16 files changed, 147 insertions, 151 deletions

diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index c48927a58e10..ad3844d9f876 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -1,6 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_HOTPLUG_CPU)		+= cpu_hotplug.o
-obj-$(CONFIG_X86)			+= fallback.o
 obj-y	+= grant-table.o features.o balloon.o manage.o preempt.o time.o
 obj-y	+= mem-reservation.o
 obj-y	+= events/
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index ceb5048de9a7..39b229f9e256 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -369,14 +369,20 @@ static enum bp_state reserve_additional_memory(void)
 	return BP_ECANCELED;
 }
 
-static void xen_online_page(struct page *page)
+static void xen_online_page(struct page *page, unsigned int order)
 {
-	__online_page_set_limits(page);
+	unsigned long i, size = (1 << order);
+	unsigned long start_pfn = page_to_pfn(page);
+	struct page *p;
 
+	pr_debug("Online %lu pages starting at pfn 0x%lx\n", size, start_pfn);
 	mutex_lock(&balloon_mutex);
-
-	__balloon_append(page);
-
+	for (i = 0; i < size; i++) {
+		p = pfn_to_page(start_pfn + i);
+		__online_page_set_limits(p);
+		__SetPageOffline(p);
+		__balloon_append(p);
+	}
 	mutex_unlock(&balloon_mutex);
 }
 
@@ -441,6 +447,7 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
 		xenmem_reservation_va_mapping_update(1, &page, &frame_list[i]);
 
 		/* Relinquish the page back to the allocator. */
+		__ClearPageOffline(page);
 		free_reserved_page(page);
 	}
 
@@ -467,6 +474,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
 			state = BP_EAGAIN;
 			break;
 		}
+		__SetPageOffline(page);
 		adjust_managed_page_count(page, -1);
 		xenmem_reservation_scrub_page(page);
 		list_add(&page->lru, &pages);
diff --git a/drivers/xen/cpu_hotplug.c b/drivers/xen/cpu_hotplug.c
index b1357aa4bc55..f192b6f42da9 100644
--- a/drivers/xen/cpu_hotplug.c
+++ b/drivers/xen/cpu_hotplug.c
@@ -54,7 +54,7 @@ static int vcpu_online(unsigned int cpu)
 }
 static void vcpu_hotplug(unsigned int cpu)
 {
-	if (!cpu_possible(cpu))
+	if (cpu >= nr_cpu_ids || !cpu_possible(cpu))
 		return;
 
