Index: lib/libkvm/kvm_minidump_aarch64.c
===================================================================
--- lib/libkvm/kvm_minidump_aarch64.c
+++ lib/libkvm/kvm_minidump_aarch64.c
@@ -82,7 +82,7 @@
 _aarch64_minidump_initvtop(kvm_t *kd)
 {
 	struct vmstate *vmst;
-	off_t off, sparse_off;
+	off_t off, dump_avail_off, sparse_off;
 
 	vmst = _kvm_malloc(kd, sizeof(*vmst));
 	if (vmst == NULL) {
@@ -102,7 +102,7 @@
 	}
 
 	vmst->hdr.version = le32toh(vmst->hdr.version);
-	if (vmst->hdr.version != MINIDUMP_VERSION) {
+	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
 		_kvm_err(kd, kd->program, "wrong minidump version. "
 		    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
 		return (-1);
@@ -114,15 +114,21 @@
 	vmst->hdr.dmapphys = le64toh(vmst->hdr.dmapphys);
 	vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase);
 	vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend);
+	vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
+	    le32toh(vmst->hdr.dumpavailsize) : 0;
 
 	/* Skip header and msgbuf */
-	off = AARCH64_PAGE_SIZE + aarch64_round_page(vmst->hdr.msgbufsize);
+	dump_avail_off = AARCH64_PAGE_SIZE + aarch64_round_page(vmst->hdr.msgbufsize);
+
+	/* Skip dump_avail */
+	off = dump_avail_off + aarch64_round_page(vmst->hdr.dumpavailsize);
 
 	/* build physical address lookup table for sparse pages */
 	sparse_off = off + aarch64_round_page(vmst->hdr.bitmapsize) +
 	    aarch64_round_page(vmst->hdr.pmapsize);
-	if (_kvm_pt_init(kd, vmst->hdr.bitmapsize, off, sparse_off,
-	    AARCH64_PAGE_SIZE, sizeof(uint64_t)) == -1) {
+	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
+	    vmst->hdr.bitmapsize, off, sparse_off, AARCH64_PAGE_SIZE,
+	    sizeof(uint64_t)) == -1) {
 		return (-1);
 	}
 	off += aarch64_round_page(vmst->hdr.bitmapsize);
@@ -257,7 +263,9 @@
 	}
 
 	while (_kvm_bitmap_next(&bm, &bmindex)) {
-		pa = bmindex * AARCH64_PAGE_SIZE;
+		pa = _kvm_bit_id_pa(kd, bmindex, AARCH64_PAGE_SIZE);
+		if (pa == _KVM_PA_INVALID)
+			break;
 		dva = vm->hdr.dmapbase + pa;
 		if (vm->hdr.dmapend < (dva + AARCH64_PAGE_SIZE))
 			break;
Index: lib/libkvm/kvm_minidump_amd64.c
===================================================================
--- lib/libkvm/kvm_minidump_amd64.c
+++ lib/libkvm/kvm_minidump_amd64.c
@@ -123,7 +123,7 @@
 _amd64_minidump_initvtop(kvm_t *kd)
 {
 	struct vmstate *vmst;
-	off_t off, sparse_off;
+	off_t off, dump_avail_off, sparse_off;
 
 	vmst = _kvm_malloc(kd, sizeof(*vmst));
 	if (vmst == NULL) {
@@ -143,10 +143,10 @@
 
 	/*
 	 * NB: amd64 minidump header is binary compatible between version 1
-	 * and version 2; this may not be the case for the future versions.
+	 * and version 2; version 3 adds the dumpavailsize field
 	 */
 	vmst->hdr.version = le32toh(vmst->hdr.version);
-	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
+	if (vmst->hdr.version > MINIDUMP_VERSION || vmst->hdr.version < 1) {
 		_kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d",
 		    MINIDUMP_VERSION, vmst->hdr.version);
 		return (-1);
@@ -157,14 +157,20 @@
 	vmst->hdr.kernbase = le64toh(vmst->hdr.kernbase);
 	vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase);
 	vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend);
+	vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
+	    le32toh(vmst->hdr.dumpavailsize) : 0;
 
 	/* Skip header and msgbuf */
-	off = AMD64_PAGE_SIZE + amd64_round_page(vmst->hdr.msgbufsize);
+	dump_avail_off = AMD64_PAGE_SIZE + amd64_round_page(vmst->hdr.msgbufsize);
+
+	/* Skip dump_avail */
+	off = dump_avail_off + amd64_round_page(vmst->hdr.dumpavailsize);
 
 	sparse_off = off + amd64_round_page(vmst->hdr.bitmapsize) +
 	    amd64_round_page(vmst->hdr.pmapsize);
-	if (_kvm_pt_init(kd, vmst->hdr.bitmapsize, off, sparse_off,
-	    AMD64_PAGE_SIZE, sizeof(uint64_t)) == -1) {
+	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
+	    vmst->hdr.bitmapsize, off, sparse_off, AMD64_PAGE_SIZE,
+	    sizeof(uint64_t)) == -1) {
 		return (-1);
 	}
 	off += amd64_round_page(vmst->hdr.bitmapsize);
@@ -372,7 +378,7 @@
 			pa = (pde & AMD64_PG_PS_FRAME) +
 			    ((va & AMD64_PDRMASK) ^ VA_OFF(vm, va));
 			dva = vm->hdr.dmapbase + pa;
-			_kvm_bitmap_set(&bm, pa, AMD64_PAGE_SIZE);
+			_kvm_bitmap_set(&bm, _kvm_pa_bit_id(kd, pa, AMD64_PAGE_SIZE));
 			if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
 			    _amd64_entry_to_prot(pde), AMD64_NBPDR, pgsz)) {
 				goto out;
@@ -392,7 +398,8 @@
 			pa = pte & AMD64_PG_FRAME;
 			dva = vm->hdr.dmapbase + pa;
 			if ((pte & AMD64_PG_V) != 0) {
-				_kvm_bitmap_set(&bm, pa, AMD64_PAGE_SIZE);
+				_kvm_bitmap_set(&bm,
+				    _kvm_pa_bit_id(kd, pa, AMD64_PAGE_SIZE));
 				if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
 				    _amd64_entry_to_prot(pte), pgsz, 0)) {
 					goto out;
@@ -403,7 +410,9 @@
 	}
 
