From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by dpdk.org (Postfix) with ESMTP id 8E1438D8B for ; Fri, 16 Oct 2015 09:49:10 +0200 (CEST) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga103.jf.intel.com with ESMTP; 16 Oct 2015 00:49:09 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,687,1437462000"; d="scan'208";a="581976687" Received: from yliu-dev.sh.intel.com (HELO yliu-dev) ([10.239.66.49]) by FMSMGA003.fm.intel.com with ESMTP; 16 Oct 2015 00:49:08 -0700 Date: Fri, 16 Oct 2015 15:50:28 +0800 From: Yuanhan Liu To: Andriy Berestovskyy Message-ID: <20151016075028.GL3115@yliu-dev.sh.intel.com> References: <1444907319-26348-1-git-send-email-marcel@redhat.com> <20151015161150-mutt-send-email-mst@redhat.com> <20151016022438.GH3115@yliu-dev.sh.intel.com> <20151016091327-mutt-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Cc: Marcel Apfelbaum , dev@dpdk.org, "Michael S. Tsirkin" Subject: Re: [dpdk-dev] [PATCH] vhost-user: enable virtio 1.0 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 16 Oct 2015 07:49:11 -0000 On Fri, Oct 16, 2015 at 09:43:09AM +0200, Andriy Berestovskyy wrote: > Hi guys, > Just a minor note: ARM is bi-endian in fact. Thank you for clarifying that my old memory is right :) --yliu > For instance, there are > both endians tool chains available on Linaro. > > Andriy > > > On Fri, Oct 16, 2015 at 8:20 AM, Michael S. Tsirkin wrote: > > On Fri, Oct 16, 2015 at 10:24:38AM +0800, Yuanhan Liu wrote: > >> On Thu, Oct 15, 2015 at 04:18:59PM +0300, Michael S. Tsirkin wrote: > >> > On Thu, Oct 15, 2015 at 02:08:39PM +0300, Marcel Apfelbaum wrote: > >> > > Make vhost-user virtio 1.0 compatible by adding it to the > >> > > supported features and keeping the header length > >> > > the same as for mergeable RX buffers. > >> > > > >> > > Signed-off-by: Marcel Apfelbaum > >> > >> Marcel, that's actually one of my TODOs in this quarter. So, thank > >> you! :) > >> > >> > > >> > Looks good to me > >> > > >> > Acked-by: Michael S. Tsirkin > >> > > >> > Just one question: dpdk is only supported on little-endian > >> > platforms at the moment, right? > >> > >> AFAIK, yes. But you might also see that there are some patch to add > >> ARM arch support showed up in the mailing list few weeks ago. > > > > Luckily, that's also little-endian. > > > >> > virtio 1 spec requires little endian. > >> > >> I made a quick list of the difference between virtio v0.95 and v1.0 > >> months ago just by reading your kernel commits of adding v1.0 support: > >> > >> +-------------------+-----------------+------------------------------+ > >> | | v0.95 | v1.0 | > >> +-------------------+-----------------+------------------------------+ > >> 1) | features bits | 32 | 64 | > >> +-------------------+-----------------+------------------------------+ > >> 2) | Endianness | nature | Little Endian | > >> +-------------------+-----------------+------------------------------+ > >> 3) | vring space | contiguous | avail and used buffer could | > >> | | memory | be on a separate memory | > > > > And desc buffer, too. > > > >> +-------------------+-----------------+------------------------------+ > >> 4) | FEATURE_OK status | No | Yes | > >> +-------------------+-----------------+------------------------------+ > >> > >> > >> > >> For 1), I guess we have been using 64 bit for storing features bits > >> for vhost since long time ago. So, there should be no extra effort. > >> > >> For 2), as stated, there might be no issue as far as DPDK is little > >> endian only. But we'd better add a wrapper for that, as it