virtio/vhost: new features for 4.8

- New vsock device support in host and guest
 - Platform IOMMU support in host and guest,
   including compatibility quirks for legacy systems.
 - Misc fixes and cleanups.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio/vhost updates from Michael Tsirkin:

 - new vsock device support in host and guest

 - platform IOMMU support in host and guest, including compatibility
   quirks for legacy systems.

 - misc fixes and cleanups.

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  VSOCK: Use kvfree()
  vhost: split out vringh Kconfig
  vhost: detect 32 bit integer wrap around
  vhost: new device IOTLB API
  vhost: drop vringh dependency
  vhost: convert pre sorted vhost memory array to interval tree
  vhost: introduce vhost memory accessors
  VSOCK: Add Makefile and Kconfig
  VSOCK: Introduce vhost_vsock.ko
  VSOCK: Introduce virtio_transport.ko
  VSOCK: Introduce virtio_vsock_common.ko
  VSOCK: defer sock removal to transports
  VSOCK: transport-specific vsock_transport functions
  vhost: drop vringh dependency
  vop: pull in vhost Kconfig
  virtio: new feature to detect IOMMU device quirk
  balloon: check the number of available pages in leak balloon
  vhost: lockless enqueuing
  vhost: simplify work flushing

MAINTAINERS

@@ -12419,6 +12419,19 @@ S:	Maintained
 F:	drivers/media/v4l2-core/videobuf2-*
 F:	include/media/videobuf2-*
 
+VIRTIO AND VHOST VSOCK DRIVER
+M:	Stefan Hajnoczi <stefanha@redhat.com>
+L:	kvm@vger.kernel.org
+L:	virtualization@lists.linux-foundation.org
+L:	netdev@vger.kernel.org
+S:	Maintained
+F:	include/linux/virtio_vsock.h
+F:	include/uapi/linux/virtio_vsock.h
+F:	net/vmw_vsock/virtio_transport_common.c
+F:	net/vmw_vsock/virtio_transport.c
+F:	drivers/vhost/vsock.c
+F:	drivers/vhost/vsock.h
+
 VIRTUAL SERIO DEVICE DRIVER
 M:	Stephen Chandler Paul <thatslyude@gmail.com>
 S:	Maintained

drivers/Makefile

@@ -138,6 +138,7 @@ obj-$(CONFIG_OF)		+= of/
 obj-$(CONFIG_SSB)		+= ssb/
 obj-$(CONFIG_BCMA)		+= bcma/
 obj-$(CONFIG_VHOST_RING)	+= vhost/
+obj-$(CONFIG_VHOST)		+= vhost/
 obj-$(CONFIG_VLYNQ)		+= vlynq/
 obj-$(CONFIG_STAGING)		+= staging/
 obj-y				+= platform/

drivers/misc/mic/Kconfig

@@ -146,3 +146,7 @@ config VOP
 	  More information about the Intel MIC family as well as the Linux
 	  OS and tools for MIC to use with this driver are available from
 	  <http://software.intel.com/en-us/mic-developer>.
+
+if VOP
+source "drivers/vhost/Kconfig.vringh"
+endif

drivers/net/caif/Kconfig

@@ -52,5 +52,5 @@ config CAIF_VIRTIO
 	The caif driver for CAIF over Virtio.
 
 if CAIF_VIRTIO
-source "drivers/vhost/Kconfig"
+source "drivers/vhost/Kconfig.vringh"
 endif

drivers/vhost/Kconfig

@@ -2,7 +2,6 @@ config VHOST_NET
 	tristate "Host kernel accelerator for virtio net"
 	depends on NET && EVENTFD && (TUN || !TUN) && (MACVTAP || !MACVTAP)
 	select VHOST
-	select VHOST_RING
 	---help---
 	  This kernel module can be loaded in host kernel to accelerate
 	  guest networking with virtio_net. Not to be confused with virtio_net
@@ -15,17 +14,24 @@ config VHOST_SCSI
 	tristate "VHOST_SCSI TCM fabric driver"
 	depends on TARGET_CORE && EVENTFD && m
 	select VHOST
-	select VHOST_RING
 	default n
 	---help---
 	Say M here to enable the vhost_scsi TCM fabric module
 	for use with virtio-scsi guests
 
-config VHOST_RING
+config VHOST_VSOCK
-	tristate
+	tristate "vhost virtio-vsock driver"
+	depends on VSOCKETS && EVENTFD
+	select VIRTIO_VSOCKETS_COMMON
+	select VHOST
+	default n
 	---help---
-	  This option is selected by any driver which needs to access
+	This kernel module can be loaded in the host kernel to provide AF_VSOCK
-	  the host side of a virtio ring.
+	sockets for communicating with guests.  The guests must have the
+	virtio_transport.ko driver loaded to use the virtio-vsock device.
+
+	To compile this driver as a module, choose M here: the module will be called
+	vhost_vsock.
 
 config VHOST
 	tristate

drivers/vhost/Kconfig.vringh

@@ -0,0 +1,5 @@
+config VHOST_RING
+	tristate
+	---help---
+	  This option is selected by any driver which needs to access
+	  the host side of a virtio ring.

drivers/vhost/Makefile

@@ -4,5 +4,9 @@ vhost_net-y := net.o
 obj-$(CONFIG_VHOST_SCSI) += vhost_scsi.o
 vhost_scsi-y := scsi.o
 
+obj-$(CONFIG_VHOST_VSOCK) += vhost_vsock.o
+vhost_vsock-y := vsock.o
+
 obj-$(CONFIG_VHOST_RING) += vringh.o
+
 obj-$(CONFIG_VHOST)	+= vhost.o

drivers/vhost/net.c

@@ -61,7 +61,8 @@ MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
 enum {
 	VHOST_NET_FEATURES = VHOST_FEATURES |
 			 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
-			 (1ULL << VIRTIO_NET_F_MRG_RXBUF)
+			 (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
+			 (1ULL << VIRTIO_F_IOMMU_PLATFORM)
 };
 
 enum {
@@ -334,7 +335,7 @@ static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
 {
 	unsigned long uninitialized_var(endtime);
 	int r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
-				    out_num, in_num, NULL, NULL);
+				  out_num, in_num, NULL, NULL);
 
 	if (r == vq->num && vq->busyloop_timeout) {
 		preempt_disable();
@@ -344,7 +345,7 @@ static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
 			cpu_relax_lowlatency();
 		preempt_enable();
 		r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
-					out_num, in_num, NULL, NULL);
+				      out_num, in_num, NULL, NULL);
 	}
 
 	return r;
@@ -377,6 +378,9 @@ static void handle_tx(struct vhost_net *net)
 	if (!sock)
 		goto out;
 
+	if (!vq_iotlb_prefetch(vq))
+		goto out;
+
 	vhost_disable_notify(&net->dev, vq);
 
 	hdr_size = nvq->vhost_hlen;
@@ -652,6 +656,10 @@ static void handle_rx(struct vhost_net *net)
 	sock = vq->private_data;
 	if (!sock)
 		goto out;
+
+	if (!vq_iotlb_prefetch(vq))
+		goto out;
+
 	vhost_disable_notify(&net->dev, vq);
 	vhost_net_disable_vq(net, vq);
 
@@ -1052,20 +1060,20 @@ static long vhost_net_reset_owner(struct vhost_net *n)
 	struct socket *tx_sock = NULL;
 	struct socket *rx_sock = NULL;
 	long err;
-	struct vhost_memory *memory;
+	struct vhost_umem *umem;
 
 	mutex_lock(&n->dev.mutex);
 	err = vhost_dev_check_owner(&n->dev);
 	if (err)
 		goto done;
-	memory = vhost_dev_reset_owner_prepare();
+	umem = vhost_dev_reset_owner_prepare();
-	if (!memory) {
+	if (!umem) {
 		err = -ENOMEM;
 		goto done;
 	}
 	vhost_net_stop(n, &tx_sock, &rx_sock);
 	vhost_net_flush(n);
-	vhost_dev_reset_owner(&n->dev, memory);
+	vhost_dev_reset_owner(&n->dev, umem);
 	vhost_net_vq_reset(n);
 done:
 	mutex_unlock(&n->dev.mutex);
@@ -1096,10 +1104,14 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features)
 	}
 	mutex_lock(&n->dev.mutex);
 	if ((features & (1 << VHOST_F_LOG_ALL)) &&
-	    !vhost_log_access_ok(&n->dev)) {
+	    !vhost_log_access_ok(&n->dev))
-		mutex_unlock(&n->dev.mutex);
+		goto out_unlock;
-		return -EFAULT;
+
+	if ((features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))) {
+		if (vhost_init_device_iotlb(&n->dev, true))
+			goto out_unlock;
 	}
+
 	for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
 		mutex_lock(&n->vqs[i].vq.mutex);
 		n->vqs[i].vq.acked_features = features;
@@ -1109,6 +1121,10 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features)
 	}
 	mutex_unlock(&n->dev.mutex);
 	return 0;
+
+out_unlock:
+	mutex_unlock(&n->dev.mutex);
+	return -EFAULT;
 }
 
 static long vhost_net_set_owner(struct vhost_net *n)
@@ -1182,9 +1198,40 @@ static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
 }
 #endif
 
+static ssize_t vhost_net_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+	struct file *file = iocb->ki_filp;
+	struct vhost_net *n = file->private_data;
+	struct vhost_dev *dev = &n->dev;
+	int noblock = file->f_flags & O_NONBLOCK;
+
+	return vhost_chr_read_iter(dev, to, noblock);
+}
+
+static ssize_t vhost_net_chr_write_iter(struct kiocb *iocb,
+					struct iov_iter *from)
+{
+	struct file *file = iocb->ki_filp;
+	struct vhost_net *n = file->private_data;
+	struct vhost_dev *dev = &n->dev;
+
+	return vhost_chr_write_iter(dev, from);
+}
+
+static unsigned int vhost_net_chr_poll(struct file *file, poll_table *wait)
+{
+	struct vhost_net *n = file->private_data;
+	struct vhost_dev *dev = &n->dev;
+
+	return vhost_chr_poll(file, dev, wait);
+}
+
 static const struct file_operations vhost_net_fops = {
 	.owner          = THIS_MODULE,
 	.release        = vhost_net_release,
+	.read_iter      = vhost_net_chr_read_iter,
+	.write_iter     = vhost_net_chr_write_iter,
+	.poll           = vhost_net_chr_poll,
 	.unlocked_ioctl = vhost_net_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl   = vhost_net_compat_ioctl,

drivers/vhost/vhost.h

@@ -15,13 +15,15 @@
 struct vhost_work;
 typedef void (*vhost_work_fn_t)(struct vhost_work *work);
 
+#define VHOST_WORK_QUEUED 1
 struct vhost_work {
-	struct list_head	  node;
+	struct llist_node	  node;
 	vhost_work_fn_t		  fn;
 	wait_queue_head_t	  done;
 	int			  flushing;
 	unsigned		  queue_seq;
 	unsigned		  done_seq;
+	unsigned long		  flags;
 };
 
 /* Poll a file (eventfd or socket) */
@@ -53,6 +55,27 @@ struct vhost_log {
 	u64 len;
 };
 
+#define START(node) ((node)->start)
+#define LAST(node) ((node)->last)
+
+struct vhost_umem_node {
+	struct rb_node rb;
+	struct list_head link;
+	__u64 start;
+	__u64 last;
+	__u64 size;
+	__u64 userspace_addr;
+	__u32 perm;
+	__u32 flags_padding;
+	__u64 __subtree_last;
+};
+
+struct vhost_umem {
+	struct rb_root umem_tree;
+	struct list_head umem_list;
+	int numem;
+};
+
 /* The virtqueue structure describes a queue attached to a device. */
 struct vhost_virtqueue {
 	struct vhost_dev *dev;
@@ -98,10 +121,12 @@ struct vhost_virtqueue {
 	u64 log_addr;
 
 	struct iovec iov[UIO_MAXIOV];
+	struct iovec iotlb_iov[64];
 	struct iovec *indirect;
 	struct vring_used_elem *heads;
 	/* Protected by virtqueue mutex. */
-	struct vhost_memory *memory;
+	struct vhost_umem *umem;
+	struct vhost_umem *iotlb;
 	void *private_data;
 	u64 acked_features;
 	/* Log write descriptors */
@@ -118,25 +143,35 @@ struct vhost_virtqueue {
 	u32 busyloop_timeout;
 };
 
+struct vhost_msg_node {
+  struct vhost_msg msg;
+  struct vhost_virtqueue *vq;
+  struct list_head node;
+};
+
 struct vhost_dev {
-	struct vhost_memory *memory;
 	struct mm_struct *mm;
 	struct mutex mutex;
 	struct vhost_virtqueue **vqs;
 	int nvqs;
 	struct file *log_file;
 	struct eventfd_ctx *log_ctx;
-	spinlock_t work_lock;
+	struct llist_head work_list;
-	struct list_head work_list;
 	struct task_struct *worker;
+	struct vhost_umem *umem;
+	struct vhost_umem *iotlb;
+	spinlock_t iotlb_lock;
+	struct list_head read_list;
+	struct list_head pending_list;
+	wait_queue_head_t wait;
 };
 
 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
 long vhost_dev_set_owner(struct vhost_dev *dev);
 bool vhost_dev_has_owner(struct vhost_dev *dev);
 long vhost_dev_check_owner(struct vhost_dev *);
-struct vhost_memory *vhost_dev_reset_owner_prepare(void);
+struct vhost_umem *vhost_dev_reset_owner_prepare(void);
-void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_memory *);
+void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *);
 void vhost_dev_cleanup(struct vhost_dev *, bool locked);
 void vhost_dev_stop(struct vhost_dev *);
 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
@@ -165,6 +200,21 @@ bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
 