 	while (_kvm_bitmap_next(&bm, &bmindex)) {
-		pa = bmindex * AMD64_PAGE_SIZE;
+		pa = _kvm_bit_id_pa(kd, bmindex, AMD64_PAGE_SIZE);
+		if (pa == _KVM_PA_INVALID)
+			break;
 		dva = vm->hdr.dmapbase + pa;
 		if (vm->hdr.dmapend < (dva + pgsz))
 			break;
Index: lib/libkvm/kvm_minidump_arm.c
===================================================================
--- lib/libkvm/kvm_minidump_arm.c
+++ lib/libkvm/kvm_minidump_arm.c
@@ -86,7 +86,7 @@
 _arm_minidump_initvtop(kvm_t *kd)
 {
 	struct vmstate *vmst;
-	off_t off, sparse_off;
+	off_t off, dump_avail_off, sparse_off;
 
 	vmst = _kvm_malloc(kd, sizeof(*vmst));
 	if (vmst == NULL) {
@@ -108,7 +108,7 @@
 		return (-1);
 	}
 	vmst->hdr.version = _kvm32toh(kd, vmst->hdr.version);
-	if (vmst->hdr.version != MINIDUMP_VERSION) {
+	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
 		_kvm_err(kd, kd->program, "wrong minidump version. "
 		    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
 		return (-1);
@@ -123,14 +123,20 @@
 		/* This is a safe default as 1K pages are not used. */
 		vmst->hdr.mmuformat = MINIDUMP_MMU_FORMAT_V6;
 	}
+	vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
+	    _kvm32toh(kd, vmst->hdr.dumpavailsize) : 0;
 
 	/* Skip header and msgbuf */
-	off = ARM_PAGE_SIZE + arm_round_page(vmst->hdr.msgbufsize);
+	dump_avail_off = ARM_PAGE_SIZE + arm_round_page(vmst->hdr.msgbufsize);
+
+	/* Skip dump_avail */
+	off = dump_avail_off + arm_round_page(vmst->hdr.dumpavailsize);
 
 	sparse_off = off + arm_round_page(vmst->hdr.bitmapsize) +
 	    arm_round_page(vmst->hdr.ptesize);
-	if (_kvm_pt_init(kd, vmst->hdr.bitmapsize, off, sparse_off,
-	    ARM_PAGE_SIZE, sizeof(uint32_t)) == -1) {
+	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
+	    vmst->hdr.bitmapsize, off, sparse_off, ARM_PAGE_SIZE,
+	    sizeof(uint32_t)) == -1) {
 		return (-1);
 	}
 	off += arm_round_page(vmst->hdr.bitmapsize);
Index: lib/libkvm/kvm_minidump_i386.c
===================================================================
--- lib/libkvm/kvm_minidump_i386.c
+++ lib/libkvm/kvm_minidump_i386.c
@@ -91,7 +91,7 @@
 _i386_minidump_initvtop(kvm_t *kd)
 {
 	struct vmstate *vmst;
-	off_t off, sparse_off;
+	off_t off, dump_avail_off, sparse_off;
 
 	vmst = _kvm_malloc(kd, sizeof(*vmst));
 	if (vmst == NULL) {
@@ -109,7 +109,7 @@
 		return (-1);
 	}
 	vmst->hdr.version = le32toh(vmst->hdr.version);
-	if (vmst->hdr.version != MINIDUMP_VERSION) {
+	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
 		_kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d",
 		    MINIDUMP_VERSION, vmst->hdr.version);
 		return (-1);
@@ -119,14 +119,20 @@
 	vmst->hdr.ptesize = le32toh(vmst->hdr.ptesize);
 	vmst->hdr.kernbase = le32toh(vmst->hdr.kernbase);
 	vmst->hdr.paemode = le32toh(vmst->hdr.paemode);
+	vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
+	    le32toh(vmst->hdr.dumpavailsize) : 0;
 
 	/* Skip header and msgbuf */
-	off = I386_PAGE_SIZE + i386_round_page(vmst->hdr.msgbufsize);
+	dump_avail_off = I386_PAGE_SIZE + i386_round_page(vmst->hdr.msgbufsize);
+
+	/* Skip dump_avail */
+	off = dump_avail_off + i386_round_page(vmst->hdr.dumpavailsize);
 
 	sparse_off = off + i386_round_page(vmst->hdr.bitmapsize) +
 	    i386_round_page(vmst->hdr.ptesize);
-	if (_kvm_pt_init(kd, vmst->hdr.bitmapsize, off, sparse_off,
-	    I386_PAGE_SIZE, sizeof(uint32_t)) == -1) {
+	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
+	    vmst->hdr.bitmapsize, off, sparse_off, I386_PAGE_SIZE,
+	    sizeof(uint32_t)) == -1) {
 		return (-1);
 	}
 	off += i386_round_page(vmst->hdr.bitmapsize);
Index: lib/libkvm/kvm_minidump_mips.c
===================================================================
--- lib/libkvm/kvm_minidump_mips.c
+++ lib/libkvm/kvm_minidump_mips.c
@@ -85,7 +85,7 @@
 _mips_minidump_initvtop(kvm_t *kd)
 {
 	struct vmstate *vmst;
-	off_t off, sparse_off;
+	off_t off, dump_avail_off, sparse_off;
 
 	vmst = _kvm_malloc(kd, sizeof(*vmst));
 	if (vmst == NULL) {
@@ -113,7 +113,7 @@
 		return (-1);
 	}
 	vmst->hdr.version = _kvm32toh(kd, vmst->hdr.version);
-	if (vmst->hdr.version != MINIDUMP_VERSION) {
+	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
 		_kvm_err(kd, kd->program, "wrong minidump version. "
 		    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
 		return (-1);
@@ -124,14 +124,20 @@
 	vmst->hdr.kernbase = _kvm64toh(kd, vmst->hdr.kernbase);
 	vmst->hdr.dmapbase = _kvm64toh(kd, vmst->hdr.dmapbase);
 	vmst->hdr.dmapend = _kvm64toh(kd, vmst->hdr.dmapend);
+	vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
+	    _kvm32toh(kd, vmst->hdr.dumpavailsize) : 0;
 
