Linux-libre 4.2-gnu

4 files changed, 172 insertions, 240 deletions

diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig
index 017a1e8a8..533eaf04f 100644
--- a/drivers/vhost/Kconfig
+++ b/drivers/vhost/Kconfig
@@ -32,3 +32,18 @@ config VHOST
 	---help---
 	  This option is selected by any driver which needs to access
 	  the core of vhost.
+
+config VHOST_CROSS_ENDIAN_LEGACY
+	bool "Cross-endian support for vhost"
+	default n
+	---help---
+	  This option allows vhost to support guests with a different byte
+	  ordering from host while using legacy virtio.
+
+	  Userspace programs can control the feature using the
+	  VHOST_SET_VRING_ENDIAN and VHOST_GET_VRING_ENDIAN ioctls.
+
+	  This is only useful on a few platforms (ppc64 and arm64). Since it
+	  adds some overhead, it is disabled by default.
+
+	  If unsure, say "N".
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index ea32b3867..dfcc02c93 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -35,13 +35,14 @@
 #include <linux/compat.h>
 #include <linux/eventfd.h>
 #include <linux/fs.h>
+#include <linux/vmalloc.h>
 #include <linux/miscdevice.h>
 #include <asm/unaligned.h>
-#include <scsi/scsi.h>
+#include <scsi/scsi_common.h>
+#include <scsi/scsi_proto.h>
 #include <target/target_core_base.h>
 #include <target/target_core_fabric.h>
 #include <target/target_core_fabric_configfs.h>
-#include <target/target_core_configfs.h>
 #include <target/configfs_macros.h>
 #include <linux/vhost.h>
 #include <linux/virtio_scsi.h>
@@ -115,15 +116,6 @@ struct vhost_scsi_nexus {
 	struct se_session *tvn_se_sess;
 };
 
-struct vhost_scsi_nacl {
-	/* Binary World Wide unique Port Name for Vhost Initiator port */
-	u64 iport_wwpn;
-	/* ASCII formatted WWPN for Sas Initiator port */
-	char iport_name[VHOST_SCSI_NAMELEN];
-	/* Returned by vhost_scsi_make_nodeacl() */
-	struct se_node_acl se_node_acl;
-};
-
 struct vhost_scsi_tpg {
 	/* Vhost port target portal group tag for TCM */
 	u16 tport_tpgt;
@@ -216,7 +208,6 @@ struct vhost_scsi {
 	int vs_events_nr; /* num of pending events, protected by vq->mutex */
 };
 
-static struct target_core_fabric_ops vhost_scsi_ops;
 static struct workqueue_struct *vhost_scsi_workqueue;
 
 /* Global spinlock to protect vhost_scsi TPG list for vhost IOCTL access */
@@ -297,28 +288,6 @@ static char *vhost_scsi_get_fabric_name(void)
 	return "vhost";
 }
 
-static u8 vhost_scsi_get_fabric_proto_ident(struct se_portal_group *se_tpg)
-{
-	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
-				struct vhost_scsi_tpg, se_tpg);
-	struct vhost_scsi_tport *tport = tpg->tport;
-
-	switch (tport->tport_proto_id) {
-	case SCSI_PROTOCOL_SAS:
-		return sas_get_fabric_proto_ident(se_tpg);
-	case SCSI_PROTOCOL_FCP:
-		return fc_get_fabric_proto_ident(se_tpg);
-	case SCSI_PROTOCOL_ISCSI:
-		return iscsi_get_fabric_proto_ident(se_tpg);
-	default:
-		pr_err("Unknown tport_proto_id: 0x%02x, using"
-			" SAS emulation\n", tport->tport_proto_id);
-		break;
-	}
-
-	return sas_get_fabric_proto_ident(se_tpg);
-}
-
 static char *vhost_scsi_get_fabric_wwn(struct se_portal_group *se_tpg)
 {
 	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
@@ -335,102 +304,6 @@ static u16 vhost_scsi_get_tpgt(struct se_portal_group *se_tpg)
 	return tpg->tport_tpgt;
 }
 
