KVM selftests changes for 6.15, part 1
- Misc cleanups and prep work.
- Annotate _no_printf() with "printf" so that pr_debug() statements are
checked by the compiler for default builds (and pr_info() when QUIET).
- Attempt to whack the last LLC references/misses mole in the Intel PMU
counters test by adding a data load and doing CLFLUSH{OPT} on the data
instead of the code being executed. The theory is that modern Intel CPUs
have learned new code prefetching tricks that bypass the PMU counters.
- Fix a flaw in the Intel PMU counters test where it asserts that an event is
counting correctly without actually knowing what the event counts on the
underlying hardware.