On 01/11/19 23:41, Suthikulpanit, Suravee wrote:
> +void kvm_request_apicv_update(struct kvm *kvm, bool activate, ulong bit)
> +{
> + if (activate) {
> + if (!test_and_clear_bit(bit, &kvm->arch.apicv_deact_msk) ||
> + !kvm_apicv_activated(kvm))
> + return;
> + } else {
> + if (test_and_set_bit(bit, &kvm->arch.apicv_deact_msk) ||
> + kvm_apicv_activated(kvm))
> + return;
> + }
> +
> + kvm_make_all_cpus_request(kvm, KVM_REQ_APICV_UPDATE);
> +}
> +EXPORT_SYMBOL_GPL(kvm_request_apicv_update);
> +
It's worth documenting the locking requirements of
kvm_request_apicv_update (it can also be negative requirements, such as
"don't hold any lock"), because kvm_make_all_cpus_request is a somewhat
deadlock-prone API.
Again, something I'll check after a more thorough review.
Paolo