 	switch (vcpu_online(cpu)) {
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 93194f3e7540..117e76b2f939 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -1650,7 +1650,7 @@ void xen_callback_vector(void)
 			xen_have_vector_callback = 0;
 			return;
 		}
-		pr_info("Xen HVM callback vector for event delivery is enabled\n");
+		pr_info_once("Xen HVM callback vector for event delivery is enabled\n");
 		alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
 				xen_hvm_callback_vector);
 	}
diff --git a/drivers/xen/fallback.c b/drivers/xen/fallback.c
deleted file mode 100644
index b04fb64c5a91..000000000000
--- a/drivers/xen/fallback.c
+++ /dev/null
@@ -1,81 +0,0 @@
-#include <linux/kernel.h>
-#include <linux/string.h>
-#include <linux/bug.h>
-#include <linux/export.h>
-#include <asm/hypervisor.h>
-#include <asm/xen/hypercall.h>
-
-int xen_event_channel_op_compat(int cmd, void *arg)
-{
-	struct evtchn_op op;
-	int rc;
-
-	op.cmd = cmd;
-	memcpy(&op.u, arg, sizeof(op.u));
-	rc = _hypercall1(int, event_channel_op_compat, &op);
-
-	switch (cmd) {
-	case EVTCHNOP_close:
-	case EVTCHNOP_send:
-	case EVTCHNOP_bind_vcpu:
-	case EVTCHNOP_unmask:
-		/* no output */
-		break;
-
-#define COPY_BACK(eop) \
-	case EVTCHNOP_##eop: \
-		memcpy(arg, &op.u.eop, sizeof(op.u.eop)); \
-		break
-
-	COPY_BACK(bind_interdomain);
-	COPY_BACK(bind_virq);
-	COPY_BACK(bind_pirq);
-	COPY_BACK(status);
-	COPY_BACK(alloc_unbound);
-	COPY_BACK(bind_ipi);
-#undef COPY_BACK
-
-	default:
-		WARN_ON(rc != -ENOSYS);
-		break;
-	}
-
-	return rc;
-}
-EXPORT_SYMBOL_GPL(xen_event_channel_op_compat);
-
-int xen_physdev_op_compat(int cmd, void *arg)
-{
-	struct physdev_op op;
-	int rc;
-
-	op.cmd = cmd;
-	memcpy(&op.u, arg, sizeof(op.u));
-	rc = _hypercall1(int, physdev_op_compat, &op);
-
-	switch (cmd) {
-	case PHYSDEVOP_IRQ_UNMASK_NOTIFY:
-	case PHYSDEVOP_set_iopl:
-	case PHYSDEVOP_set_iobitmap:
-	case PHYSDEVOP_apic_write:
-		/* no output */
-		break;
-
-#define COPY_BACK(pop, fld) \
-	case PHYSDEVOP_##pop: \
-		memcpy(arg, &op.u.fld, sizeof(op.u.fld)); \
-		break
-
-	COPY_BACK(irq_status_query, irq_status_query);
-	COPY_BACK(apic_read, apic_op);
-	COPY_BACK(ASSIGN_VECTOR, irq_op);
-#undef COPY_BACK
-
-	default:
-		WARN_ON(rc != -ENOSYS);
-		break;
-	}
-
-	return rc;
-}
-EXPORT_SYMBOL_GPL(xen_physdev_op_compat);
diff --git a/drivers/xen/gntdev-dmabuf.c b/drivers/xen/gntdev-dmabuf.c
index cba6b586bfbd..2c4f324f8626 100644
--- a/drivers/xen/gntdev-dmabuf.c
+++ b/drivers/xen/gntdev-dmabuf.c
@@ -80,6 +80,12 @@ struct gntdev_dmabuf_priv {
 	struct list_head imp_list;
 	/* This is the lock which protects dma_buf_xxx lists. */
 	struct mutex lock;
+	/*
+	 * We reference this file while exporting dma-bufs, so
+	 * the grant device context is not destroyed while there are
+	 * external users alive.
+	 */
+	struct file *filp;
 };
 
 /* DMA buffer export support. */
@@ -311,6 +317,7 @@ static void dmabuf_exp_release(struct kref *kref)
 
 	dmabuf_exp_wait_obj_signal(gntdev_dmabuf->priv, gntdev_dmabuf);
 	list_del(&gntdev_dmabuf->next);
+	fput(gntdev_dmabuf->priv->filp);
 	kfree(gntdev_dmabuf);
 }
 
@@ -423,6 +430,7 @@ static int dmabuf_exp_from_pages(struct gntdev_dmabuf_export_args *args)
 	mutex_lock(&args->dmabuf_priv->lock);
 	list_add(&gntdev_dmabuf->next, &args->dmabuf_priv->exp_list);
 	mutex_unlock(&args->dmabuf_priv->lock);
+	get_file(gntdev_dmabuf->priv->filp);
 	return 0;
 
 fail:
@@ -737,6 +745,14 @@ static int dmabuf_imp_release(struct gntdev_dmabuf_priv *priv, u32 fd)
 	return 0;
 }
 