 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
 		    unsigned int log_num, u64 len);
+int vq_iotlb_prefetch(struct vhost_virtqueue *vq);
+
+struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);
+void vhost_enqueue_msg(struct vhost_dev *dev,
+		       struct list_head *head,
+		       struct vhost_msg_node *node);
+struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
+					 struct list_head *head);
+unsigned int vhost_chr_poll(struct file *file, struct vhost_dev *dev,
+			    poll_table *wait);
+ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,
+			    int noblock);
+ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
+			     struct iov_iter *from);
+int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled);
 
 #define vq_err(vq, fmt, ...) do {                                  \
 		pr_debug(pr_fmt(fmt), ##__VA_ARGS__);       \

drivers/vhost/vsock.c

@@ -0,0 +1,719 @@
+/*
+ * vhost transport for vsock
+ *
+ * Copyright (C) 2013-2015 Red Hat, Inc.
+ * Author: Asias He <asias@redhat.com>
+ *         Stefan Hajnoczi <stefanha@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+#include <linux/miscdevice.h>
+#include <linux/atomic.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/vmalloc.h>
+#include <net/sock.h>
+#include <linux/virtio_vsock.h>
+#include <linux/vhost.h>
+
+#include <net/af_vsock.h>
+#include "vhost.h"
+
+#define VHOST_VSOCK_DEFAULT_HOST_CID	2
+
+enum {
+	VHOST_VSOCK_FEATURES = VHOST_FEATURES,
+};
+
+/* Used to track all the vhost_vsock instances on the system. */
+static DEFINE_SPINLOCK(vhost_vsock_lock);
+static LIST_HEAD(vhost_vsock_list);
+
+struct vhost_vsock {
+	struct vhost_dev dev;
+	struct vhost_virtqueue vqs[2];
+
+	/* Link to global vhost_vsock_list, protected by vhost_vsock_lock */
+	struct list_head list;
+
+	struct vhost_work send_pkt_work;
+	spinlock_t send_pkt_list_lock;
+	struct list_head send_pkt_list;	/* host->guest pending packets */
+
+	atomic_t queued_replies;
+
+	u32 guest_cid;
+};
+
+static u32 vhost_transport_get_local_cid(void)
+{
+	return VHOST_VSOCK_DEFAULT_HOST_CID;
+}
+
+static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
+{
+	struct vhost_vsock *vsock;
+
+	spin_lock_bh(&vhost_vsock_lock);
+	list_for_each_entry(vsock, &vhost_vsock_list, list) {
+		u32 other_cid = vsock->guest_cid;
+
+		/* Skip instances that have no CID yet */
+		if (other_cid == 0)
+			continue;
+
+		if (other_cid == guest_cid) {
+			spin_unlock_bh(&vhost_vsock_lock);
+			return vsock;
+		}
+	}
+	spin_unlock_bh(&vhost_vsock_lock);
+
+	return NULL;
+}
+
+static void
+vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
+			    struct vhost_virtqueue *vq)
+{
+	struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
+	bool added = false;
+	bool restart_tx = false;
+
+	mutex_lock(&vq->mutex);
+
+	if (!vq->private_data)
+		goto out;
+
+	/* Avoid further vmexits, we're already processing the virtqueue */
+	vhost_disable_notify(&vsock->dev, vq);
+
+	for (;;) {
+		struct virtio_vsock_pkt *pkt;
+		struct iov_iter iov_iter;
+		unsigned out, in;
+		size_t nbytes;
+		size_t len;
+		int head;
+
+		spin_lock_bh(&vsock->send_pkt_list_lock);
+		if (list_empty(&vsock->send_pkt_list)) {
+			spin_unlock_bh(&vsock->send_pkt_list_lock);
+			vhost_enable_notify(&vsock->dev, vq);
+			break;
+		}
+
+		pkt = list_first_entry(&vsock->send_pkt_list,
+				       struct virtio_vsock_pkt, list);
+		list_del_init(&pkt->list);
+		spin_unlock_bh(&vsock->send_pkt_list_lock);
+
+		head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
+					 &out, &in, NULL, NULL);
+		if (head < 0) {
+			spin_lock_bh(&vsock->send_pkt_list_lock);
+			list_add(&pkt->list, &vsock->send_pkt_list);
+			spin_unlock_bh(&vsock->send_pkt_list_lock);
+			break;
+		}
+
+		if (head == vq->num) {
+			spin_lock_bh(&vsock->send_pkt_list_lock);
+			list_add(&pkt->list, &vsock->send_pkt_list);
+			spin_unlock_bh(&vsock->send_pkt_list_lock);
+
+			/* We cannot finish yet if more buffers snuck in while
+			 * re-enabling notify.
+			 */
+			if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
+				vhost_disable_notify(&vsock->dev, vq);
+				continue;
+			}
+			break;
+		}
+
+		if (out) {
+			virtio_transport_free_pkt(pkt);
+			vq_err(vq, "Expected 0 output buffers, got %u\n", out);
+			break;
+		}
+
+		len = iov_length(&vq->iov[out], in);
+		iov_iter_init(&iov_iter, READ, &vq->iov[out], in, len);
+
+		nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
+		if (nbytes != sizeof(pkt->hdr)) {
+			virtio_transport_free_pkt(pkt);
+			vq_err(vq, "Faulted on copying pkt hdr\n");
+			break;
+		}
+
+		nbytes = copy_to_iter(pkt->buf, pkt->len, &iov_iter);
+		if (nbytes != pkt->len) {
+			virtio_transport_free_pkt(pkt);
+			vq_err(vq, "Faulted on copying pkt buf\n");
+			break;
+		}
+
+		vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len);
+		added = true;
+
+		if (pkt->reply) {
+			int val;
+
+			val = atomic_dec_return(&vsock->queued_replies);
+
+			/* Do we have resources to resume tx processing? */
+			if (val + 1 == tx_vq->num)
+				restart_tx = true;
+		}
+
+		virtio_transport_free_pkt(pkt);
+	}
+	if (added)
+		vhost_signal(&vsock->dev, vq);
+
+out:
+	mutex_unlock(&vq->mutex);
+
+	if (restart_tx)
+		vhost_poll_queue(&tx_vq->poll);
+}
+
+static void vhost_transport_send_pkt_work(struct vhost_work *work)
+{
+	struct vhost_virtqueue *vq;
+	struct vhost_vsock *vsock;
+
+	vsock = container_of(work, struct vhost_vsock, send_pkt_work);
+	vq = &vsock->vqs[VSOCK_VQ_RX];
+
+	vhost_transport_do_send_pkt(vsock, vq);
+}
+
+static int
+vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt)
+{
+	struct vhost_vsock *vsock;
+	struct vhost_virtqueue *vq;
+	int len = pkt->len;
+
+	/* Find the vhost_vsock according to guest context id  */
+	vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid));
+	if (!vsock) {
+		virtio_transport_free_pkt(pkt);
+		return -ENODEV;
+	}
+
+	vq = &vsock->vqs[VSOCK_VQ_RX];
+
+	if (pkt->reply)
+		atomic_inc(&vsock->queued_replies);
+
+	spin_lock_bh(&vsock->send_pkt_list_lock);
+	list_add_tail(&pkt->list, &vsock->send_pkt_list);
+	spin_unlock_bh(&vsock->send_pkt_list_lock);
+
+	vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
+	return len;
+}
+
+static struct virtio_vsock_pkt *
+vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
+		      unsigned int out, unsigned int in)
+{
+	struct virtio_vsock_pkt *pkt;
+	struct iov_iter iov_iter;
+	size_t nbytes;
+	size_t len;
+
+	if (in != 0) {
+		vq_err(vq, "Expected 0 input buffers, got %u\n", in);
+		return NULL;
+	}
+
+	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
+	if (!pkt)
+		return NULL;
+
+	len = iov_length(vq->iov, out);
+	iov_iter_init(&iov_iter, WRITE, vq->iov, out, len);
+
+	nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
+	if (nbytes != sizeof(pkt->hdr)) {
+		vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n",
+		       sizeof(pkt->hdr), nbytes);
+		kfree(pkt);
+		return NULL;
+	}
+
+	if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_STREAM)
+		pkt->len = le32_to_cpu(pkt->hdr.len);
+
+	/* No payload */
+	if (!pkt->len)
+		return pkt;
+
+	/* The pkt is too big */
+	if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
+		kfree(pkt);
+		return NULL;
+	}
+
+	pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
+	if (!pkt->buf) {
+		kfree(pkt);
+		return NULL;
+	}
+
+	nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter);
+	if (nbytes != pkt->len) {
+		vq_err(vq, "Expected %u byte payload, got %zu bytes\n",
+		       pkt->len, nbytes);
+		virtio_transport_free_pkt(pkt);
+		return NULL;
+	}
+
+	return pkt;
+}
+
+/* Is there space left for replies to rx packets? */
+static bool vhost_vsock_more_replies(struct vhost_vsock *vsock)
+{
+	struct vhost_virtqueue *vq = &vsock->vqs[VSOCK_VQ_TX];
+	int val;
+
+	smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
+	val = atomic_read(&vsock->queued_replies);
+
+	return val < vq->num;
+}
+
+static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
+{
+	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
+						  poll.work);
+	struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
+						 dev);
+	struct virtio_vsock_pkt *pkt;
+	int head;
+	unsigned int out, in;
+	bool added = false;
+
+	mutex_lock(&vq->mutex);
+
+	if (!vq->private_data)
+		goto out;
+
+	vhost_disable_notify(&vsock->dev, vq);
+	for (;;) {
+		if (!vhost_vsock_more_replies(vsock)) {
+			/* Stop tx until the device processes already
+			 * pending replies.  Leave tx virtqueue
+			 * callbacks disabled.
+			 */
+			goto no_more_replies;
+		}
+
+		head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
+					 &out, &in, NULL, NULL);
+		if (head < 0)
+			break;
+
+		if (head == vq->num) {
+			if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
+				vhost_disable_notify(&vsock->dev, vq);
+				continue;
+			}
+			break;
+		}
+
+		pkt = vhost_vsock_alloc_pkt(vq, out, in);
+		if (!pkt) {
+			vq_err(vq, "Faulted on pkt\n");
+			continue;
+		}
+
+		/* Only accept correctly addressed packets */
+		if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid)
+			virtio_transport_recv_pkt(pkt);
+		else
+			virtio_transport_free_pkt(pkt);
+
+		vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len);
+		added = true;
+	}
+
+no_more_replies:
+	if (added)
+		vhost_signal(&vsock->dev, vq);
+
+out:
+	mutex_unlock(&vq->mutex);
+}
+
+static void vhost_vsock_handle_rx_kick(struct vhost_work *work)
+{
+	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
+						poll.work);
+	struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
+						 dev);
+
+	vhost_transport_do_send_pkt(vsock, vq);
+}
+
+static int vhost_vsock_start(struct vhost_vsock *vsock)
+{
+	size_t i;
+	int ret;
+
+	mutex_lock(&vsock->dev.mutex);
+
+	ret = vhost_dev_check_owner(&vsock->dev);
+	if (ret)
+		goto err;
+
+	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
+		struct vhost_virtqueue *vq = &vsock->vqs[i];
+
+		mutex_lock(&vq->mutex);
+
+		if (!vhost_vq_access_ok(vq)) {
+			ret = -EFAULT;
+			mutex_unlock(&vq->mutex);
+			goto err_vq;
+		}
+
+		if (!vq->private_data) {
+			vq->private_data = vsock;
+			vhost_vq_init_access(vq);
+		}
+
+		mutex_unlock(&vq->mutex);
+	}
+
+	mutex_unlock(&vsock->dev.mutex);
+	return 0;
+
+err_vq:
+	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
+		struct vhost_virtqueue *vq = &vsock->vqs[i];
+
+		mutex_lock(&vq->mutex);
+		vq->private_data = NULL;
+		mutex_unlock(&vq->mutex);
+	}
+err:
+	mutex_unlock(&vsock->dev.mutex);
+	return ret;
+}
+
+static int vhost_vsock_stop(struct vhost_vsock *vsock)
+{
+	size_t i;
+	int ret;
+
+	mutex_lock(&vsock->dev.mutex);
+
+	ret = vhost_dev_check_owner(&vsock->dev);
+	if (ret)
+		goto err;
+
+	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
+		struct vhost_virtqueue *vq = &vsock->vqs[i];
+
+		mutex_lock(&vq->mutex);
+		vq->private_data = NULL;
+		mutex_unlock(&vq->mutex);
+	}
+
+err:
+	mutex_unlock(&vsock->dev.mutex);
+	return ret;
+}
+
+static void vhost_vsock_free(struct vhost_vsock *vsock)
+{
+	kvfree(vsock);
+}
+
+static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
+{
+	struct vhost_virtqueue **vqs;
+	struct vhost_vsock *vsock;
+	int ret;
+
+	/* This struct is large and allocation could fail, fall back to vmalloc
+	 * if there is no other way.
+	 */
+	vsock = kzalloc(sizeof(*vsock), GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
+	if (!vsock) {
+		vsock = vmalloc(sizeof(*vsock));
+		if (!vsock)
+			return -ENOMEM;
+	}
+
+	vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL);
+	if (!vqs) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	atomic_set(&vsock->queued_replies, 0);
+
+	vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX];
+	vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX];
+	vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
+	vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
+
+	vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs));
+
+	file->private_data = vsock;
+	spin_lock_init(&vsock->send_pkt_list_lock);
+	INIT_LIST_HEAD(&vsock->send_pkt_list);
+	vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
+
+	spin_lock_bh(&vhost_vsock_lock);
+	list_add_tail(&vsock->list, &vhost_vsock_list);
+	spin_unlock_bh(&vhost_vsock_lock);
+	return 0;
+
+out:
+	vhost_vsock_free(vsock);
+	return ret;
+}
+
+static void vhost_vsock_flush(struct vhost_vsock *vsock)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++)
+		if (vsock->vqs[i].handle_kick)
+			vhost_poll_flush(&vsock->vqs[i].poll);
+	vhost_work_flush(&vsock->dev, &vsock->send_pkt_work);
+}
+
+static void vhost_vsock_reset_orphans(struct sock *sk)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	/* vmci_transport.c doesn't take sk_lock here either.  At least we're
+	 * under vsock_table_lock so the sock cannot disappear while we're
+	 * executing.
+	 */
+
+	if (!vhost_vsock_get(vsk->local_addr.svm_cid)) {
+		sock_set_flag(sk, SOCK_DONE);
+		vsk->peer_shutdown = SHUTDOWN_MASK;
+		sk->sk_state = SS_UNCONNECTED;
+		sk->sk_err = ECONNRESET;
+		sk->sk_error_report(sk);
+	}
+}
+
+static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
+{
+	struct vhost_vsock *vsock = file->private_data;
+
+	spin_lock_bh(&vhost_vsock_lock);
+	list_del(&vsock->list);
+	spin_unlock_bh(&vhost_vsock_lock);
+
+	/* Iterating over all connections for all CIDs to find orphans is
+	 * inefficient.  Room for improvement here. */
+	vsock_for_each_connected_socket(vhost_vsock_reset_orphans);
+
+	vhost_vsock_stop(vsock);
+	vhost_vsock_flush(vsock);
+	vhost_dev_stop(&vsock->dev);
+
+	spin_lock_bh(&vsock->send_pkt_list_lock);
+	while (!list_empty(&vsock->send_pkt_list)) {
+		struct virtio_vsock_pkt *pkt;
+
+		pkt = list_first_entry(&vsock->send_pkt_list,
+				struct virtio_vsock_pkt, list);
+		list_del_init(&pkt->list);
+		virtio_transport_free_pkt(pkt);
+	}
+	spin_unlock_bh(&vsock->send_pkt_list_lock);
+
+	vhost_dev_cleanup(&vsock->dev, false);
+	kfree(vsock->dev.vqs);
+	vhost_vsock_free(vsock);
+	return 0;
+}
+
+static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
+{
+	struct vhost_vsock *other;
+
+	/* Refuse reserved CIDs */
+	if (guest_cid <= VMADDR_CID_HOST ||
+	    guest_cid == U32_MAX)
+		return -EINVAL;
+
+	/* 64-bit CIDs are not yet supported */
+	if (guest_cid > U32_MAX)
+		return -EINVAL;
+
+	/* Refuse if CID is already in use */
+	other = vhost_vsock_get(guest_cid);
+	if (other && other != vsock)
+		return -EADDRINUSE;
+
+	spin_lock_bh(&vhost_vsock_lock);
+	vsock->guest_cid = guest_cid;
+	spin_unlock_bh(&vhost_vsock_lock);
+
+	return 0;
+}
+
+static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features)
+{
+	struct vhost_virtqueue *vq;
+	int i;
+
+	if (features & ~VHOST_VSOCK_FEATURES)
+		return -EOPNOTSUPP;
+
+	mutex_lock(&vsock->dev.mutex);
+	if ((features & (1 << VHOST_F_LOG_ALL)) &&
+	    !vhost_log_access_ok(&vsock->dev)) {
+		mutex_unlock(&vsock->dev.mutex);
+		return -EFAULT;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
+		vq = &vsock->vqs[i];
+		mutex_lock(&vq->mutex);
+		vq->acked_features = features;
+		mutex_unlock(&vq->mutex);
+	}
+	mutex_unlock(&vsock->dev.mutex);
+	return 0;
+}
+
+static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
+				  unsigned long arg)
+{
+	struct vhost_vsock *vsock = f->private_data;
+	void __user *argp = (void __user *)arg;
+	u64 guest_cid;
+	u64 features;
+	int start;
+	int r;
+
+	switch (ioctl) {
+	case VHOST_VSOCK_SET_GUEST_CID:
+		if (copy_from_user(&guest_cid, argp, sizeof(guest_cid)))
+			return -EFAULT;
+		return vhost_vsock_set_cid(vsock, guest_cid);
+	case VHOST_VSOCK_SET_RUNNING:
+		if (copy_from_user(&start, argp, sizeof(start)))
+			return -EFAULT;
+		if (start)
+			return vhost_vsock_start(vsock);
+		else
+			return vhost_vsock_stop(vsock);
+	case VHOST_GET_FEATURES:
+		features = VHOST_VSOCK_FEATURES;
+		if (copy_to_user(argp, &features, sizeof(features)))
+			return -EFAULT;
+		return 0;
+	case VHOST_SET_FEATURES:
+		if (copy_from_user(&features, argp, sizeof(features)))
+			return -EFAULT;
+		return vhost_vsock_set_features(vsock, features);
+	default:
+		mutex_lock(&vsock->dev.mutex);
+		r = vhost_dev_ioctl(&vsock->dev, ioctl, argp);
+		if (r == -ENOIOCTLCMD)
+			r = vhost_vring_ioctl(&vsock->dev, ioctl, argp);
+		else
+			vhost_vsock_flush(vsock);
+		mutex_unlock(&vsock->dev.mutex);
+		return r;
+	}
+}
+
+static const struct file_operations vhost_vsock_fops = {
+	.owner          = THIS_MODULE,
+	.open           = vhost_vsock_dev_open,
+	.release        = vhost_vsock_dev_release,
+	.llseek		= noop_llseek,
+	.unlocked_ioctl = vhost_vsock_dev_ioctl,
+};
+
+static struct miscdevice vhost_vsock_misc = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "vhost-vsock",
+	.fops = &vhost_vsock_fops,
+};
+
+static struct virtio_transport vhost_transport = {
+	.transport = {
+		.get_local_cid            = vhost_transport_get_local_cid,
+
+		.init                     = virtio_transport_do_socket_init,
+		.destruct                 = virtio_transport_destruct,
+		.release                  = virtio_transport_release,
+		.connect                  = virtio_transport_connect,
+		.shutdown                 = virtio_transport_shutdown,
+
+		.dgram_enqueue            = virtio_transport_dgram_enqueue,
+		.dgram_dequeue            = virtio_transport_dgram_dequeue,
+		.dgram_bind               = virtio_transport_dgram_bind,
+		.dgram_allow              = virtio_transport_dgram_allow,
+
+		.stream_enqueue           = virtio_transport_stream_enqueue,
+		.stream_dequeue           = virtio_transport_stream_dequeue,
+		.stream_has_data          = virtio_transport_stream_has_data,
+		.stream_has_space         = virtio_transport_stream_has_space,
+		.stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
+		.stream_is_active         = virtio_transport_stream_is_active,
+		.stream_allow             = virtio_transport_stream_allow,
+
+		.notify_poll_in           = virtio_transport_notify_poll_in,
+		.notify_poll_out          = virtio_transport_notify_poll_out,
+		.notify_recv_init         = virtio_transport_notify_recv_init,
+		.notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
+		.notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
+		.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
+		.notify_send_init         = virtio_transport_notify_send_init,
+		.notify_send_pre_block    = virtio_transport_notify_send_pre_block,
+		.notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
+		.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
+
+		.set_buffer_size          = virtio_transport_set_buffer_size,
+		.set_min_buffer_size      = virtio_transport_set_min_buffer_size,
+		.set_max_buffer_size      = virtio_transport_set_max_buffer_size,
+		.get_buffer_size          = virtio_transport_get_buffer_size,
+		.get_min_buffer_size      = virtio_transport_get_min_buffer_size,
+		.get_max_buffer_size      = virtio_transport_get_max_buffer_size,
+	},
+
+	.send_pkt = vhost_transport_send_pkt,
+};
+
+static int __init vhost_vsock_init(void)
+{
+	int ret;
+
+	ret = vsock_core_init(&vhost_transport.transport);
+	if (ret < 0)
+		return ret;
+	return misc_register(&vhost_vsock_misc);
+};
+
+static void __exit vhost_vsock_exit(void)
+{
+	misc_deregister(&vhost_vsock_misc);
+	vsock_core_exit();
+};
+
+module_init(vhost_vsock_init);
+module_exit(vhost_vsock_exit);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Asias He");
+MODULE_DESCRIPTION("vhost transport for vsock ");

