From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 49601C19F2A for ; Thu, 4 Aug 2022 14:57:55 +0000 (UTC) Received: from localhost ([::1]:59038 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oJcIM-00083u-4i for qemu-devel@archiver.kernel.org; Thu, 04 Aug 2022 10:57:54 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47094) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oJcGx-000721-5T for qemu-devel@nongnu.org; Thu, 04 Aug 2022 10:56:27 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:24124) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oJcGs-0002pD-33 for qemu-devel@nongnu.org; Thu, 04 Aug 2022 10:56:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1659624980; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3ggKv28E2L0L6K7L+gbW8rAA6Ey9l9IxtjHH+OWAnuc=; b=M1I87mZQPJVk6cnvUEgtXOoUS4Whtz6c0C2qLQZdISuE9P+MiHHCWbJyeweYA+0+P23awg IaRMmSRTClg/q8Ov1PFx7leu8Ig7hy45updJLJLyGl7yAM/AknhptKqQaBhD5+42Es2ZpM jRRl53Mt4GcykVw/uwFUz1zIjRouRSg= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-361-AQjZ_KUlOhSt5JPdM7-DMA-1; Thu, 04 Aug 2022 10:56:17 -0400 X-MC-Unique: AQjZ_KUlOhSt5JPdM7-DMA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id AB4CA3C2F760; Thu, 4 Aug 2022 14:56:16 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.194.81]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 21A5E400EA8E; Thu, 4 Aug 2022 14:56:16 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 0D65621E6930; Thu, 4 Aug 2022 16:56:15 +0200 (CEST) From: Markus Armbruster To: Daniel P. =?utf-8?Q?Berrang=C3=A9?= Cc: Peter Maydell , Kevin Wolf , Hao Wu , richard.henderson@linaro.org, qemu-arm@nongnu.org, qemu-devel@nongnu.org, venture@google.com, Avi.Fishman@nuvoton.com, kfting@nuvoton.com, hskinnemoen@google.com, f4bug@amsat.org, bin.meng@windriver.com, qemu-block@nongnu.org, thuth@redhat.com, Hanna Reitz Subject: Re: [PATCH v5 5/8] blockdev: Add a new IF type IF_OTHER References: <20220714182836.89602-1-wuhaotsh@google.com> <20220714182836.89602-6-wuhaotsh@google.com> <87ilnuda33.fsf@pond.sub.org> Date: Thu, 04 Aug 2022 16:56:15 +0200 In-Reply-To: ("Daniel P. =?utf-8?Q?Berrang?= =?utf-8?Q?=C3=A9=22's?= message of "Thu, 4 Aug 2022 15:34:27 +0100") Message-ID: <877d3odpm8.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Daniel P. Berrang=C3=A9 writes: > On Thu, Jul 28, 2022 at 10:46:35AM +0100, Peter Maydell wrote: >> On Wed, 27 Jul 2022 at 20:03, Kevin Wolf wrote: >> > >> > Am 18.07.2022 um 11:49 hat Markus Armbruster geschrieben: >> > > An OTP device isn't really a parallel flash, and neither are eFuses. >> > > More fast-and-lose use of IF_PFLASH may exist in the tree, and maybe= of >> > > other interface types, too. >> > > >> > > This patch introduces IF_OTHER. The patch after next uses it for an >> > > EEPROM device. >> > > >> > > Do we want IF_OTHER? >> > >> > What would the semantics even be? Any block device that doesn't pick up >> > a different category may pick up IF_OTHER backends? >> > >> > It certainly feels like a strange interface to ask for "other" disk and >> > then getting as surprise what this other thing might be. It's >> > essentially the same as having an explicit '-device other', and I >> > suppose most people would find that strange. >> > >> > > If no, I guess we get to abuse IF_PFLASH some more. >> > > >> > > If yes, I guess we should use IF_PFLASH only for actual parallel fla= sh >> > > memory going forward. Cleaning up existing abuse of IF_PFLASH may n= ot >> > > be worth the trouble, though. >> > > >> > > Thoughts? >> > >> > If the existing types aren't good enough (I don't have an opinion on >> > whether IF_PFLASH is a good match), let's add a new one. But a specific >> > new one, not just "other". >>=20 >> I think the common thread is "this isn't what anybody actually thinks >> of as being a 'disk', but we would like to back it with a block device >> anyway". That can cover a fair range of possibilities... > > Given that, do we even want/have to use -drive for this ? We can use > -blockdev for the backend and reference that from any -device we want > to create, and leave -drive out of the picture entirely -drive is our only means to configure onboard devices. We've talked about better means a few times, but no conclusions. I can dig up pointers, if you're interested.