Index: sys/amd64/include/vmparam.h
===================================================================
--- sys/amd64/include/vmparam.h
+++ sys/amd64/include/vmparam.h
@@ -253,6 +253,11 @@
  */
 #define	VM_BATCHQUEUE_SIZE	31
 
+/*
+ * The pmap can create non-transparent large page mappings.
+ */
+#define	PMAP_HAS_LARGEPAGES	1
+
 /*
  * Need a page dump array for minidump.
  */
Index: sys/arm/include/vmparam.h
===================================================================
--- sys/arm/include/vmparam.h
+++ sys/arm/include/vmparam.h
@@ -193,6 +193,11 @@
 
 #define	DEVMAP_MAX_VADDR	ARM_VECTORS_HIGH
 
+/*
+ * No non-transparent large page support in the pmap.
+ */
+#define	PMAP_HAS_LARGEPAGES	0
+
 /*
  * Need a page dump array for minidump.
  */
Index: sys/arm64/include/vmparam.h
===================================================================
--- sys/arm64/include/vmparam.h
+++ sys/arm64/include/vmparam.h
@@ -243,6 +243,11 @@
 
 #define	DEVMAP_MAX_VADDR	VM_MAX_KERNEL_ADDRESS
 
+/*
+ * The pmap can create non-transparent large page mappings.
+ */
+#define	PMAP_HAS_LARGEPAGES	1
+
 /*
  * Need a page dump array for minidump.
  */
Index: sys/i386/include/vmparam.h
===================================================================
--- sys/i386/include/vmparam.h
+++ sys/i386/include/vmparam.h
@@ -240,6 +240,11 @@
 #define	PHYS_TO_DMAP(x)	({ panic("No direct map exists"); 0; })
 #define	DMAP_TO_PHYS(x)	({ panic("No direct map exists"); 0; })
 
+/*
+ * No non-transparent large page support in the pmap.
+ */
+#define	PMAP_HAS_LARGEPAGES	0
+
 /*
  * Need a page dump array for minidump.
  */
Index: sys/kern/uipc_shm.c
===================================================================
--- sys/kern/uipc_shm.c
+++ sys/kern/uipc_shm.c
@@ -1067,10 +1067,8 @@
 		return (EINVAL);
 
 	largepage = (shmflags & SHM_LARGEPAGE) != 0;
-#if !defined(__amd64__)
-	if (largepage)
+	if (largepage && !PMAP_HAS_LARGEPAGES)
 		return (ENOTTY);
-#endif
 
 	/*
 	 * Currently only F_SEAL_SEAL may be set when creating or opening shmfd.
Index: sys/mips/include/vmparam.h
===================================================================
--- sys/mips/include/vmparam.h
+++ sys/mips/include/vmparam.h
@@ -197,6 +197,11 @@
 #define	PHYS_TO_DMAP(x)	MIPS_PHYS_TO_DIRECT(x)
 #define	DMAP_TO_PHYS(x)	MIPS_DIRECT_TO_PHYS(x)
 
+/*
+ * No non-transparent large page support in the pmap.
+ */
+#define	PMAP_HAS_LARGEPAGES	0
+
 /*
  * Need a page dump array for minidump.
  */
Index: sys/powerpc/include/vmparam.h
===================================================================
--- sys/powerpc/include/vmparam.h
+++ sys/powerpc/include/vmparam.h
@@ -327,4 +327,9 @@
 	KASSERT(hw_direct_map, ("Direct map not provided by PMAP"));	\
 	(x) &~ DMAP_BASE_ADDRESS; })
 
+/*
+ * No non-transparent large page support in the pmap.
+ */
+#define	PMAP_HAS_LARGEPAGES	0
+
 #endif /* _MACHINE_VMPARAM_H_ */
Index: sys/riscv/include/vmparam.h
===================================================================
--- sys/riscv/include/vmparam.h
+++ sys/riscv/include/vmparam.h
@@ -236,6 +236,11 @@
 
 #define	DEVMAP_MAX_VADDR	VM_MAX_KERNEL_ADDRESS
 
+/*
+ * No non-transparent large page support in the pmap.
+ */
+#define	PMAP_HAS_LARGEPAGES	0
+
 /*
  * Need a page dump array for minidump.
  */
Index: sys/vm/vm_fault.c
===================================================================
--- sys/vm/vm_fault.c
+++ sys/vm/vm_fault.c
@@ -487,6 +487,8 @@
 	 * populate only busies the first page in superpage run.
 	 */
 	if (bdry_idx != 0) {
+		KASSERT(PMAP_HAS_LARGEPAGES,
+		    ("missing pmap support for large pages"));
 		m = vm_page_lookup(fs->first_object, pager_first);
 		vm_fault_populate_check_page(m);
 		VM_OBJECT_WUNLOCK(fs->first_object);