-static u32 vhost_scsi_get_default_depth(struct se_portal_group *se_tpg)
-{
-	return 1;
-}
-
-static u32
-vhost_scsi_get_pr_transport_id(struct se_portal_group *se_tpg,
-			      struct se_node_acl *se_nacl,
-			      struct t10_pr_registration *pr_reg,
-			      int *format_code,
-			      unsigned char *buf)
-{
-	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
-				struct vhost_scsi_tpg, se_tpg);
-	struct vhost_scsi_tport *tport = tpg->tport;
-
-	switch (tport->tport_proto_id) {
-	case SCSI_PROTOCOL_SAS:
-		return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
-					format_code, buf);
-	case SCSI_PROTOCOL_FCP:
-		return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
-					format_code, buf);
-	case SCSI_PROTOCOL_ISCSI:
-		return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
-					format_code, buf);
-	default:
-		pr_err("Unknown tport_proto_id: 0x%02x, using"
-			" SAS emulation\n", tport->tport_proto_id);
-		break;
-	}
-
-	return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
-			format_code, buf);
-}
-
-static u32
-vhost_scsi_get_pr_transport_id_len(struct se_portal_group *se_tpg,
-				  struct se_node_acl *se_nacl,
-				  struct t10_pr_registration *pr_reg,
-				  int *format_code)
-{
-	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
-				struct vhost_scsi_tpg, se_tpg);
-	struct vhost_scsi_tport *tport = tpg->tport;
-
-	switch (tport->tport_proto_id) {
-	case SCSI_PROTOCOL_SAS:
-		return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
-					format_code);
-	case SCSI_PROTOCOL_FCP:
-		return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
-					format_code);
-	case SCSI_PROTOCOL_ISCSI:
-		return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
-					format_code);
-	default:
-		pr_err("Unknown tport_proto_id: 0x%02x, using"
-			" SAS emulation\n", tport->tport_proto_id);
-		break;
-	}
-
-	return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
-			format_code);
-}
-
-static char *
-vhost_scsi_parse_pr_out_transport_id(struct se_portal_group *se_tpg,
-				    const char *buf,
-				    u32 *out_tid_len,
-				    char **port_nexus_ptr)
-{
-	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
-				struct vhost_scsi_tpg, se_tpg);
-	struct vhost_scsi_tport *tport = tpg->tport;
-
-	switch (tport->tport_proto_id) {
-	case SCSI_PROTOCOL_SAS:
-		return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
-					port_nexus_ptr);
-	case SCSI_PROTOCOL_FCP:
-		return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
-					port_nexus_ptr);
-	case SCSI_PROTOCOL_ISCSI:
-		return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
-					port_nexus_ptr);
-	default:
-		pr_err("Unknown tport_proto_id: 0x%02x, using"
-			" SAS emulation\n", tport->tport_proto_id);
-		break;
-	}
-
-	return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
-			port_nexus_ptr);
-}
-
 static int vhost_scsi_check_prot_fabric_only(struct se_portal_group *se_tpg)
 {
 	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
@@ -439,29 +312,6 @@ static int vhost_scsi_check_prot_fabric_only(struct se_portal_group *se_tpg)
 	return tpg->tv_fabric_prot_type;
 }
 
-static struct se_node_acl *
-vhost_scsi_alloc_fabric_acl(struct se_portal_group *se_tpg)
-{
-	struct vhost_scsi_nacl *nacl;
-
-	nacl = kzalloc(sizeof(struct vhost_scsi_nacl), GFP_KERNEL);
-	if (!nacl) {
-		pr_err("Unable to allocate struct vhost_scsi_nacl\n");
-		return NULL;
-	}
-
-	return &nacl->se_node_acl;
-}
-
-static void
-vhost_scsi_release_fabric_acl(struct se_portal_group *se_tpg,
-			     struct se_node_acl *se_nacl)
-{
-	struct vhost_scsi_nacl *nacl = container_of(se_nacl,
-			struct vhost_scsi_nacl, se_node_acl);
-	kfree(nacl);
-}
-
 static u32 vhost_scsi_tpg_get_inst_index(struct se_portal_group *se_tpg)
 {
 	return 1;
@@ -519,11 +369,6 @@ static void vhost_scsi_set_default_node_attrs(struct se_node_acl *nacl)
 	return;
 }
 
