And don't allow to hotplug a usb disk with "device == lun". This
is the missed pieces in previous virtio-scsi patchset:

http://www.redhat.com/archives/libvir-list/2012-February/msg01052.html

The qemu developers have made it clear that modern qemu will no
longer guarantee human monitor command stability; furthermore,
some features, such as async events, are only supported via qmp.
If we are compiled without support for handling JSON, we cannot
expect to sanely interact with modern qemu.

However, things must continue to build on RHEL 5, where qemu
is stuck at 0.10, and where yajl is not available.

Another benefit of this patch: future additions of new monitor
commands need only focus on qemu_monitor_json.c, instead of
also wasting time with qemu_monitor_text.c.

* src/qemu/qemu_capabilities.c (qemuCapsComputeCmdFlags): Report
error if yajl is missing but qemu requires qmp.
(qemuCapsParseHelpStr): Propagate error.
(qemuCapsExtractVersionInfo): Update caller.
* tests/qemuhelptest.c (testHelpStrParsing): Likewise.

I'm getting tired of remembering to backport RHEL-specific
patches when building upstream libvirt on RHEL 6.x or CentOS.
All the affected versions of RHEL qemu-kvm have backported
enough patches to a) make JSON useful, and b) modify the
-help text to mention libvirt as the preferred interface;
which means this string in the help output is a reliable
indicator that we can outsmart a strict version check,
even when upstream qemu 0.12 lacked the needed features.

* src/qemu/qemu_capabilities.c (qemuCapsComputeCmdFlags):
Recognize particular help string present when enough features were
backported to be worth using JSON.
* tests/qemuhelptest.c (mymain): Update tests accordingly.

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>

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

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.

In the past, generic SCSI commands issued from a guest to a virtio
disk were always passed through to the underlying disk by qemu, and
the kernel would also pass them on.

As a result of CVE-2011-4127 (see:
http://seclists.org/oss-sec/2011/q4/536), qemu now honors its
scsi=on|off device option for virtio-blk-pci (which enables/disables
passthrough of generic SCSI commands), and the kernel will only allow
the commands for physical devices (not for partitions or logical
volumes). The default behavior of qemu is still to allow sending
generic SCSI commands to physical disks that are presented to a guest
as virtio-blk-pci devices, but libvirt prefers to disable those
commands in the standard virtio block devices, enabling it only when
specifically requested (hopefully indicating that the requester
understands what they're asking for). For this purpose, a new libvirt
disk device type (device='lun') has been created.

device='lun' is identical to the default device='disk', except that:

1) It is only allowed if bus='virtio', type='block', and the qemu
   version is "new enough" to support it ("new enough" == qemu 0.11 or
   better), otherwise the domain will fail to start and a
   CONFIG_UNSUPPORTED error will be logged).

2) The option "scsi=on" will be added to the -device arg to allow
   SG_IO commands (if device !='lun', "scsi=off" will be added to the
   -device arg so that SG_IO commands are specifically forbidden).

Guests which continue to use disk device='disk' (the default) will no
longer be able to use SG_IO commands on the disk; those that have
their disk device changed to device='lun' will still be able to use SG_IO
commands.

*docs/formatdomain.html.in - document the new device attribute value.
*docs/schemas/domaincommon.rng - allow it in the RNG
*tests/* - update the args of several existing tests to add scsi=off, and
 add one new test that will test scsi=on.
*src/conf/domain_conf.c - update domain XML parser and formatter

*src/qemu/qemu_(command|driver|hotplug).c - treat
 VIR_DOMAIN_DISK_DEVICE_LUN *almost* identically to
 VIR_DOMAIN_DISK_DEVICE_DISK, except as indicated above.

Note that no support for this new device value was added to any
hypervisor drivers other than qemu, because it's unclear what it might
mean (if anything) to those drivers.

Latest patch a1a83c58 introduces new qemu capability flag
QEMU_CAPS_FSDEV_READONLY. However, it was missing in qemuhelptest
making test for qemu-1.0 fail.

Currently non-x86 guests must have <acpi/> defined in <features> to
prevent libvirt from running qemu with -no-acpi. Although it works, it
is a hack.

