Features/QOM/CPU

QOM CPU

Convert CPUState to QOM.

Motivation

1. Short-term: Allow inspecting and modifying CPU properties via QOM.
2. Short-term: Avoid common target code doing ifs or switches on CPU identifiers.
   • target-arm/helper.c: cpu_reset_model_id()
3. Short-term: Replace CPU_COMMON macro and duplicated reset code by inheritance.
4. Mid-term: Avoid dependency of common code on #defines from cpu.h.
5. Mid-term: Ease instantiation of mixed software-visible cores within one target, e.g.
   • NXP LPC43xx: Cortex-M4 + Cortex-M0
   • ARM big.LITTLE: Cortex-A15 + Cortex-A7
   • Freescale Vybrid VF6xx/VF7xx: Cortex-A5 + Cortex-M4
6. Long-term: Work towards allowing to compile multiple targets into one executable.
   • Renesas R-Car H1, M1A: ARM Cortex-A9 + SH-4A
   • Renesas R-Home S1: ARM Cortex-A9 + SH-4A + ARM7TDMI-S

"CPU" name conflict

Identifier	current	interim	final
struct CPU$archState or struct CPUState_$arch	defined in target-*/cpu.h		???
#define CPUState	alias to CPU$archState / CPUState_$arch		dropped in favor of CPU
struct CPUClass		class
#define CPU_CLASS(class)		cast macro for class
struct CPU		object
#define CPU(obj)		cast macro for object
#define CPU_GET_CLASS(obj)		macro to obtain class pointer

Resolved by renaming existing CPUState to CPUArchState and by using struct CPUState for the object state, while using CPU(obj) as macro for casting.

Status

QOM CPUState exists, former CPUState is renamed to CPUArchState.

Individual targets have been converted, some are pending review, other conversions are being simplified.

Field movements from CPUArchState to CPUState (and subsequent removal of CPUArchState and CPU_COMMON) are waiting on completion of conversion of all targets.

NB: Due to hosting issues, branches have moved to GitHub.

name	depends on
type_init()
qom-user	type_init()
object_class_get_list()
qom-cpu	qom-user
qom-cpu-arm	qom-cpu
qom-cpu-unicore32	qom-cpu
qom-cpu-s390	qom-cpu
qom-cpu-x86, part 1	qom-cpu
qom-cpu-sparc	qom-cpu
qom-cpu-ppc	qom-cpu
qom-cpu-alpha	qom-cpu
qom-cpu-sh4 (to be updated)	qom-cpu, object_realize()
qom-cpu-others (to be split up)	qom-cpu