diff --git a/lib/libvmmapi/vmmapi.h b/lib/libvmmapi/vmmapi.h
--- a/lib/libvmmapi/vmmapi.h
+++ b/lib/libvmmapi/vmmapi.h
@@ -111,6 +111,8 @@
 int	vm_mmap_memseg(struct vmctx *ctx, vm_paddr_t gpa, int segid,
 	    vm_ooffset_t segoff, size_t len, int prot);
 
+int	vm_munmap_memseg(struct vmctx *ctx, vm_paddr_t gpa, size_t len);
+
 int	vm_create(const char *name);
 int	vm_get_device_fd(struct vmctx *ctx);
 struct vmctx *vm_open(const char *name);
@@ -176,6 +178,8 @@
 int	vm_unassign_pptdev(struct vmctx *ctx, int bus, int slot, int func);
 int	vm_map_pptdev_mmio(struct vmctx *ctx, int bus, int slot, int func,
 			   vm_paddr_t gpa, size_t len, vm_paddr_t hpa);
+int	vm_unmap_pptdev_mmio(struct vmctx *ctx, int bus, int slot, int func,
+			     vm_paddr_t gpa, size_t len);
 int	vm_setup_pptdev_msi(struct vmctx *ctx, int vcpu, int bus, int slot,
 	    int func, uint64_t addr, uint64_t msg, int numvec);
 int	vm_setup_pptdev_msix(struct vmctx *ctx, int vcpu, int bus, int slot,
diff --git a/lib/libvmmapi/vmmapi.c b/lib/libvmmapi/vmmapi.c
--- a/lib/libvmmapi/vmmapi.c
+++ b/lib/libvmmapi/vmmapi.c
@@ -251,6 +251,19 @@
 	return (0);
 }
 
+int
+vm_munmap_memseg(struct vmctx *ctx, vm_paddr_t gpa, size_t len)
+{
+	struct vm_munmap munmap;
+	int error;
+
+	munmap.gpa = gpa;
+	munmap.len = len;
+
+	error = ioctl(ctx->fd, VM_MUNMAP_MEMSEG, &munmap);
+	return (error);
+}
+
 int
 vm_mmap_getnext(struct vmctx *ctx, vm_paddr_t *gpa, int *segid,
     vm_ooffset_t *segoff, size_t *len, int *prot, int *flags)
@@ -980,6 +993,22 @@
 	return (ioctl(ctx->fd, VM_MAP_PPTDEV_MMIO, &pptmmio));
 }
 