drivers/virtio/virtio_balloon.c

@@ -207,6 +207,8 @@ static unsigned leak_balloon(struct virtio_balloon *vb, size_t num)
 	num = min(num, ARRAY_SIZE(vb->pfns));
 
 	mutex_lock(&vb->balloon_lock);
+	/* We can't release more pages than taken */
+	num = min(num, (size_t)vb->num_pages);
 	for (vb->num_pfns = 0; vb->num_pfns < num;
 	     vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE) {
 		page = balloon_page_dequeue(vb_dev_info);

drivers/virtio/virtio_ring.c

@@ -117,7 +117,10 @@ struct vring_virtqueue {
 #define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq)
 
 /*
- * The interaction between virtio and a possible IOMMU is a mess.
+ * Modern virtio devices have feature bits to specify whether they need a
+ * quirk and bypass the IOMMU. If not there, just use the DMA API.
+ *
+ * If there, the interaction between virtio and DMA API is messy.
  *
  * On most systems with virtio, physical addresses match bus addresses,
  * and it doesn't particularly matter whether we use the DMA API.
@@ -133,10 +136,18 @@ struct vring_virtqueue {
  *
  * For the time being, we preserve historic behavior and bypass the DMA
  * API.
+ *
+ * TODO: install a per-device DMA ops structure that does the right thing
+ * taking into account all the above quirks, and use the DMA API
+ * unconditionally on data path.
  */
 
 static bool vring_use_dma_api(struct virtio_device *vdev)
 {
+	if (!virtio_has_iommu_quirk(vdev))
+		return true;
+
+	/* Otherwise, we are left to guess. */
 	/*
 	 * In theory, it's possible to have a buggy QEMU-supposed
 	 * emulated Q35 IOMMU and Xen enabled at the same time.  On
@@ -1099,6 +1110,8 @@ void vring_transport_features(struct virtio_device *vdev)
 			break;
 		case VIRTIO_F_VERSION_1:
 			break;
+		case VIRTIO_F_IOMMU_PLATFORM:
+			break;
 		default:
 			/* We don't understand this bit. */
 			__virtio_clear_bit(vdev, i);

include/linux/virtio_config.h

@@ -149,6 +149,19 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev,
 	return __virtio_test_bit(vdev, fbit);
 }
 
+/**
+ * virtio_has_iommu_quirk - determine whether this device has the iommu quirk
+ * @vdev: the device
+ */
+static inline bool virtio_has_iommu_quirk(const struct virtio_device *vdev)
+{
+	/*
+	 * Note the reverse polarity of the quirk feature (compared to most
+	 * other features), this is for compatibility with legacy systems.
+	 */
+	return !virtio_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
+}
+
 static inline
 struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
 					vq_callback_t *c, const char *n)

