Index: sys/amd64/amd64/pmap.c
===================================================================
--- sys/amd64/amd64/pmap.c
+++ sys/amd64/amd64/pmap.c
@@ -421,6 +421,8 @@
 
 static vmem_t *large_vmem;
 static u_int lm_ents;
+#define	LARGEMAP_RT_MAX_ADDRESS		\
+    (LARGEMAP_MIN_ADDRESS + NBPML4 * (u_long)lm_ents)
 
 int pmap_pcid_enabled = 1;
 SYSCTL_INT(_vm_pmap, OID_AUTO, pcid_enabled, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
@@ -1060,6 +1062,7 @@
 		    pd_entry_t pde);
 static void pmap_kenter_attr(vm_offset_t va, vm_paddr_t pa, int mode);
 static vm_page_t pmap_large_map_getptp_unlocked(void);
+static vm_paddr_t pmap_large_map_kextract(vm_offset_t va);
 static void pmap_pde_attr(pd_entry_t *pde, int cache_bits, int mask);
 #if VM_NRESERVLEVEL > 0
 static void pmap_promote_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t va,
@@ -2961,6 +2964,8 @@
 
 	if (va >= DMAP_MIN_ADDRESS && va < DMAP_MAX_ADDRESS) {
 		pa = DMAP_TO_PHYS(va);
+	} else if (LARGEMAP_MIN_ADDRESS <= va && va < LARGEMAP_RT_MAX_ADDRESS) {
+		pa = pmap_large_map_kextract(va);
 	} else {
 		pde = *vtopde(va);
 		if (pde & PG_PS) {
@@ -8775,6 +8780,39 @@
 	return ((pt_entry_t *)PHYS_TO_DMAP(mphys) + pmap_pte_index(va));
 }
 
+static vm_paddr_t
+pmap_large_map_kextract(vm_offset_t va)
+{
+	pdp_entry_t *pdpe, pdp;
+	pd_entry_t *pde, pd;
+	pt_entry_t *pte, pt;
+
+	KASSERT(LARGEMAP_MIN_ADDRESS <= va && va < LARGEMAP_RT_MAX_ADDRESS,
+	    ("not largemap range %#lx", (u_long)va));
+	pdpe = pmap_large_map_pdpe(va);
+	pdp = *pdpe;
+	KASSERT((pdp & X86_PG_V) != 0,
+	    ("invalid pdp va %#lx pdpe %#lx pdp %#lx", va,
+	    (u_long)pdpe, pdp));
+	if ((pdp & X86_PG_PS) != 0) {
+		KASSERT((amd_feature & AMDID_PAGE1GB) != 0,
+		    ("no 1G pages, va %#lx pdpe %#lx pdp %#lx", va,
+		    (u_long)pdpe, pdp));
+		return ((pdp & PG_PSPDP_FRAME) | (va & PDPMASK));
+	}
+	pde = pmap_pdpe_to_pde(pdpe, va);
+	pd = *pde;
+	KASSERT((pd & X86_PG_V) != 0,
+	    ("invalid pd va %#lx pde %#lx pd %#lx", va, (u_long)pde, pd));
+	if ((pd & X86_PG_PS) != 0)
+		return ((pd & PG_PS_FRAME) | (va & PDRMASK));
+	pte = pmap_pde_to_pte(pde, va);
+	pt = *pte;
+	KASSERT((pt & X86_PG_V) != 0,
+	    ("invalid pte va %#lx pte %#lx pt %#lx", va, (u_long)pte, pt));
+	return ((pt & PG_FRAME) | (va & PAGE_MASK));
+}
+
 static int
 pmap_large_map_getva(vm_size_t len, vm_offset_t align, vm_offset_t phase,
     vmem_addr_t *vmem_res)
@@ -8891,8 +8929,8 @@
 		return;
 
 	SLIST_INIT(&spgf);
-	KASSERT(LARGEMAP_MIN_ADDRESS <= sva && sva + len <=
-	    LARGEMAP_MAX_ADDRESS + NBPML4 * (u_long)lm_ents,
+	KASSERT(LARGEMAP_MIN_ADDRESS <= sva &&
+	    sva + len <= LARGEMAP_RT_MAX_ADDRESS,
 	    ("not largemap range %#lx %#lx", (u_long)svaa, (u_long)svaa + len));
 	PMAP_LOCK(kernel_pmap);
 	for (va = sva; va < sva + len; va += inc) {
Index: sys/amd64/include/pmap.h
===================================================================
--- sys/amd64/include/pmap.h
+++ sys/amd64/include/pmap.h
@@ -119,6 +119,7 @@
 #define	PG_PROMOTED	X86_PG_AVAIL(54)	/* PDE only */
 #define	PG_FRAME	(0x000ffffffffff000ul)
 #define	PG_PS_FRAME	(0x000fffffffe00000ul)
+#define	PG_PSPDP_FRAME	(0x000fffffc0000000ul)
 
 /*
  * Promotion to a 2MB (PDE) page mapping requires that the corresponding 4KB