A core includes a memory buffer and executes an instruction within a virtual machine. A processor tracer captures trace data and formats the trace data as trace data packets. An event-based sampler generates field data for a sampling record in response to occurrence of an event of a certain type as a result of execution of the instruction. The processor tracer, upon receipt of the field data: formats the field data into elements of the sampling record as a group of record packets; inserts the group of record packets between the trace data packets as a combined packet stream; and stores the combined packet stream in the memory buffer as a series of output pages. The core, when in guest profiling mode, executes a virtual machine monitor to map output pages of the memory buffer to host physical pages of main memory using multilevel page tables.