Commit Graph

9 Commits

Author SHA1 Message Date
Michal Privoznik
0c8ab47847 qemu: Don't generate '-machine memory-backend' and '-numa memdev'
In 88957116c9 I've switched to -machine memory-backend=ID and
-object memory-backend-* because QEMU is obsoleting -mem-path
and -mem-prealloc. However, what I did not foresee was that using
-machine memory-backend in combination with -numa is not allowed
in QEMU. This was reported upstream and fortunately not released
yet.

The problem is that if domain has NUMA nodes then we will
generate memory-backend-* objects for NUMA nodes (because if QEMU
is new enough to expose default RAM ID it also supports -numa
memdev=) and adding non-NUMA memory backend is wrong.

Reported-by: Masayoshi Mizuma <msys.mizuma@gmail.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2020-10-08 12:55:10 +02:00
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
Peter Krempa
9517890f7c tests: qemuxml2argv: Use proper replacement for 'pc-i440fx-wily' machine
This machine type comes from downstream ubuntu 15.10. Replace it with a
somewhat equivalent qemu-2.3 machine type as we do have test data for
that.

The change allows the CPU code to pick a proper default CPU in the
'-latest' cases.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-27 14:55:03 +01:00
Daniel P. Berrangé
4cf8dd0c57 qemu: add support for specifying CPU "dies" topology parameter
QEMU since 4.1.0 supports the "dies" parameter for -smp

Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-16 15:11:55 +00:00
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
Michal Privoznik
59a22be864 qemuxml2xmltest: Add memfd tests
Somehow, these were not tested. Use symlinks to point expected
output back to the input. This way we can also fix some
discrepancies in the input XMLs.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-04-03 16:37:19 +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
Marc-André Lureau
24b74d187c qemu: add memfd source type
Add a new memoryBacking source type "memfd", supported by QEMU (when
the capability is available).

A memfd is a specialized anonymous memory kind. As such, an anonymous
source type could be automatically using a memfd. However, there are
some complications when migrating from different memory backends in
qemu (mainly due to the internal object naming at this point, but
there could be more). For now, it is simpler and safer to simply
introduce a new source type "memfd". Eventually, the "anonymous" type
could learn to use memfd transparently in a separate change.

The main benefits are that it doesn't need to create filesystem files,
and it also enforces sealing, providing a bit more safety.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2018-11-16 08:57:12 +01:00