+int
+vm_unmap_pptdev_mmio(struct vmctx *ctx, int bus, int slot, int func,
+		     vm_paddr_t gpa, size_t len)
+{
+	struct vm_pptdev_mmio pptmmio;
+
+	bzero(&pptmmio, sizeof(pptmmio));
+	pptmmio.bus = bus;
+	pptmmio.slot = slot;
+	pptmmio.func = func;
+	pptmmio.gpa = gpa;
+	pptmmio.len = len;
+
+	return (ioctl(ctx->fd, VM_UNMAP_PPTDEV_MMIO, &pptmmio));
+}
+
 int
 vm_setup_pptdev_msi(struct vmctx *ctx, int vcpu, int bus, int slot, int func,
     uint64_t addr, uint64_t msg, int numvec)
@@ -1644,7 +1673,7 @@
 	/* keep in sync with machine/vmm_dev.h */
 	static const cap_ioctl_t vm_ioctl_cmds[] = { VM_RUN, VM_SUSPEND, VM_REINIT,
 	    VM_ALLOC_MEMSEG, VM_GET_MEMSEG, VM_MMAP_MEMSEG, VM_MMAP_MEMSEG,
-	    VM_MMAP_GETNEXT, VM_SET_REGISTER, VM_GET_REGISTER,
+	    VM_MMAP_GETNEXT, VM_MUNMAP_MEMSEG, VM_SET_REGISTER, VM_GET_REGISTER,
 	    VM_SET_SEGMENT_DESCRIPTOR, VM_GET_SEGMENT_DESCRIPTOR,
 	    VM_SET_REGISTER_SET, VM_GET_REGISTER_SET,
 	    VM_SET_KERNEMU_DEV, VM_GET_KERNEMU_DEV,
@@ -1654,7 +1683,7 @@
 	    VM_ISA_DEASSERT_IRQ, VM_ISA_PULSE_IRQ, VM_ISA_SET_IRQ_TRIGGER,
 	    VM_SET_CAPABILITY, VM_GET_CAPABILITY, VM_BIND_PPTDEV,
 	    VM_UNBIND_PPTDEV, VM_MAP_PPTDEV_MMIO, VM_PPTDEV_MSI,
-	    VM_PPTDEV_MSIX, VM_PPTDEV_DISABLE_MSIX,
+	    VM_PPTDEV_MSIX, VM_UNMAP_PPTDEV_MMIO, VM_PPTDEV_DISABLE_MSIX,
 	    VM_INJECT_NMI, VM_STATS, VM_STAT_DESC,
 	    VM_SET_X2APIC_STATE, VM_GET_X2APIC_STATE,
 	    VM_GET_HPET_CAPABILITIES, VM_GET_GPA_PMAP, VM_GLA2GPA,
diff --git a/sys/amd64/include/vmm.h b/sys/amd64/include/vmm.h
--- a/sys/amd64/include/vmm.h
+++ b/sys/amd64/include/vmm.h
@@ -231,6 +231,7 @@
  */
 int vm_mmap_memseg(struct vm *vm, vm_paddr_t gpa, int segid, vm_ooffset_t off,
     size_t len, int prot, int flags);
+int vm_munmap_memseg(struct vm *vm, vm_paddr_t gpa, size_t len);
 int vm_alloc_memseg(struct vm *vm, int ident, size_t len, bool sysmem);
 void vm_free_memseg(struct vm *vm, int ident);
 int vm_map_mmio(struct vm *vm, vm_paddr_t gpa, size_t len, vm_paddr_t hpa);
diff --git a/sys/amd64/include/vmm_dev.h b/sys/amd64/include/vmm_dev.h
--- a/sys/amd64/include/vmm_dev.h
+++ b/sys/amd64/include/vmm_dev.h
@@ -49,6 +49,11 @@
 #define	VM_MEMMAP_F_WIRED	0x01
 #define	VM_MEMMAP_F_IOMMU	0x02
 
+struct vm_munmap {
+	vm_paddr_t	gpa;
+	size_t		len;
+};
+
 #define	VM_MEMSEG_NAME(m)	((m)->name[0] != '\0' ? (m)->name : NULL)
 struct vm_memseg {
 	int		segid;
@@ -270,6 +275,7 @@
 	IOCNUM_MMAP_MEMSEG = 16,
 	IOCNUM_MMAP_GETNEXT = 17,
 	IOCNUM_GLA2GPA_NOFAULT = 18,
+	IOCNUM_MUNMAP_MEMSEG = 19,
 
 	/* register/state accessors */
 	IOCNUM_SET_REGISTER = 20,
@@ -302,6 +308,7 @@
 	IOCNUM_PPTDEV_MSI = 43,
 	IOCNUM_PPTDEV_MSIX = 44,
 	IOCNUM_PPTDEV_DISABLE_MSIX = 45,
+	IOCNUM_UNMAP_PPTDEV_MMIO = 46,
 
