Commit Graph

12 Commits

Author SHA1 Message Date
Markus Armbruster
79b9d4bde7 accel: Unbreak accelerator fallback
When the user specifies a list of accelerators, we pick the first one
that initializes successfully.  Recent commit 1a3ec8c156 broke that.
Reproducer:

    $ qemu-system-x86_64 --machine accel=xen:tcg
    xencall: error: Could not obtain handle on privileged command interface: No such file or directory
    xen be core: xen be core: can't open xen interface
    can't open xen interface
    qemu-system-x86_64: failed to initialize Xen: Operation not permitted
    qemu-system-x86_64: /home/armbru/work/qemu/qom/object.c:436: object_set_accelerator_compat_props: Assertion `!object_compat_props[0]' failed.

Root cause: we register accelerator compat properties even when the
accelerator fails.  The failed assertion is
object_set_accelerator_compat_props() telling us off.  Fix by calling
it only for the accelerator that succeeded.

Fixes: 1a3ec8c156
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20190401090827.20793-6-armbru@redhat.com>
2019-04-02 13:50:09 +02:00
Markus Armbruster
1a3ec8c156 qdev: Fix latent bug with compat_props and onboard devices
Compatibility properties started life as a qdev property thing: we
supported them only for qdev properties, and implemented them with the
machinery backing command line option -global.

Recent commit fa0cb34d22 put them to use (tacitly) with memory
backend objects (subtypes of TYPE_MEMORY_BACKEND).  To make that
possible, we first moved the work of applying them from the -global
machinery into TYPE_DEVICE's .instance_post_init() method
device_post_init(), in commits ea9ce8934c and b66bbee39f, then made
it available to TYPE_MEMORY_BACKEND's .instance_post_init() method
host_memory_backend_post_init() as object_apply_compat_props(), in
commit 1c3994f6d2.

Note the code smell: we now have function name starting with object_
in hw/core/qdev.c.  It has to be there rather than in qom/, because it
calls qdev_get_machine() to find the current accelerator's and
machine's compat_props.

Turns out calling qdev_get_machine() there is problematic.  If we
qdev_create() from a machine's .instance_init() method, we call
device_post_init() and thus qdev_get_machine() before main() can
create "/machine" in QOM.  qdev_get_machine() tries to get it with
container_get(), which "helpfully" creates it as "container" object,
and returns that.  object_apply_compat_props() tries to paper over the
problem by doing nothing when the value of qdev_get_machine() isn't a
TYPE_MACHINE.  But the damage is done already: when main() later
attempts to create the real "/machine", it fails with "attempt to add
duplicate property 'machine' to object (type 'container')", and
aborts.

Since no machine .instance_init() calls qdev_create() so far, the bug
is latent.  But since I want to do that, I get to fix the bug first.

Observe that object_apply_compat_props() doesn't actually need the
MachineState, only its the compat_props member of its MachineClass and
AccelClass.  This permits a simple fix: register MachineClass and
AccelClass compat_props with the object_apply_compat_props() machinery
right after these classes get selected.

This is actually similar to how things worked before commits
ea9ce8934c and b66bbee39f, except we now register much earlier.  The
old code registered them only after the machine's .instance_init()
ran, which would've broken compatibility properties for any devices
created there.

Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190308131445.17502-2-armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
2019-03-11 22:53:44 +01:00
Anthony PERARD
b0c214ce41 accel: Allow to build QEMU without TCG or KVM support
Instead of deny build of QEMU without a default accelerator, simply
report an error when the user haven't passed -accel or -machine accel=
and TCG and KVM isn't builtin.

./configure already check that at least one accelerator is available.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-11 16:33:49 +01:00
Thomas Huth
98e56ae679 accel: Improve selection of the default accelerator
When compiling with "--disable-tcg", we currently still use "tcg"
as default accelerator. "kvm" should be used in this case instead.
Also, some downstream distros provide QEMU binaries which have "kvm"
in their names (e.g. "qemu-kvm" on RHEL or "kvm" on Ubuntu) that use
KVM by default - and some users might want to do something similar
with upstream binaries, too. Accomodate them by using "kvm:tcg" as
default when we detect such a binary name.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1538748792-19444-1-git-send-email-thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 13:57:23 +01:00
Marc-André Lureau
ea9ce8934c hw: apply accel compat properties without touching globals
Instead of registering compat properties as globals, let's keep them
in their own array, to avoid mixing with user globals.

Introduce object_apply_global_props() function, to apply compatibility
properties from a GPtrArray.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com>
2019-01-07 16:18:41 +04:00
Marc-André Lureau
745a4f5ed7 accel: register global_props like machine globals
global_props is only used for Xen xen_compat_props. It's a static
array of GlobalProperty, like machine globals in SET_MACHINE_COMPAT().
Let's register the globals the same way, without extra copy allocation.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20181204142023.15982-5-marcandre.lureau@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2018-12-11 15:45:22 -02:00
Daniel P. Berrangé
20efc49ed6 accel: use g_strsplit for parsing accelerator names
Instead of re-using the get_opt_name() method from QemuOpts to split a
string on ':', just use g_strsplit().

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20180416111743.8473-2-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2018-05-09 00:13:38 +02:00
Ian Jackson
7a64c17f3b AccelClass: Introduce accel_setup_post
This is called just before os_setup_post.  Currently none of the
accelerators provide this hook, but the Xen one is going to provide
one in a moment.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
2018-04-26 16:29:50 +01:00
Markus Armbruster
922a01a013 Move include qemu/option.h from qemu-common.h to actual users
qemu-common.h includes qemu/option.h, but most places that include the
former don't actually need the latter.  Drop the include, and add it
to the places that actually need it.

While there, drop superfluous includes of both headers, and
separate #include from file comment with a blank line.

This cleanup makes the number of objects depending on qemu/option.h
drop from 4545 (out of 4743) to 284 in my "build everything" tree.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-20-armbru@redhat.com>
[Semantic conflict with commit bdd6a90a9e in block/nvme.c resolved]
2018-02-09 13:52:16 +01:00
Laurent Vivier
d73f024722 accel: cleanup error output
Only emit "XXX accelerator not found", if there are not
further accelerators listed. eg

   accel=kvm:tcg

doesn't print a "KVM accelerator not found" warning
when it falls back to tcg, but a

   accel=kvm

prints a warning, since no fallback is given.

Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20170717144527.24534-1-lvivier@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-01 17:27:33 +02:00
Peter Xu
9ffea096b9 accel: introduce AccelClass.global_props
Introduce this new field for the accelerator classes so that each
specific accelerator in the future can register its own global
properties to be used further by the system. It works just like how the
old machine compatible properties do, but only tailored for
accelerators.

Introduce register_compat_props_array() for it. Export it so that it may
be used in other codes as well in the future.

Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-3-git-send-email-peterx@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2017-06-28 11:18:38 +02:00
Yang Zhong
a9ded6017e accel: split the tcg accelerator from accel.c file
there are some types of accelerators in qemu, and all accelerators
have their own file except tcg. tcg accelerator is also defined in
accel.c file. tcg accelerator file will be splited from accel.c and
re-name to tcg-all.c. accel/ directory will be created to include
kvm and tcg related files.

Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <1496383606-18060-2-git-send-email-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-15 11:04:05 +02:00