The ARM code has a start-powered-off property in ARMCPU, which is a subclass of CPUState. This property causes arm_cpu_reset() to set CPUState::halted to 1, signalling that the CPU should start in a halted state. Other architectures also have code which aim to achieve the same effect, but without using a property.
The ppc/spapr version has a bug where QEMU does a KVM_RUN on the vcpu before cs->halted is set to 1, causing the vcpu to run while it's still in an unitialized state (more details in patch 3). Peter Maydell mentioned the ARM start-powered-off property and Eduardo Habkost suggested making it generic, so this patch series does that, for all cases which I was able to find via grep in the code. The only problem is that I was only able to test these changes on a ppc64le pseries KVM guest, so except for patches 2 and 3, all others are only build-tested. Also, my grasp of QOM lifecycle is basically non-existant so please be aware of that when reviewing this series. The last patch may be wrong, as pointed out by Eduardo, so I marked it as RFC. It may make sense to drop it. Applies cleanly on yesterday's master. Changes since v2: General: - Added Philippe's Reviewed-by to some of the patches. Patch "ppc/spapr: Use start-powered-off CPUState property" - Set the CPUState::start_powered_off variable directly rather than using object_property_set_bool(). Suggested by Philippe. Patch "sparc/sun4m: Remove main_cpu_reset()" - New patch. Suggested by Philippe. Patch "sparc/sun4m: Use start-powered-off CPUState property" - Remove secondary_cpu_reset(). Suggested by Philippe. - Remove setting of `cs->halted = 1` from cpu_devinit(). Suggested by Philippe. Patch "Don't set CPUState::halted in cpu_devinit()" - Squashed into previous patch. Suggested by Philippe. Patch "sparc/sun4m: Use one cpu_reset() function for main and secondary CPUs" - Dropped. Patch "target/s390x: Use start-powered-off CPUState property" - Set the CPUState::start_powered_off variable directly rather than using object_property_set_bool(). Suggested by Philippe. - Mention in the commit message Eduardo's observation that before this patch, the code didn't set cs->halted on reset. Thiago Jung Bauermann (8): target/arm: Move start-powered-off property to generic CPUState target/arm: Move setting of CPU halted state to generic code ppc/spapr: Use start-powered-off CPUState property ppc/e500: Use start-powered-off CPUState property mips/cps: Use start-powered-off CPUState property sparc/sun4m: Remove main_cpu_reset() sparc/sun4m: Use start-powered-off CPUState property target/s390x: Use start-powered-off CPUState property exec.c | 1 + hw/core/cpu.c | 2 +- hw/mips/cps.c | 6 +++--- hw/ppc/e500.c | 10 +++++++--- hw/ppc/spapr_cpu_core.c | 10 +++++----- hw/sparc/sun4m.c | 28 ++-------------------------- include/hw/core/cpu.h | 4 ++++ target/arm/cpu.c | 4 +--- target/arm/cpu.h | 3 --- target/arm/kvm32.c | 2 +- target/arm/kvm64.c | 2 +- target/s390x/cpu.c | 2 +- 12 files changed, 27 insertions(+), 47 deletions(-)
