From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 247C21A0191 for ; Tue, 2 Dec 2014 02:41:18 +1100 (AEDT) Received: from e8.ny.us.ibm.com (e8.ny.us.ibm.com [32.97.182.138]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 1275C14017F for ; Tue, 2 Dec 2014 02:41:16 +1100 (AEDT) Received: from /spool/local by e8.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 1 Dec 2014 10:41:14 -0500 Received: from b01cxnp22034.gho.pok.ibm.com (b01cxnp22034.gho.pok.ibm.com [9.57.198.24]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 9131438C805E for ; Mon, 1 Dec 2014 10:41:07 -0500 (EST) Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by b01cxnp22034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id sB1Ff61e23462094 for ; Mon, 1 Dec 2014 15:41:06 GMT Received: from d01av03.pok.ibm.com (localhost [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id sB1Ff5aj018834 for ; Mon, 1 Dec 2014 10:41:06 -0500 Message-ID: <547C8C0F.5070701@linux.vnet.ibm.com> Date: Mon, 01 Dec 2014 09:41:03 -0600 From: Nathan Fontenot MIME-Version: 1.0 To: Benjamin Herrenschmidt , Greg KH Subject: Re: Right location in sysfs for dlpar file References: <1417057941.5089.81.camel@kernel.crashing.org> In-Reply-To: <1417057941.5089.81.camel@kernel.crashing.org> Content-Type: text/plain; charset=utf-8 Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 11/26/2014 09:12 PM, Benjamin Herrenschmidt wrote: > Hi Greg, > > So Nathan is working on a patch series to cleanup and improve our > "DLPAR" infrastructure which is basically our hotplug mechanism when > running under the PowerVM (aka pHyp) and KVM hypervisors. The cleanup to the dlpar infrastructure will move the entire operation of hotplugging a device to the kernel instead of doing it partially in userspace and partially in the kernel as is currently done. > > I'll let Nathan give you a bit more details/background and answer > subsequent question you might have as this is really his area of > expertise. > > To cut a long story short, we need a sysfs file that allows our > userspace tools to notify the kernel of hotplug events coming from > the management console (which talks to userspace daemons using a > proprietary protocol) to "initiate" the hotplug operations, which in > turn get dispatched internally in the kernel to the right subsystem > (memory, cpu, pci, ...) based on the resource type. > > On IRC, Greg suggested /sys/firmware and /sys/hypervisor which both > look like a reasonable option to me, probably better than dlpar... For PowerVM systems we need this sysfs file to deliver what is essentially a binary blob (specifically a rtas error log) to the kernel. The current patch set is creating /sys/kernel/dlpar. As Ben mentioned we would like your input on what would be the proper place to create this file. -Nathan