From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932633AbcHKJRm (ORCPT ); Thu, 11 Aug 2016 05:17:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43228 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752425AbcHKJQm (ORCPT ); Thu, 11 Aug 2016 05:16:42 -0400 From: Vitaly Kuznetsov To: KY Srinivasan Cc: "devel\@linuxdriverproject.org" , "linux-kernel\@vger.kernel.org" , "Haiyang Zhang" Subject: Re: [PATCH 0/2] Drivers: hv: vmbus: make bus ids in sysfs persistent References: <1470732379-5013-1-git-send-email-vkuznets@redhat.com> Date: Thu, 11 Aug 2016 11:16:39 +0200 In-Reply-To: (KY Srinivasan's message of "Wed, 10 Aug 2016 19:00:37 +0000") Message-ID: <87twer8y2w.fsf@vitty.brq.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.95 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Thu, 11 Aug 2016 09:16:42 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org KY Srinivasan writes: >> -----Original Message----- >> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com] >> Sent: Tuesday, August 9, 2016 1:46 AM >> To: devel@linuxdriverproject.org >> Cc: linux-kernel@vger.kernel.org; Haiyang Zhang ; >> KY Srinivasan >> Subject: [PATCH 0/2] Drivers: hv: vmbus: make bus ids in sysfs persistent >> >> Bus ids for VMBus devices in /sys/bus/vmbus/devices/ are not guaranteed >> to be persistent across reboot or kernel restart and this causes problems >> for some tools. E.g. kexec tools use these ids to identify NIC on kdump. >> Fix the issue by using relid from channel offer as the unique id instead >> of an auto incremented counter. > > Relids are not persistent. It is only valid between a channel offer > message and a relid released message (or an unload or initiate contact > message, which invalidates all channels). This is an opaque number > that the root generates and uses to track channels. There is no > guarantee that the same type of channel (networking, storage, etc) > will get the same relid on each reboot. > Thanks for the info, can we use device_id (offermsg.offer.if_instance.b) instead? -- Vitaly