, a qemuDomainObjEndJob()
call was added at the end of the function, but a
corresponding qemuDomainObjBeginJob() was not.  Additionally,
a call to qemuDomainObj{Enter,Exit}Monitor() was also missed
in qemudDomainHotplugVcpus().  These missing calls conspired to
cause a hang in the libvirtd process after the command was
finished.  Fix this by adding the missing calls.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

As previously discussed[1], this patch removes the
qemudDomainSetMaxMemory() function, since it doesn't
work.  This means that instead of getting somewhat
cryptic errors, you will now get:

error: Unable to change MaxMemorySize
error: this function is not supported by the hypervisor: virDomainSetMaxMemory

Which describes the situation perfectly.

[1] https://www.redhat.com/archives/libvir-list/2010-February/msg00928.htmlSigned-off-by: NChris Lalancette <clalance@redhat.com>

* global: patch created by running:
for f in $(git ls-files '*.[ch]') ; do
    cppi $f > $f.t && mv $f.t $f
done

When adding domainMemoryStats API support for the qemu driver, I didn't
follow the locking rules exactly.  The job condition must be held when
executing monitor commands.  This corrects the segfaults I was seeing
when calling domainMemoryStats in a multi-threaded environment.

* src/qemu/qemu_driver.c: in qemudDomainMemoryStats() add missing
  calls to qemuDomainObjBeginJob/qemuDomainObjEndJob

doTunnelSendAll function (used by QEMU migration) uses a 64k buffer on
the stack, which could be problematic. This patch replaces that with a
buffer from the heap.

While in the neighborhood, this patch also improves error reporting in
the case that saferead fails - previously, virStreamAbort() was called
(resetting errno) before reporting the error. It's been changed to
report the error first.

* src/qemu/qemu_driver.c: fix doTunnelSendAll() to use a malloc'ed
  buffer

* src/qemu/qemu_driver.c (qemudDomainAttachSCSIDisk): Handle
the (theoretical) case of an empty controller list, so that
clang does not think the subsequent dereference of "cont"
would dereference an undefined variable (due to preceding
loop not iterating even once).

* src/qemu/qemu_driver.c (qemudDomainRestore): A corrupt save file
(in particular, a too-large header.xml_len value) would cause an
unwarranted out-of-memory error.  Do not trust the just-read
header.xml_len.  Instead, merely use that as a hint, and
read/allocate up to that number of bytes from the file.
Also verify that header.xml_len is positive; if it were negative,
passing it to virFileReadLimFD could cause trouble.

Changeset

  commit 5073aa99
  Author: Cole Robinson <crobinso@redhat.com>
  Date:   Mon Jan 11 11:40:46 2010 -0500

Added support for product/vendor based passthrough, but it only
worked at the security driver layer. The main guest XML config
was not updated with the resolved bus/device ID. When the QEMU
argv refactoring removed use of product/vendor, this then broke
launching guests.

THe solution is to move the product/vendor resolution up a layer
into the QEMU driver. So the first thing QEMU does is resolve
the product/vendor to a bus/device and updates the XML config
with this info. The rest of the code, including security drivers
and QEMU argv generated can now rely on bus/device always being
set.

* src/util/hostusb.c, src/util/hostusb.h: Split vendor/product
  resolution code out of usbGetDevice and into usbFindDevice.
  Add accessors for bus/device ID
* src/security/virt-aa-helper.c, src/security/security_selinux.c,
  src/qemu/qemu_security_dac.c: Remove vendor/product from the
  usbGetDevice() calls
* src/qemu/qemu_driver.c: Use usbFindDevice to resolve vendor/product
  into a bus/device ID

The pci_del command is not being ported to QMP. Convert all the
QEMU hotplug code over to use device_del whenever it is available
to avoid the pci_del problem

* src/qemu/qemu_driver.c: Convert unplug code to device_del

Previously hot-unplug could not be supported for USB devices
in QEMU, since usb_del required the guest visible address
which libvirt never knows. With 'device_del' command we can
now unplug based on device alias, so support that.

