Inspect virtual CPU resources
lscpu displays logical CPU count and the socket/core/thread topology exposed to the guest. nproc reports processing units available to the current process; affinity and execution limits can affect its result.
To inspect processor entries and model information directly:
processor entry represents a logical CPU visible to the guest, not necessarily a distinct physical core on the host.
Monitor use
Runtop and press 1 to display per-logical-CPU usage, or use htop if installed. CPU saturation is only one possible bottleneck; also inspect memory, disk I/O and application limits.
If the count does not match an approved upgrade, check the activation instructions and perform the required full power cycle. See CPU cores and sockets.