From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id 975198DAF for ; Thu, 14 Jan 2016 09:21:05 +0100 (CET) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP; 14 Jan 2016 00:21:04 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,293,1449561600"; d="scan'208";a="633232351" Received: from yliu-dev.sh.intel.com (HELO yliu-dev) ([10.239.66.49]) by FMSMGA003.fm.intel.com with ESMTP; 14 Jan 2016 00:21:03 -0800 Date: Thu, 14 Jan 2016 16:22:21 +0800 From: Yuanhan Liu To: "Xie, Huawei" Message-ID: <20160114082221.GO19531@yliu-dev.sh.intel.com> References: <1449719650-3482-1-git-send-email-yuanhan.liu@linux.intel.com> <1452581944-24838-1-git-send-email-yuanhan.liu@linux.intel.com> <1452581944-24838-8-git-send-email-yuanhan.liu@linux.intel.com> <20160114075040.GM19531@yliu-dev.sh.intel.com> <20160114075859.GN19531@yliu-dev.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Cc: "dev@dpdk.org" , "Michael S. Tsirkin" Subject: Re: [dpdk-dev] [PATCH v2 7/7] virtio: add 1.0 support 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: Thu, 14 Jan 2016 08:21:06 -0000 On Thu, Jan 14, 2016 at 08:08:28AM +0000, Xie, Huawei wrote: > On 1/14/2016 3:58 PM, Yuanhan Liu wrote: > > On Thu, Jan 14, 2016 at 07:51:08AM +0000, Xie, Huawei wrote: > >> On 1/14/2016 3:49 PM, Yuanhan Liu wrote: > >>> On Thu, Jan 14, 2016 at 07:47:17AM +0000, Xie, Huawei wrote: > >>>> On 1/12/2016 2:58 PM, Yuanhan Liu wrote: > >>>>> Modern (v1.0) virtio pci device defines several pci capabilities. > >>>> [snip] > >>>>> +static void > >>>>> +modern_notify_queue(struct virtio_hw *hw __rte_unused, struct virtqueue *vq) > >>>>> +{ > >>>>> + modern_write16(1, vq->notify_addr); > >>>>> +} > >>>> Does virtio 1.0 only supports MMIO? MMIO has long VMEXIT latency than > >>>> PORT IO. > >>> Virtio 1.0 supports three transport layer, including MMIO and PCI. And > >>> we use PCI only in our pmd driver. > >> I don't mean that MMIO but use memory mapped IO for configuration. > > Then, yes. > > 00:03.0 Ethernet controller: Red Hat, Inc Virtio network device > Subsystem: Red Hat, Inc Device 0001 > Physical Slot: 3 > Flags: bus master, fast devsel, latency 0, IRQ 10 > I/O ports at c100 [size=32] > Memory at febd1000 (32-bit, non-prefetchable) [size=4K] > Memory at fe000000 (64-bit, prefetchable) [size=8M] > Expansion ROM at feb40000 [disabled] [size=256K] > Capabilities: [98] MSI-X: Enable+ Count=3 Masked- > Capabilities: [84] Vendor Specific Information: Len=14 > Capabilities: [70] Vendor Specific Information: Len=14 > Capabilities: [60] Vendor Specific Information: Len=10 > Capabilities: [50] Vendor Specific Information: Len=10 > Capabilities: [40] Vendor Specific Information: Len=10 > Kernel driver in use: igb_uio > Kernel modules: virtio_pci > > c100 is still there. Yes, > For the notification, try PORT IO if possible. But it doesn't seem right to me to mix legacy registers in modern pci device. --yliu