(Cc'ing qemu-devel@ mailing list since this is a development question). On 9/19/21 19:44, Robert Henry wrote: > What is the range of the values for vcpu_index given to callbacks, such as: > > typedef void (*qemu_plugin_vcpu_udata_cb_t)(unsigned int vcpu_index, > void *userdata); > > Empirically, when QEMU is in system mode, the maximum vcpu_index is 1 > less than the -smp cpus=$(NCPUS) value. > > Empirically, when QEMU is in user mode, the values for vcpu_index slowly > increase without an apparent upper bound known statically (or when the > plugin is loaded?).
Isn't it related to clone() calls? I'd expect new threads use a new vCPU, incrementing vcpu_index. But that is just a guess without having looked at the code to corroborate... Regards, Phil.
