QEMU 2.8.0 adds support for unavailable-features in
query-cpu-definitions reply. The unavailable-features array lists CPU
features which prevent a corresponding CPU model from being usable on
current host. It can only be used when all the unavailable features are
disabled. Empty array means the CPU model can be used without
modifications.

We can use unavailable-features for providing CPU model usability info
in domain capabilities XML:

    <domainCapabilities>
      ...
      <cpu>
        <mode name='host-passthrough' supported='yes'/>
        <mode name='host-model' supported='yes'>
          <model fallback='allow'>Skylake-Client</model>
          ...
        </mode>
        <mode name='custom' supported='yes'>
          <model usable='yes'>qemu64</model>
          <model usable='yes'>qemu32</model>
          <model usable='no'>phenom</model>
          <model usable='yes'>pentium3</model>
          <model usable='yes'>pentium2</model>
          <model usable='yes'>pentium</model>
          <model usable='yes'>n270</model>
          <model usable='yes'>kvm64</model>
          <model usable='yes'>kvm32</model>
          <model usable='yes'>coreduo</model>
          <model usable='yes'>core2duo</model>
          <model usable='no'>athlon</model>
          <model usable='yes'>Westmere</model>
          <model usable='yes'>Skylake-Client</model>
          ...
        </mode>
      </cpu>
      ...
    </domainCapabilities>
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

"host" CPU model is supported by a special host-passthrough CPU mode and
users is not allowed to specify this model directly with custom mode.
Thus we should not advertise "host" CPU model in domain capabilities.
This worked well on architectures for which libvirt provides a list of
supported CPU models in cpu_map.xml (since "host" is not in the list).
But we need to explicitly filter "host" model out for all other
architectures.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

CPU models (and especially some additional details which we will start
probing for later) differ depending on the accelerator. Thus we need to
call query-cpu-definitions in both KVM and TCG mode to get all data we
want.

Tests in tests/domaincapstest.c are temporarily switched to TCG to avoid
having to squash even more stuff into this single patch. They will all
be switched back later in separate commits.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

This patch moves the CPU models formatting code from
virQEMUCapsFormatCache into a separate function.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

This patch moves the CPU models parsing code from virQEMUCapsLoadCache
into a separate function.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

The function just returned cached capabilities without checking whether
they are still valid. We should check that and refresh the capabilities
to make sure we don't return stale data. In other words, we should do
what all other lookup functions do.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

The function is made a little bit more readable and the code which
refreshes cached capabilities if they are not valid any more was moved
into a separate function (virQEMUCapsCacheValidate) so that it can be
reused in other places.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

If a user asked for a KVM domain capabilities when KVM is not available,
we would happily return data we got when probing through TCG and
pretended they were relevant for KVM. Let's just report KVM is not
supported to avoid confusion.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

When domain capabilities were introduced we did not have enough data to
decide whether KVM works on the host or not and thus working legacy/VFIO
device assignment was used as a witness. Now that we know whether KVM
was enabled when probing QEMU capabilities (and thus we know it's
working), we can use this knowledge to provide better default value for
virttype.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Since some may depend on the accelerator used when probing QEMU the
cache becomes invalid when KVM becomes available or if it is not
available anymore.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

CPU related capabilities may differ depending on accelerator used when
probing. Let's use KVM if available when probing QEMU and fall back to
TCG. The created capabilities already contain all we need to distinguish
whether KVM or TCG was used:

    - KVM was used when probing capabilities:
        QEMU_CAPS_KVM is set
        QEMU_CAPS_ENABLE_KVM is not set

    - TCG was used and QEMU supports KVM, but it failed (e.g., missing
      kernel module or wrong /dev/kvm permissions)
        QEMU_CAPS_KVM is not set
        QEMU_CAPS_ENABLE_KVM is set

    - KVM was not used and QEMU does not support it
        QEMU_CAPS_KVM is not set
        QEMU_CAPS_ENABLE_KVM is not set
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

