From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753003AbdKHF3I (ORCPT ); Wed, 8 Nov 2017 00:29:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58254 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750951AbdKHF3H (ORCPT ); Wed, 8 Nov 2017 00:29:07 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com C785E5F7AC Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=jasowang@redhat.com Subject: Re: [PATCH net-next V2 3/3] tun: add eBPF based queue selection method To: Willem de Bruijn Cc: Network Development , LKML , "Michael S. Tsirkin" , Tom Herbert References: <1509445938-4345-1-git-send-email-jasowang@redhat.com> <1509445938-4345-4-git-send-email-jasowang@redhat.com> From: Jason Wang Message-ID: <1e5256e3-72cf-fa6b-b00e-2661e29291b1@redhat.com> Date: Wed, 8 Nov 2017 14:28:53 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 08 Nov 2017 05:29:06 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017年11月04日 08:56, Willem de Bruijn wrote: > On Fri, Nov 3, 2017 at 5:56 PM, Willem de Bruijn > wrote: >> On Tue, Oct 31, 2017 at 7:32 PM, Jason Wang wrote: >>> This patch introduces an eBPF based queue selection method based on >>> the flow steering policy ops. Userspace could load an eBPF program >>> through TUNSETSTEERINGEBPF. This gives much more flexibility compare >>> to simple but hard coded policy in kernel. >>> >>> Signed-off-by: Jason Wang >>> --- >>> +static int tun_set_steering_ebpf(struct tun_struct *tun, void __user *data) >>> +{ >>> + struct bpf_prog *prog; >>> + u32 fd; >>> + >>> + if (copy_from_user(&fd, data, sizeof(fd))) >>> + return -EFAULT; >>> + >>> + prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); >> If the idea is to allow guests to pass BPF programs down to the host, >> you may want to define a new program type that is more restrictive than >> socket filter. >> >> The external functions allowed for socket filters (sk_filter_func_proto) >> are relatively few (compared to, say, clsact), but may still leak host >> information to a guest. More importantly, guest security considerations >> limits how we can extend socket filters later. > Unless the idea is for the hypervisor to prepared the BPF based on a > limited set of well defined modes that the guest can configure. Then > socket filters are fine, as the BPF is prepared by a regular host process. Yes, I think the idea is to let qemu to build a BPF program now. Passing eBPF program from guest to host is interesting, but an obvious issue is how to deal with the accessing of map. Thanks