Now that all pieces are in place (hopefully) let's enable -blockdev.

We base the capability on presence of the fix for 'auto-read-only' on
files so that blockdev works properly, mandate that qemu supports
explicit SCSI id strings to avoid ABI regression and that the fix for
'savevm' is present so that internal snapshots work.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

When starting a domain without a CPU model specified in the domain XML,
QEMU will choose a default one. Which is fine unless the domain gets
migrated to another host because libvirt doesn't perform any CPU ABI
checks and the virtual CPU provided by QEMU on the destination host can
differ from the one on the source host.

With QEMU 4.2.0 we can probe for the default CPU model used by QEMU for
a particular machine type and store it in the domain XML. This way the
chosen CPU model is more visible to users and libvirt will make sure
the guest will see the exact same CPU after migration.

Architecture specific notes
- aarch64: We only set the default CPU for TCG domains as KVM requires
  explicit "-cpu host" to work.

- ppc64: The default CPU for KVM is "host" thanks to some hacks in QEMU,
  we will translate the default model to the model corresponding to the
  host CPU ("POWER8" on a Power8 host, "POWER9" on Power9 host, etc.).
  This is not a problem as the corresponding CPU model is in fact an
  alias for "host". This is probably not ideal, but it's not wrong and
  the default virtual CPU configured by libvirt is the same QEMU would
  use. TCG uses various CPU models depending on machine type and its
  version.

- s390x: The default CPU for KVM is "host" while TCG defaults to "qemu".

- x86_64: The default CPU model (qemu64) is not runnable on any host
  with KVM, but QEMU just disables unavailable features and starts
  happily.

https://bugzilla.redhat.com/show_bug.cgi?id=1598151
https://bugzilla.redhat.com/show_bug.cgi?id=1598162Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The latter is deprecated and will be removed soon. The advised
replacement is '-overcommit mem-lock=on|off'.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

By default, qemu user's home dir points to '/' which shouldn't be used
at all. We therefore pass the HOME variable from the current variable
iff not running as SUID, which means that for systemd we never set it.
This patch makes sure, that for system QEMU this is always set to
libDir/<driver>, session mode is left untouched.
Signed-off-by: NErik Skultety <eskultet@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

For session mode, only XDG_CACHE_HOME is set, because we want to remain
integrating with services in user session, but for system mode, this
would have become reading/writing to '/' which carries the obvious issue
with permissions (also, '/' is the wrong location in 99.9% cases anyway).
Signed-off-by: NErik Skultety <eskultet@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1564270

Now that everything is prepared for qemu driver we can enable
parser feature to allow users define such domains.

At the same time, introduce bunch of tests to test the feature.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>