+static void dmabuf_imp_release_all(struct gntdev_dmabuf_priv *priv)
+{
+	struct gntdev_dmabuf *q, *gntdev_dmabuf;
+
+	list_for_each_entry_safe(gntdev_dmabuf, q, &priv->imp_list, next)
+		dmabuf_imp_release(priv, gntdev_dmabuf->fd);
+}
+
 /* DMA buffer IOCTL support. */
 
 long gntdev_ioctl_dmabuf_exp_from_refs(struct gntdev_priv *priv, int use_ptemod,
@@ -834,7 +850,7 @@ long gntdev_ioctl_dmabuf_imp_release(struct gntdev_priv *priv,
 	return dmabuf_imp_release(priv->dmabuf_priv, op.fd);
 }
 
-struct gntdev_dmabuf_priv *gntdev_dmabuf_init(void)
+struct gntdev_dmabuf_priv *gntdev_dmabuf_init(struct file *filp)
 {
 	struct gntdev_dmabuf_priv *priv;
 
@@ -847,10 +863,13 @@ struct gntdev_dmabuf_priv *gntdev_dmabuf_init(void)
 	INIT_LIST_HEAD(&priv->exp_wait_list);
 	INIT_LIST_HEAD(&priv->imp_list);
 
+	priv->filp = filp;
+
 	return priv;
 }
 
 void gntdev_dmabuf_fini(struct gntdev_dmabuf_priv *priv)
 {
+	dmabuf_imp_release_all(priv);
 	kfree(priv);
 }
diff --git a/drivers/xen/gntdev-dmabuf.h b/drivers/xen/gntdev-dmabuf.h
index 7220a53d0fc5..3d9b9cf9d5a1 100644
--- a/drivers/xen/gntdev-dmabuf.h
+++ b/drivers/xen/gntdev-dmabuf.h
@@ -14,7 +14,7 @@
 struct gntdev_dmabuf_priv;
 struct gntdev_priv;
 
-struct gntdev_dmabuf_priv *gntdev_dmabuf_init(void);
+struct gntdev_dmabuf_priv *gntdev_dmabuf_init(struct file *filp);
 
 void gntdev_dmabuf_fini(struct gntdev_dmabuf_priv *priv);
 
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 5efc5eee9544..7cf9c51318aa 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -600,7 +600,7 @@ static int gntdev_open(struct inode *inode, struct file *flip)
 	mutex_init(&priv->lock);
 
 #ifdef CONFIG_XEN_GNTDEV_DMABUF
-	priv->dmabuf_priv = gntdev_dmabuf_init();
+	priv->dmabuf_priv = gntdev_dmabuf_init(flip);
 	if (IS_ERR(priv->dmabuf_priv)) {
 		ret = PTR_ERR(priv->dmabuf_priv);
 		kfree(priv);
diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
index 2e5d845b5091..7aa64d1b119c 100644
--- a/drivers/xen/pvcalls-back.c
+++ b/drivers/xen/pvcalls-back.c
@@ -160,9 +160,10 @@ static void pvcalls_conn_back_read(void *opaque)
 
 	/* write the data, then modify the indexes */
 	virt_wmb();
-	if (ret < 0)
+	if (ret < 0) {
+		atomic_set(&map->read, 0);
 		intf->in_error = ret;
-	else
+	} else
 		intf->in_prod = prod + ret;
 	/* update the indexes, then notify the other end */
 	virt_wmb();
@@ -282,13 +283,11 @@ static int pvcalls_back_socket(struct xenbus_device *dev,
 static void pvcalls_sk_state_change(struct sock *sock)
 {
 	struct sock_mapping *map = sock->sk_user_data;
-	struct pvcalls_data_intf *intf;
 
 	if (map == NULL)
 		return;
 
-	intf = map->ring;
-	intf->in_error = -ENOTCONN;
+	atomic_inc(&map->read);
 	notify_remote_via_irq(map->irq);
 }
 
diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
index 77224d8f3e6f..8a249c95c193 100644
--- a/drivers/xen/pvcalls-front.c
+++ b/drivers/xen/pvcalls-front.c
@@ -31,6 +31,12 @@
 #define PVCALLS_NR_RSP_PER_RING __CONST_RING_SIZE(xen_pvcalls, XEN_PAGE_SIZE)
 #define PVCALLS_FRONT_MAX_SPIN 5000
 