 	/* Skip header and msgbuf */
-	off = MIPS_PAGE_SIZE + mips_round_page(vmst->hdr.msgbufsize);
+	dump_avail_off = MIPS_PAGE_SIZE + mips_round_page(vmst->hdr.msgbufsize);
+
+	/* Skip dump_avail */
+	off = dump_avail_off + mips_round_page(vmst->hdr.dumpavailsize);
 
 	sparse_off = off + mips_round_page(vmst->hdr.bitmapsize) +
 	    mips_round_page(vmst->hdr.ptesize);
-	if (_kvm_pt_init(kd, vmst->hdr.bitmapsize, off, sparse_off,
-	    MIPS_PAGE_SIZE, sizeof(uint32_t)) == -1) {
+	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
+	    vmst->hdr.bitmapsize, off, sparse_off, MIPS_PAGE_SIZE,
+	    sizeof(uint32_t)) == -1) {
 		return (-1);
 	}
 	off += mips_round_page(vmst->hdr.bitmapsize);
Index: lib/libkvm/kvm_minidump_powerpc64.c
===================================================================
--- lib/libkvm/kvm_minidump_powerpc64.c
+++ lib/libkvm/kvm_minidump_powerpc64.c
@@ -68,7 +68,7 @@
 {
 	struct vmstate *vmst;
 	struct minidumphdr *hdr;
-	off_t bitmap_off, pmap_off, sparse_off;
+	off_t dump_avail_off, bitmap_off, pmap_off, sparse_off;
 	const char *mmu_name;
 
 	/* Alloc VM */
@@ -92,7 +92,7 @@
 	}
 	/* Check version */
 	hdr->version = be32toh(hdr->version);
-	if (hdr->version != MINIDUMP_VERSION) {
+	if (hdr->version != MINIDUMP_VERSION && hdr->version != 1) {
 		_kvm_err(kd, kd->program, "wrong minidump version. "
 		    "Expected %d got %d", MINIDUMP_VERSION, hdr->version);
 		goto failed;
@@ -108,6 +108,8 @@
 	hdr->hw_direct_map	= be32toh(hdr->hw_direct_map);
 	hdr->startkernel	= be64toh(hdr->startkernel);
 	hdr->endkernel		= be64toh(hdr->endkernel);
+	hdr->dumpavailsize	= hdr->version == MINIDUMP_VERSION ?
+	    be32toh(hdr->dumpavailsize) : 0;
 
 	vmst->kimg_start = PPC64_KERNBASE;
 	vmst->kimg_end = PPC64_KERNBASE + hdr->endkernel - hdr->startkernel;
@@ -140,7 +142,8 @@
 		goto failed;
 
 	/* Get dump parts' offsets */
-	bitmap_off	= PPC64_PAGE_SIZE + ppc64_round_page(hdr->msgbufsize);
+	dump_avail_off	= PPC64_PAGE_SIZE + ppc64_round_page(hdr->msgbufsize);
+	bitmap_off	= dump_avail_off + ppc64_round_page(hdr->dumpavailsize);
 	pmap_off	= bitmap_off + ppc64_round_page(hdr->bitmapsize);
 	sparse_off	= pmap_off + ppc64_round_page(hdr->pmapsize);
 
@@ -151,8 +154,9 @@
 	    (uintmax_t)pmap_off, (uintmax_t)sparse_off);
 
 	/* build physical address lookup table for sparse pages */
-	if (_kvm_pt_init(kd, hdr->bitmapsize, bitmap_off, sparse_off,
-	    PPC64_PAGE_SIZE, sizeof(uint64_t)) == -1)
+	if (_kvm_pt_init(kd, hdr->dumpavailsize, dump_avail_off,
+	    hdr->bitmapsize, bitmap_off, sparse_off, PPC64_PAGE_SIZE,
+	    sizeof(uint64_t)) == -1)
 		goto failed;
 
 	if (_kvm_pmap_init(kd, hdr->pmapsize, pmap_off) == -1)
Index: lib/libkvm/kvm_minidump_riscv.c
===================================================================
--- lib/libkvm/kvm_minidump_riscv.c
+++ lib/libkvm/kvm_minidump_riscv.c
@@ -83,7 +83,7 @@
 _riscv_minidump_initvtop(kvm_t *kd)
 {
 	struct vmstate *vmst;
-	off_t off, sparse_off;
+	off_t off, dump_avail_off, sparse_off;
 
 	vmst = _kvm_malloc(kd, sizeof(*vmst));
 	if (vmst == NULL) {
@@ -103,7 +103,7 @@
 	}
 
 	vmst->hdr.version = le32toh(vmst->hdr.version);
-	if (vmst->hdr.version != MINIDUMP_VERSION) {
+	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
 		_kvm_err(kd, kd->program, "wrong minidump version. "
 		    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
 		return (-1);
@@ -115,15 +115,21 @@
 	vmst->hdr.dmapphys = le64toh(vmst->hdr.dmapphys);
 	vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase);
 	vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend);
+	vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
+	    le32toh(vmst->hdr.dumpavailsize) : 0;
 
 	/* Skip header and msgbuf */
-	off = RISCV_PAGE_SIZE + riscv_round_page(vmst->hdr.msgbufsize);
+	dump_avail_off = RISCV_PAGE_SIZE + riscv_round_page(vmst->hdr.msgbufsize);
+
+	/* Skip dump_avail */
+	off = dump_avail_off + riscv_round_page(vmst->hdr.dumpavailsize);
 