 	/* statistics */
 	IOCNUM_VM_STATS = 50, 
@@ -358,6 +365,8 @@
 	_IOW('v', IOCNUM_MMAP_MEMSEG, struct vm_memmap)
 #define	VM_MMAP_GETNEXT	\
 	_IOWR('v', IOCNUM_MMAP_GETNEXT, struct vm_memmap)
+#define	VM_MUNMAP_MEMSEG	\
+	_IOW('v', IOCNUM_MUNMAP_MEMSEG, struct vm_munmap)
 #define	VM_SET_REGISTER \
 	_IOW('v', IOCNUM_SET_REGISTER, struct vm_register)
 #define	VM_GET_REGISTER \
@@ -416,6 +425,8 @@
 	_IOW('v', IOCNUM_PPTDEV_MSIX, struct vm_pptdev_msix)
 #define	VM_PPTDEV_DISABLE_MSIX \
 	_IOW('v', IOCNUM_PPTDEV_DISABLE_MSIX, struct vm_pptdev)
+#define	VM_UNMAP_PPTDEV_MMIO \
+	_IOW('v', IOCNUM_UNMAP_PPTDEV_MMIO, struct vm_pptdev_mmio)
 #define VM_INJECT_NMI \
 	_IOW('v', IOCNUM_INJECT_NMI, struct vm_nmi)
 #define	VM_STATS \
diff --git a/sys/amd64/vmm/io/ppt.h b/sys/amd64/vmm/io/ppt.h
--- a/sys/amd64/vmm/io/ppt.h
+++ b/sys/amd64/vmm/io/ppt.h
@@ -34,6 +34,8 @@
 int	ppt_unassign_all(struct vm *vm);
 int	ppt_map_mmio(struct vm *vm, int bus, int slot, int func,
 		     vm_paddr_t gpa, size_t len, vm_paddr_t hpa);
+int	ppt_unmap_mmio(struct vm *vm, int bus, int slot, int func,
+		       vm_paddr_t gpa, size_t len);
 int	ppt_setup_msi(struct vm *vm, int vcpu, int bus, int slot, int func,
 		      uint64_t addr, uint64_t msg, int numvec);
 int	ppt_setup_msix(struct vm *vm, int vcpu, int bus, int slot, int func,
diff --git a/sys/amd64/vmm/io/ppt.c b/sys/amd64/vmm/io/ppt.c
--- a/sys/amd64/vmm/io/ppt.c
+++ b/sys/amd64/vmm/io/ppt.c
@@ -224,7 +224,7 @@
 }
 
 static void
-ppt_unmap_mmio(struct vm *vm, struct pptdev *ppt)
+ppt_unmap_all_mmio(struct vm *vm, struct pptdev *ppt)
 {
 	int i;
 	struct pptseg *seg;
@@ -412,7 +412,7 @@
 	pci_save_state(ppt->dev);
 	ppt_pci_reset(ppt->dev);
 	pci_restore_state(ppt->dev);
-	ppt_unmap_mmio(vm, ppt);
+	ppt_unmap_all_mmio(vm, ppt);
 	ppt_teardown_msi(ppt);
 	ppt_teardown_msix(ppt);
 	iommu_remove_device(vm_iommu_domain(vm), pci_get_rid(ppt->dev));
@@ -466,6 +466,32 @@
 	return (ENOSPC);
 }
 
+int
+ppt_unmap_mmio(struct vm *vm, int bus, int slot, int func,
+	       vm_paddr_t gpa, size_t len)
+{
+	int i, error;
+	struct pptseg *seg;
+	struct pptdev *ppt;
+
+	error = ppt_find(vm, bus, slot, func, &ppt);
+	if (error)
+		return (error);
+
+	for (i = 0; i < MAX_MMIOSEGS; i++) {
+		seg = &ppt->mmio[i];
+		if (seg->gpa == gpa && seg->len == len) {
+			error = vm_unmap_mmio(vm, seg->gpa, seg->len);
+			if (error == 0) {
+				seg->gpa = 0;
+				seg->len = 0;
+			}
+			return (error);
+		}
+	}
+	return (ENOENT);
+}
+
 static int
 pptintr(void *arg)
 {
diff --git a/sys/amd64/vmm/vmm.c b/sys/amd64/vmm/vmm.c
--- a/sys/amd64/vmm/vmm.c
+++ b/sys/amd64/vmm/vmm.c
@@ -797,6 +797,24 @@
 	return (0);
 }
 
+int
+vm_munmap_memseg(struct vm *vm, vm_paddr_t gpa, size_t len)
+{
+	struct mem_map *m;
+	int i;
+
+	for (i = 0; i < VM_MAX_MEMMAPS; i++) {
+		m = &vm->mem_maps[i];
+		if (m->gpa == gpa && m->len == len &&
+		    (m->flags & VM_MEMMAP_F_IOMMU) == 0) {
+			vm_free_memmap(vm, i);
+			return (0);
+		}
+	}
+
+	return (EINVAL);
+}
+
 int
 vm_mmap_getnext(struct vm *vm, vm_paddr_t *gpa, int *segid,
     vm_ooffset_t *segoff, size_t *len, int *prot, int *flags)
diff --git a/sys/amd64/vmm/vmm_dev.c b/sys/amd64/vmm/vmm_dev.c
--- a/sys/amd64/vmm/vmm_dev.c
+++ b/sys/amd64/vmm/vmm_dev.c
@@ -381,6 +381,7 @@
 	struct vm_rtc_time *rtctime;
 	struct vm_rtc_data *rtcdata;
 	struct vm_memmap *mm;
+	struct vm_munmap *mu;
 	struct vm_cpu_topology *topology;
 	struct vm_readwrite_kernemu_device *kernemu;
 	uint64_t *regvals;
@@ -435,6 +436,7 @@
 		break;
 
