On Thu, 7 Dec 2017 16:05:50 +0000 Peter Maydell <peter.mayd...@linaro.org> wrote:
> Hi; I'm currently writing '-cpu max' support for ARM. For that I'd > like to be able to do the "probe host kernel for its supported feature > set" in the CPU object's instance-init function, but I'd like to do > it just once and cache the answer. Can I rely on something or other > having the BQL or otherwise ensuring that two threads don't run > the instance_init method in parallel (eg in a hotplug situation), > or do I need to create and use my own mutex to protect the cached > answer data? considering cached data shouldn't change during qemu lifetime it shouldn't be possible for instance_init() to clash at hotplug time as object_new(cpu) calls serialized within monitor/qmp loop. But why cpu's instance_init, we could cache host's value at configure_accelerator() time (could be different depending on accel). CCing Eduardo as he is the one who worked on -cpu max for x86 (If I recall correctly) > > thanks > -- PMM >
