AMD64_EVENTSEL_HOST_GUEST_MASK
if (data & AMD64_EVENTSEL_HOST_GUEST_MASK)
pmu->reserved_bits &= ~AMD64_EVENTSEL_HOST_GUEST_MASK;
host_guest_bits = pmc->eventsel & AMD64_EVENTSEL_HOST_GUEST_MASK;
if (host_guest_bits == AMD64_EVENTSEL_HOST_GUEST_MASK)