When starting QEMU more than once during a single probing process,
qemucapsprobe utility would save QMP greeting several times, which
doesn't play well with our test monitor.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Let's set QEMU_CAPS_KVM and QEMU_CAPS_ENABLE_KVM early so that the rest
of the probing code can use these capabilities to handle KVM/TCG replies
differently.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Using -machine instead of -M for QMP probing is safe because any QEMU
binary which is capable of QMP probing supports -machine.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

The code that runs a new QEMU process to be used for probing
capabilities is separated into four reusable functions so that any code
that wants to probe a QEMU process may just follow a few simple steps:

    cmd = virQEMUCapsInitQMPCommandNew(...);
    virQEMUCapsInitQMPCommandRun(cmd);

    /* talk to the running QEMU process using its QMP monitor */

    if (reprobeIsRequired) {
        virQEMUCapsInitQMPCommandAbort(cmd, ...);
        virQEMUCapsInitQMPCommandRun(cmd);

        /* talk to the running QEMU process again */
    }

    virQEMUCapsInitQMPCommandFree(cmd);
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

This reverts commit 3a6cf6fc.

Mistakenly this commit was pushed because I thought I missed the
corret one b880ff42 while in fact I didn't.
Signed-off-by: NMaxim Nestratov <mnestratov@virtuozzo.com>

We have couple of functions that operate over NULL terminated
lits of strings. However, our naming sucks:

virStringJoin
virStringFreeList
virStringFreeListCount
virStringArrayHasString
virStringGetFirstWithPrefix

We can do better:

virStringListJoin
virStringListFree
virStringListFreeCount
virStringListHasString
virStringListGetFirstWithPrefix
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Catch up with changes that have been pushed but didn't include
updates to the NEWS file themselves.

If libvirt is compiled without NUMACTL support starting libvirtd
reports a libvirt internal error "NUMA isn't available on this host"
without checking if NUMA support is compiled into the libvirt binaries.
This patch adds the missing NUMA support check to prevent the internal error.
It also includes a check if the cgroup controller cpuset is available before
using it.

The error was noticed when libvirtd was restarted with running domains and
on libvirtd start the qemuConnectCgroup gets called during qemuProcessReconnect.
Signed-off-by: NBoris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Reviewed-by: NBjoern Walk <bwalk@linux.vnet.ibm.com>

With the QEMU components in place, provide the XML parsing to
invoke that code when given the following XML snippet:

    <hostdev mode='subsystem' type='scsi_host'>
      <source protocol='vhost' wwpn='naa.501234567890abcd'/>
    </hostdev>

An optional address element can be specified within the hostdev
(pick CCW or PCI as necessary):

    <address type='ccw' cssid='0xfe' ssid='0x0' devno='0x0625'/>
    <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>

Add basic vhost-scsi tests which were cloned from hostdev-scsi-virtio-scsi
in both xml2argv and xml2xml. Added ones for both vhost-scsi-ccw and
vhost-scsi-pci since the syntaxes are slightly different between them.

Also adjusted the docs to describe the changes.
Signed-off-by: NEric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: NBoris Fiuczynski <fiuczy@linux.vnet.ibm.com>

Ensure that the vhost-scsi wwpn information is passed to the
different security policies.
Signed-off-by: NEric Farman <farman@linux.vnet.ibm.com>

Adjust the device string that is built for vhost-scsi devices so that it
can be invoked from hotplug.

From the QEMU command line, the file descriptors are expect to be numeric only.
However, for hotplug, the file descriptors are expected to begin with at least
one alphabetic character else this error occurs:

  # virsh attach-device guest_0001 ~/vhost.xml
  error: Failed to attach device from /root/vhost.xml
  error: internal error: unable to execute QEMU command 'getfd':
  Parameter 'fdname' expects a name not starting with a digit

We also close the file descriptor in this case, so that shutting down the
guest cleans up the host cgroup entries and allows future guests to use
vhost-scsi devices.  (Otherwise the guest will silently end.)
Signed-off-by: NEric Farman <farman@linux.vnet.ibm.com>