include/linux/virtio_vsock.h

@@ -0,0 +1,154 @@
+#ifndef _LINUX_VIRTIO_VSOCK_H
+#define _LINUX_VIRTIO_VSOCK_H
+
+#include <uapi/linux/virtio_vsock.h>
+#include <linux/socket.h>
+#include <net/sock.h>
+#include <net/af_vsock.h>
+
+#define VIRTIO_VSOCK_DEFAULT_MIN_BUF_SIZE	128
+#define VIRTIO_VSOCK_DEFAULT_BUF_SIZE		(1024 * 256)
+#define VIRTIO_VSOCK_DEFAULT_MAX_BUF_SIZE	(1024 * 256)
+#define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE	(1024 * 4)
+#define VIRTIO_VSOCK_MAX_BUF_SIZE		0xFFFFFFFFUL
+#define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE		(1024 * 64)
+
+enum {
+	VSOCK_VQ_RX     = 0, /* for host to guest data */
+	VSOCK_VQ_TX     = 1, /* for guest to host data */
+	VSOCK_VQ_EVENT  = 2,
+	VSOCK_VQ_MAX    = 3,
+};
+
+/* Per-socket state (accessed via vsk->trans) */
+struct virtio_vsock_sock {
+	struct vsock_sock *vsk;
+
+	/* Protected by lock_sock(sk_vsock(trans->vsk)) */
+	u32 buf_size;
+	u32 buf_size_min;
+	u32 buf_size_max;
+
+	spinlock_t tx_lock;
+	spinlock_t rx_lock;
+
+	/* Protected by tx_lock */
+	u32 tx_cnt;
+	u32 buf_alloc;
+	u32 peer_fwd_cnt;
+	u32 peer_buf_alloc;
+
+	/* Protected by rx_lock */
+	u32 fwd_cnt;
+	u32 rx_bytes;
+	struct list_head rx_queue;
+};
+
+struct virtio_vsock_pkt {
+	struct virtio_vsock_hdr	hdr;
+	struct work_struct work;
+	struct list_head list;
+	void *buf;
+	u32 len;
+	u32 off;
+	bool reply;
+};
+
+struct virtio_vsock_pkt_info {
+	u32 remote_cid, remote_port;
+	struct msghdr *msg;
+	u32 pkt_len;
+	u16 type;
+	u16 op;
+	u32 flags;
+	bool reply;
+};
+
+struct virtio_transport {
+	/* This must be the first field */
+	struct vsock_transport transport;
+
+	/* Takes ownership of the packet */
+	int (*send_pkt)(struct virtio_vsock_pkt *pkt);
+};
+
+ssize_t
+virtio_transport_stream_dequeue(struct vsock_sock *vsk,
+				struct msghdr *msg,
+				size_t len,
+				int type);
+int
+virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
+			       struct msghdr *msg,
+			       size_t len, int flags);
+
+s64 virtio_transport_stream_has_data(struct vsock_sock *vsk);
+s64 virtio_transport_stream_has_space(struct vsock_sock *vsk);
+
+int virtio_transport_do_socket_init(struct vsock_sock *vsk,
+				 struct vsock_sock *psk);
+u64 virtio_transport_get_buffer_size(struct vsock_sock *vsk);
+u64 virtio_transport_get_min_buffer_size(struct vsock_sock *vsk);
+u64 virtio_transport_get_max_buffer_size(struct vsock_sock *vsk);
+void virtio_transport_set_buffer_size(struct vsock_sock *vsk, u64 val);
+void virtio_transport_set_min_buffer_size(struct vsock_sock *vsk, u64 val);
+void virtio_transport_set_max_buffer_size(struct vsock_sock *vs, u64 val);
+int
+virtio_transport_notify_poll_in(struct vsock_sock *vsk,
+				size_t target,
+				bool *data_ready_now);
+int
+virtio_transport_notify_poll_out(struct vsock_sock *vsk,
+				 size_t target,
+				 bool *space_available_now);
+
+int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
+	size_t target, struct vsock_transport_recv_notify_data *data);
+int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
+	size_t target, struct vsock_transport_recv_notify_data *data);
+int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
+	size_t target, struct vsock_transport_recv_notify_data *data);
+int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
+	size_t target, ssize_t copied, bool data_read,
+	struct vsock_transport_recv_notify_data *data);
+int virtio_transport_notify_send_init(struct vsock_sock *vsk,
+	struct vsock_transport_send_notify_data *data);
+int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
+	struct vsock_transport_send_notify_data *data);
+int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
+	struct vsock_transport_send_notify_data *data);
+int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
+	ssize_t written, struct vsock_transport_send_notify_data *data);
+
+u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk);
+bool virtio_transport_stream_is_active(struct vsock_sock *vsk);
+bool virtio_transport_stream_allow(u32 cid, u32 port);
+int virtio_transport_dgram_bind(struct vsock_sock *vsk,
+				struct sockaddr_vm *addr);
+bool virtio_transport_dgram_allow(u32 cid, u32 port);
+
+int virtio_transport_connect(struct vsock_sock *vsk);
+
+int virtio_transport_shutdown(struct vsock_sock *vsk, int mode);
+
+void virtio_transport_release(struct vsock_sock *vsk);
+
+ssize_t
+virtio_transport_stream_enqueue(struct vsock_sock *vsk,
+				struct msghdr *msg,
+				size_t len);
+int
+virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
+			       struct sockaddr_vm *remote_addr,
+			       struct msghdr *msg,
+			       size_t len);
+
+void virtio_transport_destruct(struct vsock_sock *vsk);
+
+void virtio_transport_recv_pkt(struct virtio_vsock_pkt *pkt);
+void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt);
+void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt);
+u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 wanted);
+void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit);
+
+#endif /* _LINUX_VIRTIO_VSOCK_H */

include/net/af_vsock.h

@@ -63,6 +63,8 @@ struct vsock_sock {
 	struct list_head accept_queue;
 	bool rejected;
 	struct delayed_work dwork;
+	struct delayed_work close_work;
+	bool close_work_scheduled;
 	u32 peer_shutdown;
 	bool sent_request;
 	bool ignore_connecting_rst;
@@ -165,6 +167,9 @@ static inline int vsock_core_init(const struct vsock_transport *t)
 }
 void vsock_core_exit(void);
 
+/* The transport may downcast this to access transport-specific functions */
+const struct vsock_transport *vsock_core_get_transport(void);
+
 /**** UTILS ****/
 
 void vsock_release_pending(struct sock *pending);
@@ -177,6 +182,7 @@ void vsock_remove_connected(struct vsock_sock *vsk);
 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr);
 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
 					 struct sockaddr_vm *dst);
+void vsock_remove_sock(struct vsock_sock *vsk);
 void vsock_for_each_connected_socket(void (*fn)(struct sock *sk));
 
 #endif /* __AF_VSOCK_H__ */

include/trace/events/vsock_virtio_transport_common.h

@@ -0,0 +1,144 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM vsock
+
+#if !defined(_TRACE_VSOCK_VIRTIO_TRANSPORT_COMMON_H) || \
+    defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_VSOCK_VIRTIO_TRANSPORT_COMMON_H
+
+#include <linux/tracepoint.h>
+
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_TYPE_STREAM);
+
+#define show_type(val) \
+	__print_symbolic(val, { VIRTIO_VSOCK_TYPE_STREAM, "STREAM" })
+
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_INVALID);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_REQUEST);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_RESPONSE);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_RST);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_SHUTDOWN);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_RW);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_CREDIT_UPDATE);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_CREDIT_REQUEST);
+
+#define show_op(val) \
+	__print_symbolic(val, \
+			 { VIRTIO_VSOCK_OP_INVALID, "INVALID" }, \
+			 { VIRTIO_VSOCK_OP_REQUEST, "REQUEST" }, \
+			 { VIRTIO_VSOCK_OP_RESPONSE, "RESPONSE" }, \
+			 { VIRTIO_VSOCK_OP_RST, "RST" }, \
+			 { VIRTIO_VSOCK_OP_SHUTDOWN, "SHUTDOWN" }, \
+			 { VIRTIO_VSOCK_OP_RW, "RW" }, \
+			 { VIRTIO_VSOCK_OP_CREDIT_UPDATE, "CREDIT_UPDATE" }, \
+			 { VIRTIO_VSOCK_OP_CREDIT_REQUEST, "CREDIT_REQUEST" })
+
+TRACE_EVENT(virtio_transport_alloc_pkt,
+	TP_PROTO(
+		 __u32 src_cid, __u32 src_port,
+		 __u32 dst_cid, __u32 dst_port,
+		 __u32 len,
+		 __u16 type,
+		 __u16 op,
+		 __u32 flags
+	),
+	TP_ARGS(
+		src_cid, src_port,
+		dst_cid, dst_port,
+		len,
+		type,
+		op,
+		flags
+	),
+	TP_STRUCT__entry(
+		__field(__u32, src_cid)
+		__field(__u32, src_port)
+		__field(__u32, dst_cid)
+		__field(__u32, dst_port)
+		__field(__u32, len)
+		__field(__u16, type)
+		__field(__u16, op)
+		__field(__u32, flags)
+	),
+	TP_fast_assign(
+		__entry->src_cid = src_cid;
+		__entry->src_port = src_port;
+		__entry->dst_cid = dst_cid;
+		__entry->dst_port = dst_port;
+		__entry->len = len;
+		__entry->type = type;
+		__entry->op = op;
+		__entry->flags = flags;
+	),
+	TP_printk("%u:%u -> %u:%u len=%u type=%s op=%s flags=%#x",
+		  __entry->src_cid, __entry->src_port,
+		  __entry->dst_cid, __entry->dst_port,
+		  __entry->len,
+		  show_type(__entry->type),
+		  show_op(__entry->op),
+		  __entry->flags)
+);
+
+TRACE_EVENT(virtio_transport_recv_pkt,
+	TP_PROTO(
+		 __u32 src_cid, __u32 src_port,
+		 __u32 dst_cid, __u32 dst_port,
+		 __u32 len,
+		 __u16 type,
+		 __u16 op,
+		 __u32 flags,
+		 __u32 buf_alloc,
+		 __u32 fwd_cnt
+	),
+	TP_ARGS(
+		src_cid, src_port,
+		dst_cid, dst_port,
+		len,
+		type,
+		op,
+		flags,
+		buf_alloc,
+		fwd_cnt
+	),
+	TP_STRUCT__entry(
+		__field(__u32, src_cid)
+		__field(__u32, src_port)
+		__field(__u32, dst_cid)
+		__field(__u32, dst_port)
+		__field(__u32, len)
+		__field(__u16, type)
+		__field(__u16, op)
+		__field(__u32, flags)
+		__field(__u32, buf_alloc)
+		__field(__u32, fwd_cnt)
+	),
+	TP_fast_assign(
+		__entry->src_cid = src_cid;
+		__entry->src_port = src_port;
+		__entry->dst_cid = dst_cid;
+		__entry->dst_port = dst_port;
+		__entry->len = len;
+		__entry->type = type;
+		__entry->op = op;
+		__entry->flags = flags;
+		__entry->buf_alloc = buf_alloc;
+		__entry->fwd_cnt = fwd_cnt;
+	),
+	TP_printk("%u:%u -> %u:%u len=%u type=%s op=%s flags=%#x "
+		  "buf_alloc=%u fwd_cnt=%u",
+		  __entry->src_cid, __entry->src_port,
+		  __entry->dst_cid, __entry->dst_port,
+		  __entry->len,
+		  show_type(__entry->type),
+		  show_op(__entry->op),
+		  __entry->flags,
+		  __entry->buf_alloc,
+		  __entry->fwd_cnt)
+);
+
+#endif /* _TRACE_VSOCK_VIRTIO_TRANSPORT_COMMON_H */
+
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE vsock_virtio_transport_common
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>

include/uapi/linux/Kbuild

@@ -454,6 +454,7 @@ header-y += virtio_ring.h
 header-y += virtio_rng.h
 header-y += virtio_scsi.h
 header-y += virtio_types.h
+header-y += virtio_vsock.h
 header-y += vm_sockets.h
 header-y += vt.h
 header-y += vtpm_proxy.h

include/uapi/linux/vhost.h

@@ -47,6 +47,32 @@ struct vhost_vring_addr {
 	__u64 log_guest_addr;
 };
 
+/* no alignment requirement */
+struct vhost_iotlb_msg {
+	__u64 iova;
+	__u64 size;
+	__u64 uaddr;
+#define VHOST_ACCESS_RO      0x1
+#define VHOST_ACCESS_WO      0x2
+#define VHOST_ACCESS_RW      0x3
+	__u8 perm;
+#define VHOST_IOTLB_MISS           1
+#define VHOST_IOTLB_UPDATE         2
+#define VHOST_IOTLB_INVALIDATE     3
+#define VHOST_IOTLB_ACCESS_FAIL    4
+	__u8 type;
+};
+
+#define VHOST_IOTLB_MSG 0x1
+
+struct vhost_msg {
+	int type;
+	union {
+		struct vhost_iotlb_msg iotlb;
+		__u8 padding[64];
+	};
+};
+
 struct vhost_memory_region {
 	__u64 guest_phys_addr;
 	__u64 memory_size; /* bytes */
@@ -146,6 +172,8 @@ struct vhost_memory {
 #define VHOST_F_LOG_ALL 26
 /* vhost-net should add virtio_net_hdr for RX, and strip for TX packets. */
 #define VHOST_NET_F_VIRTIO_NET_HDR 27
+/* Vhost have device IOTLB */
+#define VHOST_F_DEVICE_IOTLB 63
 
 /* VHOST_SCSI specific definitions */
 
@@ -175,4 +203,9 @@ struct vhost_scsi_target {
 #define VHOST_SCSI_SET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x43, __u32)
 #define VHOST_SCSI_GET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x44, __u32)
 
+/* VHOST_VSOCK specific defines */
+
+#define VHOST_VSOCK_SET_GUEST_CID	_IOW(VHOST_VIRTIO, 0x60, __u64)
+#define VHOST_VSOCK_SET_RUNNING		_IOW(VHOST_VIRTIO, 0x61, int)
+
 #endif

include/uapi/linux/virtio_config.h

@@ -49,7 +49,7 @@
  * transport being used (eg. virtio_ring), the rest are per-device feature
  * bits. */
 #define VIRTIO_TRANSPORT_F_START	28
-#define VIRTIO_TRANSPORT_F_END		33
+#define VIRTIO_TRANSPORT_F_END		34
 
 #ifndef VIRTIO_CONFIG_NO_LEGACY
 /* Do we get callbacks when the ring is completely used, even if we've
@@ -63,4 +63,12 @@
 /* v1.0 compliant. */
 #define VIRTIO_F_VERSION_1		32
 
+/*
+ * If clear - device has the IOMMU bypass quirk feature.
+ * If set - use platform tools to detect the IOMMU.
+ *
+ * Note the reverse polarity (compared to most other features),
+ * this is for compatibility with legacy systems.
+ */
+#define VIRTIO_F_IOMMU_PLATFORM		33
 #endif /* _UAPI_LINUX_VIRTIO_CONFIG_H */

include/uapi/linux/virtio_ids.h

@@ -41,5 +41,6 @@
 #define VIRTIO_ID_CAIF	       12 /* Virtio caif */
 #define VIRTIO_ID_GPU          16 /* virtio GPU */
 #define VIRTIO_ID_INPUT        18 /* virtio input */
+#define VIRTIO_ID_VSOCK        19 /* virtio vsock transport */
 