 	/* build physical address lookup table for sparse pages */
 	sparse_off = off + riscv_round_page(vmst->hdr.bitmapsize) +
 	    riscv_round_page(vmst->hdr.pmapsize);
-	if (_kvm_pt_init(kd, vmst->hdr.bitmapsize, off, sparse_off,
-	    RISCV_PAGE_SIZE, sizeof(uint64_t)) == -1) {
+	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
+	    vmst->hdr.bitmapsize, off, sparse_off, RISCV_PAGE_SIZE,
+	    sizeof(uint64_t)) == -1) {
 		return (-1);
 	}
 	off += riscv_round_page(vmst->hdr.bitmapsize);
@@ -258,7 +264,9 @@
 	}
 
 	while (_kvm_bitmap_next(&bm, &bmindex)) {
-		pa = bmindex * RISCV_PAGE_SIZE;
+		pa = _kvm_bit_id_pa(kd, bmindex, RISCV_PAGE_SIZE);
+		if (pa == _KVM_PA_INVALID)
+			break;
 		dva = vm->hdr.dmapbase + pa;
 		if (vm->hdr.dmapend < (dva + RISCV_PAGE_SIZE))
 			break;
Index: lib/libkvm/kvm_private.h
===================================================================
--- lib/libkvm/kvm_private.h
+++ lib/libkvm/kvm_private.h
@@ -106,6 +106,8 @@
 	/* Page table lookup structures. */
 	uint64_t	*pt_map;
 	size_t		pt_map_size;
+	uint64_t	*dump_avail;	/* actually word sized */
+	size_t		dump_avail_size;
 	off_t		pt_sparse_off;
 	uint64_t	pt_sparse_size;
 	uint32_t	*pt_popcounts;
@@ -152,8 +154,13 @@
 		return (be64toh(val));
 }
 
+uint64_t _kvm_pa_bit_id(kvm_t *kd, uint64_t pa, unsigned int page_size);
+uint64_t _kvm_bit_id_pa(kvm_t *kd, uint64_t bit_id, unsigned int page_size);
+#define _KVM_PA_INVALID		ULONG_MAX
+#define _KVM_BIT_ID_INVALID	ULONG_MAX
+
 int	 _kvm_bitmap_init(struct kvm_bitmap *, u_long, u_long *);
-void	 _kvm_bitmap_set(struct kvm_bitmap *, u_long, unsigned int);
+void	 _kvm_bitmap_set(struct kvm_bitmap *, u_long);
 int	 _kvm_bitmap_next(struct kvm_bitmap *, u_long *);
 void	 _kvm_bitmap_deinit(struct kvm_bitmap *);
 
@@ -173,7 +180,7 @@
 int	 _kvm_probe_elf_kernel(kvm_t *, int, int);
 int	 _kvm_is_minidump(kvm_t *);
 int	 _kvm_read_core_phdrs(kvm_t *, size_t *, GElf_Phdr **);
-int	 _kvm_pt_init(kvm_t *, size_t, off_t, off_t, int, int);
+int	 _kvm_pt_init(kvm_t *, size_t, off_t, size_t, off_t, off_t, int, int);
 off_t	 _kvm_pt_find(kvm_t *, uint64_t, unsigned int);
 int	 _kvm_visit_cb(kvm_t *, kvm_walk_pages_cb_t *, void *, u_long,
 	    u_long, u_long, vm_prot_t, size_t, unsigned int);
Index: lib/libkvm/kvm_private.c
===================================================================
--- lib/libkvm/kvm_private.c
+++ lib/libkvm/kvm_private.c
@@ -290,8 +290,9 @@
 }
 
 int
-_kvm_pt_init(kvm_t *kd, size_t map_len, off_t map_off, off_t sparse_off,
-    int page_size, int word_size)
+_kvm_pt_init(kvm_t *kd, size_t dump_avail_size, off_t dump_avail_off,
+    size_t map_len, off_t map_off, off_t sparse_off, int page_size,
+    int word_size)
 {
 	uint64_t *addr;
 	uint32_t *popcount_bin;
@@ -299,6 +300,27 @@
 	uint64_t pc_bins, res;
 	ssize_t rd;
 
+	kd->dump_avail_size = dump_avail_size;
+	if (dump_avail_size > 0) {
+		kd->dump_avail = mmap(NULL, kd->dump_avail_size, PROT_READ,
+		    MAP_PRIVATE, kd->pmfd, dump_avail_off);
+	} else {
+		/*
+		 * Older version minidumps don't provide dump_avail[],
+		 * so the bitmap is fully populated from 0 to
+		 * last_pa. Create an implied dump_avail that
+		 * expresses this.
+		 */
+		kd->dump_avail = calloc(4, word_size);
+		if (word_size == sizeof(uint32_t)) {
+			((uint32_t *)kd->dump_avail)[1] = _kvm32toh(kd,
+			    map_len * 8 * page_size);
+		} else {
+			kd->dump_avail[1] = _kvm64toh(kd,
+			    map_len * 8 * page_size);
+		}
+	}
+
 	/*
 	 * Map the bitmap specified by the arguments.
 	 */
@@ -394,6 +416,55 @@
 	return (0);
 }
 