-static u32 vhost_scsi_get_task_tag(struct se_cmd *se_cmd)
-{
-	return 0;
-}
-
 static int vhost_scsi_get_cmd_state(struct se_cmd *se_cmd)
 {
 	return 0;
@@ -607,7 +452,7 @@ static void vhost_scsi_free_cmd(struct vhost_scsi_cmd *cmd)
 
 static int vhost_scsi_check_stop_free(struct se_cmd *se_cmd)
 {
-	return target_put_sess_cmd(se_cmd->se_sess, se_cmd);
+	return target_put_sess_cmd(se_cmd);
 }
 
 static void
@@ -968,6 +813,7 @@ static void vhost_scsi_submission_work(struct work_struct *work)
 	}
 	tv_nexus = cmd->tvc_nexus;
 
+	se_cmd->tag = 0;
 	rc = target_submit_cmd_map_sgls(se_cmd, tv_nexus->tvn_se_sess,
 			cmd->tvc_cdb, &cmd->tvc_sense_buf[0],
 			cmd->tvc_lun, cmd->tvc_exp_data_len,
@@ -1822,50 +1668,6 @@ static void vhost_scsi_port_unlink(struct se_portal_group *se_tpg,
 	mutex_unlock(&vhost_scsi_mutex);
 }
 
-static struct se_node_acl *
-vhost_scsi_make_nodeacl(struct se_portal_group *se_tpg,
-		       struct config_group *group,
-		       const char *name)
-{
-	struct se_node_acl *se_nacl, *se_nacl_new;
-	struct vhost_scsi_nacl *nacl;
-	u64 wwpn = 0;
-	u32 nexus_depth;
-
-	/* vhost_scsi_parse_wwn(name, &wwpn, 1) < 0)
-		return ERR_PTR(-EINVAL); */
-	se_nacl_new = vhost_scsi_alloc_fabric_acl(se_tpg);
-	if (!se_nacl_new)
-		return ERR_PTR(-ENOMEM);
-
-	nexus_depth = 1;
-	/*
-	 * se_nacl_new may be released by core_tpg_add_initiator_node_acl()
-	 * when converting a NodeACL from demo mode -> explict
-	 */
-	se_nacl = core_tpg_add_initiator_node_acl(se_tpg, se_nacl_new,
-				name, nexus_depth);
-	if (IS_ERR(se_nacl)) {
-		vhost_scsi_release_fabric_acl(se_tpg, se_nacl_new);
-		return se_nacl;
-	}
-	/*
-	 * Locate our struct vhost_scsi_nacl and set the FC Nport WWPN
-	 */
-	nacl = container_of(se_nacl, struct vhost_scsi_nacl, se_node_acl);
-	nacl->iport_wwpn = wwpn;
-
-	return se_nacl;
-}
-
-static void vhost_scsi_drop_nodeacl(struct se_node_acl *se_acl)
-{
-	struct vhost_scsi_nacl *nacl = container_of(se_acl,
-				struct vhost_scsi_nacl, se_node_acl);
-	core_tpg_del_initiator_node_acl(se_acl->se_tpg, se_acl, 1);
-	kfree(nacl);
-}
-
 static void vhost_scsi_free_cmd_map_res(struct vhost_scsi_nexus *nexus,
 				       struct se_session *se_sess)
 {
@@ -2200,8 +2002,7 @@ vhost_scsi_make_tpg(struct se_wwn *wwn,
 	tpg->tport = tport;
 	tpg->tport_tpgt = tpgt;
 