 #endif /* _LINUX_VIRTIO_IDS_H */

include/uapi/linux/virtio_vsock.h

@@ -0,0 +1,94 @@
+/*
+ * This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so
+ * anyone can use the definitions to implement compatible drivers/servers:
+ *
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of IBM nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * Copyright (C) Red Hat, Inc., 2013-2015
+ * Copyright (C) Asias He <asias@redhat.com>, 2013
+ * Copyright (C) Stefan Hajnoczi <stefanha@redhat.com>, 2015
+ */
+
+#ifndef _UAPI_LINUX_VIRTIO_VSOCK_H
+#define _UAPI_LINUX_VIRTIO_VOSCK_H
+
+#include <linux/types.h>
+#include <linux/virtio_ids.h>
+#include <linux/virtio_config.h>
+
+struct virtio_vsock_config {
+	__le64 guest_cid;
+} __attribute__((packed));
+
+enum virtio_vsock_event_id {
+	VIRTIO_VSOCK_EVENT_TRANSPORT_RESET = 0,
+};
+
+struct virtio_vsock_event {
+	__le32 id;
+} __attribute__((packed));
+
+struct virtio_vsock_hdr {
+	__le64	src_cid;
+	__le64	dst_cid;
+	__le32	src_port;
+	__le32	dst_port;
+	__le32	len;
+	__le16	type;		/* enum virtio_vsock_type */
+	__le16	op;		/* enum virtio_vsock_op */
+	__le32	flags;
+	__le32	buf_alloc;
+	__le32	fwd_cnt;
+} __attribute__((packed));
+
+enum virtio_vsock_type {
+	VIRTIO_VSOCK_TYPE_STREAM = 1,
+};
+
+enum virtio_vsock_op {
+	VIRTIO_VSOCK_OP_INVALID = 0,
+
+	/* Connect operations */
+	VIRTIO_VSOCK_OP_REQUEST = 1,
+	VIRTIO_VSOCK_OP_RESPONSE = 2,
+	VIRTIO_VSOCK_OP_RST = 3,
+	VIRTIO_VSOCK_OP_SHUTDOWN = 4,
+
+	/* To send payload */
+	VIRTIO_VSOCK_OP_RW = 5,
+
+	/* Tell the peer our credit info */
+	VIRTIO_VSOCK_OP_CREDIT_UPDATE = 6,
+	/* Request the peer to send the credit info to us */
+	VIRTIO_VSOCK_OP_CREDIT_REQUEST = 7,
+};
+
+/* VIRTIO_VSOCK_OP_SHUTDOWN flags values */
+enum virtio_vsock_shutdown {
+	VIRTIO_VSOCK_SHUTDOWN_RCV = 1,
+	VIRTIO_VSOCK_SHUTDOWN_SEND = 2,
+};
+
+#endif /* _UAPI_LINUX_VIRTIO_VSOCK_H */

net/vmw_vsock/Kconfig

@@ -26,3 +26,23 @@ config VMWARE_VMCI_VSOCKETS
 
 	  To compile this driver as a module, choose M here: the module
 	  will be called vmw_vsock_vmci_transport. If unsure, say N.
+
+config VIRTIO_VSOCKETS
+	tristate "virtio transport for Virtual Sockets"
+	depends on VSOCKETS && VIRTIO
+	select VIRTIO_VSOCKETS_COMMON
+	help
+	  This module implements a virtio transport for Virtual Sockets.
+
+	  Enable this transport if your Virtual Machine host supports Virtual
+	  Sockets over virtio.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called vmw_vsock_virtio_transport. If unsure, say N.
+
+config VIRTIO_VSOCKETS_COMMON
+	tristate
+	help
+	  This option is selected by any driver which needs to access
+	  the virtio_vsock.  The module will be called
+	  vmw_vsock_virtio_transport_common.

net/vmw_vsock/Makefile

@@ -1,7 +1,13 @@
 obj-$(CONFIG_VSOCKETS) += vsock.o
 obj-$(CONFIG_VMWARE_VMCI_VSOCKETS) += vmw_vsock_vmci_transport.o
+obj-$(CONFIG_VIRTIO_VSOCKETS) += vmw_vsock_virtio_transport.o
+obj-$(CONFIG_VIRTIO_VSOCKETS_COMMON) += vmw_vsock_virtio_transport_common.o
 
 vsock-y += af_vsock.o vsock_addr.o
 
 vmw_vsock_vmci_transport-y += vmci_transport.o vmci_transport_notify.o \
 	vmci_transport_notify_qstate.o
+
+vmw_vsock_virtio_transport-y += virtio_transport.o
+
+vmw_vsock_virtio_transport_common-y += virtio_transport_common.o

net/vmw_vsock/af_vsock.c

@@ -344,6 +344,16 @@ static bool vsock_in_connected_table(struct vsock_sock *vsk)
 	return ret;
 }
 
+void vsock_remove_sock(struct vsock_sock *vsk)
+{
+	if (vsock_in_bound_table(vsk))
+		vsock_remove_bound(vsk);
+
+	if (vsock_in_connected_table(vsk))
+		vsock_remove_connected(vsk);
+}
+EXPORT_SYMBOL_GPL(vsock_remove_sock);
+
 void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
 {
 	int i;
@@ -660,12 +670,6 @@ static void __vsock_release(struct sock *sk)
 		vsk = vsock_sk(sk);
 		pending = NULL;	/* Compiler warning. */
 
-		if (vsock_in_bound_table(vsk))
-			vsock_remove_bound(vsk);
-
-		if (vsock_in_connected_table(vsk))
-			vsock_remove_connected(vsk);
-
 		transport->release(vsk);
 
 		lock_sock(sk);
@@ -1995,6 +1999,15 @@ void vsock_core_exit(void)
 }
 EXPORT_SYMBOL_GPL(vsock_core_exit);
 
+const struct vsock_transport *vsock_core_get_transport(void)
+{
+	/* vsock_register_mutex not taken since only the transport uses this
+	 * function and only while registered.
+	 */
+	return transport;
+}
+EXPORT_SYMBOL_GPL(vsock_core_get_transport);
+
 MODULE_AUTHOR("VMware, Inc.");
 MODULE_DESCRIPTION("VMware Virtual Socket Family");
 MODULE_VERSION("1.0.1.0-k");

