VHOST_MEMORY_F_LOG = 0x1,
};
+static unsigned vhost_zcopy_mask __read_mostly;
+
#define vhost_used_event(vq) ((u16 __user *)&vq->avail->ring[vq->num])
#define vhost_avail_event(vq) ((u16 __user *)&vq->used->ring[vq->num])
vq->call_ctx = NULL;
vq->call = NULL;
vq->log_ctx = NULL;
+ vq->upend_idx = 0;
+ vq->done_idx = 0;
+ vq->ubufs = NULL;
}
static int vhost_worker(void *data)
if (work) {
__set_current_state(TASK_RUNNING);
work->fn(work);
+ if (need_resched())
+ schedule();
} else
schedule();
return 0;
}
+static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq)
+{
+ kfree(vq->indirect);
+ vq->indirect = NULL;
+ kfree(vq->log);
+ vq->log = NULL;
+ kfree(vq->heads);
+ vq->heads = NULL;
+ kfree(vq->ubuf_info);
+ vq->ubuf_info = NULL;
+}
+
+void vhost_enable_zcopy(int vq)
+{
+ vhost_zcopy_mask |= 0x1 << vq;
+}
+
/* Helper to allocate iovec buffers for all vqs. */
static long vhost_dev_alloc_iovecs(struct vhost_dev *dev)
{
int i;
+ bool zcopy;
for (i = 0; i < dev->nvqs; ++i) {
dev->vqs[i].indirect = kmalloc(sizeof *dev->vqs[i].indirect *
GFP_KERNEL);
dev->vqs[i].heads = kmalloc(sizeof *dev->vqs[i].heads *
UIO_MAXIOV, GFP_KERNEL);
-
+ zcopy = vhost_zcopy_mask & (0x1 << i);
+ if (zcopy)
+ dev->vqs[i].ubuf_info =
+ kmalloc(sizeof *dev->vqs[i].ubuf_info *
+ UIO_MAXIOV, GFP_KERNEL);
if (!dev->vqs[i].indirect || !dev->vqs[i].log ||
- !dev->vqs[i].heads)
+ !dev->vqs[i].heads ||
+ (zcopy && !dev->vqs[i].ubuf_info))
goto err_nomem;
}
return 0;
err_nomem:
- for (; i >= 0; --i) {
- kfree(dev->vqs[i].indirect);
- kfree(dev->vqs[i].log);
- kfree(dev->vqs[i].heads);
- }
+ for (; i >= 0; --i)
+ vhost_vq_free_iovecs(&dev->vqs[i]);
return -ENOMEM;
}
{
int i;
- for (i = 0; i < dev->nvqs; ++i) {
- kfree(dev->vqs[i].indirect);
- dev->vqs[i].indirect = NULL;
- kfree(dev->vqs[i].log);
- dev->vqs[i].log = NULL;
- kfree(dev->vqs[i].heads);
- dev->vqs[i].heads = NULL;
- }
+ for (i = 0; i < dev->nvqs; ++i)
+ vhost_vq_free_iovecs(&dev->vqs[i]);
}
long vhost_dev_init(struct vhost_dev *dev,
dev->vqs[i].log = NULL;
dev->vqs[i].indirect = NULL;
dev->vqs[i].heads = NULL;
+ dev->vqs[i].ubuf_info = NULL;
dev->vqs[i].dev = dev;
mutex_init(&dev->vqs[i].mutex);
vhost_vq_reset(dev, dev->vqs + i);
return 0;
}
+/* In case of DMA done not in order in lower device driver for some reason.
+ * upend_idx is used to track end of used idx, done_idx is used to track head
+ * of used idx. Once lower device DMA done contiguously, we will signal KVM
+ * guest used idx.
+ */
+int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq)
+{
+ int i;
+ int j = 0;
+
+ for (i = vq->done_idx; i != vq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
+ if ((vq->heads[i].len == VHOST_DMA_DONE_LEN)) {
+ vq->heads[i].len = VHOST_DMA_CLEAR_LEN;
+ vhost_add_used_and_signal(vq->dev, vq,
+ vq->heads[i].id, 0);
+ ++j;
+ } else
+ break;
+ }
+ if (j)
+ vq->done_idx = i;
+ return j;
+}
+
/* Caller should have device mutex */
void vhost_dev_cleanup(struct vhost_dev *dev)
{
vhost_poll_stop(&dev->vqs[i].poll);
vhost_poll_flush(&dev->vqs[i].poll);
}
+ /* Wait for all lower device DMAs done. */
+ if (dev->vqs[i].ubufs)
+ vhost_ubuf_put_and_wait(dev->vqs[i].ubufs);
+
+ /* Signal guest as appropriate. */
+ vhost_zerocopy_signal_used(&dev->vqs[i]);
+
if (dev->vqs[i].error_ctx)
eventfd_ctx_put(dev->vqs[i].error_ctx);
if (dev->vqs[i].error)
return 0;
}
-static int init_used(struct vhost_virtqueue *vq,
- struct vring_used __user *used)
-{
- int r = put_user(vq->used_flags, &used->flags);
-
- if (r)
- return r;
- vq->signalled_used_valid = false;
- return get_user(vq->last_used_idx, &used->idx);
-}
-
static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp)
{
struct file *eventfp, *filep = NULL,
}
}
- r = init_used(vq, (struct vring_used __user *)(unsigned long)
- a.used_user_addr);
- if (r)
- break;
vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG));
vq->desc = (void __user *)(unsigned long)a.desc_user_addr;
vq->avail = (void __user *)(unsigned long)a.avail_user_addr;
return 0;
}
