From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755882AbcLTSAL (ORCPT ); Tue, 20 Dec 2016 13:00:11 -0500 Received: from mga02.intel.com ([134.134.136.20]:50287 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750927AbcLTSAI (ORCPT ); Tue, 20 Dec 2016 13:00:08 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,379,1477983600"; d="scan'208";a="1074507573" Date: Tue, 20 Dec 2016 10:52:41 -0700 From: Scott Bauer To: Christoph Hellwig Cc: Keith Busch , linux-nvme@lists.infradead.org, Rafael.Antognolli@intel.com, axboe@fb.com, jonathan.derrick@intel.com, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, sagi@grimberg.me Subject: Re: [PATCH v3 4/5] nvme: Implement resume_from_suspend and SED Allocation code. Message-ID: <20161220175239.GA2426@sbauer-Z170X-UD5> References: <1482176149-2257-1-git-send-email-scott.bauer@intel.com> <1482176149-2257-5-git-send-email-scott.bauer@intel.com> <20161219215954.GB10634@localhost.localdomain> <20161219222311.GA2056@sbauer-Z170X-UD5> <20161220061744.GB4765@infradead.org> <20161220154916.GC10634@localhost.localdomain> <20161220154639.GA16393@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161220154639.GA16393@infradead.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 20, 2016 at 07:46:39AM -0800, Christoph Hellwig wrote: > On Tue, Dec 20, 2016 at 10:49:16AM -0500, Keith Busch wrote: > > On Mon, Dec 19, 2016 at 10:17:44PM -0800, Christoph Hellwig wrote: > > > As far as I can tell Security Send / Receive has always been intended to > > > apply to the whole controller, even if that's something I would not > > > personally think is a good idea. > > > > NVMe security commands required the namespace ID since the very > > beginning. It's currently documented in figure 42 of section 5, > > "Namespace Identifier Used" column. > > Oh, for some reason I read a no there when looking it up. > Good to know, although TCG spec still seem to ignore it. Before I submit another version I want to address a few design issues we seem to be walking around a bit: The other reviews you gave for the series are fine and will be implemented, thank you for that. The main development issue seems to be how the drivers/block layer interact with the core sed. 1) We will move the core from lib/ back to block/ and add CONFIGS in kconfig. 2) Do we want to continue passing around a sed_context to the core? Instead of a block_device struct like we did in previous versions. 2a) If we do wish to do wish to continue passng sed_contexts to the core I have to add a new variable to the block_device structure for our sed_context. Will this be acceptable? It wasn't acceptable for the file struct. The reason I need a new variable in the struct is: On the ioctl path, if we intercept the SED call in the block layer ioctl and have the call chain be: uland -> blk_ioctl -> sed_ioctl() -> sedcore -> sec_send/recv -> nvme then I need to be able to pass a sed_ctx struct in blk_ioctl to sed-ioctl and the only way is to have it sitting in our block_device structure. The other way which was sorta nack'd last time is the following call chain: uland -> blk_ioctl -> nvme_ioctl -> sed_ioctl -> sedcore -> send/rcv -> nvme In this call chain in nvme_ioctl we have access to our block device struct and from there we can do blkdev->bd_disk->private_data to get our ns and then eventually our sed_ctx to pass to sed_ioctl. I could add the ns to the sec_data pointer in sed_context. This would give us access to ns without having to pass around a block device or store it anywhere. In the first scenario I can't work at all with opaque pointers like we can in the drivers itself (private_data). I don't know what they are, the drivers have the domain knowledge of what type they actually stored in private_data. That's why I need an explicit member in the block_device for the first scenario. 3) For NVMe we need access to our ns ID. It's in the block_device behind a few pointers. What I can do is if we want to continue with the first ioctl path described above is something like: sed_ioctl(struct block_device *bdev, ...) { sed_context *ctx = bdev->sed_ctx; ctx->sed_data = bdev->bd_disk->private_data; switch(cmd) { ... ... return some_opal_cmd(ctx); } } While this works for NVMe I don't know if this is acceptible for *all* users. Since this is in a generic ioctl that is supposed to work with all drivers, who knows what the hell they're putting in private_data and whether its useful for their implementation of sec_send/recv. I think that's all I have for now. If I think of anything throughout the day I'll reply to to this email.