Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull vhost fixes and cleanups from Michael S Tsirkin:
 "This includes some fixes and cleanups for vhost net and scsi drivers"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost/test: update test after vhost cleanups
  vhost: Make local function static
  vhost: Make vhost a separate module
  vhost-scsi: Rename struct tcm_vhost_cmd *tv_cmd to *cmd
  vhost-scsi: Rename struct tcm_vhost_tpg *tv_tpg to *tpg
  vhost-scsi: Make func indention more consistent
  vhost-scsi: Rename struct vhost_scsi *s to *vs
  vhost-scsi: Remove unnecessary forward struct vhost_scsi declaration
  vhost: Simplify dev->vqs[i] access
  vhost-net: fix use-after-free in vhost_net_flush

drivers/vhost/Kconfig

 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
@@ -13,6 +14,7 @@ config VHOST_NET
 config VHOST_SCSI
 	tristate "VHOST_SCSI TCM fabric driver"
 	depends on TARGET_CORE && EVENTFD && m
+	select VHOST
 	select VHOST_RING
 	default n
 	---help---
@@ -24,3 +26,9 @@ config VHOST_RING
 	---help---
 	  This option is selected by any driver which needs to access
 	  the host side of a virtio ring.
+
+config VHOST
+	tristate
+	---help---
+	  This option is selected by any driver which needs to access
+	  the core of vhost.

drivers/vhost/Makefile

 obj-$(CONFIG_VHOST_NET) += vhost_net.o
-vhost_net-y := vhost.o net.o
+vhost_net-y := net.o
 
 obj-$(CONFIG_VHOST_SCSI) += vhost_scsi.o
 vhost_scsi-y := scsi.o
 
 obj-$(CONFIG_VHOST_RING) += vringh.o
+obj-$(CONFIG_VHOST)	+= vhost.o

drivers/vhost/net.c

@@ -168,7 +168,7 @@ static void vhost_net_clear_ubuf_info(struct vhost_net *n)
 	}
 }
 
-int vhost_net_set_ubuf_info(struct vhost_net *n)
+static int vhost_net_set_ubuf_info(struct vhost_net *n)
 {
 	bool zcopy;
 	int i;
@@ -189,7 +189,7 @@ int vhost_net_set_ubuf_info(struct vhost_net *n)
 	return -ENOMEM;
 }
 
-void vhost_net_vq_reset(struct vhost_net *n)
+static void vhost_net_vq_reset(struct vhost_net *n)
 {
 	int i;
 

drivers/vhost/test.c

@@ -18,7 +18,7 @@
 #include <linux/slab.h>
 
 #include "test.h"
-#include "vhost.c"
+#include "vhost.h"
 
 /* Max number of bytes transferred before requeueing the job.
  * Using this limit prevents one virtqueue from starving others. */
@@ -38,17 +38,19 @@ struct vhost_test {
  * read-size critical section for our kind of RCU. */
 static void handle_vq(struct vhost_test *n)
 {
-	struct vhost_virtqueue *vq = &n->dev.vqs[VHOST_TEST_VQ];
+	struct vhost_virtqueue *vq = &n->vqs[VHOST_TEST_VQ];
 	unsigned out, in;
 	int head;
 	size_t len, total_len = 0;
 	void *private;
 
-	private = rcu_dereference_check(vq->private_data, 1);
-	if (!private)
+	mutex_lock(&vq->mutex);
+	private = vq->private_data;
+	if (!private) {
+		mutex_unlock(&vq->mutex);
 		return;
+	}
 
