From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yuanhan Liu Subject: Re: [PATCH] lib/librte_vhost: remove redundant logic judgement Date: Wed, 27 Dec 2017 22:29:19 +0800 Message-ID: <20171227142919.GG8818@yliu-mob> References: <20171225091617.60387-1-zhiyong.yang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: dev@dpdk.org, maxime.coquelin@redhat.com To: Zhiyong Yang Return-path: Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com [66.111.4.26]) by dpdk.org (Postfix) with ESMTP id 2E30A1B265 for ; Wed, 27 Dec 2017 15:29:24 +0100 (CET) Content-Disposition: inline In-Reply-To: <20171225091617.60387-1-zhiyong.yang@intel.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Mon, Dec 25, 2017 at 05:16:17PM +0800, Zhiyong Yang wrote: > At the beginning of vring_translate, the code > if(!(dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))) already judges > if IOMMU_PLATFORM is supported. The function vhost_iova_to_vva always > repeats the logic, __vhost_iova_to_vva can be used directly to avoid it > here. > > Signed-off-by: Zhiyong Yang > --- > lib/librte_vhost/vhost.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c > index 4f8b73a09..bb615fd2a 100644 > --- a/lib/librte_vhost/vhost.c > +++ b/lib/librte_vhost/vhost.c > @@ -157,7 +157,7 @@ vring_translate(struct virtio_net *dev, struct vhost_virtqueue *vq) > goto out; > > size = sizeof(struct vring_desc) * vq->size; > - vq->desc = (struct vring_desc *)(uintptr_t)vhost_iova_to_vva(dev, vq, > + vq->desc = (struct vring_desc *)(uintptr_t)__vhost_iova_to_vva(dev, vq, > vq->ring_addrs.desc_user_addr, > size, VHOST_ACCESS_RW); I don't see strong reason to bother doing the change. It's not in the datapath after all. I'd like to keep the code as it is, to keep it simpler: user just has to call vhost_iova_to_vva() and let it to handle the details. --yliu > if (!vq->desc) > @@ -165,7 +165,8 @@ vring_translate(struct virtio_net *dev, struct vhost_virtqueue *vq) > > size = sizeof(struct vring_avail); > size += sizeof(uint16_t) * vq->size; > - vq->avail = (struct vring_avail *)(uintptr_t)vhost_iova_to_vva(dev, vq, > + vq->avail = (struct vring_avail *)(uintptr_t)__vhost_iova_to_vva(dev, > + vq, > vq->ring_addrs.avail_user_addr, > size, VHOST_ACCESS_RW); > if (!vq->avail) > @@ -173,7 +174,7 @@ vring_translate(struct virtio_net *dev, struct vhost_virtqueue *vq) > > size = sizeof(struct vring_used); > size += sizeof(struct vring_used_elem) * vq->size; > - vq->used = (struct vring_used *)(uintptr_t)vhost_iova_to_vva(dev, vq, > + vq->used = (struct vring_used *)(uintptr_t)__vhost_iova_to_vva(dev, vq, > vq->ring_addrs.used_user_addr, > size, VHOST_ACCESS_RW); > if (!vq->used) > -- > 2.13.3