On Wed, Jun 10, 2026, Ritesh Harjani (IBM) wrote:

From: Nicholas Piggin <npiggin@gmail.com>

powerpc's maximum permitted vCPU ID depends on the VM's SMT mode, and
the maximum reported by KVM_CAP_MAX_VCPU_ID exceeds a simple non-SMT
VM's limit.

The powerpc KVM selftest port uses non-SMT VMs, so add a workaround
to the kvm_create_max_vcpus test case to limit vCPU IDs to
KVM_CAP_MAX_VCPUS on powerpc.

How is this not a KVM bug?  Literally the reason this test exists is to validate
KVM's advertised KVM_CAP_MAX_VCPU_ID and KVM_CAP_MAX_VCPUS.