Re: [PATCH v9 3/3] tcm_vhost: Add ioctl to get and set events missed flag

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Apr 25, 2013 at 11:10:06AM +0800, Asias He wrote:
> Signed-off-by: Asias He <asias@redhat.com>

Please merge with patch 2 so we can use feature flag to
know whether ioctl is supported.

> ---
>  drivers/vhost/tcm_vhost.c | 17 +++++++++++++++++
>  drivers/vhost/tcm_vhost.h |  3 +++
>  2 files changed, 20 insertions(+)
> 
> diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c
> index 137ae34..9c01d2a 100644
> --- a/drivers/vhost/tcm_vhost.c
> +++ b/drivers/vhost/tcm_vhost.c
> @@ -1202,8 +1202,11 @@ static long vhost_scsi_ioctl(struct file *f, unsigned int ioctl,
>  	struct vhost_scsi_target backend;
>  	void __user *argp = (void __user *)arg;
>  	u64 __user *featurep = argp;
> +	u32 __user *eventsp = argp;
> +	u32 events_missed;
>  	u64 features;
>  	int r, abi_version = VHOST_SCSI_ABI_VERSION;
> +	struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT];
>  
>  	switch (ioctl) {
>  	case VHOST_SCSI_SET_ENDPOINT:
> @@ -1224,6 +1227,20 @@ static long vhost_scsi_ioctl(struct file *f, unsigned int ioctl,
>  		if (copy_to_user(argp, &abi_version, sizeof abi_version))
>  			return -EFAULT;
>  		return 0;
> +	case VHOST_SCSI_SET_EVENTS_MISSED:
> +		if (get_user(events_missed, eventsp))
> +			return -EFAULT;
> +		mutex_lock(&vq->mutex);
> +		vs->vs_events_missed = events_missed;
> +		mutex_unlock(&vq->mutex);
> +		return 0;
> +	case VHOST_SCSI_GET_EVENTS_MISSED:
> +		mutex_lock(&vq->mutex);
> +		events_missed = vs->vs_events_missed;
> +		mutex_unlock(&vq->mutex);
> +		if (put_user(events_missed, eventsp))
> +			return -EFAULT;
> +		return 0;
>  	case VHOST_GET_FEATURES:
>  		features = VHOST_SCSI_FEATURES;
>  		if (copy_to_user(featurep, &features, sizeof features))
> diff --git a/drivers/vhost/tcm_vhost.h b/drivers/vhost/tcm_vhost.h
> index a545a5b..514b9fd 100644
> --- a/drivers/vhost/tcm_vhost.h
> +++ b/drivers/vhost/tcm_vhost.h
> @@ -123,3 +123,6 @@ struct vhost_scsi_target {
>  #define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
>  /* Changing this breaks userspace. */
>  #define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
> +/* Set and get the events missed flag */
> +#define VHOST_SCSI_SET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x43, __u32)
> +#define VHOST_SCSI_GET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x44, __u32)
> -- 
> 1.8.1.4