Instead add a capability flag which indicates whether qemu understands
the -no-acpi option. Use it to control whether libvirt emits -no-acpi.

Current versions of qemu always display -no-acpi in their help output,
so this patch has no effect. However the development version of qemu
has been modified such that -no-acpi is only displayed when it is
actually supported.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>

I got this failure on FreeBSD:

shunloadtest.c: In function 'main':
shunloadtest.c:150: error: 'EXIT_AM_SKIP' undeclared (first use in this function)

but inspection showed several other problems, all fixed here.

* tests/domainsnapshotxml2xmltest.c [!WITH_QEMU]: Ensure
EXIT_AM_SKIP is defined.
* tests/esxutilstest.c [!WITH_ESX]: Likewise.
* tests/openvzutilstest.c [!WITH_OPENVZ]: Likewise.
* tests/qemuargv2xmltest.c [!WITH_QEMU]: Likewise.
* tests/qemuhelptest.c [!WITH_QEMU]: Likewise.
* tests/qemuxml2argvtest.c [!WITH_QEMU]: Likewise.
* tests/qemuxml2xmltest.c [!WITH_QEMU]: Likewise.
* tests/qemuxmlnstest.c [!WITH_QEMU]: Likewise.
* tests/shunloadtest.c [!linux]: Likewise.
* tests/vmx2xmltest.c [!WITH_VMX]: Likewise.
* tests/xml2vmxtest.c [!WITH_VMX]: Likewise.

Rather than making all clients of monitor commands that are JSON-only
check whether yajl support was compiled in, it is simpler to just
avoid setting the capability bit up front if we can't use the capability.

* src/qemu/qemu_capabilities.c (qemuCapsComputeCmdFlags): Only set
capability bit if we also have yajl library to use it.
* src/qemu/qemu_driver.c (qemuDomainReboot): Drop #ifdefs.
* src/qemu/qemu_process.c (qemuProcessStart): Likewise.
* tests/qemuhelptest.c (testHelpStrParsing): Pass test even
without yajl.
* tests/qemuxml2argvtest.c (mymain): Simplify use of json flag.
* tests/qemuxml2argvdata/qemuxml2argv-disk-drive-error-*.args:
Update expected results to match.

Now that RHEL 6.2 Beta is out, it would be nice to test multifunction
devices on that platform.  This changes things so that the multifunction
cap bit can be set in two different ways: by version comparison (needed
for qemu 0.13 which lacked a -device query), and by -device query
(provided by qemu.git and backported to the RHEL beta build of
qemu-kvm which still claims to be a modified 0.12, and therefore needed
for RHEL).

* src/qemu/qemu_capabilities.c (qemuCapsParseDeviceStr): Allow
second method of setting multifunction cap bit.
* tests/qemuhelptest.c (mymain): Test it.
* tests/qemuhelpdata/qemu-kvm-0.12.1.2-rhel62-beta: New file.
* tests/qemuhelpdata/qemu-kvm-0.12.1.2-rhel62-beta-device: Likewise.

This patch was made in response to:

  https://bugzilla.redhat.com/show_bug.cgi?id=738095

In short, qemu's default for the rombar setting (which makes the
firmware ROM of a PCI device visible/not on the guest) was previously
0 (not visible), but they recently changed the default to 1
(visible). Unfortunately, there are some PCI devices that fail in the
guest when rombar is 1, so the setting must be exposed in libvirt to
prevent a regression in behavior (it will still require explicitly
setting <rom bar='off'/> in the guest XML).

rombar is forced on/off by adding:

  <rom bar='on|off'/>

inside a <hostdev> element that defines a PCI device. It is currently
ignored for all other types of devices.

At the moment there is no clean method to determine whether or not the
rombar option is supported by QEMU - this patch uses the advice of a
QEMU developer to assume support for qemu-0.12+. There is currently a
patch in the works to put this information in the output of "qemu-kvm
-device pci-assign,?", but of course if we switch to keying off that,
we would lose support for setting rombar on all the versions of qemu
between 0.12 and whatever version gets that patch.

QEMU 0.13 introduced cache=unsafe for -drive, this patch exposes
it in the libvirt layer.

  * Introduced a new QEMU capability flag ($prefix_CACHE_UNSAFE),
    as even if $prefix_CACHE_V2 is set, we can't know if unsafe
    is supported.