+static int vhost_update_used_flags(struct vhost_virtqueue *vq)
+{
+ void __user *used;
+ if (__put_user(vq->used_flags, &vq->used->flags) < 0)
+ return -EFAULT;
+ if (unlikely(vq->log_used)) {
+ /* Make sure the flag is seen before log. */
+ smp_wmb();
+ /* Log used flag write. */
+ used = &vq->used->flags;
+ log_write(vq->log_base, vq->log_addr +
+ (used - (void __user *)vq->used),
+ sizeof vq->used->flags);
+ if (vq->log_ctx)
+ eventfd_signal(vq->log_ctx, 1);
+ }
+ return 0;
+}
+
+static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event)
+{
+ if (__put_user(vq->avail_idx, vhost_avail_event(vq)))
+ return -EFAULT;
+ if (unlikely(vq->log_used)) {
+ void __user *used;
+ /* Make sure the event is seen before log. */
+ smp_wmb();
+ /* Log avail event write */
+ used = vhost_avail_event(vq);
+ log_write(vq->log_base, vq->log_addr +
+ (used - (void __user *)vq->used),
+ sizeof *vhost_avail_event(vq));
+ if (vq->log_ctx)
+ eventfd_signal(vq->log_ctx, 1);
+ }
+ return 0;
+}
+
+int vhost_init_used(struct vhost_virtqueue *vq)
+{
+ int r;
+ if (!vq->private_data)
+ return 0;
+
+ r = vhost_update_used_flags(vq);
+ if (r)
+ return r;
+ vq->signalled_used_valid = false;
+ return get_user(vq->last_used_idx, &vq->used->idx);
+}
+
static int translate_desc(struct vhost_dev *dev, u64 addr, u32 len,
struct iovec iov[], int iov_size)
{
return false;
vq->used_flags &= ~VRING_USED_F_NO_NOTIFY;
if (!vhost_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
- r = put_user(vq->used_flags, &vq->used->flags);
+ r = vhost_update_used_flags(vq);
if (r) {
vq_err(vq, "Failed to enable notification at %p: %d\n",
&vq->used->flags, r);
return false;
}
} else {
- r = put_user(vq->avail_idx, vhost_avail_event(vq));
+ r = vhost_update_avail_event(vq, vq->avail_idx);
if (r) {
vq_err(vq, "Failed to update avail event index at %p: %d\n",
vhost_avail_event(vq), r);
return false;
}
}
- if (unlikely(vq->log_used)) {
- void __user *used;
- /* Make sure data is seen before log. */
- smp_wmb();
- used = vhost_has_feature(dev, VIRTIO_RING_F_EVENT_IDX) ?
- &vq->used->flags : vhost_avail_event(vq);
- /* Log used flags or event index entry write. Both are 16 bit
- * fields. */
- log_write(vq->log_base, vq->log_addr +
- (used - (void __user *)vq->used),
- sizeof(u16));
- if (vq->log_ctx)
- eventfd_signal(vq->log_ctx, 1);
- }
/* They could have slipped one in as we were doing that: make
* sure it's written, then check again. */
smp_mb();
return;
vq->used_flags |= VRING_USED_F_NO_NOTIFY;
if (!vhost_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
- r = put_user(vq->used_flags, &vq->used->flags);
+ r = vhost_update_used_flags(vq);
if (r)
vq_err(vq, "Failed to enable notification at %p: %d\n",
&vq->used->flags, r);
}
}
+
+static void vhost_zerocopy_done_signal(struct kref *kref)
+{
+ struct vhost_ubuf_ref *ubufs = container_of(kref, struct vhost_ubuf_ref,
+ kref);
+ wake_up(&ubufs->wait);
+}
+
+struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *vq,
+ bool zcopy)
+{
+ struct vhost_ubuf_ref *ubufs;
+ /* No zero copy backend? Nothing to count. */
+ if (!zcopy)
+ return NULL;
+ ubufs = kmalloc(sizeof *ubufs, GFP_KERNEL);
+ if (!ubufs)
+ return ERR_PTR(-ENOMEM);
+ kref_init(&ubufs->kref);
+ init_waitqueue_head(&ubufs->wait);
+ ubufs->vq = vq;
+ return ubufs;
+}
+
+void vhost_ubuf_put(struct vhost_ubuf_ref *ubufs)
+{
+ kref_put(&ubufs->kref, vhost_zerocopy_done_signal);
+}
+
+void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *ubufs)
+{
+ kref_put(&ubufs->kref, vhost_zerocopy_done_signal);
+ wait_event(ubufs->wait, !atomic_read(&ubufs->kref.refcount));
+ kfree(ubufs);
+}
+
+void vhost_zerocopy_callback(void *arg)
+{
+ struct ubuf_info *ubuf = arg;
+ struct vhost_ubuf_ref *ubufs = ubuf->arg;
+ struct vhost_virtqueue *vq = ubufs->vq;
+
+ /* set len = 1 to mark this desc buffers done DMA */
+ vq->heads[ubuf->desc].len = VHOST_DMA_DONE_LEN;
+ kref_put(&ubufs->kref, vhost_zerocopy_done_signal);
+}
git.openpandora.org / pandora-kernel.git / blobdiff