-	mutex_lock(&vq->mutex);
 	vhost_disable_notify(&n->dev, vq);
 
 	for (;;) {
@@ -102,15 +104,23 @@ static int vhost_test_open(struct inode *inode, struct file *f)
 {
 	struct vhost_test *n = kmalloc(sizeof *n, GFP_KERNEL);
 	struct vhost_dev *dev;
+	struct vhost_virtqueue **vqs;
 	int r;
 
 	if (!n)
 		return -ENOMEM;
+	vqs = kmalloc(VHOST_TEST_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
+	if (!vqs) {
+		kfree(n);
+		return -ENOMEM;
+	}
 
 	dev = &n->dev;
+	vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ];
 	n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;
-	r = vhost_dev_init(dev, n->vqs, VHOST_TEST_VQ_MAX);
+	r = vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX);
 	if (r < 0) {
+		kfree(vqs);
 		kfree(n);
 		return r;
 	}
@@ -126,9 +136,8 @@ static void *vhost_test_stop_vq(struct vhost_test *n,
 	void *private;
 
 	mutex_lock(&vq->mutex);
-	private = rcu_dereference_protected(vq->private_data,
-					 lockdep_is_held(&vq->mutex));
-	rcu_assign_pointer(vq->private_data, NULL);
+	private = vq->private_data;
+	vq->private_data = NULL;
 	mutex_unlock(&vq->mutex);
 	return private;
 }
@@ -140,7 +149,7 @@ static void vhost_test_stop(struct vhost_test *n, void **privatep)
 
 static void vhost_test_flush_vq(struct vhost_test *n, int index)
 {
-	vhost_poll_flush(&n->dev.vqs[index].poll);
+	vhost_poll_flush(&n->vqs[index].poll);
 }
 
 static void vhost_test_flush(struct vhost_test *n)
@@ -268,14 +277,14 @@ static long vhost_test_ioctl(struct file *f, unsigned int ioctl,
 			return -EFAULT;
 		return vhost_test_run(n, test);
 	case VHOST_GET_FEATURES:
-		features = VHOST_NET_FEATURES;
+		features = VHOST_FEATURES;
 		if (copy_to_user(featurep, &features, sizeof features))
 			return -EFAULT;
 		return 0;
 	case VHOST_SET_FEATURES:
 		if (copy_from_user(&features, featurep, sizeof features))
 			return -EFAULT;
-		if (features & ~VHOST_NET_FEATURES)
+		if (features & ~VHOST_FEATURES)
 			return -EOPNOTSUPP;
 		return vhost_test_set_features(n, features);
 	case VHOST_RESET_OWNER:

drivers/vhost/vhost.c

@@ -25,6 +25,7 @@
 #include <linux/slab.h>
 #include <linux/kthread.h>
 #include <linux/cgroup.h>
+#include <linux/module.h>
 
 #include "vhost.h"
 
@@ -66,6 +67,7 @@ void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn)
 	work->flushing = 0;
 	work->queue_seq = work->done_seq = 0;
 }
+EXPORT_SYMBOL_GPL(vhost_work_init);
 
 /* Init poll structure */
 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
@@ -79,6 +81,7 @@ void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
 
 	vhost_work_init(&poll->work, fn);
 }
+EXPORT_SYMBOL_GPL(vhost_poll_init);
 
 /* Start polling a file. We add ourselves to file's wait queue. The caller must
  * keep a reference to a file until after vhost_poll_stop is called. */
@@ -101,6 +104,7 @@ int vhost_poll_start(struct vhost_poll *poll, struct file *file)
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(vhost_poll_start);
 
 /* Stop polling a file. After this function returns, it becomes safe to drop the
  * file reference. You must also flush afterwards. */
@@ -111,6 +115,7 @@ void vhost_poll_stop(struct vhost_poll *poll)
 		poll->wqh = NULL;
 	}
 }
+EXPORT_SYMBOL_GPL(vhost_poll_stop);
 
 static bool vhost_work_seq_done(struct vhost_dev *dev, struct vhost_work *work,
 				unsigned seq)
@@ -123,7 +128,7 @@ static bool vhost_work_seq_done(struct vhost_dev *dev, struct vhost_work *work,
 	return left <= 0;
 }
 
