KVM: selftests: Test consistency of CPUID with num of gp counters

Add a test to verify that KVM correctly emulates MSR-based accesses to
general purpose counters based on guest CPUID, e.g. that accesses to
non-existent counters #GP and accesses to existent counters succeed.

Note, for compatibility reasons, KVM does not emulate #GP when
MSR_P6_PERFCTR[0|1] is not present (writes should be dropped).

Co-developed-by: Like Xu <likexu@tencent.com>
Signed-off-by: Like Xu <likexu@tencent.com>
Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Tested-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://lore.kernel.org/r/20240109230250.424295-19-seanjc@google.com


Signed-off-by: Sean Christopherson <seanjc@google.com>