-	ret = core_tpg_register(&vhost_scsi_ops, wwn,
-				&tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
+	ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
 	if (ret < 0) {
 		kfree(tpg);
 		return NULL;
@@ -2325,20 +2126,13 @@ static struct target_core_fabric_ops vhost_scsi_ops = {
 	.module				= THIS_MODULE,
 	.name				= "vhost",
 	.get_fabric_name		= vhost_scsi_get_fabric_name,
-	.get_fabric_proto_ident		= vhost_scsi_get_fabric_proto_ident,
 	.tpg_get_wwn			= vhost_scsi_get_fabric_wwn,
 	.tpg_get_tag			= vhost_scsi_get_tpgt,
-	.tpg_get_default_depth		= vhost_scsi_get_default_depth,
-	.tpg_get_pr_transport_id	= vhost_scsi_get_pr_transport_id,
-	.tpg_get_pr_transport_id_len	= vhost_scsi_get_pr_transport_id_len,
-	.tpg_parse_pr_out_transport_id	= vhost_scsi_parse_pr_out_transport_id,
 	.tpg_check_demo_mode		= vhost_scsi_check_true,
 	.tpg_check_demo_mode_cache	= vhost_scsi_check_true,
 	.tpg_check_demo_mode_write_protect = vhost_scsi_check_false,
 	.tpg_check_prod_mode_write_protect = vhost_scsi_check_false,
 	.tpg_check_prot_fabric_only	= vhost_scsi_check_prot_fabric_only,
-	.tpg_alloc_fabric_acl		= vhost_scsi_alloc_fabric_acl,
-	.tpg_release_fabric_acl		= vhost_scsi_release_fabric_acl,
 	.tpg_get_inst_index		= vhost_scsi_tpg_get_inst_index,
 	.release_cmd			= vhost_scsi_release_cmd,
 	.check_stop_free		= vhost_scsi_check_stop_free,
@@ -2349,7 +2143,6 @@ static struct target_core_fabric_ops vhost_scsi_ops = {
 	.write_pending			= vhost_scsi_write_pending,
 	.write_pending_status		= vhost_scsi_write_pending_status,
 	.set_default_node_attributes	= vhost_scsi_set_default_node_attrs,
-	.get_task_tag			= vhost_scsi_get_task_tag,
 	.get_cmd_state			= vhost_scsi_get_cmd_state,
 	.queue_data_in			= vhost_scsi_queue_data_in,
 	.queue_status			= vhost_scsi_queue_status,
@@ -2364,10 +2157,6 @@ static struct target_core_fabric_ops vhost_scsi_ops = {
 	.fabric_drop_tpg		= vhost_scsi_drop_tpg,
 	.fabric_post_link		= vhost_scsi_port_link,
 	.fabric_pre_unlink		= vhost_scsi_port_unlink,
-	.fabric_make_np			= NULL,
-	.fabric_drop_np			= NULL,
-	.fabric_make_nodeacl		= vhost_scsi_make_nodeacl,
-	.fabric_drop_nodeacl		= vhost_scsi_drop_nodeacl,
 
 	.tfc_wwn_attrs			= vhost_scsi_wwn_attrs,
 	.tfc_tpg_base_attrs		= vhost_scsi_tpg_attrs,
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index fa49d3294..eec2f1180 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -22,20 +22,97 @@
 #include <linux/file.h>
 #include <linux/highmem.h>
 #include <linux/slab.h>
+#include <linux/vmalloc.h>
 #include <linux/kthread.h>
 #include <linux/cgroup.h>
 #include <linux/module.h>
+#include <linux/sort.h>
 
 #include "vhost.h"
 
+static ushort max_mem_regions = 64;
+module_param(max_mem_regions, ushort, 0444);
+MODULE_PARM_DESC(max_mem_regions,
+	"Maximum number of memory regions in memory map. (default: 64)");
+
 enum {
-	VHOST_MEMORY_MAX_NREGIONS = 64,
 	VHOST_MEMORY_F_LOG = 0x1,
 };
 
 #define vhost_used_event(vq) ((__virtio16 __user *)&vq->avail->ring[vq->num])
 #define vhost_avail_event(vq) ((__virtio16 __user *)&vq->used->ring[vq->num])
 