+static inline uint64_t
+dump_avail_n(kvm_t *kd, long i)
+{
+	uint32_t *d32;
+
+	if (kd->pt_word_size == sizeof(uint32_t)) {
+		d32 = (uint32_t *)kd->dump_avail;
+		return (_kvm32toh(kd, d32[i]));
+	} else
+		return (_kvm64toh(kd, kd->dump_avail[i]));
+}
+
+uint64_t
+_kvm_pa_bit_id(kvm_t *kd, uint64_t pa, unsigned int page_size)
+{
+	uint64_t adj;
+	long i;
+
+	adj = 0;
+	for (i = 0; dump_avail_n(kd, i + 1) != 0; i += 2) {
+		if (pa >= dump_avail_n(kd, i + 1)) {
+			adj += howmany(dump_avail_n(kd, i + 1), page_size) -
+			    dump_avail_n(kd, i) / page_size;
+		} else {
+			return (pa / page_size -
+			    dump_avail_n(kd, i) / page_size + adj);
+		}
+	}
+	return (_KVM_BIT_ID_INVALID);
+}
+
+uint64_t
+_kvm_bit_id_pa(kvm_t *kd, uint64_t bit_id, unsigned int page_size)
+{
+	uint64_t sz;
+	long i;
+
+	for (i = 0; dump_avail_n(kd, i + 1) != 0; i += 2) {
+		sz = howmany(dump_avail_n(kd, i + 1), page_size) -
+		    dump_avail_n(kd, i) / page_size;
+		if (bit_id < sz) {
+			return (rounddown2(dump_avail_n(kd, i), page_size) +
+			    bit_id * page_size);
+		}
+		bit_id -= sz;
+	}
+	return (_KVM_PA_INVALID);
+}
+
 /*
  * Find the offset for the given physical page address; returns -1 otherwise.
  *
@@ -412,7 +483,7 @@
 _kvm_pt_find(kvm_t *kd, uint64_t pa, unsigned int page_size)
 {
 	uint64_t *bitmap = kd->pt_map;
-	uint64_t pte_bit_id = pa / page_size;
+	uint64_t pte_bit_id = _kvm_pa_bit_id(kd, pa, page_size);
 	uint64_t pte_u64 = pte_bit_id / BITS_IN(*bitmap);
 	uint64_t popcount_id = pte_bit_id / POPCOUNT_BITS;
 	uint64_t pte_mask = 1ULL << (pte_bit_id % BITS_IN(*bitmap));
@@ -420,7 +491,8 @@
 	uint32_t count;
 
 	/* Check whether the page address requested is in the dump. */
-	if (pte_bit_id >= (kd->pt_map_size * NBBY) ||
+	if (pte_bit_id == _KVM_BIT_ID_INVALID ||
+	    pte_bit_id >= (kd->pt_map_size * NBBY) ||
 	    (bitmap[pte_u64] & pte_mask) == 0)
 		return (-1);
 
@@ -714,12 +786,12 @@
 }
 
 void
-_kvm_bitmap_set(struct kvm_bitmap *bm, u_long pa, unsigned int page_size)
+_kvm_bitmap_set(struct kvm_bitmap *bm, u_long bm_index)
 {
-	u_long bm_index = pa / page_size;
 	uint8_t *byte = &bm->map[bm_index / 8];
 
-	*byte |= (1UL << (bm_index % 8));
+	if (bm_index / 8 < bm->size)
+		*byte |= (1UL << (bm_index % 8));
 }
 
 int
Index: sys/amd64/amd64/minidump_machdep.c
===================================================================
--- sys/amd64/amd64/minidump_machdep.c
+++ sys/amd64/amd64/minidump_machdep.c
@@ -299,6 +299,7 @@
 	/* Calculate dump size. */
 	dumpsize = pmapsize;
 	dumpsize += round_page(msgbufp->msg_size);
+	dumpsize += round_page(sizeof(dump_avail));
 	dumpsize += round_page(BITSET_SIZE(vm_page_dump_pages));
 	VM_PAGE_DUMP_FOREACH(pa) {
 		/* Clear out undumpable pages now if needed */
@@ -322,6 +323,7 @@
 	mdhdr.kernbase = VM_MIN_KERNEL_ADDRESS;
 	mdhdr.dmapbase = DMAP_MIN_ADDRESS;
 	mdhdr.dmapend = DMAP_MAX_ADDRESS;
+	mdhdr.dumpavailsize = round_page(sizeof(dump_avail));
 
 	dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_AMD64_VERSION,
 	    dumpsize);
@@ -345,6 +347,15 @@
 	if (error)
 		goto fail;
 
+	/* Dump dump_avail */
+	_Static_assert(sizeof(dump_avail) <= sizeof(fakepd),
+	    "Large dump_avail not handled");
+	bzero(&fakepd, sizeof(fakepd));
+	memcpy(fakepd, dump_avail, sizeof(dump_avail));
+	error = blk_write(di, (char *)fakepd, 0, PAGE_SIZE);
+	if (error)
+		goto fail;
+
 	/* Dump bitmap */
 	error = blk_write(di, (char *)vm_page_dump, 0,
 	    round_page(BITSET_SIZE(vm_page_dump_pages)));
Index: sys/amd64/include/minidump.h
===================================================================
--- sys/amd64/include/minidump.h
+++ sys/amd64/include/minidump.h
@@ -32,7 +32,7 @@
 #define	_MACHINE_MINIDUMP_H_ 1
 
 #define	MINIDUMP_MAGIC		"minidump FreeBSD/amd64"
-#define	MINIDUMP_VERSION	2
+#define	MINIDUMP_VERSION	3
 
 struct minidumphdr {
 	char magic[24];
@@ -43,6 +43,7 @@
 	uint64_t kernbase;
 	uint64_t dmapbase;
 	uint64_t dmapend;
+	uint32_t dumpavailsize;
 };
 
 #endif /* _MACHINE_MINIDUMP_H_ */
Index: sys/arm/arm/minidump_machdep.c
===================================================================
--- sys/arm/arm/minidump_machdep.c
+++ sys/arm/arm/minidump_machdep.c
@@ -206,6 +206,7 @@
 	/* Calculate dump size. */
 	dumpsize = ptesize;
 	dumpsize += round_page(msgbufp->msg_size);
+	dumpsize += round_page(sizeof(dump_avail));
 	dumpsize += round_page(BITSET_SIZE(vm_page_dump_pages));
 	VM_PAGE_DUMP_FOREACH(pa) {
 		/* Clear out undumpable pages now if needed */
@@ -232,6 +233,7 @@
 #else
 	mdhdr.mmuformat = MINIDUMP_MMU_FORMAT_V4;
 #endif
+	mdhdr.dumpavailsize = round_page(sizeof(dump_avail));
 	dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_ARM_VERSION,
 	    dumpsize);
 
@@ -255,6 +257,15 @@
 	if (error)
 		goto fail;
 
