Commit Graph

12 Commits

Author SHA1 Message Date
Peter Krempa
c9b13e0557 qemu: Use JSON directly for '-device'
Starting with QEMU-6.2 started accepting a JSON object as argument for
'-device' which will also become the only syntax considered stable by
qemu in the future.

Since libvirt was recently converted to generate the properties via JSON
to begin wit we can start using it on the commandline as well, by simply
enabling the QEMU_CAPS_DEVICE_JSON capability, which we do by probing
for the 'json-cli' feature flag of 'device_add'.

Normally a change which changes a commandline output should be happening
only after the impacted real-caps test files are forked in the version
preceding the change, but in this case it's not necessary as the logic
for generating the device properties stays identical and we just change
the output format (avoid conversion). Additionally we still have a lot
of tests validating the conversion to the old commandline options.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-10-18 14:00:58 +02:00
Peter Krempa
d8f04f1575 qemuBuildControllerPCIDevStr: Format via JSON properties
Internally format the PCI controller properties into JSON, but convert
it back to a string so that we for now change just the SCSI controller.

The change in tests is expected as the 'port' field for various PCI
controllers is expected to be a number and thus can't be represented as
a hexadecimal value in JSON.

QEMU expects the following types:

'pci-bridge'
  chassis_nr=<uint8>     -  (default: 0)

'pxb-pcie':
  bus_nr=<uint8>         -  (default: 0)

'pcie-root-port'
  port=<uint8>           -  (default: 0)
  chassis=<uint8>        -  (default: 0)
  hotplug=<bool>         -  (default: true)

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-10-12 10:26:05 +02:00
Peter Krempa
0046e0b1c2 qemuxml2argvtest: Use internal wrapping of command line arguments
virCommandToString has the possibility to return an already wrapped
string with better format than what we get from the test wrapper script.

The main advantage is that arguments for an option are always on the
same line which makes it more easy to see what changed in a diff and
prevents re-wrapping of the line if a wrapping point moves over the
threshold.

Additionally the used output is the same we have in the VM log file when
a VM is starting.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
2021-04-12 15:55:10 +02:00
Peter Krempa
f763b6e439 qemu: capabilities: Enable detection of QEMU_CAPS_OBJECT_QAPIFIED
Base the detection on the presence of the 'secret' qom-type entry, which
isn't conditionally compiled in qemu.

All caps-based test now switch to using JSON for -object.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-03-23 14:06:31 +01:00
Daniel P. Berrangé
d96fb5cb31 qemu: add support for generating -audiodev arguments
The -audiodev argument is replacing the QEMU_AUDIO_DRV env variable (and
its relations).

Sadly we still have to use the SDL_AUDIODRIVER env variable because that
wasn't mapped into QAPI schema.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2021-03-09 22:58:36 +00:00
Daniel P. Berrangé
43c9c0859f qemu: use long on|off syntax for -chardev boolean option values
The preferred syntax for boolean options is to set the value "on" or
"off". QEMU 7.1.0 will deprecate the short format we currently use.

The long format has been supported with -chardev since at least 1.5.3,
so we don't need to check for it.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2021-02-16 12:38:20 +00:00
Michal Privoznik
88957116c9 qemu: Use memory-backend-* for regular guest memory
So far, Libvirt configures memory-backend-* for memory hotplug,
possibly NUMA nodes and in a few other cases. This patch
switches to constructing the memory-backend-* command line for
all cases. To keep ability to migrate guests a little hack is
used: the ID of the object is set to the one that QEMU uses
internally anyways. These IDs are stable (first started to appear
somewhere around v0.13.0-rc0~96) and can't change.

In fact, this patch does exactly what QEMU does internally. The
reason for moving the logic into Libvirt is that QEMU wants to
deprecate the old style of specifying memory.

So far, only x84_64 test cases are changed, because tests for
other architectures use older capabilities, which still lack the
QEMU_CAPS_MACHINE_MEMORY_BACKEND capability and they don't report
the RAM ID.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1836043

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2020-10-01 12:06:22 +02:00
Jiri Denemark
5e939cea89 qemu: Store default CPU in domain XML
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=1598162

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-11-20 17:22:07 +01:00
Michal Privoznik
e8c2c8bd07 qemu_command: Prefer '-overcommit mem-lock' over -realtime mlock'
The latter is deprecated and will be removed soon. The advised
replacement is '-overcommit mem-lock=on|off'.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-04-12 14:13:45 +02:00
Erik Skultety
75a9169881 qemu: command: Override HOME variable for system QEMU
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: Erik Skultety <eskultet@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2019-03-15 16:41:26 +01:00
Erik Skultety
7e73137495 qemu: command: Enforce setting XDG variables for system QEMU
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: Erik Skultety <eskultet@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2019-03-15 16:41:26 +01:00
Martin Kletzander
d60b730b48 qemu: Add support for setting the TSEG size
The default is stable per machine type so there should be no need to keep that.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1469338

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2018-06-08 10:28:46 +02:00