-static void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work)
+void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work)
 {
 	unsigned seq;
 	int flushing;
@@ -138,6 +143,7 @@ static void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work)
 	spin_unlock_irq(&dev->work_lock);
 	BUG_ON(flushing < 0);
 }
+EXPORT_SYMBOL_GPL(vhost_work_flush);
 
 /* Flush any work that has been scheduled. When calling this, don't hold any
  * locks that are also used by the callback. */
@@ -145,6 +151,7 @@ void vhost_poll_flush(struct vhost_poll *poll)
 {
 	vhost_work_flush(poll->dev, &poll->work);
 }
+EXPORT_SYMBOL_GPL(vhost_poll_flush);
 
 void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work)
 {
@@ -158,11 +165,13 @@ void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work)
 	}
 	spin_unlock_irqrestore(&dev->work_lock, flags);
 }
+EXPORT_SYMBOL_GPL(vhost_work_queue);
 
 void vhost_poll_queue(struct vhost_poll *poll)
 {
 	vhost_work_queue(poll->dev, &poll->work);
 }
+EXPORT_SYMBOL_GPL(vhost_poll_queue);
 
 static void vhost_vq_reset(struct vhost_dev *dev,
 			   struct vhost_virtqueue *vq)
@@ -251,17 +260,16 @@ static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq)
 /* Helper to allocate iovec buffers for all vqs. */
 static long vhost_dev_alloc_iovecs(struct vhost_dev *dev)
 {
+	struct vhost_virtqueue *vq;
 	int i;
 
 	for (i = 0; i < dev->nvqs; ++i) {
-		dev->vqs[i]->indirect = kmalloc(sizeof *dev->vqs[i]->indirect *
-					       UIO_MAXIOV, GFP_KERNEL);
-		dev->vqs[i]->log = kmalloc(sizeof *dev->vqs[i]->log * UIO_MAXIOV,
-					  GFP_KERNEL);
-		dev->vqs[i]->heads = kmalloc(sizeof *dev->vqs[i]->heads *
-					    UIO_MAXIOV, GFP_KERNEL);
-		if (!dev->vqs[i]->indirect || !dev->vqs[i]->log ||
-			!dev->vqs[i]->heads)
+		vq = dev->vqs[i];
+		vq->indirect = kmalloc(sizeof *vq->indirect * UIO_MAXIOV,
+				       GFP_KERNEL);
+		vq->log = kmalloc(sizeof *vq->log * UIO_MAXIOV, GFP_KERNEL);
+		vq->heads = kmalloc(sizeof *vq->heads * UIO_MAXIOV, GFP_KERNEL);
+		if (!vq->indirect || !vq->log || !vq->heads)
 			goto err_nomem;
 	}
 	return 0;
@@ -283,6 +291,7 @@ static void vhost_dev_free_iovecs(struct vhost_dev *dev)
 long vhost_dev_init(struct vhost_dev *dev,
 		    struct vhost_virtqueue **vqs, int nvqs)
 {
+	struct vhost_virtqueue *vq;
 	int i;
 
 	dev->vqs = vqs;
@@ -297,19 +306,21 @@ long vhost_dev_init(struct vhost_dev *dev,
 	dev->worker = NULL;
 
 	for (i = 0; i < dev->nvqs; ++i) {
-		dev->vqs[i]->log = NULL;
-		dev->vqs[i]->indirect = NULL;
-		dev->vqs[i]->heads = NULL;
-		dev->vqs[i]->dev = dev;
-		mutex_init(&dev->vqs[i]->mutex);
-		vhost_vq_reset(dev, dev->vqs[i]);
-		if (dev->vqs[i]->handle_kick)
-			vhost_poll_init(&dev->vqs[i]->poll,
-					dev->vqs[i]->handle_kick, POLLIN, dev);
+		vq = dev->vqs[i];
+		vq->log = NULL;
+		vq->indirect = NULL;
+		vq->heads = NULL;
+		vq->dev = dev;
+		mutex_init(&vq->mutex);
+		vhost_vq_reset(dev, vq);
+		if (vq->handle_kick)
+			vhost_poll_init(&vq->poll, vq->handle_kick,
+					POLLIN, dev);
 	}
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(vhost_dev_init);
 