  * Improved the reliability of qemu cache type detection.

  * qemuhelptest prints test case name on failure.

The commit that prevents disk corruption on domain shutdown
(96fc4784) causes regression with QEMU
0.14.* and 0.15.* because of a regression bug in QEMU that was fixed
only recently in QEMU git. The affected versions of QEMU do not quit on
SIGTERM if started with -no-shutdown, which we use to implement fake
reboot. Since -no-shutdown tells QEMU not to quit automatically on guest
shutdown, domains started using the affected QEMU cannot be shutdown
properly and stay in a paused state.

This patch disables fake reboot feature on such QEMU by not using
-no-shutdown, which makes shutdown work as expected. However,
virDomainReboot will not work in this case and it will report "Requested
operation is not valid: Reboot is not supported with this QEMU binary".

domain parsing and serialization code, qemu driver backend and
a couple of test

For virtio disks and interfaces, qemu allows users to enable or disable
ioeventfd feature. This means, qemu can execute domain code, while
another thread waits for I/O event. Basically, in some cases it is win,
in some loss. This feature is available via 'ioeventfd' attribute in disk
and interface <driver> element. It accepts 'on' and 'off'. Leaving this
attribute out defaults to hypervisor decision.

qemu supports multi function PCI device at least version 0.13.0.

NB: the enum that uses the string vnet-host (now changed to vhost-net)
is used in XML, but fortunately that hasn't been in an official
release yet, so it can still be fixed.

Make virtTestLoadFile allocate the buffer to read the file into.

Fix logic error in virtTestLoadFile, stop reading on the first empty line.

Use virFileReadLimFD in virtTestCaptureProgramOutput to avoid manual
buffer handling.

A few of the tests were missing basic sanity checks, while most
of them were doing copy-and-paste initialization (in fact, some
of them pasted the argc > 1 check more than once!).  It's much
nicer to do things in one common place, and minimizes the size of
the next patch that fixes getcwd usage.

* tests/testutils.h (EXIT_AM_HARDFAIL): New define.
(progname, abs_srcdir): Define for all tests.
(VIRT_TEST_MAIN): Change callback signature.
* tests/testutils.c (virtTestMain): Do more common init.
* tests/commandtest.c (mymain): Simplify.
* tests/cputest.c (mymain): Likewise.
* tests/esxutilstest.c (mymain): Likewise.
* tests/eventtest.c (mymain): Likewise.
* tests/hashtest.c (mymain): Likewise.
* tests/networkxml2xmltest.c (mymain): Likewise.
* tests/nodedevxml2xmltest.c (myname): Likewise.
* tests/nodeinfotest.c (mymain): Likewise.
* tests/nwfilterxml2xmltest.c (mymain): Likewise.
* tests/qemuargv2xmltest.c (mymain): Likewise.
* tests/qemuhelptest.c (mymain): Likewise.
* tests/qemuxml2argvtest.c (mymain): Likewise.
* tests/qemuxml2xmltest.c (mymain): Likewise.
* tests/qparamtest.c (mymain): Likewise.
* tests/sexpr2xmltest.c (mymain): Likewise.
* tests/sockettest.c (mymain): Likewise.
* tests/statstest.c (mymain): Likewise.
* tests/storagepoolxml2xmltest.c (mymain): Likewise.
* tests/storagevolxml2xmltest.c (mymain): Likewise.
* tests/virbuftest.c (mymain): Likewise.
* tests/virshtest.c (mymain): Likewise.
* tests/vmx2xmltest.c (mymain): Likewise.
* tests/xencapstest.c (mymain): Likewise.
* tests/xmconfigtest.c (mymain): Likewise.
* tests/xml2sexprtest.c (mymain): Likewise.
* tests/xml2vmxtest.c (mymain): Likewise.

For qemu names the primary vga as "qxl-vga":

  1) if vram is specified for 2nd qxl device:

    -vga qxl -global qxl-vga.vram_size=$SIZE \
    -device qxl,id=video1,vram_size=$SIZE,...

  2) if vram is not specified for 2nd qxl device, (use the default
     set by global):

    -vga qxl -global qxl-vga.vram_size=$SIZE \
    -device qxl,id=video1,...

