vhost: avoid backend flush on vring ops

vring changes already do a flush internally where appropriate, so we do
not need a second flush.

It's currently not very expensive but a follow-up patch makes flush more
heavy-weight, so remove the extra flush here to avoid regressing
performance if call or kick fds are changed on data path.

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

1 files changed, 3 insertions, 4 deletions

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 5a3d0f1eaf94..34389f75fe65 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -607,7 +607,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
         return 0;
 }
 
-static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp)
+long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp)
 {
         struct file *eventfp, *filep = NULL;
         bool pollstart = false, pollstop = false;
@@ -802,9 +802,8 @@ static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp)
 }
 
 /* Caller must have device mutex */
-long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, unsigned long arg)
+long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp)
 {
-        void __user *argp = (void __user *)arg;
         struct file *eventfp, *filep = NULL;
         struct eventfd_ctx *ctx = NULL;
         u64 p;
@@ -875,7 +874,7 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, unsigned long arg)
                         fput(filep);
                 break;
         default:
-                r = vhost_set_vring(d, ioctl, argp);
+                r = -ENOIOCTLCMD;
                 break;
         }
 done: