Merge tag 'kvm-x86-selftests_6.15-1' of https://github.com/kvm-x86/linux into HEAD

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.