net/vmw_vsock/virtio_transport.c

@@ -0,0 +1,624 @@
+/*
+ * virtio transport for vsock
+ *
+ * Copyright (C) 2013-2015 Red Hat, Inc.
+ * Author: Asias He <asias@redhat.com>
+ *         Stefan Hajnoczi <stefanha@redhat.com>
+ *
+ * Some of the code is take from Gerd Hoffmann <kraxel@redhat.com>'s
+ * early virtio-vsock proof-of-concept bits.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/atomic.h>
+#include <linux/virtio.h>
+#include <linux/virtio_ids.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_vsock.h>
+#include <net/sock.h>
+#include <linux/mutex.h>
+#include <net/af_vsock.h>
+
+static struct workqueue_struct *virtio_vsock_workqueue;
+static struct virtio_vsock *the_virtio_vsock;
+static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */
+
+struct virtio_vsock {
+	struct virtio_device *vdev;
+	struct virtqueue *vqs[VSOCK_VQ_MAX];
+
+	/* Virtqueue processing is deferred to a workqueue */
+	struct work_struct tx_work;
+	struct work_struct rx_work;
+	struct work_struct event_work;
+
+	/* The following fields are protected by tx_lock.  vqs[VSOCK_VQ_TX]
+	 * must be accessed with tx_lock held.
+	 */
+	struct mutex tx_lock;
+
+	struct work_struct send_pkt_work;
+	spinlock_t send_pkt_list_lock;
+	struct list_head send_pkt_list;
+
+	atomic_t queued_replies;
+
+	/* The following fields are protected by rx_lock.  vqs[VSOCK_VQ_RX]
+	 * must be accessed with rx_lock held.
+	 */
+	struct mutex rx_lock;
+	int rx_buf_nr;
+	int rx_buf_max_nr;
+
+	/* The following fields are protected by event_lock.
+	 * vqs[VSOCK_VQ_EVENT] must be accessed with event_lock held.
+	 */
+	struct mutex event_lock;
+	struct virtio_vsock_event event_list[8];
+
+	u32 guest_cid;
+};
+
+static struct virtio_vsock *virtio_vsock_get(void)
+{
+	return the_virtio_vsock;
+}
+
+static u32 virtio_transport_get_local_cid(void)
+{
+	struct virtio_vsock *vsock = virtio_vsock_get();
+
+	return vsock->guest_cid;
+}
+
+static void
+virtio_transport_send_pkt_work(struct work_struct *work)
+{
+	struct virtio_vsock *vsock =
+		container_of(work, struct virtio_vsock, send_pkt_work);
+	struct virtqueue *vq;
+	bool added = false;
+	bool restart_rx = false;
+
+	mutex_lock(&vsock->tx_lock);
+
+	vq = vsock->vqs[VSOCK_VQ_TX];
+
+	/* Avoid unnecessary interrupts while we're processing the ring */
+	virtqueue_disable_cb(vq);
+
+	for (;;) {
+		struct virtio_vsock_pkt *pkt;
+		struct scatterlist hdr, buf, *sgs[2];
+		int ret, in_sg = 0, out_sg = 0;
+		bool reply;
+
+		spin_lock_bh(&vsock->send_pkt_list_lock);
+		if (list_empty(&vsock->send_pkt_list)) {
+			spin_unlock_bh(&vsock->send_pkt_list_lock);
+			virtqueue_enable_cb(vq);
+			break;
+		}
+
+		pkt = list_first_entry(&vsock->send_pkt_list,
+				       struct virtio_vsock_pkt, list);
+		list_del_init(&pkt->list);
+		spin_unlock_bh(&vsock->send_pkt_list_lock);
+
+		reply = pkt->reply;
+
+		sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
+		sgs[out_sg++] = &hdr;
+		if (pkt->buf) {
+			sg_init_one(&buf, pkt->buf, pkt->len);
+			sgs[out_sg++] = &buf;
+		}
+
+		ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt, GFP_KERNEL);
+		if (ret < 0) {
+			spin_lock_bh(&vsock->send_pkt_list_lock);
+			list_add(&pkt->list, &vsock->send_pkt_list);
+			spin_unlock_bh(&vsock->send_pkt_list_lock);
+
+			if (!virtqueue_enable_cb(vq) && ret == -ENOSPC)
+				continue; /* retry now that we have more space */
+			break;
+		}
+
+		if (reply) {
+			struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
+			int val;
+
+			val = atomic_dec_return(&vsock->queued_replies);
+
+			/* Do we now have resources to resume rx processing? */
+			if (val + 1 == virtqueue_get_vring_size(rx_vq))
+				restart_rx = true;
+		}
+
+		added = true;
+	}
+
+	if (added)
+		virtqueue_kick(vq);
+
+	mutex_unlock(&vsock->tx_lock);
+
+	if (restart_rx)
+		queue_work(virtio_vsock_workqueue, &vsock->rx_work);
+}
+
+static int
+virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt)
+{
+	struct virtio_vsock *vsock;
+	int len = pkt->len;
+
+	vsock = virtio_vsock_get();
+	if (!vsock) {
+		virtio_transport_free_pkt(pkt);
+		return -ENODEV;
+	}
+
+	if (pkt->reply)
+		atomic_inc(&vsock->queued_replies);
+
+	spin_lock_bh(&vsock->send_pkt_list_lock);
+	list_add_tail(&pkt->list, &vsock->send_pkt_list);
+	spin_unlock_bh(&vsock->send_pkt_list_lock);
+
+	queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
+	return len;
+}
+
+static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
+{
+	int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
+	struct virtio_vsock_pkt *pkt;
+	struct scatterlist hdr, buf, *sgs[2];
+	struct virtqueue *vq;
+	int ret;
+
+	vq = vsock->vqs[VSOCK_VQ_RX];
+
+	do {
+		pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
+		if (!pkt)
+			break;
+
+		pkt->buf = kmalloc(buf_len, GFP_KERNEL);
+		if (!pkt->buf) {
+			virtio_transport_free_pkt(pkt);
+			break;
+		}
+
+		pkt->len = buf_len;
+
+		sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
+		sgs[0] = &hdr;
+
+		sg_init_one(&buf, pkt->buf, buf_len);
+		sgs[1] = &buf;
+		ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL);
+		if (ret) {
+			virtio_transport_free_pkt(pkt);
+			break;
+		}
+		vsock->rx_buf_nr++;
+	} while (vq->num_free);
+	if (vsock->rx_buf_nr > vsock->rx_buf_max_nr)
+		vsock->rx_buf_max_nr = vsock->rx_buf_nr;
+	virtqueue_kick(vq);
+}
+
+static void virtio_transport_tx_work(struct work_struct *work)
+{
+	struct virtio_vsock *vsock =
+		container_of(work, struct virtio_vsock, tx_work);
+	struct virtqueue *vq;
+	bool added = false;
+
+	vq = vsock->vqs[VSOCK_VQ_TX];
+	mutex_lock(&vsock->tx_lock);
+	do {
+		struct virtio_vsock_pkt *pkt;
+		unsigned int len;
+
+		virtqueue_disable_cb(vq);
+		while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) {
+			virtio_transport_free_pkt(pkt);
+			added = true;
+		}
+	} while (!virtqueue_enable_cb(vq));
+	mutex_unlock(&vsock->tx_lock);
+
+	if (added)
+		queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
+}
+
+/* Is there space left for replies to rx packets? */
+static bool virtio_transport_more_replies(struct virtio_vsock *vsock)
+{
+	struct virtqueue *vq = vsock->vqs[VSOCK_VQ_RX];
+	int val;
+
+	smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
+	val = atomic_read(&vsock->queued_replies);
+
+	return val < virtqueue_get_vring_size(vq);
+}
+
+static void virtio_transport_rx_work(struct work_struct *work)
+{
+	struct virtio_vsock *vsock =
+		container_of(work, struct virtio_vsock, rx_work);
+	struct virtqueue *vq;
+
+	vq = vsock->vqs[VSOCK_VQ_RX];
+
+	mutex_lock(&vsock->rx_lock);
+
+	do {
+		virtqueue_disable_cb(vq);
+		for (;;) {
+			struct virtio_vsock_pkt *pkt;
+			unsigned int len;
+
+			if (!virtio_transport_more_replies(vsock)) {
+				/* Stop rx until the device processes already
+				 * pending replies.  Leave rx virtqueue
+				 * callbacks disabled.
+				 */
+				goto out;
+			}
+
+			pkt = virtqueue_get_buf(vq, &len);
+			if (!pkt) {
+				break;
+			}
+
+			vsock->rx_buf_nr--;
+
+			/* Drop short/long packets */
+			if (unlikely(len < sizeof(pkt->hdr) ||
+				     len > sizeof(pkt->hdr) + pkt->len)) {
+				virtio_transport_free_pkt(pkt);
+				continue;
+			}
+
+			pkt->len = len - sizeof(pkt->hdr);
+			virtio_transport_recv_pkt(pkt);
+		}
+	} while (!virtqueue_enable_cb(vq));
+
+out:
+	if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2)
+		virtio_vsock_rx_fill(vsock);
+	mutex_unlock(&vsock->rx_lock);
+}
+
+/* event_lock must be held */
+static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock,
+				       struct virtio_vsock_event *event)
+{
+	struct scatterlist sg;
+	struct virtqueue *vq;
+
+	vq = vsock->vqs[VSOCK_VQ_EVENT];
+
+	sg_init_one(&sg, event, sizeof(*event));
+
+	return virtqueue_add_inbuf(vq, &sg, 1, event, GFP_KERNEL);
+}
+
+/* event_lock must be held */
+static void virtio_vsock_event_fill(struct virtio_vsock *vsock)
+{
+	size_t i;
+
+	for (i = 0; i < ARRAY_SIZE(vsock->event_list); i++) {
+		struct virtio_vsock_event *event = &vsock->event_list[i];
+
+		virtio_vsock_event_fill_one(vsock, event);
+	}
+
+	virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
+}
+
+static void virtio_vsock_reset_sock(struct sock *sk)
+{
+	lock_sock(sk);
+	sk->sk_state = SS_UNCONNECTED;
+	sk->sk_err = ECONNRESET;
+	sk->sk_error_report(sk);
+	release_sock(sk);
+}
+
+static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock)
+{
+	struct virtio_device *vdev = vsock->vdev;
+	u64 guest_cid;
+
+	vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid),
+			  &guest_cid, sizeof(guest_cid));
+	vsock->guest_cid = le64_to_cpu(guest_cid);
+}
+
+/* event_lock must be held */
+static void virtio_vsock_event_handle(struct virtio_vsock *vsock,
+				      struct virtio_vsock_event *event)
+{
+	switch (le32_to_cpu(event->id)) {
+	case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET:
+		virtio_vsock_update_guest_cid(vsock);
+		vsock_for_each_connected_socket(virtio_vsock_reset_sock);
+		break;
+	}
+}
+
+static void virtio_transport_event_work(struct work_struct *work)
+{
+	struct virtio_vsock *vsock =
+		container_of(work, struct virtio_vsock, event_work);
+	struct virtqueue *vq;
+
+	vq = vsock->vqs[VSOCK_VQ_EVENT];
+
+	mutex_lock(&vsock->event_lock);
+
+	do {
+		struct virtio_vsock_event *event;
+		unsigned int len;
+
+		virtqueue_disable_cb(vq);
+		while ((event = virtqueue_get_buf(vq, &len)) != NULL) {
+			if (len == sizeof(*event))
+				virtio_vsock_event_handle(vsock, event);
+
+			virtio_vsock_event_fill_one(vsock, event);
+		}
+	} while (!virtqueue_enable_cb(vq));
+
+	virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
+
+	mutex_unlock(&vsock->event_lock);
+}
+
+static void virtio_vsock_event_done(struct virtqueue *vq)
+{
+	struct virtio_vsock *vsock = vq->vdev->priv;
+
+	if (!vsock)
+		return;
+	queue_work(virtio_vsock_workqueue, &vsock->event_work);
+}
+
+static void virtio_vsock_tx_done(struct virtqueue *vq)
+{
+	struct virtio_vsock *vsock = vq->vdev->priv;
+
+	if (!vsock)
+		return;
+	queue_work(virtio_vsock_workqueue, &vsock->tx_work);
+}
+
+static void virtio_vsock_rx_done(struct virtqueue *vq)
+{
+	struct virtio_vsock *vsock = vq->vdev->priv;
+
+	if (!vsock)
+		return;
+	queue_work(virtio_vsock_workqueue, &vsock->rx_work);
+}
+
+static struct virtio_transport virtio_transport = {
+	.transport = {
+		.get_local_cid            = virtio_transport_get_local_cid,
+
+		.init                     = virtio_transport_do_socket_init,
+		.destruct                 = virtio_transport_destruct,
+		.release                  = virtio_transport_release,
+		.connect                  = virtio_transport_connect,
+		.shutdown                 = virtio_transport_shutdown,
+
+		.dgram_bind               = virtio_transport_dgram_bind,
+		.dgram_dequeue            = virtio_transport_dgram_dequeue,
+		.dgram_enqueue            = virtio_transport_dgram_enqueue,
+		.dgram_allow              = virtio_transport_dgram_allow,
+
+		.stream_dequeue           = virtio_transport_stream_dequeue,
+		.stream_enqueue           = virtio_transport_stream_enqueue,
+		.stream_has_data          = virtio_transport_stream_has_data,
+		.stream_has_space         = virtio_transport_stream_has_space,
+		.stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
+		.stream_is_active         = virtio_transport_stream_is_active,
+		.stream_allow             = virtio_transport_stream_allow,
+
+		.notify_poll_in           = virtio_transport_notify_poll_in,
+		.notify_poll_out          = virtio_transport_notify_poll_out,
+		.notify_recv_init         = virtio_transport_notify_recv_init,
+		.notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
+		.notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
+		.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
+		.notify_send_init         = virtio_transport_notify_send_init,
+		.notify_send_pre_block    = virtio_transport_notify_send_pre_block,
+		.notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
+		.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
+
+		.set_buffer_size          = virtio_transport_set_buffer_size,
+		.set_min_buffer_size      = virtio_transport_set_min_buffer_size,
+		.set_max_buffer_size      = virtio_transport_set_max_buffer_size,
+		.get_buffer_size          = virtio_transport_get_buffer_size,
+		.get_min_buffer_size      = virtio_transport_get_min_buffer_size,
+		.get_max_buffer_size      = virtio_transport_get_max_buffer_size,
+	},
+
+	.send_pkt = virtio_transport_send_pkt,
+};
+
+static int virtio_vsock_probe(struct virtio_device *vdev)
+{
+	vq_callback_t *callbacks[] = {
+		virtio_vsock_rx_done,
+		virtio_vsock_tx_done,
+		virtio_vsock_event_done,
+	};
+	static const char * const names[] = {
+		"rx",
+		"tx",
+		"event",
+	};
+	struct virtio_vsock *vsock = NULL;
+	int ret;
+
+	ret = mutex_lock_interruptible(&the_virtio_vsock_mutex);
+	if (ret)
+		return ret;
+
+	/* Only one virtio-vsock device per guest is supported */
+	if (the_virtio_vsock) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
+	if (!vsock) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	vsock->vdev = vdev;
+
+	ret = vsock->vdev->config->find_vqs(vsock->vdev, VSOCK_VQ_MAX,
+					    vsock->vqs, callbacks, names);
+	if (ret < 0)
+		goto out;
+
+	virtio_vsock_update_guest_cid(vsock);
+
+	ret = vsock_core_init(&virtio_transport.transport);
+	if (ret < 0)
+		goto out_vqs;
+
+	vsock->rx_buf_nr = 0;
+	vsock->rx_buf_max_nr = 0;
+	atomic_set(&vsock->queued_replies, 0);
+
+	vdev->priv = vsock;
+	the_virtio_vsock = vsock;
+	mutex_init(&vsock->tx_lock);
+	mutex_init(&vsock->rx_lock);
+	mutex_init(&vsock->event_lock);
+	spin_lock_init(&vsock->send_pkt_list_lock);
+	INIT_LIST_HEAD(&vsock->send_pkt_list);
+	INIT_WORK(&vsock->rx_work, virtio_transport_rx_work);
+	INIT_WORK(&vsock->tx_work, virtio_transport_tx_work);
+	INIT_WORK(&vsock->event_work, virtio_transport_event_work);
+	INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
+
+	mutex_lock(&vsock->rx_lock);
+	virtio_vsock_rx_fill(vsock);
+	mutex_unlock(&vsock->rx_lock);
+
+	mutex_lock(&vsock->event_lock);
+	virtio_vsock_event_fill(vsock);
+	mutex_unlock(&vsock->event_lock);
+
+	mutex_unlock(&the_virtio_vsock_mutex);
+	return 0;
+
+out_vqs:
+	vsock->vdev->config->del_vqs(vsock->vdev);
+out:
+	kfree(vsock);
+	mutex_unlock(&the_virtio_vsock_mutex);
+	return ret;
+}
+
+static void virtio_vsock_remove(struct virtio_device *vdev)
+{
+	struct virtio_vsock *vsock = vdev->priv;
+	struct virtio_vsock_pkt *pkt;
+
+	flush_work(&vsock->rx_work);
+	flush_work(&vsock->tx_work);
+	flush_work(&vsock->event_work);
+	flush_work(&vsock->send_pkt_work);
+
+	vdev->config->reset(vdev);
+
+	mutex_lock(&vsock->rx_lock);
+	while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX])))
+		virtio_transport_free_pkt(pkt);
+	mutex_unlock(&vsock->rx_lock);
+
+	mutex_lock(&vsock->tx_lock);
+	while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX])))
+		virtio_transport_free_pkt(pkt);
+	mutex_unlock(&vsock->tx_lock);
+
+	spin_lock_bh(&vsock->send_pkt_list_lock);
+	while (!list_empty(&vsock->send_pkt_list)) {
+		pkt = list_first_entry(&vsock->send_pkt_list,
+				       struct virtio_vsock_pkt, list);
+		list_del(&pkt->list);
+		virtio_transport_free_pkt(pkt);
+	}
+	spin_unlock_bh(&vsock->send_pkt_list_lock);
+
+	mutex_lock(&the_virtio_vsock_mutex);
+	the_virtio_vsock = NULL;
+	vsock_core_exit();
+	mutex_unlock(&the_virtio_vsock_mutex);
+
+	vdev->config->del_vqs(vdev);
+
+	kfree(vsock);
+}
+
+static struct virtio_device_id id_table[] = {
+	{ VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID },
+	{ 0 },
+};
+
+static unsigned int features[] = {
+};
+
+static struct virtio_driver virtio_vsock_driver = {
+	.feature_table = features,
+	.feature_table_size = ARRAY_SIZE(features),
+	.driver.name = KBUILD_MODNAME,
+	.driver.owner = THIS_MODULE,
+	.id_table = id_table,
+	.probe = virtio_vsock_probe,
+	.remove = virtio_vsock_remove,
+};
+
+static int __init virtio_vsock_init(void)
+{
+	int ret;
+
+	virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0);
+	if (!virtio_vsock_workqueue)
+		return -ENOMEM;
+	ret = register_virtio_driver(&virtio_vsock_driver);
+	if (ret)
+		destroy_workqueue(virtio_vsock_workqueue);
+	return ret;
+}
+
+static void __exit virtio_vsock_exit(void)
+{
+	unregister_virtio_driver(&virtio_vsock_driver);
+	destroy_workqueue(virtio_vsock_workqueue);
+}
+
+module_init(virtio_vsock_init);
+module_exit(virtio_vsock_exit);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Asias He");
+MODULE_DESCRIPTION("virtio transport for vsock");
+MODULE_DEVICE_TABLE(virtio, id_table);