+	/* Dump dump_avail */
+	_Static_assert(sizeof(dump_avail) <= sizeof(dumpbuf),
+	    "Large dump_avail not handled");
+	bzero(dumpbuf, sizeof(dumpbuf));
+	memcpy(dumpbuf, dump_avail, sizeof(dump_avail));
+	error = blk_write(di, dumpbuf, 0, PAGE_SIZE);
+	if (error)
+		goto fail;
+
 	/* Dump bitmap */
 	error = blk_write(di, (char *)vm_page_dump, 0,
 	    round_page(BITSET_SIZE(vm_page_dump_pages)));
Index: sys/arm/include/minidump.h
===================================================================
--- sys/arm/include/minidump.h
+++ sys/arm/include/minidump.h
@@ -33,7 +33,7 @@
 #define	_MACHINE_MINIDUMP_H_
 
 #define	MINIDUMP_MAGIC		"minidump FreeBSD/arm"
-#define	MINIDUMP_VERSION	1
+#define	MINIDUMP_VERSION	2
 
 /*
  * The first page of vmcore is dedicated to the following header.
@@ -51,6 +51,7 @@
 	uint32_t kernbase;
 	uint32_t arch;
 	uint32_t mmuformat;
+	uint32_t dumpavailsize;
 };
 
 #define MINIDUMP_MMU_FORMAT_UNKNOWN	0
Index: sys/arm64/arm64/minidump_machdep.c
===================================================================
--- sys/arm64/arm64/minidump_machdep.c
+++ sys/arm64/arm64/minidump_machdep.c
@@ -249,6 +249,7 @@
 	/* Calculate dump size. */
 	dumpsize = pmapsize;
 	dumpsize += round_page(msgbufp->msg_size);
+	dumpsize += round_page(sizeof(dump_avail));
 	dumpsize += round_page(BITSET_SIZE(vm_page_dump_pages));
 	VM_PAGE_DUMP_FOREACH(pa) {
 		if (is_dumpable(pa))
@@ -271,6 +272,7 @@
 	mdhdr.dmapphys = DMAP_MIN_PHYSADDR;
 	mdhdr.dmapbase = DMAP_MIN_ADDRESS;
 	mdhdr.dmapend = DMAP_MAX_ADDRESS;
+	mdhdr.dumpavailsize = round_page(sizeof(dump_avail));
 
 	dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_AARCH64_VERSION,
 	    dumpsize);
@@ -295,6 +297,15 @@
 	if (error)
 		goto fail;
 
+	/* Dump dump_avail */
+	_Static_assert(sizeof(dump_avail) <= sizeof(tmpbuffer),
+	    "Large dump_avail not handled");
+	bzero(tmpbuffer, sizeof(tmpbuffer));
+	memcpy(tmpbuffer, dump_avail, sizeof(dump_avail));
+	error = blk_write(di, (char *)&tmpbuffer, 0, PAGE_SIZE);
+	if (error)
+		goto fail;
+
 	/* Dump bitmap */
 	error = blk_write(di, (char *)vm_page_dump, 0,
 	    round_page(BITSET_SIZE(vm_page_dump_pages)));
Index: sys/arm64/include/minidump.h
===================================================================
--- sys/arm64/include/minidump.h
+++ sys/arm64/include/minidump.h
@@ -31,7 +31,7 @@
 #define	_MACHINE_MINIDUMP_H_ 1
 
 #define	MINIDUMP_MAGIC		"minidump FreeBSD/arm64"
-#define	MINIDUMP_VERSION	1
+#define	MINIDUMP_VERSION	2
 
 struct minidumphdr {
 	char magic[24];
@@ -43,6 +43,7 @@
 	uint64_t dmapphys;
 	uint64_t dmapbase;
 	uint64_t dmapend;
+	uint32_t dumpavailsize;
 };
 
 #endif /* _MACHINE_MINIDUMP_H_ */
Index: sys/i386/i386/minidump_machdep_base.c
===================================================================
--- sys/i386/i386/minidump_machdep_base.c
+++ sys/i386/i386/minidump_machdep_base.c
@@ -224,6 +224,7 @@
 	/* Calculate dump size. */
 	dumpsize = ptesize;
 	dumpsize += round_page(msgbufp->msg_size);
+	dumpsize += round_page(sizeof(dump_avail));
 	dumpsize += round_page(BITSET_SIZE(vm_page_dump_pages));
 	VM_PAGE_DUMP_FOREACH(pa) {
 		/* Clear out undumpable pages now if needed */
@@ -246,6 +247,7 @@
 	mdhdr.ptesize = ptesize;
 	mdhdr.kernbase = KERNBASE;
 	mdhdr.paemode = pae_mode;
+	mdhdr.dumpavailsize = round_page(sizeof(dump_avail));
 
 	dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_I386_VERSION,
 	    dumpsize);
@@ -269,6 +271,15 @@
 	if (error)
 		goto fail;
 
+	/* Dump dump_avail */
+	_Static_assert(sizeof(dump_avail) <= sizeof(fakept),
+	    "Large dump_avail not handled");
+	bzero(fakept, sizeof(fakept));
+	memcpy(fakept, dump_avail, sizeof(dump_avail));
+	error = blk_write(di, (char *)&fakept, 0, PAGE_SIZE);
+	if (error)
+		goto fail;
+
 	/* Dump bitmap */
 	error = blk_write(di, (char *)vm_page_dump, 0,
 	    round_page(BITSET_SIZE(vm_page_dump_pages)));
Index: sys/i386/include/minidump.h
===================================================================
--- sys/i386/include/minidump.h
+++ sys/i386/include/minidump.h
@@ -32,7 +32,7 @@
 #define	_MACHINE_MINIDUMP_H_ 1
 
 #define	MINIDUMP_MAGIC		"minidump FreeBSD/i386"
-#define	MINIDUMP_VERSION	1
+#define	MINIDUMP_VERSION	2
 
 struct minidumphdr {
 	char magic[24];
@@ -42,6 +42,7 @@
 	uint32_t ptesize;
 	uint32_t kernbase;
 	uint32_t paemode;
+	uint32_t dumpavailsize;
 };
 
 #endif /* _MACHINE_MINIDUMP_H_ */
Index: sys/mips/include/minidump.h
===================================================================
--- sys/mips/include/minidump.h
+++ sys/mips/include/minidump.h
@@ -32,7 +32,7 @@
 #define	_MACHINE_MINIDUMP_H_ 1
 