+#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
+static void vhost_vq_reset_user_be(struct vhost_virtqueue *vq)
+{
+	vq->user_be = !virtio_legacy_is_little_endian();
+}
+
+static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp)
+{
+	struct vhost_vring_state s;
+
+	if (vq->private_data)
+		return -EBUSY;
+
+	if (copy_from_user(&s, argp, sizeof(s)))
+		return -EFAULT;
+
+	if (s.num != VHOST_VRING_LITTLE_ENDIAN &&
+	    s.num != VHOST_VRING_BIG_ENDIAN)
+		return -EINVAL;
+
+	vq->user_be = s.num;
+
+	return 0;
+}
+
+static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx,
+				   int __user *argp)
+{
+	struct vhost_vring_state s = {
+		.index = idx,
+		.num = vq->user_be
+	};
+
+	if (copy_to_user(argp, &s, sizeof(s)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static void vhost_init_is_le(struct vhost_virtqueue *vq)
+{
+	/* Note for legacy virtio: user_be is initialized at reset time
+	 * according to the host endianness. If userspace does not set an
+	 * explicit endianness, the default behavior is native endian, as
+	 * expected by legacy virtio.
+	 */
+	vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) || !vq->user_be;
+}
+#else
+static void vhost_vq_reset_user_be(struct vhost_virtqueue *vq)
+{
+}
+
+static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp)
+{
+	return -ENOIOCTLCMD;
+}
+
+static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx,
+				   int __user *argp)
+{
+	return -ENOIOCTLCMD;
+}
+
+static void vhost_init_is_le(struct vhost_virtqueue *vq)
+{
+	if (vhost_has_feature(vq, VIRTIO_F_VERSION_1))
+		vq->is_le = true;
+}
+#endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */
+
 static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh,
 			    poll_table *pt)
 {
@@ -199,6 +276,8 @@ static void vhost_vq_reset(struct vhost_dev *dev,
 	vq->call = NULL;
 	vq->log_ctx = NULL;
 	vq->memory = NULL;
+	vq->is_le = virtio_legacy_is_little_endian();
+	vhost_vq_reset_user_be(vq);
 }
 
 static int vhost_worker(void *data)
@@ -470,7 +549,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev, bool locked)
 		fput(dev->log_file);
 	dev->log_file = NULL;
 	/* No one will access memory at this point */
-	kfree(dev->memory);
+	kvfree(dev->memory);
 	dev->memory = NULL;
 	WARN_ON(!list_empty(&dev->work_list));
 	if (dev->worker) {
@@ -590,6 +669,25 @@ int vhost_vq_access_ok(struct vhost_virtqueue *vq)
 }
 EXPORT_SYMBOL_GPL(vhost_vq_access_ok);
 
+static int vhost_memory_reg_sort_cmp(const void *p1, const void *p2)
+{
+	const struct vhost_memory_region *r1 = p1, *r2 = p2;
+	if (r1->guest_phys_addr < r2->guest_phys_addr)
+		return 1;
+	if (r1->guest_phys_addr > r2->guest_phys_addr)
+		return -1;
+	return 0;
+}
+
+static void *vhost_kvzalloc(unsigned long size)
+{
+	void *n = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
+
+	if (!n)
+		n = vzalloc(size);
+	return n;
+}
+
 static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
 {
 	struct vhost_memory mem, *newmem, *oldmem;
@@ -600,21 +698,23 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
 		return -EFAULT;
 	if (mem.padding)
 		return -EOPNOTSUPP;
-	if (mem.nregions > VHOST_MEMORY_MAX_NREGIONS)
+	if (mem.nregions > max_mem_regions)
 		return -E2BIG;
-	newmem = kmalloc(size + mem.nregions * sizeof *m->regions, GFP_KERNEL);
+	newmem = vhost_kvzalloc(size + mem.nregions * sizeof(*m->regions));
 	if (!newmem)
 		return -ENOMEM;
 
