diff --git a/Documentation/kvm/cpuid.txt b/Documentation/kvm/cpuid.txt
index 14a12ea..8820685 100644
--- a/Documentation/kvm/cpuid.txt
+++ b/Documentation/kvm/cpuid.txt
@@ -36,6 +36,9 @@
 KVM_FEATURE_CLOCKSOURCE2           ||     3 || kvmclock available at msrs
                                    ||       || 0x4b564d00 and 0x4b564d01
 ------------------------------------------------------------------------------
+KVM_FEATURE_ASYNC_PF               ||     4 || async pf can be enabled by
+                                   ||       || writing to msr 0x4b564d02
+------------------------------------------------------------------------------
 KVM_FEATURE_CLOCKSOURCE_STABLE_BIT ||    24 || host will warn if no guest-side
                                    ||       || per-cpu warps are expected in
                                    ||       || kvmclock.