Commit Graph

11 Commits

Author SHA1 Message Date
Peter Krempa
a52c68443d qemu_command: Always use modern syntax of '-m'
Specify the memory size by using '-m size=2048k' instead of just '-m 2'.

The new syntax is used when memory hotplug is enabled. To preserve
memory sizing, if memory hotplug is disabled the size is rounded down to
the nearest mebibyte.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2023-06-26 12:58:23 +02:00
Andrea Bolognani
0b464cd84f tests: Drop more QEMU driver config overrides
These are allegedly necessary to keep the output consistent,
but now that we're using a privileged config for the driver we
get the desired behavior out of the box, and as a bonus the
paths match what you would actually see on a regular host.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
2023-03-06 14:44:13 +01:00
Peter Krempa
98c4e3d073 qemu: Use '-machine acpi=on/off' instead of deprecated '-no-acpi'
QEMU deprecated the '-no-acpi' option, thus we should switch to the
modern way to use '-machine'.

Certain ARM machine types don't support ACPI. Given our historically
broken design of using '<acpi/>' without attribute to enable ACPI and
qemu's default of enabling it without '-no-acpi' such configurations
would not work.

Now when qemu reports whether given machine type supports ACPI we can do
a better decision and un-break those configs. Unfortunately not
retroactively.

Resolves: https://gitlab.com/libvirt/libvirt/-/issues/297
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2023-03-06 13:35:28 +01:00
Michal Privoznik
8ff8fe3f8a qemuBuildThreadContextProps: Generate ThreadContext less frequently
Currently, the ThreadContext object is generated whenever we see
.host-nodes attribute for a memory-backend-* object. The idea was
that when the backend is pinned to a specific set of host NUMA
nodes, then the allocation could be happening on CPUs from those
nodes too. But this may not be always possible.

Users might configure their guests in such way that vCPUs and
corresponding guest NUMA nodes are on different host NUMA nodes
than emulator thread. In this case, ThreadContext won't work,
because ThreadContext objects live in context of the emulator
thread (vCPU threads are moved around by us later, when emulator
thread finished its setup and spawned vCPU threads - see
qemuProcessSetupVcpus()). Therefore, memory allocation is done by
emulator thread which is pinned to a subset of host NUMA nodes,
but tries to create a ThreadContext object with a disjoint subset
of host NUMA nodes, which fails.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2154750
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2023-01-13 08:43:30 +01:00
Michal Privoznik
f1154a4825 qemu_command: Generate thread-context object for main guest memory
When generating memory for main guest memory memory-backend-*
might be used. This means, we may need to generate thread-context
objects too.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
2022-11-15 11:56:08 +01:00
Peter Krempa
1a691fe1c8 qemu: capabilities: Re-enable JSON syntax for -device
Now that qemu fixed device unplug when JSON syntax is used with -device
we can re-enable the feature.

Since the old capability string representation is condemned by
suggesting filtering it as a workaround we must introduce a new string.
To achieve this the original capability position is renamed to
X_QEMU_CAPS_DEVICE_JSON_BROKEN_HOTPLUG and a new position with the
original name QEMU_CAPS_DEVICE_JSON is introduced to prevent us having
to change the rest of the code.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2022-01-17 09:26:17 +01:00
Peter Krempa
bd3d00babc qemu: Revert to using non-JSON commandline for -device
When -device is configured via JSON a bug [1] is triggered in qemu were
the DEVICE_DELETED event for the removal of the device frontend is no
longer delivered to libvirt. Without the DEVICE_DELETED event we don't
remove the corresponding entries in the VM XML.

Until qemu will be fixed we must stop using the JSON syntax for -device.

This patch removes the detection of the capability. The capability is
used only during startup of a fresh VM so we don't need to consider any
compaitibility steps for existing VMs.

For users who wish to use 'libvirt-7.9' and 'libvirt-7.10' with
'qemu-6.2' there are two possible workarounds:

 - filter out the 'device.json' qemu capability '/etc/libvirt/qemu.conf':

   capability_filters = [ "device.json" ]

 - filter out the 'device.json' qemu capability via qemu namespace XML:

   <domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
     [...]
     <qemu:capabilities>
       <qemu:del capability='device.json'/>
     </qemu:capabilities>
   </domain>

We must never again use the same capability name as we are now
instructing users to filter it as a workaround so once qemu is fixed
we'll need to pick a new capability value for it.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=2036669

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2035237
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ani Sinha <ani@anisinha.ca>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2022-01-10 09:35:00 +01:00
Michal Privoznik
c1355849e4 qemu_command: do use host-nodes for system memory
After previous commit, it's no longer possible to change nodeset
for strict numatune. Therefore, we can start generating
host-nodes onto command line again.

This partially reverts d73265af6e.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
2021-12-17 13:21:55 +01:00
Michal Privoznik
d20ebdda28 qemu: Switch to -accel
We currently use -machine accel=XXX which is just a syntax sugar
for -accel XXX. The former doesn't allow specifying arguments for
accelerator, because all arguments passed to -machine are
treated as arguments of machine itself.

The -accel argument was introduced in QEMU commit
v2.9.0-rc0~70^2~19 and since our minimum required version is
newer (2.11.0) we can safely assume its existence and use it
without any capability.

Resolves: https://gitlab.com/libvirt/libvirt/-/issues/233
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Tested-by: Kashyap Chamarthy <kchamart@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2021-11-22 13:06:54 +01:00
Peter Krempa
279c64dccb qemu: command: Use JSON for parameters of -audiodev
'-audiodev' as a modern implementation based on QAPI already takes JSON
as the argument. Convert our code to use it directly.

The declaration of the QAPI types can be found in
'qemu.git/qapi/audio.json'.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-17 12:04:11 +01:00
Pavel Hrdina
d73265af6e qemu_command: do not use host-nodes for system memory
Commit 88957116c9 switched to use
memory-backend-* for regular VM memory as well. That change indirectly
started using 'host-nodes' for system memory which results in QEMU
calling mbind() to bind the system memory to specific NUMA node if the
VM XML contains the configuration similar to this:

  ...
  <numatune>
    <memory mode='strict' nodeset='0'/>
  </numatune>
  ...

Once the VM was started with that configuration it was no longer
possible to change the memory NUMA nodeset.

Fixes: 677c90cc1d
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-11-10 11:17:44 +01:00