diff --git a/lib/libvmmapi/vmmapi.h b/lib/libvmmapi/vmmapi.h
--- a/lib/libvmmapi/vmmapi.h
+++ b/lib/libvmmapi/vmmapi.h
@@ -180,6 +180,14 @@
 			   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_mmap_mmio(struct vmctx *const ctx, const vm_paddr_t gpa,
+    const vm_paddr_t len, const vm_paddr_t hpa);
+int vm_munmap_mmio(struct vmctx *const ctx, const vm_paddr_t gpa,
+    const vm_paddr_t len);
+int vm_mwire_gpa(struct vmctx *const ctx, const vm_paddr_t gpa,
+    const vm_paddr_t len);
+int vm_munwire_gpa(struct vmctx *const ctx, const vm_paddr_t gpa,
+    const vm_paddr_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
@@ -1012,6 +1012,52 @@
 	return (ioctl(ctx->fd, VM_UNMAP_PPTDEV_MMIO, &pptmmio));
 }
 
+/*
+ * Modifies the second level address translation (SLAT) of the guest memory
+ * space.
+ */
+static int
+vm_mmodify_slat(struct vmctx *const ctx, const vm_paddr_t gpa, const vm_paddr_t len,
+    const vm_paddr_t hpa, const enum slat_op_type type)
+{
+	struct vm_slat_op slat_op = {
+		.gpa = gpa,
+		.len = len,
+		.hpa = hpa,
+		.type = type,
+	};
+
+	return ioctl(ctx->fd, VM_MODIFY_SLAT, &slat_op);
+}
+
+int
+vm_mmap_mmio(struct vmctx *const ctx, const vm_paddr_t gpa,
+    const vm_paddr_t len, const vm_paddr_t hpa)
+{
+	return vm_mmodify_slat(ctx, gpa, len, hpa, VM_MAP_MMIO);
+}
+
+int
+vm_munmap_mmio(struct vmctx *const ctx, const vm_paddr_t gpa,
+    const vm_paddr_t len)
+{
+	return vm_mmodify_slat(ctx, gpa, len, 0, VM_UNMAP_MMIO);
+}
+
+int
+vm_mwire_gpa(struct vmctx *const ctx, const vm_paddr_t gpa,
+    const vm_paddr_t len)
+{
+	return vm_mmodify_slat(ctx, gpa, len, 0, VM_WIRE_GPA);
+}
+
+int
+vm_munwire_gpa(struct vmctx *const ctx, const vm_paddr_t gpa,
+    const vm_paddr_t len)
+{
+	return vm_mmodify_slat(ctx, gpa, len, 0, VM_UNWIRE_GPA);
+}
+
 int
 vm_setup_pptdev_msi(struct vmctx *ctx, int vcpu, int bus, int slot, int func,
     uint64_t addr, uint64_t msg, int numvec)
@@ -1687,7 +1733,7 @@
 	    VM_SET_CAPABILITY, VM_GET_CAPABILITY, VM_BIND_PPTDEV,
 	    VM_UNBIND_PPTDEV, VM_MAP_PPTDEV_MMIO, VM_PPTDEV_MSI,
 	    VM_PPTDEV_MSIX, VM_UNMAP_PPTDEV_MMIO, VM_PPTDEV_DISABLE_MSIX,
-	    VM_INJECT_NMI, VM_STATS, VM_STAT_DESC,
+	    VM_MODIFY_SLAT, 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,
 	    VM_GLA2GPA_NOFAULT,
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
@@ -236,6 +236,10 @@
 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);
 int vm_unmap_mmio(struct vm *vm, vm_paddr_t gpa, size_t len);
+int vm_wire_gpa(struct vm *const vm, const vm_paddr_t gpa,
+    const vm_paddr_t len);
+int vm_unwire_gpa(struct vm *const vm, const vm_paddr_t gpa,
+    const vm_paddr_t len);
 int vm_assign_pptdev(struct vm *vm, int bus, int slot, int func);
 int vm_unassign_pptdev(struct vm *vm, int bus, int slot, int func);
 