 #define	MINIDUMP_MAGIC		"minidump FreeBSD/mips"
-#define	MINIDUMP_VERSION	1
+#define	MINIDUMP_VERSION	2
 
 struct minidumphdr {
 	char magic[24];
@@ -43,6 +43,7 @@
 	uint64_t kernbase;
 	uint64_t dmapbase;
 	uint64_t dmapend;
+	uint32_t dumpavailsize;
 };
 
 #endif /* _MACHINE_MINIDUMP_H_ */
Index: sys/mips/mips/minidump_machdep.c
===================================================================
--- sys/mips/mips/minidump_machdep.c
+++ sys/mips/mips/minidump_machdep.c
@@ -205,6 +205,7 @@
 	/* Calculate dump size. */
 	dumpsize = ptesize;
 	dumpsize += round_page(msgbufp->msg_size);
+	dumpsize += round_page(sizeof(dump_avail));
 	dumpsize += round_page(BITSET_SIZE(vm_page_dump_pages));
 	VM_PAGE_DUMP_FOREACH(pa) {
 		/* Clear out undumpable pages now if needed */
@@ -225,6 +226,7 @@
 	mdhdr.bitmapsize = round_page(BITSET_SIZE(vm_page_dump_pages));
 	mdhdr.ptesize = ptesize;
 	mdhdr.kernbase = VM_MIN_KERNEL_ADDRESS;
+	mdhdr.dumpavailsize = round_page(sizeof(dump_avail));
 
 	dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_MIPS_VERSION,
 	    dumpsize);
@@ -249,6 +251,15 @@
 	if (error)
 		goto fail;
 
+	/* Dump dump_avail */
+	_Static_assert(sizeof(dump_avail) <= sizeof(tmpbuffer),
+	    "Large dump_avail not handled");
+	bzero(tmpbuffer, sizeof(tmpbuffer));
+	memcpy(tmpbuffer, dump_avail, sizeof(dump_avail));
+	error = write_buffer(di, tmpbuffer, PAGE_SIZE);
+	if (error)
+		goto fail;
+
 	/* Dump bitmap */
 	error = write_buffer(di, (char *)vm_page_dump,
 	    round_page(BITSET_SIZE(vm_page_dump_pages)));
Index: sys/powerpc/include/minidump.h
===================================================================
--- sys/powerpc/include/minidump.h
+++ sys/powerpc/include/minidump.h
@@ -31,7 +31,7 @@
 #define	_MACHINE_MINIDUMP_H_ 1
 
 #define	MINIDUMP_MAGIC		"minidump FreeBSD/powerpc64"
-#define	MINIDUMP_VERSION	1
+#define	MINIDUMP_VERSION	2
 
 struct minidumphdr {
 	char magic[32];
@@ -47,6 +47,7 @@
 	int hw_direct_map;
 	uint64_t startkernel;
 	uint64_t endkernel;
+	uint32_t dumpavailsize;
 };
 
 #endif /* _MACHINE_MINIDUMP_H_ */
Index: sys/powerpc/powerpc/minidump_machdep.c
===================================================================
--- sys/powerpc/powerpc/minidump_machdep.c
+++ sys/powerpc/powerpc/minidump_machdep.c
@@ -271,6 +271,7 @@
 	/* Calculate dump size */
 	dumpsize = PAGE_SIZE;				/* header */
 	dumpsize += round_page(msgbufp->msg_size);
+	dumpsize += round_page(sizeof(dump_avail));
 	dumpsize += round_page(BITSET_SIZE(vm_page_dump_pages));
 	dumpsize += pmapsize;
 	VM_PAGE_DUMP_FOREACH(pa) {
@@ -297,6 +298,7 @@
 	mdhdr.hw_direct_map = hw_direct_map;
 	mdhdr.startkernel = __startkernel;
 	mdhdr.endkernel = __endkernel;
+	mdhdr.dumpavailsize = round_page(sizeof(dump_avail));
 
 	dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_POWERPC_VERSION,
 	    dumpsize);
@@ -321,6 +323,16 @@
 	    round_page(msgbufp->msg_size));
 	dump_total("msgbuf", round_page(msgbufp->msg_size));
 
+	/* Dump dump_avail */
+	_Static_assert(sizeof(dump_avail) <= sizeof(pgbuf),
+	    "Large dump_avail not handled");
+	bzero(pgbuf, sizeof(mdhdr));
+	memcpy(pgbuf, dump_avail, sizeof(dump_avail));
+	error = blk_write(di, pgbuf, 0, PAGE_SIZE);
+	if (error)
+		goto fail;
+	dump_total("dump_avail", round_page(sizeof(dump_avail)));
+
 	/* Dump bitmap */
 	error = blk_write(di, (char *)vm_page_dump, 0,
 	    round_page(BITSET_SIZE(vm_page_dump_pages)));
Index: sys/riscv/include/minidump.h
===================================================================
--- sys/riscv/include/minidump.h
+++ sys/riscv/include/minidump.h
@@ -31,7 +31,7 @@
 #define	_MACHINE_MINIDUMP_H_ 1
 
 #define	MINIDUMP_MAGIC		"minidump FreeBSD/riscv"
-#define	MINIDUMP_VERSION	1
+#define	MINIDUMP_VERSION	2
 
 struct minidumphdr {
 	char magic[24];
@@ -43,6 +43,7 @@
 	uint64_t dmapphys;
 	uint64_t dmapbase;
 	uint64_t dmapend;
+	uint32_t dumpavailsize;
 };
 