net/vmw_vsock/virtio_transport_common.c

@@ -0,0 +1,992 @@
+/*
+ * common code for virtio vsock
+ *
+ * Copyright (C) 2013-2015 Red Hat, Inc.
+ * Author: Asias He <asias@redhat.com>
+ *         Stefan Hajnoczi <stefanha@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/ctype.h>
+#include <linux/list.h>
+#include <linux/virtio.h>
+#include <linux/virtio_ids.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_vsock.h>
+
+#include <net/sock.h>
+#include <net/af_vsock.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/vsock_virtio_transport_common.h>
+
+/* How long to wait for graceful shutdown of a connection */
+#define VSOCK_CLOSE_TIMEOUT (8 * HZ)
+
+static const struct virtio_transport *virtio_transport_get_ops(void)
+{
+	const struct vsock_transport *t = vsock_core_get_transport();
+
+	return container_of(t, struct virtio_transport, transport);
+}
+
+struct virtio_vsock_pkt *
+virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info,
+			   size_t len,
+			   u32 src_cid,
+			   u32 src_port,
+			   u32 dst_cid,
+			   u32 dst_port)
+{
+	struct virtio_vsock_pkt *pkt;
+	int err;
+
+	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
+	if (!pkt)
+		return NULL;
+
+	pkt->hdr.type		= cpu_to_le16(info->type);
+	pkt->hdr.op		= cpu_to_le16(info->op);
+	pkt->hdr.src_cid	= cpu_to_le64(src_cid);
+	pkt->hdr.dst_cid	= cpu_to_le64(dst_cid);
+	pkt->hdr.src_port	= cpu_to_le32(src_port);
+	pkt->hdr.dst_port	= cpu_to_le32(dst_port);
+	pkt->hdr.flags		= cpu_to_le32(info->flags);
+	pkt->len		= len;
+	pkt->hdr.len		= cpu_to_le32(len);
+	pkt->reply		= info->reply;
+
+	if (info->msg && len > 0) {
+		pkt->buf = kmalloc(len, GFP_KERNEL);
+		if (!pkt->buf)
+			goto out_pkt;
+		err = memcpy_from_msg(pkt->buf, info->msg, len);
+		if (err)
+			goto out;
+	}
+
+	trace_virtio_transport_alloc_pkt(src_cid, src_port,
+					 dst_cid, dst_port,
+					 len,
+					 info->type,
+					 info->op,
+					 info->flags);
+
+	return pkt;
+
+out:
+	kfree(pkt->buf);
+out_pkt:
+	kfree(pkt);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_alloc_pkt);
+
+static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
+					  struct virtio_vsock_pkt_info *info)
+{
+	u32 src_cid, src_port, dst_cid, dst_port;
+	struct virtio_vsock_sock *vvs;
+	struct virtio_vsock_pkt *pkt;
+	u32 pkt_len = info->pkt_len;
+
+	src_cid = vm_sockets_get_local_cid();
+	src_port = vsk->local_addr.svm_port;
+	if (!info->remote_cid) {
+		dst_cid	= vsk->remote_addr.svm_cid;
+		dst_port = vsk->remote_addr.svm_port;
+	} else {
+		dst_cid = info->remote_cid;
+		dst_port = info->remote_port;
+	}
+
+	vvs = vsk->trans;
+
+	/* we can send less than pkt_len bytes */
+	if (pkt_len > VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE)
+		pkt_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
+
+	/* virtio_transport_get_credit might return less than pkt_len credit */
+	pkt_len = virtio_transport_get_credit(vvs, pkt_len);
+
+	/* Do not send zero length OP_RW pkt */
+	if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
+		return pkt_len;
+
+	pkt = virtio_transport_alloc_pkt(info, pkt_len,
+					 src_cid, src_port,
+					 dst_cid, dst_port);
+	if (!pkt) {
+		virtio_transport_put_credit(vvs, pkt_len);
+		return -ENOMEM;
+	}
+
+	virtio_transport_inc_tx_pkt(vvs, pkt);
+
+	return virtio_transport_get_ops()->send_pkt(pkt);
+}
+
+static void virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
+					struct virtio_vsock_pkt *pkt)
+{
+	vvs->rx_bytes += pkt->len;
+}
+
+static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
+					struct virtio_vsock_pkt *pkt)
+{
+	vvs->rx_bytes -= pkt->len;
+	vvs->fwd_cnt += pkt->len;
+}
+
+void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt)
+{
+	spin_lock_bh(&vvs->tx_lock);
+	pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
+	pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc);
+	spin_unlock_bh(&vvs->tx_lock);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
+
+u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit)
+{
+	u32 ret;
+
+	spin_lock_bh(&vvs->tx_lock);
+	ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
+	if (ret > credit)
+		ret = credit;
+	vvs->tx_cnt += ret;
+	spin_unlock_bh(&vvs->tx_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_get_credit);
+
+void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit)
+{
+	spin_lock_bh(&vvs->tx_lock);
+	vvs->tx_cnt -= credit;
+	spin_unlock_bh(&vvs->tx_lock);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_put_credit);
+
+static int virtio_transport_send_credit_update(struct vsock_sock *vsk,
+					       int type,
+					       struct virtio_vsock_hdr *hdr)
+{
+	struct virtio_vsock_pkt_info info = {
+		.op = VIRTIO_VSOCK_OP_CREDIT_UPDATE,
+		.type = type,
+	};
+
+	return virtio_transport_send_pkt_info(vsk, &info);
+}
+
+static ssize_t
+virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
+				   struct msghdr *msg,
+				   size_t len)
+{
+	struct virtio_vsock_sock *vvs = vsk->trans;
+	struct virtio_vsock_pkt *pkt;
+	size_t bytes, total = 0;
+	int err = -EFAULT;
+
+	spin_lock_bh(&vvs->rx_lock);
+	while (total < len && !list_empty(&vvs->rx_queue)) {
+		pkt = list_first_entry(&vvs->rx_queue,
+				       struct virtio_vsock_pkt, list);
+
+		bytes = len - total;
+		if (bytes > pkt->len - pkt->off)
+			bytes = pkt->len - pkt->off;
+
+		/* sk_lock is held by caller so no one else can dequeue.
+		 * Unlock rx_lock since memcpy_to_msg() may sleep.
+		 */
+		spin_unlock_bh(&vvs->rx_lock);
+
+		err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes);
+		if (err)
+			goto out;
+
+		spin_lock_bh(&vvs->rx_lock);
+
+		total += bytes;
+		pkt->off += bytes;
+		if (pkt->off == pkt->len) {
+			virtio_transport_dec_rx_pkt(vvs, pkt);
+			list_del(&pkt->list);
+			virtio_transport_free_pkt(pkt);
+		}
+	}
+	spin_unlock_bh(&vvs->rx_lock);
+
+	/* Send a credit pkt to peer */
+	virtio_transport_send_credit_update(vsk, VIRTIO_VSOCK_TYPE_STREAM,
+					    NULL);
+
+	return total;
+
+out:
+	if (total)
+		err = total;
+	return err;
+}
+
+ssize_t
+virtio_transport_stream_dequeue(struct vsock_sock *vsk,
+				struct msghdr *msg,
+				size_t len, int flags)
+{
+	if (flags & MSG_PEEK)
+		return -EOPNOTSUPP;
+
+	return virtio_transport_stream_do_dequeue(vsk, msg, len);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);
+
+int
+virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
+			       struct msghdr *msg,
+			       size_t len, int flags)
+{
+	return -EOPNOTSUPP;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
+
+s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
+{
+	struct virtio_vsock_sock *vvs = vsk->trans;
+	s64 bytes;
+
+	spin_lock_bh(&vvs->rx_lock);
+	bytes = vvs->rx_bytes;
+	spin_unlock_bh(&vvs->rx_lock);
+
+	return bytes;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data);
+
+static s64 virtio_transport_has_space(struct vsock_sock *vsk)
+{
+	struct virtio_vsock_sock *vvs = vsk->trans;
+	s64 bytes;
+
+	bytes = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
+	if (bytes < 0)
+		bytes = 0;
+
+	return bytes;
+}
+
+s64 virtio_transport_stream_has_space(struct vsock_sock *vsk)
+{
+	struct virtio_vsock_sock *vvs = vsk->trans;
+	s64 bytes;
+
+	spin_lock_bh(&vvs->tx_lock);
+	bytes = virtio_transport_has_space(vsk);
+	spin_unlock_bh(&vvs->tx_lock);
+
+	return bytes;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space);
+
+int virtio_transport_do_socket_init(struct vsock_sock *vsk,
+				    struct vsock_sock *psk)
+{
+	struct virtio_vsock_sock *vvs;
+
+	vvs = kzalloc(sizeof(*vvs), GFP_KERNEL);
+	if (!vvs)
+		return -ENOMEM;
+
+	vsk->trans = vvs;
+	vvs->vsk = vsk;
+	if (psk) {
+		struct virtio_vsock_sock *ptrans = psk->trans;
+
+		vvs->buf_size	= ptrans->buf_size;
+		vvs->buf_size_min = ptrans->buf_size_min;
+		vvs->buf_size_max = ptrans->buf_size_max;
+		vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
+	} else {
+		vvs->buf_size = VIRTIO_VSOCK_DEFAULT_BUF_SIZE;
+		vvs->buf_size_min = VIRTIO_VSOCK_DEFAULT_MIN_BUF_SIZE;
+		vvs->buf_size_max = VIRTIO_VSOCK_DEFAULT_MAX_BUF_SIZE;
+	}
+
+	vvs->buf_alloc = vvs->buf_size;
+
+	spin_lock_init(&vvs->rx_lock);
+	spin_lock_init(&vvs->tx_lock);
+	INIT_LIST_HEAD(&vvs->rx_queue);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init);
+
+u64 virtio_transport_get_buffer_size(struct vsock_sock *vsk)
+{
+	struct virtio_vsock_sock *vvs = vsk->trans;
+
+	return vvs->buf_size;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_get_buffer_size);
+
+u64 virtio_transport_get_min_buffer_size(struct vsock_sock *vsk)
+{
+	struct virtio_vsock_sock *vvs = vsk->trans;
+
+	return vvs->buf_size_min;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_get_min_buffer_size);
+
+u64 virtio_transport_get_max_buffer_size(struct vsock_sock *vsk)
+{
+	struct virtio_vsock_sock *vvs = vsk->trans;
+
+	return vvs->buf_size_max;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_get_max_buffer_size);
+
+void virtio_transport_set_buffer_size(struct vsock_sock *vsk, u64 val)
+{
+	struct virtio_vsock_sock *vvs = vsk->trans;
+
+	if (val > VIRTIO_VSOCK_MAX_BUF_SIZE)
+		val = VIRTIO_VSOCK_MAX_BUF_SIZE;
+	if (val < vvs->buf_size_min)
+		vvs->buf_size_min = val;
+	if (val > vvs->buf_size_max)
+		vvs->buf_size_max = val;
+	vvs->buf_size = val;
+	vvs->buf_alloc = val;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_set_buffer_size);
+
+void virtio_transport_set_min_buffer_size(struct vsock_sock *vsk, u64 val)
+{
+	struct virtio_vsock_sock *vvs = vsk->trans;
+
+	if (val > VIRTIO_VSOCK_MAX_BUF_SIZE)
+		val = VIRTIO_VSOCK_MAX_BUF_SIZE;
+	if (val > vvs->buf_size)
+		vvs->buf_size = val;
+	vvs->buf_size_min = val;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_set_min_buffer_size);
+
+void virtio_transport_set_max_buffer_size(struct vsock_sock *vsk, u64 val)
+{
+	struct virtio_vsock_sock *vvs = vsk->trans;
+
+	if (val > VIRTIO_VSOCK_MAX_BUF_SIZE)
+		val = VIRTIO_VSOCK_MAX_BUF_SIZE;
+	if (val < vvs->buf_size)
+		vvs->buf_size = val;
+	vvs->buf_size_max = val;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_set_max_buffer_size);
+
+int
+virtio_transport_notify_poll_in(struct vsock_sock *vsk,
+				size_t target,
+				bool *data_ready_now)
+{
+	if (vsock_stream_has_data(vsk))
+		*data_ready_now = true;
+	else
+		*data_ready_now = false;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in);
+
+int
+virtio_transport_notify_poll_out(struct vsock_sock *vsk,
+				 size_t target,
+				 bool *space_avail_now)
+{
+	s64 free_space;
+
+	free_space = vsock_stream_has_space(vsk);
+	if (free_space > 0)
+		*space_avail_now = true;
+	else if (free_space == 0)
+		*space_avail_now = false;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out);
+
+int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
+	size_t target, struct vsock_transport_recv_notify_data *data)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init);
+
+int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
+	size_t target, struct vsock_transport_recv_notify_data *data)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block);
+
+int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
+	size_t target, struct vsock_transport_recv_notify_data *data)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_dequeue);
+
+int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
+	size_t target, ssize_t copied, bool data_read,
+	struct vsock_transport_recv_notify_data *data)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue);
+
+int virtio_transport_notify_send_init(struct vsock_sock *vsk,
+	struct vsock_transport_send_notify_data *data)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init);
+
+int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
+	struct vsock_transport_send_notify_data *data)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block);
+
+int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
+	struct vsock_transport_send_notify_data *data)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_enqueue);
+
+int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
+	ssize_t written, struct vsock_transport_send_notify_data *data)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue);
+
+u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk)
+{
+	struct virtio_vsock_sock *vvs = vsk->trans;
+
+	return vvs->buf_size;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat);
+
+bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
+{
+	return true;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
+
+bool virtio_transport_stream_allow(u32 cid, u32 port)
+{
+	return true;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
+
+int virtio_transport_dgram_bind(struct vsock_sock *vsk,
+				struct sockaddr_vm *addr)
+{