seems > >> adding big endian support would come in near future. > > > > OK, but it probably doesn't > > > >> For 3), are we actually doing that? I just saw that there is a kernel > >> patch to introduce two functions for getting the avail and used buffer > >> address, respectively. But I didn't see that the two buffer are > >> allocated in non-contiguous memory. > > > > That will soon happen, anyone claiming support for virtio 1 > > > > But vhost user already sends each ring part separately. > > Does dpdk assume they are contigious? > > > >> For 4), it's a work we should do at virtio PMD driver. And it seems > >> that there are far more work need to be done at virtio PDM driver than > >> at vhost lib, say, adding the virtio morden PCI support. > >> > >> Besides those 4 differs, did I miss anyting? > > > > > > From virtio PMD point of view? There are more > > differences. The trick is to find "legacy interface" > > sections and go over them, that compares 0.9 to 1.0. > > > >> > >> BTW, since we already have same TODOs, I guess it'd be better to > >> share what we have in our TODO list. Here are what I got till the > >> time writing this email (in order of priority): > >> > >> - a vhost performance issue (it might last long; it might not). > >> > >> - vhost-user live migration support > >> > >> - virtio 1.0 support, including PMD and vhost lib (and you guys have > >> already done that :) > >> > >> Thanks. > > > > This patch only touches the vhost lib, though. > > > >> --yliu > >> > >> > >> > > --- > >> > > > >> > > To be applied on top of: > >> > > [dpdk-dev] [PATCH v6 00/13] vhost-user multiple queues enabling > >> > > > >> > > Thanks, > >> > > Marcel > >> > > > >> > > lib/librte_vhost/virtio-net.c | 15 ++++++++------- > >> > > 1 file changed, 8 insertions(+), 7 deletions(-) > >> > > > >> > > diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c > >> > > index a51327d..ee4650e 100644 > >> > > --- a/lib/librte_vhost/virtio-net.c > >> > > +++ b/lib/librte_vhost/virtio-net.c > >> > > @@ -75,6 +75,7 @@ static struct virtio_net_config_ll *ll_root; > >> > > (1ULL << VIRTIO_NET_F_CTRL_VQ) | \ > >> > > (1ULL << VIRTIO_NET_F_CTRL_RX) | \ > >> > > (1ULL << VIRTIO_NET_F_MQ) | \ > >> > > + (1ULL << VIRTIO_F_VERSION_1) | \ > >> > > (1ULL << VHOST_F_LOG_ALL) | \ > >> > > (1ULL << VHOST_USER_F_PROTOCOL_FEATURES)) > >> > > static uint64_t VHOST_FEATURES = VHOST_SUPPORTED_FEATURES; > >> > > @@ -477,17 +478,17 @@ set_features(struct vhost_device_ctx ctx, uint64_t *pu) > >> > > return -1; > >> > > > >> > > dev->features = *pu; > >> > > - if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF)) { > >> > > - LOG_DEBUG(VHOST_CONFIG, > >> > > - "(%"PRIu64") Mergeable RX buffers enabled\n", > >> > > - dev->device_fh); > >> > > + if (dev->features & > >> > > + ((1 << VIRTIO_NET_F_MRG_RXBUF) | (1ULL << VIRTIO_F_VERSION_1))) { > >> > > vhost_hlen = sizeof(struct virtio_net_hdr_mrg_rxbuf); > >> > > } else { > >> > > - LOG_DEBUG(VHOST_CONFIG, > >> > > - "(%"PRIu64") Mergeable RX buffers disabled\n", > >> > > - dev->device_fh); > >> > > vhost_hlen = sizeof(struct virtio_net_hdr); > >> > > } > >> > > + LOG_DEBUG(VHOST_CONFIG, > >> > > + "(%"PRIu64") Mergeable RX buffers %s, virtio 1 %s\n", > >> > > + dev->device_fh, > >> > > + (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ? "on" : "off", > >> > > + (dev->features & (1ULL << VIRTIO_F_VERSION_1)) ? "on" : "off"); > >> > > > >> > > for (i = 0; i < dev->virt_qp_nb; i++) { > >> > > uint16_t base_idx = i * VIRTIO_QNUM; > >> > > -- > >> > > 2.1.0 > > > > -- > Andriy Berestovskyy