[dpdk-dev] [PATCH v6 05/10] vhost: checkout and cleanup the resubmit inflight information

[Yu, Jin]

> -----Original Message-----
> From: Maxime Coquelin [mailto:maxime.coquelin at redhat.com]
> Sent: Monday, September 9, 2019 6:21 PM
> To: Yu, Jin <jin.yu at intel.com>; dev at dpdk.org
> Cc: Liu, Changpeng <changpeng.liu at intel.com>; Bie, Tiwei
> <tiwei.bie at intel.com>; Wang, Zhihong <zhihong.wang at intel.com>; Lin Li
> <lilin24 at baidu.com>; Xun Ni <nixun at baidu.com>; Yu Zhang
> <zhangyu31 at baidu.com>
> Subject: Re: [PATCH v6 05/10] vhost: checkout and cleanup the resubmit inflight
> information
> 
> 
> 
> On 8/29/19 4:12 PM, JinYu wrote:
> > This patch shows how to checkout the inflight ring and construct the
> > resubmit information also include destroying resubmit info.
> >
> > Signed-off-by: Lin Li <lilin24 at baidu.com>
> > Signed-off-by: Xun Ni <nixun at baidu.com>
> > Signed-off-by: Yu Zhang <zhangyu31 at baidu.com>
> > Signed-off-by: Jin Yu <jin.yu at intel.com>
> > ---
> >  lib/librte_vhost/rte_vhost.h  |  19 ++++
> >  lib/librte_vhost/vhost.c      |  29 ++++-
> >  lib/librte_vhost/vhost.h      |   9 ++
> >  lib/librte_vhost/vhost_user.c | 197
> > ++++++++++++++++++++++++++++++++++
> >  4 files changed, 253 insertions(+), 1 deletion(-)
> >
> ...
> > +static int
> > +vhost_check_queue_inflights_packed(struct virtio_net *dev,
> > +						 struct vhost_virtqueue *vq)
> > +{
> > +	uint16_t i = 0;
> > +	uint16_t resubmit_num = 0, old_used_idx, num;
> > +	struct rte_vhost_resubmit_info *resubmit = NULL;
> > +	struct inflight_info_packed *inflight_packed;
> > +
> > +	if (!(dev->protocol_features &
> > +		(1ULL << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)))
> > +		return RTE_VHOST_MSG_RESULT_OK;
> > +
> > +	if (!vq->inflight_packed->version) {
> > +		vq->inflight_packed->version = INFLIGHT_VERSION;
> > +		return RTE_VHOST_MSG_RESULT_OK;
> > +	}
> > +
> > +	if ((!vq->inflight_packed))
> > +		return RTE_VHOST_MSG_RESULT_ERR;
> 
> It needs to be checked before before being dereferenced.
Sorry I don't understand, you means I should check the vq pointer?
> 
> > +
> > +	inflight_packed = vq->inflight_packed;
> > +	vq->resubmit_inflight = NULL;
> > +	vq->global_counter = 0;
> > +	old_used_idx = inflight_packed->old_used_idx;
> > +
> > +	if (inflight_packed->used_idx != old_used_idx) {
> > +		if (inflight_packed->desc[old_used_idx].inflight == 0) {
> > +			inflight_packed->old_used_idx =
> > +				inflight_packed->used_idx;
> > +			inflight_packed->old_used_wrap_counter =
> > +				inflight_packed->used_wrap_counter;
> > +			inflight_packed->old_free_head =
> > +				inflight_packed->free_head;
> > +		} else {
> > +			inflight_packed->used_idx =
> > +				inflight_packed->old_used_idx;
> > +			inflight_packed->used_wrap_counter =
> > +				inflight_packed->old_used_wrap_counter;
> > +			inflight_packed->free_head =
> > +				inflight_packed->old_free_head;
> > +		}
> > +	}
> > +
> > +	for (i = 0; i < inflight_packed->desc_num; i++) {
> > +		if (inflight_packed->desc[i].inflight == 1)
> > +			resubmit_num++;
> > +	}
> > +
> > +	if (resubmit_num) {
> > +		resubmit = calloc(1, sizeof(struct rte_vhost_resubmit_info));
> > +		if (resubmit == NULL) {
> > +			RTE_LOG(ERR, VHOST_CONFIG,
> > +			 "Failed to allocate memory for resubmit info.\n");
> > +			return RTE_VHOST_MSG_RESULT_ERR;
> > +		}
> > +
> > +		resubmit->resubmit_list = calloc(resubmit_num,
> > +			sizeof(struct rte_vhost_resubmit_desc));
> > +		if (resubmit->resubmit_list == NULL) {
> > +			RTE_LOG(ERR, VHOST_CONFIG,
> > +			 "Failed to allocate memory for resubmit desc.\n");
> > +			return RTE_VHOST_MSG_RESULT_ERR;
> > +		}
> > +
> > +		num = 0;
> > +		for (i = 0; i < inflight_packed->desc_num; i++) {
> > +			if (vq->inflight_packed->desc[i].inflight == 1) {
> > +				resubmit->resubmit_list[num].index = i;
> > +				resubmit->resubmit_list[num].counter =
> > +					inflight_packed->desc[i].counter;
> > +				num++;
> > +			}
> > +		}
> > +		resubmit->resubmit_num = num;
> > +
> > +		if (resubmit->resubmit_num > 1)
> > +			qsort(resubmit->resubmit_list, resubmit-
> >resubmit_num,
> > +				sizeof(struct rte_vhost_resubmit_desc),
> > +				resubmit_desc_compare);
> > +
> > +		vq->global_counter = resubmit->resubmit_list[0].counter + 1;
> > +		vq->resubmit_inflight = resubmit;
> > +	}
> > +
> > +	return RTE_VHOST_MSG_RESULT_OK;
> > +}