For qemu names all qxl devices as "qxl":

  1) if vram is specified for 2nd qxl device:

    -vga qxl -global qxl.vram_size=$SIZE \
    -device qxl,id=video1,vram_size=$SIZE ...

  2) if vram is not specified for 2nd qxl device:

    -vga qxl -global qxl-vga.vram_size=$SIZE \
    -device qxl,id=video1,...

"-global" is the only way to define vram_size for the primary qxl
device, regardless of how qemu names it, (It's not good a good
way, as original idea of "-global" is to set a global default for
a driver property, but to specify vram for first qxl device, we
have to use it).

For other qxl devices, as they are represented by "-device", could
specify it directly and seperately for each, and it overrides the
default set by "-global" if specified.

v1 - v2:
  * modify "virDomainVideoDefaultRAM" so that it returns 16M as the
    default vram_size for qxl device.

  * vram_size * 1024 (qemu accepts bytes for vram_size).

  * apply default vram_size for qxl device for which vram_size is
    not specified.

  * modify "graphics-spice" tests (more sensiable vram_size)

  * Add an argument of virDomainDefPtr type for qemuBuildVideoDevStr,
    to use virDomainVideoDefaultRAM in qemuBuildVideoDevStr).

v2 - v3:
  * Modify default video memory size for qxl device from 16M to 24M

  * Update codes to be consistent with changes on qemu_capabilities.*

This is done for two reasons:
- we are getting very close to 64 flags which is the maximum we can use
  with unsigned long long
- by using LL constants in enum we already violates C99 constraint that
  enum values have to fit into int

Three new functions (qemuCapsSet, qemuCapsClear, and qemuCapsGet) were
introduced replacing direct bit operations.

The new names comply more with the fact that they are all members of
enum qemuCapsFlags.

This is in response to:

   https://bugzilla.redhat.com/show_bug.cgi?id=629662

Explanation

qemu's virtio-net-pci driver allows setting the algorithm used for tx
packets to either "bh" or "timer". This is done by adding ",tx=bh" or
",tx=timer" to the "-device virtio-net-pci" commandline option.

'bh' stands for 'bottom half'; when this is set, packet tx is all done
in an iothread in the bottom half of the driver. (In libvirt, this
option is called the more descriptive "iothread".)

'timer' means that tx work is done in qemu, and if there is more tx
data than can be sent at the present time, a timer is set before qemu
moves on to do other things; when the timer fires, another attempt is
made to send more data. (libvirt retains the name "timer" for this
option.)

The resulting difference, according to the qemu developer who added
the option is:

    bh makes tx more asynchronous and reduces latency, but potentially
    causes more processor bandwidth contention since the cpu doing the
    tx isn't necessarily the cpu where the guest generated the
    packets.

Solution

This patch provides a libvirt domain xml knob to change the option on
the qemu commandline, by adding a new attribute "txmode" to the
<driver> element that can be placed inside any <interface> element in
a domain definition. It's use would be something like this:

    <interface ...>
      ...
      <model type='virtio'/>
      <driver txmode='iothread'/>
      ...
    </interface>

I chose to put this setting as an attribute to <driver> rather than as
a sub-element to <tune> because it is specific to the virtio-net
driver, not something that is generally usable by all network drivers.
(note that this is the same placement as the "driver name=..."
attribute used to choose kernel vs. userland backend for the
virtio-net driver.)

Actually adding the tx=xxx option to the qemu commandline is only done
if the version of qemu being used advertises it in the output of

    qemu -device virtio-net-pci,?

If a particular txmode is requested in the XML, and the option isn't
listed in that help output, an UNSUPPORTED_CONFIG error is logged, and
the domain fails to start.

qemu 0.13.0 (at least as built for Fedora 14, and also backported to
RHEL 6.0 qemu) supported an older syntax for a spicevmc channel; it's
not as flexible (it has an implicit name and hides the chardev
aspect), but now that we support spicevmc, we might as well target
both variants.