+	return -EOPNOTSUPP;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
+
+bool virtio_transport_dgram_allow(u32 cid, u32 port)
+{
+	return false;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
+
+int virtio_transport_connect(struct vsock_sock *vsk)
+{
+	struct virtio_vsock_pkt_info info = {
+		.op = VIRTIO_VSOCK_OP_REQUEST,
+		.type = VIRTIO_VSOCK_TYPE_STREAM,
+	};
+
+	return virtio_transport_send_pkt_info(vsk, &info);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_connect);
+
+int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
+{
+	struct virtio_vsock_pkt_info info = {
+		.op = VIRTIO_VSOCK_OP_SHUTDOWN,
+		.type = VIRTIO_VSOCK_TYPE_STREAM,
+		.flags = (mode & RCV_SHUTDOWN ?
+			  VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
+			 (mode & SEND_SHUTDOWN ?
+			  VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
+	};
+
+	return virtio_transport_send_pkt_info(vsk, &info);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_shutdown);
+
+int
+virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
+			       struct sockaddr_vm *remote_addr,
+			       struct msghdr *msg,
+			       size_t dgram_len)
+{
+	return -EOPNOTSUPP;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
+
+ssize_t
+virtio_transport_stream_enqueue(struct vsock_sock *vsk,
+				struct msghdr *msg,
+				size_t len)
+{
+	struct virtio_vsock_pkt_info info = {
+		.op = VIRTIO_VSOCK_OP_RW,
+		.type = VIRTIO_VSOCK_TYPE_STREAM,
+		.msg = msg,
+		.pkt_len = len,
+	};
+
+	return virtio_transport_send_pkt_info(vsk, &info);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue);
+
+void virtio_transport_destruct(struct vsock_sock *vsk)
+{
+	struct virtio_vsock_sock *vvs = vsk->trans;
+
+	kfree(vvs);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_destruct);
+
+static int virtio_transport_reset(struct vsock_sock *vsk,
+				  struct virtio_vsock_pkt *pkt)
+{
+	struct virtio_vsock_pkt_info info = {
+		.op = VIRTIO_VSOCK_OP_RST,
+		.type = VIRTIO_VSOCK_TYPE_STREAM,
+		.reply = !!pkt,
+	};
+
+	/* Send RST only if the original pkt is not a RST pkt */
+	if (pkt && le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
+		return 0;
+
+	return virtio_transport_send_pkt_info(vsk, &info);
+}
+
+/* Normally packets are associated with a socket.  There may be no socket if an
+ * attempt was made to connect to a socket that does not exist.
+ */
+static int virtio_transport_reset_no_sock(struct virtio_vsock_pkt *pkt)
+{
+	struct virtio_vsock_pkt_info info = {
+		.op = VIRTIO_VSOCK_OP_RST,
+		.type = le16_to_cpu(pkt->hdr.type),
+		.reply = true,
+	};
+
+	/* Send RST only if the original pkt is not a RST pkt */
+	if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
+		return 0;
+
+	pkt = virtio_transport_alloc_pkt(&info, 0,
+					 le32_to_cpu(pkt->hdr.dst_cid),
+					 le32_to_cpu(pkt->hdr.dst_port),
+					 le32_to_cpu(pkt->hdr.src_cid),
+					 le32_to_cpu(pkt->hdr.src_port));
+	if (!pkt)
+		return -ENOMEM;
+
+	return virtio_transport_get_ops()->send_pkt(pkt);
+}
+
+static void virtio_transport_wait_close(struct sock *sk, long timeout)
+{
+	if (timeout) {
+		DEFINE_WAIT(wait);
+
+		do {
+			prepare_to_wait(sk_sleep(sk), &wait,
+					TASK_INTERRUPTIBLE);
+			if (sk_wait_event(sk, &timeout,
+					  sock_flag(sk, SOCK_DONE)))
+				break;
+		} while (!signal_pending(current) && timeout);
+
+		finish_wait(sk_sleep(sk), &wait);
+	}
+}
+
+static void virtio_transport_do_close(struct vsock_sock *vsk,
+				      bool cancel_timeout)
+{
+	struct sock *sk = sk_vsock(vsk);
+
+	sock_set_flag(sk, SOCK_DONE);
+	vsk->peer_shutdown = SHUTDOWN_MASK;
+	if (vsock_stream_has_data(vsk) <= 0)
+		sk->sk_state = SS_DISCONNECTING;
+	sk->sk_state_change(sk);
+
+	if (vsk->close_work_scheduled &&
+	    (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
+		vsk->close_work_scheduled = false;
+
+		vsock_remove_sock(vsk);
+
+		/* Release refcnt obtained when we scheduled the timeout */
+		sock_put(sk);
+	}
+}
+
+static void virtio_transport_close_timeout(struct work_struct *work)
+{
+	struct vsock_sock *vsk =
+		container_of(work, struct vsock_sock, close_work.work);
+	struct sock *sk = sk_vsock(vsk);
+
+	sock_hold(sk);
+	lock_sock(sk);
+
+	if (!sock_flag(sk, SOCK_DONE)) {
+		(void)virtio_transport_reset(vsk, NULL);
+
+		virtio_transport_do_close(vsk, false);
+	}
+
+	vsk->close_work_scheduled = false;
+
+	release_sock(sk);
+	sock_put(sk);
+}
+
+/* User context, vsk->sk is locked */
+static bool virtio_transport_close(struct vsock_sock *vsk)
+{
+	struct sock *sk = &vsk->sk;
+
+	if (!(sk->sk_state == SS_CONNECTED ||
+	      sk->sk_state == SS_DISCONNECTING))
+		return true;
+
+	/* Already received SHUTDOWN from peer, reply with RST */
+	if ((vsk->peer_shutdown & SHUTDOWN_MASK) == SHUTDOWN_MASK) {
+		(void)virtio_transport_reset(vsk, NULL);
+		return true;
+	}
+
+	if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
+		(void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
+
+	if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING))
+		virtio_transport_wait_close(sk, sk->sk_lingertime);
+
+	if (sock_flag(sk, SOCK_DONE)) {
+		return true;
+	}
+
+	sock_hold(sk);
+	INIT_DELAYED_WORK(&vsk->close_work,
+			  virtio_transport_close_timeout);
+	vsk->close_work_scheduled = true;
+	schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT);
+	return false;
+}
+
+void virtio_transport_release(struct vsock_sock *vsk)
+{
+	struct sock *sk = &vsk->sk;
+	bool remove_sock = true;
+
+	lock_sock(sk);
+	if (sk->sk_type == SOCK_STREAM)
+		remove_sock = virtio_transport_close(vsk);
+	release_sock(sk);
+
+	if (remove_sock)
+		vsock_remove_sock(vsk);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_release);
+
+static int
+virtio_transport_recv_connecting(struct sock *sk,
+				 struct virtio_vsock_pkt *pkt)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+	int err;
+	int skerr;
+
+	switch (le16_to_cpu(pkt->hdr.op)) {
+	case VIRTIO_VSOCK_OP_RESPONSE:
+		sk->sk_state = SS_CONNECTED;
+		sk->sk_socket->state = SS_CONNECTED;
+		vsock_insert_connected(vsk);
+		sk->sk_state_change(sk);
+		break;
+	case VIRTIO_VSOCK_OP_INVALID:
+		break;
+	case VIRTIO_VSOCK_OP_RST:
+		skerr = ECONNRESET;
+		err = 0;
+		goto destroy;
+	default:
+		skerr = EPROTO;
+		err = -EINVAL;
+		goto destroy;
+	}
+	return 0;
+
+destroy:
+	virtio_transport_reset(vsk, pkt);
+	sk->sk_state = SS_UNCONNECTED;
+	sk->sk_err = skerr;
+	sk->sk_error_report(sk);
+	return err;
+}
+
+static int
+virtio_transport_recv_connected(struct sock *sk,
+				struct virtio_vsock_pkt *pkt)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+	struct virtio_vsock_sock *vvs = vsk->trans;
+	int err = 0;
+
+	switch (le16_to_cpu(pkt->hdr.op)) {
+	case VIRTIO_VSOCK_OP_RW:
+		pkt->len = le32_to_cpu(pkt->hdr.len);
+		pkt->off = 0;
+
+		spin_lock_bh(&vvs->rx_lock);
+		virtio_transport_inc_rx_pkt(vvs, pkt);
+		list_add_tail(&pkt->list, &vvs->rx_queue);
+		spin_unlock_bh(&vvs->rx_lock);
+
+		sk->sk_data_ready(sk);
+		return err;
+	case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
+		sk->sk_write_space(sk);
+		break;
+	case VIRTIO_VSOCK_OP_SHUTDOWN:
+		if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
+			vsk->peer_shutdown |= RCV_SHUTDOWN;
+		if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
+			vsk->peer_shutdown |= SEND_SHUTDOWN;
+		if (vsk->peer_shutdown == SHUTDOWN_MASK &&
+		    vsock_stream_has_data(vsk) <= 0)
+			sk->sk_state = SS_DISCONNECTING;
+		if (le32_to_cpu(pkt->hdr.flags))
+			sk->sk_state_change(sk);
+		break;
+	case VIRTIO_VSOCK_OP_RST:
+		virtio_transport_do_close(vsk, true);
+		break;
+	default:
+		err = -EINVAL;
+		break;
+	}
+
+	virtio_transport_free_pkt(pkt);
+	return err;
+}
+
+static void
+virtio_transport_recv_disconnecting(struct sock *sk,
+				    struct virtio_vsock_pkt *pkt)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
+		virtio_transport_do_close(vsk, true);
+}
+
+static int
+virtio_transport_send_response(struct vsock_sock *vsk,
+			       struct virtio_vsock_pkt *pkt)
+{
+	struct virtio_vsock_pkt_info info = {
+		.op = VIRTIO_VSOCK_OP_RESPONSE,
+		.type = VIRTIO_VSOCK_TYPE_STREAM,
+		.remote_cid = le32_to_cpu(pkt->hdr.src_cid),
+		.remote_port = le32_to_cpu(pkt->hdr.src_port),
+		.reply = true,
+	};
+
+	return virtio_transport_send_pkt_info(vsk, &info);
+}
+
+/* Handle server socket */
+static int
+virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+	struct vsock_sock *vchild;
+	struct sock *child;
+
+	if (le16_to_cpu(pkt->hdr.op) != VIRTIO_VSOCK_OP_REQUEST) {
+		virtio_transport_reset(vsk, pkt);
+		return -EINVAL;
+	}
+
+	if (sk_acceptq_is_full(sk)) {
+		virtio_transport_reset(vsk, pkt);
+		return -ENOMEM;
+	}
+
+	child = __vsock_create(sock_net(sk), NULL, sk, GFP_KERNEL,
+			       sk->sk_type, 0);
+	if (!child) {
+		virtio_transport_reset(vsk, pkt);
+		return -ENOMEM;
+	}
+
+	sk->sk_ack_backlog++;
+
+	lock_sock_nested(child, SINGLE_DEPTH_NESTING);
+
+	child->sk_state = SS_CONNECTED;
+
+	vchild = vsock_sk(child);
+	vsock_addr_init(&vchild->local_addr, le32_to_cpu(pkt->hdr.dst_cid),
+			le32_to_cpu(pkt->hdr.dst_port));
+	vsock_addr_init(&vchild->remote_addr, le32_to_cpu(pkt->hdr.src_cid),
+			le32_to_cpu(pkt->hdr.src_port));
+
+	vsock_insert_connected(vchild);
+	vsock_enqueue_accept(sk, child);
+	virtio_transport_send_response(vchild, pkt);
+
+	release_sock(child);
+
+	sk->sk_data_ready(sk);
+	return 0;
+}
+
+static bool virtio_transport_space_update(struct sock *sk,
+					  struct virtio_vsock_pkt *pkt)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+	struct virtio_vsock_sock *vvs = vsk->trans;
+	bool space_available;
+
+	/* buf_alloc and fwd_cnt is always included in the hdr */
+	spin_lock_bh(&vvs->tx_lock);
+	vvs->peer_buf_alloc = le32_to_cpu(pkt->hdr.buf_alloc);
+	vvs->peer_fwd_cnt = le32_to_cpu(pkt->hdr.fwd_cnt);
+	space_available = virtio_transport_has_space(vsk);
+	spin_unlock_bh(&vvs->tx_lock);
+	return space_available;
+}
+
+/* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
+ * lock.
+ */
+void virtio_transport_recv_pkt(struct virtio_vsock_pkt *pkt)
+{
+	struct sockaddr_vm src, dst;
+	struct vsock_sock *vsk;
+	struct sock *sk;
+	bool space_available;
+
+	vsock_addr_init(&src, le32_to_cpu(pkt->hdr.src_cid),
+			le32_to_cpu(pkt->hdr.src_port));
+	vsock_addr_init(&dst, le32_to_cpu(pkt->hdr.dst_cid),
+			le32_to_cpu(pkt->hdr.dst_port));
+
+	trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
+					dst.svm_cid, dst.svm_port,
+					le32_to_cpu(pkt->hdr.len),
+					le16_to_cpu(pkt->hdr.type),
+					le16_to_cpu(pkt->hdr.op),
+					le32_to_cpu(pkt->hdr.flags),
+					le32_to_cpu(pkt->hdr.buf_alloc),
+					le32_to_cpu(pkt->hdr.fwd_cnt));
+
+	if (le16_to_cpu(pkt->hdr.type) != VIRTIO_VSOCK_TYPE_STREAM) {
+		(void)virtio_transport_reset_no_sock(pkt);
+		goto free_pkt;
+	}
+
+	/* The socket must be in connected or bound table
+	 * otherwise send reset back
+	 */
+	sk = vsock_find_connected_socket(&src, &dst);
+	if (!sk) {
+		sk = vsock_find_bound_socket(&dst);
+		if (!sk) {
+			(void)virtio_transport_reset_no_sock(pkt);
+			goto free_pkt;
+		}
+	}
+
+	vsk = vsock_sk(sk);
+
+	space_available = virtio_transport_space_update(sk, pkt);
+
+	lock_sock(sk);
+
+	/* Update CID in case it has changed after a transport reset event */
+	vsk->local_addr.svm_cid = dst.svm_cid;
+
+	if (space_available)
+		sk->sk_write_space(sk);
+
+	switch (sk->sk_state) {
+	case VSOCK_SS_LISTEN:
+		virtio_transport_recv_listen(sk, pkt);
+		virtio_transport_free_pkt(pkt);
+		break;
+	case SS_CONNECTING:
+		virtio_transport_recv_connecting(sk, pkt);
+		virtio_transport_free_pkt(pkt);
+		break;
+	case SS_CONNECTED:
+		virtio_transport_recv_connected(sk, pkt);
+		break;
+	case SS_DISCONNECTING:
+		virtio_transport_recv_disconnecting(sk, pkt);
+		virtio_transport_free_pkt(pkt);
+		break;
+	default:
+		virtio_transport_free_pkt(pkt);
+		break;
+	}
+	release_sock(sk);
+
+	/* Release refcnt obtained when we fetched this socket out of the
+	 * bound or connected list.
+	 */
+	sock_put(sk);
+	return;
+
+free_pkt:
+	virtio_transport_free_pkt(pkt);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
+
+void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt)
+{
+	kfree(pkt->buf);
+	kfree(pkt);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_free_pkt);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Asias He");
+MODULE_DESCRIPTION("common code for virtio vsock");

net/vmw_vsock/vmci_transport.c

@@ -1644,6 +1644,8 @@ static void vmci_transport_destruct(struct vsock_sock *vsk)
 
 static void vmci_transport_release(struct vsock_sock *vsk)
 {
+	vsock_remove_sock(vsk);
+
 	if (!vmci_handle_is_invalid(vmci_trans(vsk)->dg_handle)) {
 		vmci_datagram_destroy_handle(vmci_trans(vsk)->dg_handle);
 		vmci_trans(vsk)->dg_handle = VMCI_INVALID_HANDLE;