vhost: Make vhost a separate module

Currently, vhost-net and vhost-scsi are sharing the vhost core code.
However, vhost-scsi shares the code by including the vhost.c file
directly.

Making vhost a separate module makes it is easier to share code with
other vhost devices.

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

6 files changed, 63 insertions, 4 deletions

diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig
index 8b9226da3f54..017a1e8a8f6f 100644
--- a/drivers/vhost/Kconfig
+++ b/drivers/vhost/Kconfig
@@ -1,6 +1,7 @@
 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.
diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile
index 654e9afb11f5..e0441c34db1c 100644
--- a/drivers/vhost/Makefile
+++ b/drivers/vhost/Makefile
@@ -1,7 +1,8 @@
 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
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 03765e17c154..5531ebcc7276 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -49,7 +49,6 @@
 #include <linux/llist.h>
 #include <linux/bitmap.h>
 
-#include "vhost.c"
 #include "vhost.h"
 
 #define TCM_VHOST_VERSION  "v0.1"
diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c
index 1ee45bc85f67..9b71a577f7bd 100644
--- a/drivers/vhost/test.c
+++ b/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. */
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 4d135b1a861e..e58cf0001cee 100644
--- a/drivers/vhost/vhost.c
+++ b/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)
@@ -311,6 +320,7 @@ long vhost_dev_init(struct vhost_dev *dev,
 
         return 0;
 }
+EXPORT_SYMBOL_GPL(vhost_dev_init);
 
 /* Caller should have device mutex */
 long vhost_dev_check_owner(struct vhost_dev *dev)
@@ -318,6 +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;
@@ -349,6 +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)
@@ -392,11 +404,13 @@ err_worker:
 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)
@@ -407,6 +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)
 {
@@ -419,6 +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)
@@ -459,6 +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)
 {
@@ -544,6 +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 */
@@ -569,6 +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)
 {
@@ -798,6 +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)
@@ -878,6 +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)
@@ -969,6 +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)
 {
@@ -1020,6 +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)
@@ -1296,12 +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. */
@@ -1350,6 +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,
@@ -1419,6 +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)
 {
@@ -1463,6 +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,
@@ -1472,6 +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,
@@ -1481,6 +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)
@@ -1518,6 +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)
@@ -1534,3 +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");
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 64adcf99ff33..42298cd23c73 100644
--- a/drivers/vhost/vhost.h
+++ b/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;