From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f175.google.com (mail-io0-f175.google.com [209.85.223.175]) by dpdk.org (Postfix) with ESMTP id B1DA88DA7 for ; Fri, 2 Oct 2015 04:33:16 +0200 (CEST) Received: by ioiz6 with SMTP id z6so106679590ioi.2 for ; Thu, 01 Oct 2015 19:33:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:to:references:cc:from:message-id:date:user-agent :mime-version:in-reply-to:content-type:content-transfer-encoding; bh=wdEqVq5K0ZruQo9CVX0xwpt+yEM+WSJwfkEv7JzFoZc=; b=gVXf2rWsFolDEXictfqQ+AtDYZHNmA/bsj6AYSgU7RbDeZgwbLLBJQhouOsNhMjRvS OxPVMKjlTTDjwTShBjvzFKZlp8veaNos7YVCq175xJsQvDkACK83DxVED/+RAbhJj6Fv imlg0mvzcrVbVwsymWPcNwxyhEWziS5aj7FBSUb8X2TLRNbM+nOwpgpUHGTIGSNKVW3M FFxS9KczptRAguntnFfQP0XRB6xrvJAcKZtfjlenoVx8KDI320VUyBa0flRPLqAY7vUv vjkreZo9JPFcuH2/J8TzrC1BRhWl0n1Ps2+CW0S5lVuyB4qNkj86I1ykzJUQgpkYTDhg mbQw== X-Received: by 10.107.160.143 with SMTP id j137mr15066855ioe.13.1443753196069; Thu, 01 Oct 2015 19:33:16 -0700 (PDT) Received: from [192.168.1.188] (static-50-53-21-5.bvtn.or.frontiernet.net. [50.53.21.5]) by smtp.googlemail.com with ESMTPSA id 21sm4123874ioo.16.2015.10.01.19.33.14 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 01 Oct 2015 19:33:15 -0700 (PDT) To: Stephen Hemminger References: <1443652138-31782-1-git-send-email-stephen@networkplumber.org> <1443652138-31782-3-git-send-email-stephen@networkplumber.org> <560DC45A.3050507@gmail.com> <20151001170452.0e6a90c2@urahara> From: Alexander Duyck Message-ID: <560DECE9.8020408@gmail.com> Date: Thu, 1 Oct 2015 19:33:13 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <20151001170452.0e6a90c2@urahara> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: dev@dpdk.org, hjk@hansjkoch.de, gregkh@linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [dpdk-dev] [PATCH 2/2] uio: new driver to support PCI MSI-X 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, 02 Oct 2015 02:33:17 -0000 On 10/01/2015 05:04 PM, Stephen Hemminger wrote: > On Thu, 1 Oct 2015 16:40:10 -0700 > Alexander Duyck wrote: > >> Do you really need to map IORESOURCE bars? Most drivers I can think of >> don't use IO BARs anymore. Maybe we could look at just dropping the >> code and adding it back later if we have a use case that absolutely >> needs it. > Mapping is not strictly necessary, but for virtio it acts a way to communicate > the regions. I think I see what you are saying. I was hoping we could get away from having to map any I/O ports but it looks like virtio is still using them for BAR 0, or at least that is what I am seeing on my VM with virtio_net. I was really hoping we could get away from that since a 16b address space is far too restrictive anyway. >> Also how many devices actually need resources beyond BAR 0? I'm just >> curious as I know BAR 2 on many of the Intel devices is the register >> space related to MSI-X so now we have both the PCIe subsystem and user >> space with access to this region. > VMXNet3 needs 2 bars. Most use only one. So essentially we are needing to make exceptions for the virtual interfaces. I guess there isn't much we can do then and we probably need to map any and all base address registers we can find for the given device. I was hoping for something a bit more surgical since we are opening a security hole of sorts, but I guess it can't be helped if we want to support multiple devices and they all have such radically different configurations. - Alex