+static struct proto pvcalls_proto = {
+	.name	= "PVCalls",
+	.owner	= THIS_MODULE,
+	.obj_size = sizeof(struct sock),
+};
+
 struct pvcalls_bedata {
 	struct xen_pvcalls_front_ring ring;
 	grant_ref_t ref;
@@ -335,6 +341,42 @@ int pvcalls_front_socket(struct socket *sock)
 	return ret;
 }
 
+static void free_active_ring(struct sock_mapping *map)
+{
+	if (!map->active.ring)
+		return;
+
+	free_pages((unsigned long)map->active.data.in,
+			map->active.ring->ring_order);
+	free_page((unsigned long)map->active.ring);
+}
+
+static int alloc_active_ring(struct sock_mapping *map)
+{
+	void *bytes;
+
+	map->active.ring = (struct pvcalls_data_intf *)
+		get_zeroed_page(GFP_KERNEL);
+	if (!map->active.ring)
+		goto out;
+
+	map->active.ring->ring_order = PVCALLS_RING_ORDER;
+	bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+					PVCALLS_RING_ORDER);
+	if (!bytes)
+		goto out;
+
+	map->active.data.in = bytes;
+	map->active.data.out = bytes +
+		XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER);
+
+	return 0;
+
+out:
+	free_active_ring(map);
+	return -ENOMEM;
+}
+
 static int create_active(struct sock_mapping *map, int *evtchn)
 {
 	void *bytes;
@@ -343,15 +385,7 @@ static int create_active(struct sock_mapping *map, int *evtchn)
 	*evtchn = -1;
 	init_waitqueue_head(&map->active.inflight_conn_req);
 
-	map->active.ring = (struct pvcalls_data_intf *)
-		__get_free_page(GFP_KERNEL | __GFP_ZERO);
-	if (map->active.ring == NULL)
-		goto out_error;
-	map->active.ring->ring_order = PVCALLS_RING_ORDER;
-	bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
-					PVCALLS_RING_ORDER);
-	if (bytes == NULL)
-		goto out_error;
+	bytes = map->active.data.in;
 	for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++)
 		map->active.ring->ref[i] = gnttab_grant_foreign_access(
 			pvcalls_front_dev->otherend_id,
@@ -361,10 +395,6 @@ static int create_active(struct sock_mapping *map, int *evtchn)
 		pvcalls_front_dev->otherend_id,
 		pfn_to_gfn(virt_to_pfn((void *)map->active.ring)), 0);
 
-	map->active.data.in = bytes;
-	map->active.data.out = bytes +
-		XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER);
-
 	ret = xenbus_alloc_evtchn(pvcalls_front_dev, evtchn);
 	if (ret)
 		goto out_error;
@@ -385,8 +415,6 @@ static int create_active(struct sock_mapping *map, int *evtchn)
 out_error:
 	if (*evtchn >= 0)
 		xenbus_free_evtchn(pvcalls_front_dev, *evtchn);
-	free_pages((unsigned long)map->active.data.in, PVCALLS_RING_ORDER);
-	free_page((unsigned long)map->active.ring);
 	return ret;
 }
 
