diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index c509dcc2f7d..025c3c365de 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -1487,6 +1487,12 @@ hammer_time(u_int64_t modulep, u_int64_t physfree)
 
 	finishidentcpu();	/* Final stage of CPU initialization */
 
+	invlpgb_works = (amd_extended_feature_extensions &
+	    AMDFEID_INVLPGB) != 0;
+	TUNABLE_INT_FETCH("vm.pmap.invlpgb_works", &invlpgb_works);
+	if (invlpgb_works)
+		invlpgb_maxcnt = cpu_procinfo3 & AMDID_INVLPGB_MAXCNT;
+
 	/*
 	 * Initialize the clock before the console so that console
 	 * initialization can use DELAY().
diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index cf0fc7184f5..ff5c229b765 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -550,6 +550,10 @@ SYSCTL_INT(_vm_pmap, OID_AUTO, pcid_enabled, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
 int invpcid_works = 0;
 SYSCTL_INT(_vm_pmap, OID_AUTO, invpcid_works, CTLFLAG_RD, &invpcid_works, 0,
     "Is the invpcid instruction available ?");
+int invlpgb_works;
+SYSCTL_INT(_vm_pmap, OID_AUTO, invlpgb_works, CTLFLAG_RD, &invlpgb_works, 0,
+    "Is the invlpgb instruction available?");
+int invlpgb_maxcnt;
 int pmap_pcid_invlpg_workaround = 0;
 SYSCTL_INT(_vm_pmap, OID_AUTO, pcid_invlpg_workaround,
     CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
diff --git a/sys/amd64/include/pmap.h b/sys/amd64/include/pmap.h
index 273693e1f78..0819b3bc294 100644
--- a/sys/amd64/include/pmap.h
+++ b/sys/amd64/include/pmap.h
@@ -424,6 +424,8 @@ extern vm_offset_t virtual_end;
 extern vm_paddr_t dmaplimit;
 extern int pmap_pcid_enabled;
 extern int invpcid_works;
+extern int invlpgb_works;
+extern int invlpgb_maxcnt;
 extern int pmap_pcid_invlpg_workaround;
 extern int pmap_pcid_invlpg_workaround_uena;