On 8/17/20 6:47 AM, David Gibson wrote: > On Wed, Jul 22, 2020 at 11:56:49PM -0300, Thiago Jung Bauermann wrote: >> 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. > > This series appears to break the Travis build for a MIPS target: > > Unexpected error in qdev_prop_set_after_realize() at > /home/travis/build/dgibson/qemu/hw/core/qdev-properties.c:30: > qemu-system-mips64el: Attempt to set property 'start-powered-off' on > anonymous device (type 'I6400-mips64-cpu') after it was realized > Broken pipe > /home/travis/build/dgibson/qemu/tests/qtest/libqtest.c:175: kill_qemu() > detected QEMU death from signal 6 (Aborted) (core dumped) > Aborted (core dumped) > ERROR qom-test - too few tests run (expected 8, got 0) > /home/travis/build/dgibson/qemu/tests/Makefile.include:650: recipe for target > 'check-qtest-mips64el' failed
Good catch. hw/mips/cps.c, hw/ppc/e500.c and hw/sparc/sun4m.c are incorrectly setting the property after the cpu is realized because the cpu is created with cpu_create(). We need to create them with object_initialize_child() and realize them manually with qdev_realize().