 	case VM_MAP_PPTDEV_MMIO:
+	case VM_UNMAP_PPTDEV_MMIO:
 	case VM_BIND_PPTDEV:
 	case VM_UNBIND_PPTDEV:
 #ifdef COMPAT_FREEBSD12
@@ -442,6 +444,7 @@
 #endif
 	case VM_ALLOC_MEMSEG:
 	case VM_MMAP_MEMSEG:
+	case VM_MUNMAP_MEMSEG:
 	case VM_REINIT:
 		/*
 		 * ioctls that operate on the entire virtual machine must
@@ -525,6 +528,11 @@
 				     pptmmio->func, pptmmio->gpa, pptmmio->len,
 				     pptmmio->hpa);
 		break;
+	case VM_UNMAP_PPTDEV_MMIO:
+		pptmmio = (struct vm_pptdev_mmio *)data;
+		error = ppt_unmap_mmio(sc->vm, pptmmio->bus, pptmmio->slot,
+				       pptmmio->func, pptmmio->gpa, pptmmio->len);
+		break;
 	case VM_BIND_PPTDEV:
 		pptdev = (struct vm_pptdev *)data;
 		error = vm_assign_pptdev(sc->vm, pptdev->bus, pptdev->slot,
@@ -643,6 +651,10 @@
 		error = vm_mmap_memseg(sc->vm, mm->gpa, mm->segid, mm->segoff,
 		    mm->len, mm->prot, mm->flags);
 		break;
+	case VM_MUNMAP_MEMSEG:
+		mu = (struct vm_munmap *)data;
+		error = vm_munmap_memseg(sc->vm, mu->gpa, mu->len);
+		break;
 #ifdef COMPAT_FREEBSD12
 	case VM_ALLOC_MEMSEG_FBSD12:
 		error = alloc_memseg(sc, (struct vm_memseg *)data,
diff --git a/usr.sbin/bhyve/pci_emul.h b/usr.sbin/bhyve/pci_emul.h
--- a/usr.sbin/bhyve/pci_emul.h
+++ b/usr.sbin/bhyve/pci_emul.h
@@ -76,6 +76,9 @@
 				struct pci_devinst *pi, int baridx,
 				uint64_t offset, int size);
 
+	void	(*pe_baraddr)(struct vmctx *ctx, struct pci_devinst *pi,
+			      int baridx, int enabled, uint64_t address);
+
 	/* Save/restore device state */
 	int	(*pe_snapshot)(struct vm_snapshot_meta *meta);
 	int	(*pe_pause)(struct vmctx *ctx, struct pci_devinst *pi);
diff --git a/usr.sbin/bhyve/pci_emul.c b/usr.sbin/bhyve/pci_emul.c
--- a/usr.sbin/bhyve/pci_emul.c
+++ b/usr.sbin/bhyve/pci_emul.c
@@ -506,10 +506,12 @@
 static void
 modify_bar_registration(struct pci_devinst *pi, int idx, int registration)
 {
+	struct pci_devemu *pe;
 	int error;
 	struct inout_port iop;
 	struct mem_range mr;
 