@@ -406,17 +434,24 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
 		return PTR_ERR(map);
 
 	bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
+	ret = alloc_active_ring(map);
+	if (ret < 0) {
+		pvcalls_exit_sock(sock);
+		return ret;
+	}
 
 	spin_lock(&bedata->socket_lock);
 	ret = get_request(bedata, &req_id);
 	if (ret < 0) {
 		spin_unlock(&bedata->socket_lock);
+		free_active_ring(map);
 		pvcalls_exit_sock(sock);
 		return ret;
 	}
 	ret = create_active(map, &evtchn);
 	if (ret < 0) {
 		spin_unlock(&bedata->socket_lock);
+		free_active_ring(map);
 		pvcalls_exit_sock(sock);
 		return ret;
 	}
@@ -469,8 +504,10 @@ static int __write_ring(struct pvcalls_data_intf *intf,
 	virt_mb();
 
 	size = pvcalls_queued(prod, cons, array_size);
-	if (size >= array_size)
+	if (size > array_size)
 		return -EINVAL;
+	if (size == array_size)
+		return 0;
 	if (len > array_size - size)
 		len = array_size - size;
 
@@ -560,15 +597,13 @@ static int __read_ring(struct pvcalls_data_intf *intf,
 	error = intf->in_error;
 	/* get pointers before reading from the ring */
 	virt_rmb();
-	if (error < 0)
-		return error;
 
 	size = pvcalls_queued(prod, cons, array_size);
 	masked_prod = pvcalls_mask(prod, array_size);
 	masked_cons = pvcalls_mask(cons, array_size);
 
 	if (size == 0)
-		return 0;
+		return error ?: size;
 
 	if (len > size)
 		len = size;
@@ -780,25 +815,36 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
 		}
 	}
 
-	spin_lock(&bedata->socket_lock);
-	ret = get_request(bedata, &req_id);
-	if (ret < 0) {
+	map2 = kzalloc(sizeof(*map2), GFP_KERNEL);
+	if (map2 == NULL) {
 		clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
 			  (void *)&map->passive.flags);
-		spin_unlock(&bedata->socket_lock);
+		pvcalls_exit_sock(sock);
+		return -ENOMEM;
+	}
+	ret = alloc_active_ring(map2);
+	if (ret < 0) {
+		clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
+				(void *)&map->passive.flags);
+		kfree(map2);
 		pvcalls_exit_sock(sock);
 		return ret;
 	}
-	map2 = kzalloc(sizeof(*map2), GFP_ATOMIC);
-	if (map2 == NULL) {
+	spin_lock(&bedata->socket_lock);
+	ret = get_request(bedata, &req_id);
+	if (ret < 0) {
 		clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
 			  (void *)&map->passive.flags);
 		spin_unlock(&bedata->socket_lock);
+		free_active_ring(map2);
+		kfree(map2);
 		pvcalls_exit_sock(sock);
-		return -ENOMEM;
+		return ret;
 	}
+
 	ret = create_active(map2, &evtchn);
 	if (ret < 0) {
+		free_active_ring(map2);
 		kfree(map2);
 		clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
 			  (void *)&map->passive.flags);
@@ -839,7 +885,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
 
