From 935cdee7ee159569b0aaa10bd9244660f6672b08 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 6 Dec 2012 14:03:34 +0200 Subject: [PATCH] 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 --- drivers/vhost/net.c | 7 +++++-- drivers/vhost/tcm_vhost.c | 5 ++++- drivers/vhost/vhost.c | 7 +++---- drivers/vhost/vhost.h | 3 ++- 4 files changed, 14 insertions(+), 8 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index ff6c91995c9..1802ab66208 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -942,8 +942,11 @@ static long vhost_net_ioctl(struct file *f, unsigned int ioctl, return vhost_net_reset_owner(n); default: mutex_lock(&n->dev.mutex); - r = vhost_dev_ioctl(&n->dev, ioctl, arg); - vhost_net_flush(n); + r = vhost_dev_ioctl(&n->dev, ioctl, argp); + if (r == -ENOIOCTLCMD) + r = vhost_vring_ioctl(&n->dev, ioctl, argp); + else + vhost_net_flush(n); mutex_unlock(&n->dev.mutex); return r; } diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c index ef888448243..33e5f90dfcf 100644 --- a/drivers/vhost/tcm_vhost.c +++ b/drivers/vhost/tcm_vhost.c @@ -970,7 +970,10 @@ static long vhost_scsi_ioctl(struct file *f, unsigned int ioctl, return vhost_scsi_set_features(vs, features); default: mutex_lock(&vs->dev.mutex); - r = vhost_dev_ioctl(&vs->dev, ioctl, arg); + r = vhost_dev_ioctl(&vs->dev, ioctl, argp); + /* TODO: flush backend after dev ioctl. */ + if (r == -ENOIOCTLCMD) + r = vhost_vring_ioctl(&vs->dev, ioctl, argp); mutex_unlock(&vs->dev.mutex); return r; } diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 5a3d0f1eaf9..34389f75fe6 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: diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 5e19e3d5db8..2639c58b23a 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -164,7 +164,8 @@ long vhost_dev_check_owner(struct vhost_dev *); long vhost_dev_reset_owner(struct vhost_dev *); 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, unsigned long arg); +long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); +long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp); int vhost_vq_access_ok(struct vhost_virtqueue *vq); int vhost_log_access_ok(struct vhost_dev *); -- 2.43.2