+	pe = pi->pi_d;
 	switch (pi->pi_bar[idx].type) {
 	case PCIBAR_IO:
 		bzero(&iop, sizeof(struct inout_port));
@@ -523,6 +525,9 @@
 			error = register_inout(&iop);
 		} else
 			error = unregister_inout(&iop);
+		if (pe->pe_baraddr != NULL)
+			(*pe->pe_baraddr)(pi->pi_vmctx, pi, idx, registration,
+					  pi->pi_bar[idx].addr);
 		break;
 	case PCIBAR_MEM32:
 	case PCIBAR_MEM64:
@@ -538,6 +543,9 @@
 			error = register_mem(&mr);
 		} else
 			error = unregister_mem(&mr);
+		if (pe->pe_baraddr != NULL)
+			(*pe->pe_baraddr)(pi->pi_vmctx, pi, idx, registration,
+					  pi->pi_bar[idx].addr);
 		break;
 	default:
 		error = EINVAL;
diff --git a/usr.sbin/bhyve/pci_fbuf.c b/usr.sbin/bhyve/pci_fbuf.c
--- a/usr.sbin/bhyve/pci_fbuf.c
+++ b/usr.sbin/bhyve/pci_fbuf.c
@@ -216,6 +216,30 @@
 	return (value);
 }
 
+static void
+pci_fbuf_baraddr(struct vmctx *ctx, struct pci_devinst *pi, int baridx,
+		 int enabled, uint64_t address)
+{
+	struct pci_fbuf_softc *sc;
+	int prot;
+
+	if (baridx != 1)
+		return;
+
+	sc = pi->pi_arg;
+	if (!enabled && sc->fbaddr != 0) {
+		if (vm_munmap_memseg(ctx, sc->fbaddr, FB_SIZE) != 0)
+			EPRINTLN("pci_fbuf: munmap_memseg failed");
+		sc->fbaddr = 0;
+	} else if (sc->fb_base != NULL && sc->fbaddr == 0) {
+		prot = PROT_READ | PROT_WRITE;
+		if (vm_mmap_memseg(ctx, address, VM_FRAMEBUFFER, 0, FB_SIZE, prot) != 0)
+			EPRINTLN("pci_fbuf: mmap_memseg failed");
+		sc->fbaddr = address;
+	}
+}
+
+
 static int
 pci_fbuf_parse_config(struct pci_fbuf_softc *sc, nvlist_t *nvl)
 {
@@ -457,6 +481,7 @@
 	.pe_init =	pci_fbuf_init,
 	.pe_barwrite =	pci_fbuf_write,
 	.pe_barread =	pci_fbuf_read,
+	.pe_baraddr =	pci_fbuf_baraddr,
 #ifdef BHYVE_SNAPSHOT
 	.pe_snapshot =	pci_fbuf_snapshot,
 #endif
diff --git a/usr.sbin/bhyve/pci_passthru.c b/usr.sbin/bhyve/pci_passthru.c
--- a/usr.sbin/bhyve/pci_passthru.c
+++ b/usr.sbin/bhyve/pci_passthru.c
@@ -441,8 +441,8 @@
 init_msix_table(struct vmctx *ctx, struct passthru_softc *sc, uint64_t base)
 {
 	int b, s, f;
-	int error, idx;
-	size_t len, remaining;
+	int idx;
+	size_t remaining;
 	uint32_t table_size, table_offset;
 	uint32_t pba_size, pba_offset;
 	vm_paddr_t start;
@@ -504,31 +504,6 @@
 		}
 	}
 
-	/* Map everything before the MSI-X table */
-	if (table_offset > 0) {
-		len = table_offset;
-		error = vm_map_pptdev_mmio(ctx, b, s, f, start, len, base);
-		if (error)
-			return (error);
-
-		base += len;
-		start += len;
-		remaining -= len;
-	}
-
-	/* Skip the MSI-X table */
-	base += table_size;
-	start += table_size;
-	remaining -= table_size;
-
-	/* Map everything beyond the end of the MSI-X table */
-	if (remaining > 0) {
-		len = remaining;
-		error = vm_map_pptdev_mmio(ctx, b, s, f, start, len, base);
-		if (error)
-			return (error);
-	}
-
 	return (0);
 }
 
@@ -595,13 +570,6 @@
 			error = init_msix_table(ctx, sc, base);
 			if (error) 
 				return (-1);
-		} else if (bartype != PCIBAR_IO) {
-			/* Map the physical BAR in the guest MMIO space */
-			error = vm_map_pptdev_mmio(ctx, sc->psc_sel.pc_bus,
-				sc->psc_sel.pc_dev, sc->psc_sel.pc_func,
-				pi->pi_bar[i].addr, pi->pi_bar[i].size, base);
-			if (error)
-				return (-1);
 		}
 
 		/*
@@ -988,6 +956,92 @@
 	return (val);
 }
 
+static void
+passthru_msix_addr(struct vmctx *ctx, struct pci_devinst *pi, int baridx,
+		   int enabled, uint64_t address)
+{
+	struct passthru_softc *sc;
+	size_t remaining;
+	uint32_t table_size, table_offset;
+
+	sc = pi->pi_arg;
+	table_offset = rounddown2(pi->pi_msix.table_offset, 4096);
+	if (table_offset > 0) {
+		if (!enabled) {
+			if (vm_unmap_pptdev_mmio(ctx, sc->psc_sel.pc_bus,
+						 sc->psc_sel.pc_dev,
+						 sc->psc_sel.pc_func, address,
+						 table_offset) != 0)
+				warnx("pci_passthru: unmap_pptdev_mmio failed");
+		} else {
+			if (vm_map_pptdev_mmio(ctx, sc->psc_sel.pc_bus,
+					       sc->psc_sel.pc_dev,
+					       sc->psc_sel.pc_func, address,
+					       table_offset,
+					       sc->psc_bar[baridx].addr) != 0)
+				warnx("pci_passthru: map_pptdev_mmio failed");
+		}
+	}
+	table_size = pi->pi_msix.table_offset - table_offset;
+	table_size += pi->pi_msix.table_count * MSIX_TABLE_ENTRY_SIZE;
+	table_size = roundup2(table_size, 4096);
+	remaining = pi->pi_bar[baridx].size - table_offset - table_size;
+	if (remaining > 0) {
+		address += table_offset + table_size;
+		if (!enabled) {
+			if (vm_unmap_pptdev_mmio(ctx, sc->psc_sel.pc_bus,
+						 sc->psc_sel.pc_dev,
+						 sc->psc_sel.pc_func, address,
+						 remaining) != 0)
+				warnx("pci_passthru: unmap_pptdev_mmio failed");
+		} else {
+			if (vm_map_pptdev_mmio(ctx, sc->psc_sel.pc_bus,
+					       sc->psc_sel.pc_dev,
+					       sc->psc_sel.pc_func, address,
+					       remaining,
+					       sc->psc_bar[baridx].addr +
+					       table_offset + table_size) != 0)
+				warnx("pci_passthru: map_pptdev_mmio failed");
+		}
+	}
+}
+
+static void
+passthru_mmio_addr(struct vmctx *ctx, struct pci_devinst *pi, int baridx,
+		   int enabled, uint64_t address)
+{
+	struct passthru_softc *sc;
+
+	sc = pi->pi_arg;
+	if (!enabled) {
+		if (vm_unmap_pptdev_mmio(ctx, sc->psc_sel.pc_bus,
+					 sc->psc_sel.pc_dev,
+					 sc->psc_sel.pc_func, address,
+					 sc->psc_bar[baridx].size) != 0)
+			warnx("pci_passthru: unmap_pptdev_mmio failed");
+	} else {
+		if (vm_map_pptdev_mmio(ctx, sc->psc_sel.pc_bus,
+				       sc->psc_sel.pc_dev,
+				       sc->psc_sel.pc_func, address,
+				       sc->psc_bar[baridx].size,
+				       sc->psc_bar[baridx].addr) != 0)
+			warnx("pci_passthru: map_pptdev_mmio failed");
+	}
+}
+
+static void
+passthru_addr(struct vmctx *ctx, struct pci_devinst *pi, int baridx,
+	      int enabled, uint64_t address)
+{
+
+	if (pi->pi_bar[baridx].type == PCIBAR_IO)
+		return;
+	if (baridx == pci_msix_table_bar(pi))
+		passthru_msix_addr(ctx, pi, baridx, enabled, address);
+	else
+		passthru_mmio_addr(ctx, pi, baridx, enabled, address);
+}
+
 struct pci_devemu passthru = {
 	.pe_emu		= "passthru",
 	.pe_init	= passthru_init,
@@ -996,5 +1050,6 @@
 	.pe_cfgread	= passthru_cfgread,
 	.pe_barwrite 	= passthru_write,
 	.pe_barread    	= passthru_read,
+	.pe_baraddr	= passthru_addr,
 };
 PCI_EMUL_SET(passthru);