 received:
 	map2->sock = newsock;
-	newsock->sk = kzalloc(sizeof(*newsock->sk), GFP_KERNEL);
+	newsock->sk = sk_alloc(sock_net(sock->sk), PF_INET, GFP_KERNEL, &pvcalls_proto, false);
 	if (!newsock->sk) {
 		bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
 		map->passive.inflight_req_id = PVCALLS_INVALID_ID;
@@ -1032,8 +1078,8 @@ int pvcalls_front_release(struct socket *sock)
 		spin_lock(&bedata->socket_lock);
 		list_del(&map->list);
 		spin_unlock(&bedata->socket_lock);
-		if (READ_ONCE(map->passive.inflight_req_id) !=
-		    PVCALLS_INVALID_ID) {
+		if (READ_ONCE(map->passive.inflight_req_id) != PVCALLS_INVALID_ID &&
+			READ_ONCE(map->passive.inflight_req_id) != 0) {
 			pvcalls_front_free_map(bedata,
 					       map->passive.accept_map);
 		}
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 989cf872b98c..877baf2a94f4 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -214,10 +214,13 @@ retry:
 	/*
 	 * Get IO TLB memory from any location.
 	 */
-	if (early)
+	if (early) {
 		xen_io_tlb_start = memblock_alloc(PAGE_ALIGN(bytes),
 						  PAGE_SIZE);
-	else {
+		if (!xen_io_tlb_start)
+			panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+			      __func__, PAGE_ALIGN(bytes), PAGE_SIZE);
+	} else {
 #define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
 #define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
 		while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
@@ -645,7 +648,7 @@ xen_swiotlb_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 		     void *cpu_addr, dma_addr_t dma_addr, size_t size,
 		     unsigned long attrs)
 {
-#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
+#ifdef CONFIG_ARM
 	if (xen_get_dma_ops(dev)->mmap)
 		return xen_get_dma_ops(dev)->mmap(dev, vma, cpu_addr,
 						    dma_addr, size, attrs);
@@ -662,7 +665,7 @@ xen_swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
 			void *cpu_addr, dma_addr_t handle, size_t size,
 			unsigned long attrs)
 {
-#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
+#ifdef CONFIG_ARM
 	if (xen_get_dma_ops(dev)->get_sgtable) {
 #if 0
 	/*
diff --git a/drivers/xen/xen-acpi-processor.c b/drivers/xen/xen-acpi-processor.c
index fbb9137c7d02..98e35644fda7 100644
--- a/drivers/xen/xen-acpi-processor.c
+++ b/drivers/xen/xen-acpi-processor.c
@@ -410,21 +410,21 @@ static int check_acpi_ids(struct acpi_processor *pr_backup)
 	/* All online CPUs have been processed at this stage. Now verify
 	 * whether in fact "online CPUs" == physical CPUs.
 	 */
-	acpi_id_present = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
+	acpi_id_present = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL);
 	if (!acpi_id_present)
 		return -ENOMEM;
 
-	acpi_id_cst_present = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
+	acpi_id_cst_present = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL);
 	if (!acpi_id_cst_present) {
-		kfree(acpi_id_present);
+		bitmap_free(acpi_id_present);
 		return -ENOMEM;
 	}
 
 	acpi_psd = kcalloc(nr_acpi_bits, sizeof(struct acpi_psd_package),
 			   GFP_KERNEL);
 	if (!acpi_psd) {
-		kfree(acpi_id_present);
-		kfree(acpi_id_cst_present);
+		bitmap_free(acpi_id_present);
+		bitmap_free(acpi_id_cst_present);
 		return -ENOMEM;
 	}
 
@@ -533,14 +533,14 @@ static int __init xen_acpi_processor_init(void)
 		return -ENODEV;
 
 	nr_acpi_bits = get_max_acpi_id() + 1;
-	acpi_ids_done = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
+	acpi_ids_done = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL);
 	if (!acpi_ids_done)
 		return -ENOMEM;
 
 	acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
 	if (!acpi_perf_data) {
 		pr_debug("Memory allocation error for acpi_perf_data\n");
-		kfree(acpi_ids_done);
+		bitmap_free(acpi_ids_done);
 		return -ENOMEM;
 	}
 	for_each_possible_cpu(i) {
@@ -584,7 +584,7 @@ err_unregister:
 err_out:
 	/* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
 	free_acpi_perf_data();
-	kfree(acpi_ids_done);
+	bitmap_free(acpi_ids_done);
 	return rc;
 }
 static void __exit xen_acpi_processor_exit(void)
@@ -592,9 +592,9 @@ static void __exit xen_acpi_processor_exit(void)
 	int i;
 
 	unregister_syscore_ops(&xap_syscore_ops);
-	kfree(acpi_ids_done);
-	kfree(acpi_id_present);
-	kfree(acpi_id_cst_present);
+	bitmap_free(acpi_ids_done);
+	bitmap_free(acpi_id_present);
+	bitmap_free(acpi_id_cst_present);
 	kfree(acpi_psd);
 	for_each_possible_cpu(i)
 		acpi_processor_unregister_performance(i);
diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c
index 2acbfe104e46..a67236b02452 100644
--- a/drivers/xen/xen-balloon.c
+++ b/drivers/xen/xen-balloon.c
@@ -37,6 +37,7 @@
 #include <linux/mm_types.h>
 #include <linux/init.h>
 #include <linux/capability.h>
+#include <linux/memory_hotplug.h>
 
