diff options
| -rw-r--r-- | drivers/vhost/vhost.c | 18 | ||||
| -rw-r--r-- | drivers/vhost/vhost.h | 8 |
2 files changed, 19 insertions, 7 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 1f80eac5d6ae..60c9ebd629dd 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1600,17 +1600,25 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg r = -EFAULT; break; } - if (s.num > 0xffff) { - r = -EINVAL; - break; + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) { + vq->last_avail_idx = s.num & 0xffff; + vq->last_used_idx = (s.num >> 16) & 0xffff; + } else { + if (s.num > 0xffff) { + r = -EINVAL; + break; + } + vq->last_avail_idx = s.num; } - vq->last_avail_idx = s.num; /* Forget the cached index value. */ vq->avail_idx = vq->last_avail_idx; break; case VHOST_GET_VRING_BASE: s.index = idx; - s.num = vq->last_avail_idx; + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) + s.num = (u32)vq->last_avail_idx | ((u32)vq->last_used_idx << 16); + else + s.num = vq->last_avail_idx; if (copy_to_user(argp, &s, sizeof s)) r = -EFAULT; break; diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 305ec8593d46..fc900be504b3 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -92,13 +92,17 @@ struct vhost_virtqueue { /* The routine to call when the Guest pings us, or timeout. */ vhost_work_fn_t handle_kick; - /* Last available index we saw. */ + /* Last available index we saw. + * Values are limited to 0x7fff, and the high bit is used as + * a wrap counter when using VIRTIO_F_RING_PACKED. */ u16 last_avail_idx; /* Caches available index value from user. */ u16 avail_idx; - /* Last index we used. */ + /* Last index we used. + * Values are limited to 0x7fff, and the high bit is used as + * a wrap counter when using VIRTIO_F_RING_PACKED. */ u16 last_used_idx; /* Used flags */ |