Commit 8bd15fa1 authored by Dariusz Stojaczyk's avatar Dariusz Stojaczyk Committed by Jim Harris
Browse files

rte_virtio: check against descriptor table overflow 



Don't allow enqueueing a request when not
enough free descriptors are available.

While here, also clarify some other
vq_desc_tail_idx code.

Change-Id: Ibcec2e31b2f609f2fd71f2426ce1a91728ed82f6
Signed-off-by: default avatarDariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/378154


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
parent 3459b5a9

lib/bdev/virtio/rte_virtio/virtio_rxtx.c

+10 −2
Original line number Diff line number Diff line
@@ -139,6 +139,12 @@ virtqueue_enqueue_xmit(struct virtqueue *vq, struct virtio_req *req) 
	uint32_t total_iovs = req->iovcnt + 2;

	struct iovec *iov = req->iov;



	if (total_iovs > vq->vq_free_cnt) {

		PMD_DRV_LOG(ERR, "not enough free descriptors. requested %"PRIu32", got %"PRIu32"\n",

			total_iovs, vq->vq_free_cnt);

		return;

	}



	head_idx = vq->vq_desc_head_idx;

	idx = head_idx;

	dxp = &vq->vq_descx[idx];
@@ -175,8 +181,10 @@ virtqueue_enqueue_xmit(struct virtqueue *vq, struct virtio_req *req) 
	}



	vq->vq_desc_head_idx = idx;

	if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)

		vq->vq_desc_tail_idx = idx;

	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;

	}

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

	vq_update_avail_ring(vq, head_idx);

}

lib/bdev/virtio/rte_virtio/virtqueue.h

+6 −0
Original line number Diff line number Diff line
@@ -97,6 +97,12 @@ struct virtqueue { 
	 * VQ_RING_DESC_CHAIN_END.

	 */

	uint16_t  vq_desc_head_idx;



	/**

	 * Tail of the free chain in desc table. If

	 * there are no free descriptors, this will be set to

	 * VQ_RING_DESC_CHAIN_END.

	 */

	uint16_t  vq_desc_tail_idx;

	uint16_t  vq_queue_index;   /**< PCI queue index */

	uint16_t  *notify_addr;