 #include <xen/xen.h>
 #include <xen/interface/xen.h>
@@ -50,6 +51,10 @@
 
 #define BALLOON_CLASS_NAME "xen_memory"
 
+#ifdef CONFIG_MEMORY_HOTPLUG
+u64 xen_saved_max_mem_size = 0;
+#endif
+
 static struct device balloon_dev;
 
 static int register_balloon(struct device *dev);
@@ -63,6 +68,12 @@ static void watch_target(struct xenbus_watch *watch,
 	static bool watch_fired;
 	static long target_diff;
 
+#ifdef CONFIG_MEMORY_HOTPLUG
+	/* The balloon driver will take care of adding memory now. */
+	if (xen_saved_max_mem_size)
+		max_mem_size = xen_saved_max_mem_size;
+#endif
+
 	err = xenbus_scanf(XBT_NIL, "memory", "target", "%llu", &new_target);
 	if (err != 1) {
 		/* This is ok (for domain0 at least) - so just return */
diff --git a/drivers/xen/xen-pciback/pciback_ops.c b/drivers/xen/xen-pciback/pciback_ops.c
index ea4a08b83fa0..787966f44589 100644
--- a/drivers/xen/xen-pciback/pciback_ops.c
+++ b/drivers/xen/xen-pciback/pciback_ops.c
@@ -127,8 +127,6 @@ void xen_pcibk_reset_device(struct pci_dev *dev)
 		if (pci_is_enabled(dev))
 			pci_disable_device(dev);
 
-		pci_write_config_word(dev, PCI_COMMAND, 0);
-
 		dev->is_busmaster = 0;
 	} else {
 		pci_read_config_word(dev, PCI_COMMAND, &cmd);
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index 581c4e1a8b82..23f7f6ec7d1f 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -544,7 +544,7 @@ static void xen_pcibk_frontend_changed(struct xenbus_device *xdev,
 		xenbus_switch_state(xdev, XenbusStateClosed);
 		if (xenbus_dev_is_online(xdev))
 			break;
-		/* fall through if not online */
+		/* fall through - if not online */
 	case XenbusStateUnknown:
 		dev_dbg(&xdev->dev, "frontend is gone! unregister device\n");
 		device_unregister(&xdev->dev);
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index c9e23a126218..ba0942e481bc 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -1184,7 +1184,7 @@ static void scsiback_frontend_changed(struct xenbus_device *dev,
 		xenbus_switch_state(dev, XenbusStateClosed);
 		if (xenbus_dev_is_online(dev))
 			break;
-		/* fall through if not online */
+		/* fall through - if not online */
 	case XenbusStateUnknown:
 		device_unregister(&dev->dev);
 		break;
@@ -1404,11 +1404,6 @@ static int scsiback_write_pending(struct se_cmd *se_cmd)
 	return 0;
 }
 
-static int scsiback_write_pending_status(struct se_cmd *se_cmd)
-{
-	return 0;
-}
-
 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
 {
 }
@@ -1818,7 +1813,6 @@ static const struct target_core_fabric_ops scsiback_ops = {
 	.sess_get_index			= scsiback_sess_get_index,
 	.sess_get_initiator_sid		= NULL,
 	.write_pending			= scsiback_write_pending,
-	.write_pending_status		= scsiback_write_pending_status,
 	.set_default_node_attributes	= scsiback_set_default_node_attrs,
 	.get_cmd_state			= scsiback_get_cmd_state,
 	.queue_data_in			= scsiback_queue_data_in,