Commit a26b8bd3 authored by Vasilii Ivanov's avatar Vasilii Ivanov Committed by Konrad Sztyber
Browse files

virtio: handle iov split correctly in virtqueue_req_add_iovs 



During copying data to virtqueue descriptors iov can be splitted
between different hugemem pages. Such case require explicit descriptor
and memory translation.

Fixes #3189

Change-Id: I14a4029864ee1e1bf7da0a6f4ff2bb993e0add2b
Signed-off-by: default avatarVasilii Ivanov <ivanov.vas@xinnor.io>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/20634


Community-CI: Mellanox Build Bot
Reviewed-by: default avatarJim Harris <jim.harris@samsung.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
parent e1f15ba5

lib/virtio/virtio.c

+33 −18
Original line number Diff line number Diff line
@@ -395,7 +395,8 @@ virtqueue_req_start(struct virtqueue *vq, void *cookie, int iovcnt) 
{

	struct vq_desc_extra *dxp;



	if (iovcnt > vq->vq_free_cnt) {

	/* Reserve enough entries to handle iov split */

	if (2 * iovcnt > vq->vq_free_cnt) {

		return iovcnt > vq->vq_nentries ? -EINVAL : -ENOMEM;

	}
@@ -470,6 +471,9 @@ virtqueue_req_add_iovs(struct virtqueue *vq, struct iovec *iovs, uint16_t iovcnt 
	struct vring_desc *desc;

	struct vq_desc_extra *dxp;

	uint16_t i, prev_head, new_head;

	uint64_t processed_length, iovec_length, current_length;

	void *current_base;

	uint16_t used_desc_count = 0;



	assert(vq->req_start != VQ_RING_DESC_CHAIN_END);

	assert(iovcnt <= vq->vq_free_cnt);
@@ -481,15 +485,21 @@ virtqueue_req_add_iovs(struct virtqueue *vq, struct iovec *iovs, uint16_t iovcnt 
	prev_head = vq->req_end;

	new_head = vq->vq_desc_head_idx;

	for (i = 0; i < iovcnt; ++i) {

		processed_length = 0;

		iovec_length = iovs[i].iov_len;

		current_base = iovs[i].iov_base;



		while (processed_length < iovec_length) {

			desc = &vq->vq_ring.desc[new_head];

			current_length = iovec_length - processed_length;



			if (!vq->vdev->is_hw) {

			desc->addr  = (uintptr_t)iovs[i].iov_base;

				desc->addr  = (uintptr_t)current_base;

			} else {

			desc->addr = spdk_vtophys(iovs[i].iov_base, NULL);

				desc->addr = spdk_vtophys(current_base, &current_length);

			}



		desc->len = iovs[i].iov_len;

			desc->len = current_length;

			/* always set NEXT flag. unset it on the last descriptor

			 * in the request-ending function.

			 */
@@ -497,14 +507,19 @@ virtqueue_req_add_iovs(struct virtqueue *vq, struct iovec *iovs, uint16_t iovcnt 


			prev_head = new_head;

			new_head = desc->next;

			used_desc_count++;



			processed_length += current_length;

			current_base += current_length;

		}

	}



	dxp = &vq->vq_descx[vq->req_start];

	dxp->ndescs += iovcnt;

	dxp->ndescs += used_desc_count;



	vq->req_end = prev_head;

	vq->vq_desc_head_idx = new_head;

	vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - iovcnt);

	vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - used_desc_count);

	if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END) {

		assert(vq->vq_free_cnt == 0);

		vq->vq_desc_tail_idx = VQ_RING_DESC_CHAIN_END;