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
@@ -146,6 +146,21 @@
 	size_t		len;
 };
 
+/* second level address translation */
+enum slat_op_type {
+	VM_MAP_MMIO,
+	VM_UNMAP_MMIO,
+	VM_WIRE_GPA,
+	VM_UNWIRE_GPA
+};
+
+struct vm_slat_op {
+	vm_paddr_t gpa;
+	vm_paddr_t len;
+	vm_paddr_t hpa;
+	enum slat_op_type type;
+};
+
 struct vm_pptdev_msi {
 	int		vcpu;
 	int		bus;
@@ -309,6 +324,7 @@
 	IOCNUM_PPTDEV_MSIX = 44,
 	IOCNUM_PPTDEV_DISABLE_MSIX = 45,
 	IOCNUM_UNMAP_PPTDEV_MMIO = 46,
+	IOCNUM_MODIFY_SLAT = 48,
 
 	/* statistics */
 	IOCNUM_VM_STATS = 50, 
@@ -427,6 +443,8 @@
 	_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_MODIFY_SLAT \
+	_IOW('v', IOCNUM_MODIFY_SLAT, struct vm_slat_op)
 #define VM_INJECT_NMI \
 	_IOW('v', IOCNUM_INJECT_NMI, struct vm_nmi)
 #define	VM_STATS \
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
@@ -636,6 +636,20 @@
 	return (0);
 }
 
+int
+vm_wire_gpa(struct vm *const vm, const vm_paddr_t gpa, const vm_paddr_t len)
+{
+	return vm_map_wire(&vm->vmspace->vm_map, gpa, gpa + len,
+	    VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
+}
+
+int
+vm_unwire_gpa(struct vm *const vm, const vm_paddr_t gpa, const vm_paddr_t len)
+{
+	return vm_map_unwire(&vm->vmspace->vm_map, gpa, gpa + len,
+	    VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
+}
+
 /*
  * Return 'true' if 'gpa' is allocated in the guest address space.
  *
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
@@ -373,6 +373,7 @@
 	struct vm_capability *vmcap;
 	struct vm_pptdev *pptdev;
 	struct vm_pptdev_mmio *pptmmio;
+	struct vm_slat_op *slat_op;
 	struct vm_pptdev_msi *pptmsi;
 	struct vm_pptdev_msix *pptmsix;
 	struct vm_nmi *vmnmi;
@@ -453,6 +454,7 @@
 	case VM_MMAP_MEMSEG:
 	case VM_MUNMAP_MEMSEG:
 	case VM_REINIT:
+	case VM_MODIFY_SLAT:
 		/*
 		 * ioctls that operate on the entire virtual machine must
 		 * prevent all vcpus from running.
@@ -540,6 +542,26 @@
 		error = ppt_unmap_mmio(sc->vm, pptmmio->bus, pptmmio->slot,
 				       pptmmio->func, pptmmio->gpa, pptmmio->len);
 		break;
+	case VM_MODIFY_SLAT:
+		slat_op = (struct vm_slat_op *)data;
+		switch (slat_op->type) {
+		case VM_MAP_MMIO:
+			error = vm_map_mmio(sc->vm, slat_op->gpa, slat_op->len,
+			    slat_op->hpa);
+			break;
+		case VM_UNMAP_MMIO:
+			error = vm_unmap_mmio(sc->vm, slat_op->gpa,
+			    slat_op->len);
+			break;
+		case VM_WIRE_GPA:
+			error = vm_wire_gpa(sc->vm, slat_op->gpa, slat_op->len);
+			break;
+		case VM_UNWIRE_GPA:
+			error = vm_unwire_gpa(sc->vm, slat_op->gpa,
+			    slat_op->len);
+			break;
+		}
+		break;
 	case VM_BIND_PPTDEV:
 		pptdev = (struct vm_pptdev *)data;
 		error = vm_assign_pptdev(sc->vm, pptdev->bus, pptdev->slot,