 /* Caller should have device mutex */
 long vhost_dev_check_owner(struct vhost_dev *dev)
@@ -317,6 +328,7 @@ long vhost_dev_check_owner(struct vhost_dev *dev)
 	/* Are you the owner? If not, I don't think you mean to do that */
 	return dev->mm == current->mm ? 0 : -EPERM;
 }
+EXPORT_SYMBOL_GPL(vhost_dev_check_owner);
 
 struct vhost_attach_cgroups_struct {
 	struct vhost_work work;
@@ -348,6 +360,7 @@ bool vhost_dev_has_owner(struct vhost_dev *dev)
 {
 	return dev->mm;
 }
+EXPORT_SYMBOL_GPL(vhost_dev_has_owner);
 
 /* Caller should have device mutex */
 long vhost_dev_set_owner(struct vhost_dev *dev)
@@ -391,11 +404,13 @@ long vhost_dev_set_owner(struct vhost_dev *dev)
 err_mm:
 	return err;
 }
+EXPORT_SYMBOL_GPL(vhost_dev_set_owner);
 
 struct vhost_memory *vhost_dev_reset_owner_prepare(void)
 {
 	return kmalloc(offsetof(struct vhost_memory, regions), GFP_KERNEL);
 }
+EXPORT_SYMBOL_GPL(vhost_dev_reset_owner_prepare);
 
 /* Caller should have device mutex */
 void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_memory *memory)
@@ -406,6 +421,7 @@ void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_memory *memory)
 	memory->nregions = 0;
 	RCU_INIT_POINTER(dev->memory, memory);
 }
+EXPORT_SYMBOL_GPL(vhost_dev_reset_owner);
 
 void vhost_dev_stop(struct vhost_dev *dev)
 {
@@ -418,6 +434,7 @@ void vhost_dev_stop(struct vhost_dev *dev)
 		}
 	}
 }
+EXPORT_SYMBOL_GPL(vhost_dev_stop);
 
 /* Caller should have device mutex if and only if locked is set */
 void vhost_dev_cleanup(struct vhost_dev *dev, bool locked)
@@ -458,6 +475,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev, bool locked)
 		mmput(dev->mm);
 	dev->mm = NULL;
 }
+EXPORT_SYMBOL_GPL(vhost_dev_cleanup);
 
 static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz)
 {
@@ -543,6 +561,7 @@ int vhost_log_access_ok(struct vhost_dev *dev)
 				       lockdep_is_held(&dev->mutex));
 	return memory_access_ok(dev, mp, 1);
 }
+EXPORT_SYMBOL_GPL(vhost_log_access_ok);
 
 /* Verify access for write logging. */
 /* Caller should have vq mutex and device mutex */
@@ -568,6 +587,7 @@ int vhost_vq_access_ok(struct vhost_virtqueue *vq)
 	return vq_access_ok(vq->dev, vq->num, vq->desc, vq->avail, vq->used) &&
 		vq_log_access_ok(vq->dev, vq, vq->log_base);
 }
+EXPORT_SYMBOL_GPL(vhost_vq_access_ok);
 
 static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
 {
@@ -797,6 +817,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp)
 		vhost_poll_flush(&vq->poll);
 	return r;
 }
+EXPORT_SYMBOL_GPL(vhost_vring_ioctl);
 
