[Qemu-devel] [RFC 00/25] QOMify accelerator code

[Eduardo Habkost <ehabkost@redhat.com>]

Git tree:
  https://github.com/ehabkost/qemu-hacks/tree/accel-qom.v1

This is an attempt to convert the accel initialization and registration code
to be QOM-based. I see two use cases for this:

 * KVM-specific CPU compat bits;
 * Probing for accelerator-specific CPU model "runnable" information.

= KVM-specific compat bits =

Currently, the PC compat code that deals with KVM-specific CPUID compat bits
can't use compat_props to control compatibility, because it needs to affect the
X86CPU CPUID initialization behavior only when KVM is enabled. The solution I
propose is to have a "x86-kvm-accel" class which would be responsible for the
KVM-specific CPU initialization behavior. Any compatibility properties for that
behavior could then be tuned using "x86-kvm-accel" compat properties.

To be able to implement x86-specific accelerator methods, a TYPE_X86_ACCEL
interface was introduced.

Patches 19-24 implements this (except for the actual compat properties).

= Accel-specific runnable information =

There are plans to eventually make the "query-cpu-definitions" QMP command
return "runnable" information, which is accelerator-specific (e.g. some CPU
models may be runnable when using KVM, but not when using TCG). The existing
accelerator code maintains lots of global state, and the QOM-based approach will
allow us to eventually make query-cpu-definitions instantiate short-lived
accelerator objects (without affecting any machine and/or global state) to query
for accelerator-specific information.

Cc: Michael Mueller <mimu@linux.vnet.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: "Jason J. Herne" <jjherne@linux.vnet.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andreas Färber <afaerber@suse.de>
Cc: Marcel Apfelbaum <marcel.a@redhat.com>

Eduardo Habkost (25):
  vl.c: Small coding style fix
  accel: Move accel code to accel.c
  accel: Create struct AccelType
  accel: Simplify configure_accelerator() using AccelType *acc variable
  accel: Move accel name lookup to separate function
  accel: Use QOM classes for accel types
  accel: Make AccelClass.available() optional
  accel: Move KVM accel registration to kvm-all.c
  accel: Move Xen registration code to xen-common.c
  accel: Move qtest accel registration to qtest.c
  accel: Remove tcg_available() function
  accel: Move accel init/allowed code to separate function
  accel: Rename 'init' method to 'init_machine'
  accel: Pass MachineState object to accel init functions
  accel: Create accel object when initializing machine
  accel: Save AccelState on MachineState when initializing
  kvm: Make KVMState be the TYPE_KVM_ACCEL instance struct
  accel: Get target name as argument when initializing accelerator
  accel: Use target-specific accel class if available
  accel: TYPE_X86_ACCEL interface
  kvm: x86 KVM accelerator subclass
  target-i386: Add AccelState parameter to cpu_x86_create()
  target-i386: Move accelerator-specific code outside
    X86CPU.instance_init
  target-i386: Accept "host" as value for CPU vendor
  target-i386: Move KVM CPUID hacking to accelerator cpu_post_init hook

 arch_init.c                |  11 +--
 hw/core/Makefile.objs      |   1 +
 hw/core/accel.c            | 171 +++++++++++++++++++++++++++++++++++++++++++++
 hw/i386/pc.c               |   3 +-
 include/hw/accel.h         |  60 ++++++++++++++++
 include/hw/boards.h        |   1 +
 include/hw/i386/accel.h    |  42 +++++++++++
 include/hw/xen/xen.h       |   1 -
 include/qemu/typedefs.h    |   5 ++
 include/sysemu/arch_init.h |   1 -
 include/sysemu/kvm.h       |   5 +-
 include/sysemu/qtest.h     |   1 -
 kvm-all.c                  |  40 +++++++++--
 kvm-stub.c                 |   5 --
 qtest.c                    |  27 ++++++-
 target-i386/Makefile.objs  |   1 +
 target-i386/accel.c        |  38 ++++++++++
 target-i386/cpu.c          | 101 +++++++++++---------------
 target-i386/cpu.h          |   2 +-
 target-i386/kvm.c          |  70 +++++++++++++++++++
 vl.c                       |  83 +---------------------
 xen-common-stub.c          |   6 --
 xen-common.c               |  25 ++++++-
 23 files changed, 528 insertions(+), 172 deletions(-)
 create mode 100644 hw/core/accel.c
 create mode 100644 include/hw/accel.h
 create mode 100644 include/hw/i386/accel.h
 create mode 100644 target-i386/accel.c

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1.9.3