On Tue, Sep 22, 2026, Ritesh Harjani (IBM) wrote:
> diff --git a/tools/testing/selftests/kvm/kvm_create_max_vcpus.c
> b/tools/testing/selftests/kvm/kvm_create_max_vcpus.c
> index 59ddc3757943..45a9d8b369b5 100644
> --- a/tools/testing/selftests/kvm/kvm_create_max_vcpus.c
> +++ b/tools/testing/selftests/kvm/kvm_create_max_vcpus.c
> @@ -20,16 +20,29 @@
> void test_vcpu_creation(int first_vcpu_id, int num_vcpus)
> {
> struct kvm_vm *vm;
> - int i;
> + struct kvm_vcpu *vcpu;
> + int i, created = 0;
>
> pr_info("Testing creating %d vCPUs, with IDs %d...%d.\n",
> num_vcpus, first_vcpu_id, first_vcpu_id + num_vcpus - 1);
>
> vm = vm_create_barebones();
>
> - for (i = first_vcpu_id; i < first_vcpu_id + num_vcpus; i++)
> - /* This asserts that the vCPU was created. */
> - __vm_vcpu_add(vm, i);
> + for (i = first_vcpu_id; i < first_vcpu_id + num_vcpus; i++) {
> + vcpu = __vm_vcpu_try_add(vm, i);
> + if (vcpu) {
> + created++;
> + continue;
> + }
Oof. I dislike this, to put it very mildly. Is this the KVM_CAP_PPC_SMT thing
again, or something else?
Assuming it's KVM_CAP_PPC_SMT, is there really no way userspace can pre-probe
the
"real" limit? Or modify the test to enable KVM_CAP_PPC_SMT and do the proper
striding? Eating -ENOMEM is all kinds of gross, and I really don't want to add
__vm_vcpu_try_add().