* src/qemu/qemu_driver.c: Use device_del to remove USB devices

QEMU has a monitor command 'set_cpu' which allows a specific
CPU to be toggled between online& offline state. libvirt CPU
hotplug does not work in terms of individual indexes CPUs.
Thus to support this, we iteratively toggle the online state
when the total number of vCPUs is adjusted via libvirt

NB, currently untested since QEMU segvs when running this!

* src/qemu/qemu_driver.c: Toggle online state for CPUs when
  doing hotplug
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h,
  src/qemu/qemu_monitor_text.c, src/qemu/qemu_monitor_text.h: Add
  monitor API for toggling a CPU's online status via 'set_cpu

The code to remove the cgroup after QEMU failed to startup could
be obscuring a real error from earlier on. It is not neccessary
to raise an error in this case, so tell cgroups to keep quiet

* src/qemu/qemu_driver.c: Don't raise cgroups error in QEMU start
  cleanup code.

The QEMU hotunplug code for PCI devices was looking at host
devices in the guest config without first filtering non
PCI devices. This means it was reading garbage

* src/qemu/qemu_driver.c: Filter out non-PCI devices

Commit 3c12a67b added
a dependency on the NFS_SUPER_MAGIC macro, which is
defined in linux/magic.h.  Unfortunately linux/magic.h
is not available in RHEL-5, and causes a compile error.
Just define it locally, since this is something that
can't change.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

Move *all* file operations related to creation and writing of libvirt
header to the domain save file into a hook function that is called by
virFileOperation. First try to call virFileOperation as root. If that
fails with EACCESS, and (in the case of Linux) statfs says that we're
trying to save the file on an NFS share, rerun virFileOperation,
telling it to fork a child process and setuid to the qemu user. This
is the only way we can successfully create a file on a root-squashed
NFS server.

This patch (along with setting dynamic_ownership=0 in qemu.conf)
makes qemudDomainSave work on root-squashed NFS.

* src/qemu/qemu_driver.c: provide new qemudDomainSaveFileOpHook()
  utility, use it in qemudDomainSave() if normal creation of the
  file as root failed, and after checking the filesystem type for
  the storage is NFS. In that case we also bypass the security
  driver, as this would fail on NFS.

If qemudDomainRestore fails to open the domain save file, create a
pipe, then fork a process that does setuid(qemu_user) and opens the
file, then reads this file and stuffs it into the pipe. the parent
libvirtd process will use the other end of the pipe as its fd, then
reap the child process after it's done reading.

This makes domain restore work on a root-squash NFS share that is only
visible to the qemu user.

* src/qemu/qemu_driver.c: add new qemudOpenAsUID() helper function,
  and use it in qemudDomainRestore() if reading as root directly failed.

The USB/PCI device hotplug code for the QEMU driver was forgetting
to allocate a unique device alias.

* src/qemu/qemu_driver.c: Fill in device alias for USB/PCI devices

When a VM save attempt failed, the VM would be left in a paused
state. It is neccessary to resume CPU execution upon failure
if it was running originally

* src/qemu/qemu_driver.c: Resume CPUs upon save failure

This supports cancellation of jobs for the QEMU driver against
the virDomainMigrate, virDomainSave and virDomainCoreDump APIs.
It is not yet supported for the virDomainRestore API, although
it is desirable.

* src/qemu/qemu_driver.c: Issue 'migrate_cancel' command if
  virDomainAbortJob is issued during a migration operation
* tools/virsh.c: Add a domjobabort command

This provides the internal glue for the driver API

* src/driver.h: Internal API contract
* src/libvirt.c, src/libvirt_public.syms: Connect public API
  to driver API
* src/esx/esx_driver.c, src/lxc/lxc_driver.c, src/opennebula/one_driver.c,
  src/openvz/openvz_driver.c, src/phyp/phyp_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: Stub out entry points

Introduce support for  virDomainGetJobInfo in the QEMU driver. This
allows for monitoring of any API that uses the 'info migrate' monitor
command. ie virDomainMigrate, virDomainSave and virDomainCoreDump

Unfortunately QEMU does not provide a way to monitor incoming migration
so we can't wire up virDomainRestore yet.