* src/qemu/qemu_capabilities.h (QEMUD_CMD_FLAG_DEVICE_SPICEVMC):
New flag.
* src/qemu/qemu_capabilities.c (qemuCapsParseDeviceStr): Set it
correctly.
* src/qemu/qemu_command.h (qemuBuildVirtioSerialPortDevStr): Drop
declaration.
* src/qemu/qemu_command.c (qemuBuildVirtioSerialPortDevStr): Alter
signature, check flag.
(qemuBuildCommandLine): Adjust caller and check flag.
* tests/qemuhelptest.c (mymain): Update test.
* tests/qemuxml2argvtest.c (mymain): New test.
* tests/qemuxml2argvdata/qemuxml2argv-channel-spicevmc-old.xml:
New file.
* tests/qemuxml2argvdata/qemuxml2argv-channel-spicevmc-old.args:
Likewise.

Qemu smartcard/spicevmc support exists on branches (such as
http://cgit.freedesktop.org/~alon/qemu/commit/?h=usb_ccid.v15&id=024a37b)
but is not yet upstream.  The added -help output matches a scratch build
that will be close to the RHEL 6.1 qemu-kvm.

* src/qemu/qemu_capabilities.h (QEMUD_CMD_FLAG_CCID_EMULATED)
(QEMUD_CMD_FLAG_CCID_PASSTHRU, QEMUD_CMD_FLAG_CHARDEV_SPICEVMC):
New flags.
* src/qemu/qemu_capabilities.c (qemuCapsComputeCmdFlags)
(qemuCapsParseDeviceStr): Check for smartcard capabilities.
(qemuCapsExtractVersionInfo): Tweak comment.
* tests/qemuhelptest.c (mymain): New test.
* tests/qemuhelpdata/qemu-kvm-0.12.1.2-rhel61: New file.
* tests/qemuhelpdata/qemu-kvm-0.12.1.2-rhel61-device: Likewise.

Signed-off-by: NEric Blake <eblake@redhat.com>

* src/qemu/qemu_capabilities.h (qemuCapsParseDeviceStr): New
prototype.
* src/qemu/qemu_capabilities.c (qemuCapsParsePCIDeviceStrs)
Rename and split...
(qemuCapsExtractDeviceStr, qemuCapsParseDeviceStr): ...to make it
easier to add and test device-specific checks.
(qemuCapsExtractVersionInfo): Update caller.
* tests/qemuhelptest.c (testHelpStrParsing): Also test parsing of
device-related flags.
(mymain): Update expected flags.
* tests/qemuhelpdata/qemu-0.12.1-device: New file.
* tests/qemuhelpdata/qemu-kvm-0.12.1.2-rhel60-device: New file.
* tests/qemuhelpdata/qemu-kvm-0.12.3-device: New file.
* tests/qemuhelpdata/qemu-kvm-0.13.0-device: New file.

* src/qemu/qemu_capabilities.h (QEMUD_CMD_FLAG_MIGRATE_QEMU_FD):
New enum value.
* src/qemu/qemu_capabilities.c (qemuCapsComputeCmdFlags): Populate
flags according to qemu version.
* tests/qemuhelptest.c (mymain): Adjust test.

* qemuargv2xmltest.c, qemuhelptest.c,
  qemuxml2argvtest.c, testutilsqemu.c: Update includes and
  cope with API renames

* tests/qemuhelpdata/qemu-kvm-0.13.0: New file.
* tests/qemuhelptest.c (mymain): New test from Fedora 14 qemu-kvm,
which covers some options (like -fstype passthrough) not tested elsewhere.

* tests/qemuhelpdata/qemu-kvm-0.12.1.2-rhel60: New file.
* tests/qemuhelptest.c (mymain): New test from RHEL 6.0 qemu-kvm,
which covers some options (like -vga=qxl) not tested elsewhere.
* .x-sc_prohibit_empty_lines_at_EOF: Exempt qemu help output.

Commit febc5916 introduced -vga none in
case no video card is included in domain XML. However, old qemu
versions do not support this and such domain cannot be successfully
started.

* docs/schemas/domain.rng: Fix merge error which left SPICE channel
  elements under VNC schema.
* tests/qemuhelptest.c: Add SPICE flag to kvm-83 test
* tests/qemuxml2argvdata/qemuxml2argv-graphics-spice.xml: Add
  <memballoon> element