 /* Caller must have device mutex */
 long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp)
@@ -877,6 +898,7 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp)
 done:
 	return r;
 }
+EXPORT_SYMBOL_GPL(vhost_dev_ioctl);
 
 static const struct vhost_memory_region *find_region(struct vhost_memory *mem,
 						     __u64 addr, __u32 len)
@@ -968,6 +990,7 @@ int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
 	BUG();
 	return 0;
 }
+EXPORT_SYMBOL_GPL(vhost_log_write);
 
 static int vhost_update_used_flags(struct vhost_virtqueue *vq)
 {
@@ -1019,6 +1042,7 @@ int vhost_init_used(struct vhost_virtqueue *vq)
 	vq->signalled_used_valid = false;
 	return get_user(vq->last_used_idx, &vq->used->idx);
 }
+EXPORT_SYMBOL_GPL(vhost_init_used);
 
 static int translate_desc(struct vhost_dev *dev, u64 addr, u32 len,
 			  struct iovec iov[], int iov_size)
@@ -1295,12 +1319,14 @@ int vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq,
 	BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY));
 	return head;
 }
+EXPORT_SYMBOL_GPL(vhost_get_vq_desc);
 
 /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */
 void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n)
 {
 	vq->last_avail_idx -= n;
 }
+EXPORT_SYMBOL_GPL(vhost_discard_vq_desc);
 
 /* After we've used one of their buffers, we tell them about it.  We'll then
  * want to notify the guest, using eventfd. */
@@ -1349,6 +1375,7 @@ int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len)
 		vq->signalled_used_valid = false;
 	return 0;
 }
+EXPORT_SYMBOL_GPL(vhost_add_used);
 
 static int __vhost_add_used_n(struct vhost_virtqueue *vq,
 			    struct vring_used_elem *heads,
@@ -1418,6 +1445,7 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads,
 	}
 	return r;
 }
+EXPORT_SYMBOL_GPL(vhost_add_used_n);
 
 static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 {
@@ -1462,6 +1490,7 @@ void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 	if (vq->call_ctx && vhost_notify(dev, vq))
 		eventfd_signal(vq->call_ctx, 1);
 }
+EXPORT_SYMBOL_GPL(vhost_signal);
 
 /* And here's the combo meal deal.  Supersize me! */
 void vhost_add_used_and_signal(struct vhost_dev *dev,
@@ -1471,6 +1500,7 @@ void vhost_add_used_and_signal(struct vhost_dev *dev,
 	vhost_add_used(vq, head, len);
 	vhost_signal(dev, vq);
 }
+EXPORT_SYMBOL_GPL(vhost_add_used_and_signal);
 
 /* multi-buffer version of vhost_add_used_and_signal */
 void vhost_add_used_and_signal_n(struct vhost_dev *dev,
@@ -1480,6 +1510,7 @@ void vhost_add_used_and_signal_n(struct vhost_dev *dev,
 	vhost_add_used_n(vq, heads, count);
 	vhost_signal(dev, vq);
 }
+EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n);
 
 /* OK, now we need to know about added descriptors. */
 bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
@@ -1517,6 +1548,7 @@ bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 
 	return avail_idx != vq->avail_idx;
 }
+EXPORT_SYMBOL_GPL(vhost_enable_notify);
 
 /* We don't need to be notified again. */
 void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
@@ -1533,3 +1565,21 @@ void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 			       &vq->used->flags, r);
 	}
 }
+EXPORT_SYMBOL_GPL(vhost_disable_notify);
+
+static int __init vhost_init(void)
+{
+	return 0;
+}
+
+static void __exit vhost_exit(void)
+{
+}
+
+module_init(vhost_init);
+module_exit(vhost_exit);
+
+MODULE_VERSION("0.0.1");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Michael S. Tsirkin");
+MODULE_DESCRIPTION("Host kernel accelerator for virtio");

drivers/vhost/vhost.h

@@ -46,6 +46,8 @@ int vhost_poll_start(struct vhost_poll *poll, struct file *file);
 void vhost_poll_stop(struct vhost_poll *poll);
 void vhost_poll_flush(struct vhost_poll *poll);
 void vhost_poll_queue(struct vhost_poll *poll);
+void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
+long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
 
 struct vhost_log {
 	u64 addr;