The virsh tool gets a new command 'domjobinfo' to query status

* src/qemu/qemu_driver.c: Record virDomainJobInfo and start time
  in qemuDomainObjPrivatePtr objects. Add generic shared handler
  for calling 'info migrate' with all migration based APIs.
* src/qemu/qemu_monitor_text.c: Fix parsing of 'info migration' reply
* tools/virsh.c: add new 'domjobinfo' command to query progress

The internal glue layer for the new pubic API

* src/driver.h: Define internal driver API contract
* src/libvirt.c, src/libvirt_public.syms: Wire up public
  API to internal driver API
* src/esx/esx_driver.c, src/lxc/lxc_driver.c, src/opennebula/one_driver.c,
  src/openvz/openvz_driver.c, src/phyp/phyp_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: Stub new entry point

The USB hotplug method was mistakenly generating a PCI address
string

* src/qemu/qemu_driver.c: Fix USB hotplug device string

when the underlying qemu supports the drive/device model and the
controller has been added this way.
* src/qemu/qemu_driver.c: use qemuMonitorDelDevice() when detaching
  PCI controller and if supported
* src/qemu/qemu_monitor.[ch]: add new qemuMonitorDelDevice() function
* src/qemu/qemu_monitor_json.[ch]: JSON backend for DelDevice command
* src/qemu/qemu_monitor_text.[ch]: Text backend for DelDevice command

* src/qemu/qemu_driver.c: in qemudDomainDetachPciControllerDevice()
  when a controller is not present in the system anymore, the PCI
  address must be deleted from libvirt's hashtable because it can
  be re-used for other purposes.

* src/qemu/qemu_driver.c: in qemudDomainAttachDevice(), one must not
  delete the data part when the operation succeeds because it is
  required later on. The correct pattern to handlethe parsed
  representation of the device information on success
  is dev->data.controller = NULL; virDomainDeviceDefFree(dev);,
  which leaves the structure pointed at by data in memory.

If the hostname as returned by "gethostname" resolves
to "localhost" (as it does with the broken Fedora-12
installer), then live migration will fail because the
source will try to migrate to itself.  Detect this
situation up-front and abort the live migration before
we do any real work.

* src/util/util.h src/util/util.c: add a new virGetHostnameLocalhost
  with an optional localhost check, and rewire virGetHostname() to use
  it
* src/libvirt_private.syms: expose the new function
* src/qemu/qemu_driver.c: use it in qemudDomainMigratePrepare2()

This patch adds the mac_filter support to the macvtap device.

This patch sets or unsets the IFF_VNET_HDR flag depending on what device
is used in the VM. The manipulation of the flag is done in the open
function and is only fatal if the IFF_VNET_HDR flag could not be cleared
although it has to be (or if an ioctl generally fails). In that case the
macvtap tap is closed again and the macvtap interface torn.

* src/qemu/qemu_conf.c src/qemu/qemu_conf.h: pass qemuCmdFlags to
  qemudPhysIfaceConnect()
* src/util/macvtap.c src/util/macvtap.h: add vnet_hdr boolean to
  openMacvtapTap(), and private function configMacvtapTap()
* src/qemu/qemu_driver.c: add extra qemuCmdFlags when calling
  qemudPhysIfaceConnect()

* src/qemu/qemu_driver.c: qemudStartVMDaemon() fix typo in comment

Rework and simplification of teardown of the macvtap device.

Basically all devices with the same MAC address and link device are kept
alive and not attempted to be torn down. If a macvtap device linked to a
physical interface with a certain MAC address 'M' is to be created it
will automatically fail if the interface is 'up'ed and another macvtap
with the same properties (MAC addr 'M', link dev) happens to be 'up'.
This will prevent the VM from starting or the device from being attached
to a running VM. Stale interfaces are assumed to be there for some
reason and not stem from libvirt.

In the VM shutdown path, it's assuming that an interface name is always
available so that if the device type is DIRECT it can be torn down
using its name.

* src/util/macvtap.h src/libvirt_macvtap.syms: change of deleting routine
* src/util/macvtap.c: cleanups and change of deleting routine
* src/qemu/qemu_driver.c: change cleanup on shutdown
* src/qemu/qemu_conf.c: don't delete Macvtap in qemudPhysIfaceConnect()