tcm_vhost: Add ioctl to get and set events missed flag

Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2 files changed, 20 insertions, 0 deletions

diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c
index 5340fd759c6e..07217d818ad7 100644
--- a/drivers/vhost/tcm_vhost.c
+++ b/drivers/vhost/tcm_vhost.c
@@ -1200,8 +1200,11 @@ 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:
@@ -1222,6 +1225,20 @@ 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 a545a5b766a3..514b9fda230e 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)