From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.droids-corp.org (zoll.droids-corp.org [94.23.50.67]) by dpdk.org (Postfix) with ESMTP id 0C232A499; Mon, 22 Jan 2018 11:39:06 +0100 (CET) Received: from lfbn-lil-1-110-231.w90-45.abo.wanadoo.fr ([90.45.197.231] helo=droids-corp.org) by mail.droids-corp.org with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1edZVK-0006Sg-5l; Mon, 22 Jan 2018 11:39:07 +0100 Received: by droids-corp.org (sSMTP sendmail emulation); Mon, 22 Jan 2018 11:38:58 +0100 Date: Mon, 22 Jan 2018 11:38:58 +0100 From: Olivier Matz To: Tiwei Bie Cc: dev@dpdk.org, Yuanhan Liu , Maxime Coquelin , stable@dpdk.org Message-ID: <20180122103858.n76gdigdmqeiwlik@platinum> References: <20180118090733.12728-1-olivier.matz@6wind.com> <20180119155556.32597-1-olivier.matz@6wind.com> <20180119155556.32597-2-olivier.matz@6wind.com> <20180122025641.t4vgozvbjbms3edn@debian-xvivbkq.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180122025641.t4vgozvbjbms3edn@debian-xvivbkq.sh.intel.com> User-Agent: NeoMutt/20170113 (1.7.2) Subject: Re: [dpdk-stable] [PATCH v2 1/4] net/virtio: fix queue flushing with vector Rx enabled X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Jan 2018 10:39:06 -0000 On Mon, Jan 22, 2018 at 10:56:41AM +0800, Tiwei Bie wrote: > On Fri, Jan 19, 2018 at 04:55:53PM +0100, Olivier Matz wrote: > > When using vector Rx mode (use_simple_rx = 1), vq->vq_descx[] is not > > kept up to date. To properly detach the mbufs in this case, browse > > sw_ring[] instead, as it's done in virtqueue_rxvq_flush(). > > > > Since we need virtio_get_queue_type(), also move this function in > > virtqueue.h as a static inline. > > > > Fixes: fc3d66212fed ("virtio: add vector Rx") > > Cc: stable@dpdk.org > > > > Signed-off-by: Olivier Matz > > --- > > > > Tiwei, > > > > While it passes my test plan, please carefully check that what I did in > > virtqueue_detatch_unused() is correct. I tried to reproduce what is done > > in virtqueue_rxvq_flush(), but I may be mistaking due to the different > > ring layout assumption and mbuf management between standard and vector. > > > > Thanks > > Olivier > > > > > > drivers/net/virtio/virtio_ethdev.c | 11 ----------- > > drivers/net/virtio/virtqueue.c | 17 +++++++++++++++-- > > drivers/net/virtio/virtqueue.h | 11 +++++++++++ > > 3 files changed, 26 insertions(+), 13 deletions(-) > > > [...] > > struct rte_mbuf * > > virtqueue_detatch_unused(struct virtqueue *vq) > > { > > + struct virtio_hw *hw = vq->hw; > > struct rte_mbuf *cookie; > > int idx; > > + int type = virtio_get_queue_type(hw, vq->vq_queue_index); > > + > > + if (vq == NULL) > > + return NULL; > > > > - if (vq != NULL) > > - for (idx = 0; idx < vq->vq_nentries; idx++) { > > + for (idx = 0; idx < vq->vq_nentries; idx++) { > > + if (hw->use_simple_rx && type == VTNET_RQ) { > > + cookie = vq->sw_ring[idx]; > > + if (cookie != NULL) { > > + vq->sw_ring[idx] = NULL; > > Thanks for working on this! > > The vq->sw_ring[idx] isn't zeroed during Rx. So besides the > check of (cookie != NULL), some other check is also needed > to avoid freeing the mbufs already delivered to application. > > The mbufs in below interval belong to application: > > start: sw_ring[vq->vq_avail_idx & (vq->vq_nentries - 1)] (included) > end: sw_ring[(vq->vq_avail_idx + vq->vq_free_cnt) & (vq->vq_nentries - 1)] (excluded) > > PS. (vq->vq_avail_idx & (vq->vq_nentries - 1)) can be greater than > (vq->vq_avail_idx + vq->vq_free_cnt) & (vq->vq_nentries - 1). Thank you for the review. What about something like this? struct rte_mbuf * virtqueue_detach_unused(struct virtqueue *vq) { struct rte_mbuf *cookie; struct virtio_hw *hw; uint16_t start, end; int type, idx; if (vq == NULL) return NULL; hw = vq->hw; type = virtio_get_queue_type(hw, vq->vq_queue_index); start = vq->vq_avail_idx & (vq->vq_nentries - 1); end = (vq->vq_avail_idx + vq->vq_free_cnt) & (vq->vq_nentries - 1); end = (vq->vq_avail_idx + vq->vq_free_cnt) & (vq->vq_nentries - 1); for (idx = 0; idx < vq->vq_nentries; idx++) { if (hw->use_simple_rx && type == VTNET_RQ) { if (start <= end && idx >= start && idx < end) continue; if (start > end && (idx >= start || idx < end)) continue; cookie = vq->sw_ring[idx]; if (cookie == NULL) continue; vq->sw_ring[idx] = NULL; return cookie; } else { cookie = vq->vq_descx[idx].cookie; if (cookie != NULL) { vq->vq_descx[idx].cookie = NULL; return cookie; } } } return NULL; } Regards, Olivier