 #endif /* _MACHINE_MINIDUMP_H_ */
Index: sys/riscv/riscv/minidump_machdep.c
===================================================================
--- sys/riscv/riscv/minidump_machdep.c
+++ sys/riscv/riscv/minidump_machdep.c
@@ -257,6 +257,7 @@
 	/* Calculate dump size */
 	dumpsize = pmapsize;
 	dumpsize += round_page(msgbufp->msg_size);
+	dumpsize += round_page(sizeof(dump_avail));
 	dumpsize += round_page(BITSET_SIZE(vm_page_dump_pages));
 	VM_PAGE_DUMP_FOREACH(pa) {
 		/* Clear out undumpable pages now if needed */
@@ -280,6 +281,7 @@
 	mdhdr.dmapphys = DMAP_MIN_PHYSADDR;
 	mdhdr.dmapbase = DMAP_MIN_ADDRESS;
 	mdhdr.dmapend = DMAP_MAX_ADDRESS;
+	mdhdr.dumpavailsize = round_page(sizeof(dump_avail));
 
 	dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_RISCV_VERSION,
 	    dumpsize);
@@ -304,6 +306,15 @@
 	if (error)
 		goto fail;
 
+	/* Dump dump_avail */
+	_Static_assert(sizeof(dump_avail) <= sizeof(tmpbuffer),
+	    "Large dump_avail not handled");
+	bzero(tmpbuffer, sizeof(tmpbuffer));
+	memcpy(tmpbuffer, dump_avail, sizeof(dump_avail));
+	error = blk_write(di, (char *)&tmpbuffer, 0, PAGE_SIZE);
+	if (error)
+		goto fail;
+
 	/* Dump bitmap */
 	error = blk_write(di, (char *)vm_page_dump, 0,
 	    round_page(BITSET_SIZE(vm_page_dump_pages)));
Index: sys/vm/vm_page.h
===================================================================
--- sys/vm/vm_page.h
+++ sys/vm/vm_page.h
@@ -589,22 +589,65 @@
 
 extern struct bitset *vm_page_dump;
 extern long vm_page_dump_pages;
+extern vm_paddr_t dump_avail[];
 
 static inline void
 dump_add_page(vm_paddr_t pa)
 {
-	BIT_SET_ATOMIC(vm_page_dump_pages, pa >> PAGE_SHIFT, vm_page_dump);
+	vm_pindex_t adj;
+	int i;
+
+	adj = 0;
+	for (i = 0; dump_avail[i + 1] != 0; i += 2) {
+		if (pa >= dump_avail[i] && pa < dump_avail[i + 1]) {
+			BIT_SET_ATOMIC(vm_page_dump_pages,
+			    (pa >> PAGE_SHIFT) - (dump_avail[i] >> PAGE_SHIFT) +
+			    adj, vm_page_dump);
+			return;
+		}
+		adj += howmany(dump_avail[i + 1], PAGE_SIZE) -
+		    dump_avail[i] / PAGE_SIZE;
+	}
 }
 
 static inline void
 dump_drop_page(vm_paddr_t pa)
 {
-	BIT_CLR_ATOMIC(vm_page_dump_pages, pa >> PAGE_SHIFT, vm_page_dump);
+	vm_pindex_t adj;
+	int i;
+
+	adj = 0;
+	for (i = 0; dump_avail[i + 1] != 0; i += 2) {
+		if (pa >= dump_avail[i] && pa < dump_avail[i + 1]) {
+			BIT_CLR_ATOMIC(vm_page_dump_pages,
+			    (pa >> PAGE_SHIFT) - (dump_avail[i] >> PAGE_SHIFT) +
+			    adj, vm_page_dump);
+			return;
+		}
+		adj += howmany(dump_avail[i + 1], PAGE_SIZE) -
+		    dump_avail[i] / PAGE_SIZE;
+	}
+}
+
+static inline vm_paddr_t
+vm_page_dump_index_to_pa(int bit)
+{
+	int i, tot;
+
+	for (i = 0; dump_avail[i + 1] != 0; i += 2) {
+		tot = howmany(dump_avail[i + 1], PAGE_SIZE) -
+		    dump_avail[i] / PAGE_SIZE;
+		if (bit < tot)
+			return ((vm_paddr_t)bit * PAGE_SIZE +
+			    dump_avail[i] & ~PAGE_MASK);
+		bit -= tot;
+	}
+	return ((vm_paddr_t)NULL);
 }
 
 #define VM_PAGE_DUMP_FOREACH(pa)						\
 	for (vm_pindex_t __b = BIT_FFS(vm_page_dump_pages, vm_page_dump);	\
-	    (pa) = (__b - 1) * PAGE_SIZE, __b != 0;				\
+	    (pa) = vm_page_dump_index_to_pa(__b - 1), __b != 0;			\
 	    __b = BIT_FFS_AT(vm_page_dump_pages, vm_page_dump, __b))
 
 bool vm_page_busy_acquire(vm_page_t m, int allocflags);
Index: sys/vm/vm_page.c
===================================================================
--- sys/vm/vm_page.c
+++ sys/vm/vm_page.c
@@ -607,10 +607,13 @@
 	 * included should the sf_buf code decide to use them.
 	 */
 	last_pa = 0;
-	for (i = 0; dump_avail[i + 1] != 0; i += 2)
+	vm_page_dump_pages = 0;
+	for (i = 0; dump_avail[i + 1] != 0; i += 2) {
+		vm_page_dump_pages += howmany(dump_avail[i + 1], PAGE_SIZE) -
+		    dump_avail[i] / PAGE_SIZE;
 		if (dump_avail[i + 1] > last_pa)
 			last_pa = dump_avail[i + 1];
-	vm_page_dump_pages = last_pa / PAGE_SIZE;
+	}
 	vm_page_dump_size = round_page(BITSET_SIZE(vm_page_dump_pages));
 	new_end -= vm_page_dump_size;
 	vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end,
Index: sys/vm/vm_phys.h
===================================================================
--- sys/vm/vm_phys.h
+++ sys/vm/vm_phys.h
@@ -46,8 +46,8 @@
 #define	VM_NFREEORDER_MAX	VM_NFREEORDER
 #endif
 
-extern vm_paddr_t phys_avail[];
-extern vm_paddr_t dump_avail[];
+extern vm_paddr_t phys_avail[PHYS_AVAIL_COUNT];
+extern vm_paddr_t dump_avail[PHYS_AVAIL_COUNT];
 
 /* Domains must be dense (non-sparse) and zero-based. */
 struct mem_affinity {