 	memcpy(newmem, &mem, size);
 	if (copy_from_user(newmem->regions, m->regions,
 			   mem.nregions * sizeof *m->regions)) {
-		kfree(newmem);
+		kvfree(newmem);
 		return -EFAULT;
 	}
+	sort(newmem->regions, newmem->nregions, sizeof(*newmem->regions),
+		vhost_memory_reg_sort_cmp, NULL);
 
 	if (!memory_access_ok(d, newmem, 0)) {
-		kfree(newmem);
+		kvfree(newmem);
 		return -EFAULT;
 	}
 	oldmem = d->memory;
@@ -626,7 +726,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
 		d->vqs[i]->memory = newmem;
 		mutex_unlock(&d->vqs[i]->mutex);
 	}
-	kfree(oldmem);
+	kvfree(oldmem);
 	return 0;
 }
 
@@ -806,6 +906,12 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp)
 		} else
 			filep = eventfp;
 		break;
+	case VHOST_SET_VRING_ENDIAN:
+		r = vhost_set_vring_endian(vq, argp);
+		break;
+	case VHOST_GET_VRING_ENDIAN:
+		r = vhost_get_vring_endian(vq, idx, argp);
+		break;
 	default:
 		r = -ENOIOCTLCMD;
 	}
@@ -914,17 +1020,22 @@ EXPORT_SYMBOL_GPL(vhost_dev_ioctl);
 static const struct vhost_memory_region *find_region(struct vhost_memory *mem,
 						     __u64 addr, __u32 len)
 {
-	struct vhost_memory_region *reg;
-	int i;
+	const struct vhost_memory_region *reg;
+	int start = 0, end = mem->nregions;
 
-	/* linear search is not brilliant, but we really have on the order of 6
-	 * regions in practice */
-	for (i = 0; i < mem->nregions; ++i) {
-		reg = mem->regions + i;
-		if (reg->guest_phys_addr <= addr &&
-		    reg->guest_phys_addr + reg->memory_size - 1 >= addr)
-			return reg;
+	while (start < end) {
+		int slot = start + (end - start) / 2;
+		reg = mem->regions + slot;
+		if (addr >= reg->guest_phys_addr)
+			end = slot;
+		else
+			start = slot + 1;
 	}
+
+	reg = mem->regions + start;
+	if (addr >= reg->guest_phys_addr &&
+		reg->guest_phys_addr + reg->memory_size > addr)
+		return reg;
 	return NULL;
 }
 
@@ -1045,8 +1156,12 @@ int vhost_init_used(struct vhost_virtqueue *vq)
 {
 	__virtio16 last_used_idx;
 	int r;
-	if (!vq->private_data)
+	if (!vq->private_data) {
+		vq->is_le = virtio_legacy_is_little_endian();
 		return 0;
+	}
+
+	vhost_init_is_le(vq);
 
 	r = vhost_update_used_flags(vq);
 	if (r)
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 8c1c79290..ce6f6da4b 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -106,6 +106,14 @@ struct vhost_virtqueue {
 	/* Log write descriptors */
 	void __user *log_base;
 	struct vhost_log *log;
+
+	/* Ring endianness. Defaults to legacy native endianness.
+	 * Set to true when starting a modern virtio device. */
+	bool is_le;
+#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
+	/* Ring endianness requested by userspace for cross-endian support. */
+	bool user_be;
+#endif
 };
 
 struct vhost_dev {
@@ -173,34 +181,39 @@ static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
 	return vq->acked_features & (1ULL << bit);
 }
 
+static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
+{
+	return vq->is_le;
+}
+
 /* Memory accessors */
 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
 {
-	return __virtio16_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+	return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
 }
 
 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
 {
-	return __cpu_to_virtio16(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+	return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
 }
 
 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
 {
-	return __virtio32_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+	return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
 }
 
 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
 {
-	return __cpu_to_virtio32(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+	return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
 }
 
 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
 {
-	return __virtio64_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+	return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
 }
 
 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
 {
-	return __cpu_to_virtio64(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+	return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
 }
 #endif