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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 13116C433FE for ; Thu, 3 Feb 2022 16:52:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352207AbiBCQwo (ORCPT ); Thu, 3 Feb 2022 11:52:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229983AbiBCQwo (ORCPT ); Thu, 3 Feb 2022 11:52:44 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F338C061714; Thu, 3 Feb 2022 08:52:44 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2D7046155C; Thu, 3 Feb 2022 16:52:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA6E2C340E8; Thu, 3 Feb 2022 16:52:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643907162; bh=iaJxhtwIma6dUrbx3J2yiskIUAG+/AQHCMEnNS5R1Zo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ObXVLD8ZVfN8qLcAA/cwoT+F0WWY34fjcADHx5mxOicfMCp8LmOGroDLA0lzLs2+b Szc599IvtTtOtG5u3jWUjJia4KUNl++iTz8H9EtbTS8+8ihtbUNLjCQz8bBNy6zEhW tJ/k1LRfKEKD/xNnBjpj1Y90bf9/d8eACkulsewXmQ+dI70vPQfQJJe38hpojfYcBi +cYzFIxxxvCItLLi907bFuQgWEak+eRpVROajgoWHfmOqFSCwPBJWZbiAfVVIc1bgQ ocAeiEZLhJSmQ3RJ2JgSQsCmFy6VhcH9r3hvQ/7f6brbnG7hwKcBtPGM+YF8UnNvux WHcaWzUgxRwag== Date: Thu, 3 Feb 2022 08:52:38 -0800 From: Keith Busch To: Luis Chamberlain Cc: Chaitanya Kulkarni , Mikulas Patocka , "linux-block@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "dm-devel@redhat.com" , "linux-nvme@lists.infradead.org" , Javier =?iso-8859-1?Q?Gonz=E1lez?= , linux-fsdevel , Jens Axboe , "msnitzer@redhat.com >> msnitzer@redhat.com" , Bart Van Assche , "martin.petersen@oracle.com >> Martin K. Petersen" , "roland@purestorage.com" , Hannes Reinecke , Christoph Hellwig , "Frederick.Knight@netapp.com" , "zach.brown@ni.com" , "osandov@fb.com" , "lsf-pc@lists.linux-foundation.org" , "djwong@kernel.org" , "josef@toxicpanda.com" , "clm@fb.com" , "dsterba@suse.com" , "tytso@mit.edu" , "jack@suse.com" , Kanchan Joshi Subject: Re: [RFC PATCH 3/3] nvme: add the "debug" host driver Message-ID: <20220203165238.GA142129@dhcp-10-100-145-180.wdc.com> References: <20220201102122.4okwj2gipjbvuyux@mpHalley-2> <270f30df-f14c-b9e4-253f-bff047d32ff0@nvidia.com> <20220203153843.szbd4n65ru4fx5hx@garbanzo> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220203153843.szbd4n65ru4fx5hx@garbanzo> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Feb 03, 2022 at 07:38:43AM -0800, Luis Chamberlain wrote: > On Wed, Feb 02, 2022 at 08:00:12AM +0000, Chaitanya Kulkarni wrote: > > Mikulas, > > > > On 2/1/22 10:33 AM, Mikulas Patocka wrote: > > > External email: Use caution opening links or attachments > > > > > > > > > This patch adds a new driver "nvme-debug". It uses memory as a backing > > > store and it is used to test the copy offload functionality. > > > > > > Signed-off-by: Mikulas Patocka > > > > > > > > > NVMe Controller specific memory backed features needs to go into > > QEMU which are targeted for testing and debugging, just like what > > we have done for NVMe ZNS QEMU support and not in kernel. > > > > I don't see any special reason to make copy offload an exception. > > One can instantiate scsi devices with qemu by using fake scsi devices, > but one can also just use scsi_debug to do the same. I see both efforts > as desirable, so long as someone mantains this. > > For instance, blktests uses scsi_debug for simplicity. > > In the end you decide what you want to use. Can we use the nvme-loop target instead? 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 us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 ECE86C43217 for ; Fri, 4 Feb 2022 09:41:57 +0000 (UTC) Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-158-wM2GHshiMMSUvYaEuJa68g-1; Fri, 04 Feb 2022 04:41:51 -0500 X-MC-Unique: wM2GHshiMMSUvYaEuJa68g-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 404FC8143E5; Fri, 4 Feb 2022 09:41:47 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1C80F78C1B; Fri, 4 Feb 2022 09:41:47 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id DFA024BB7C; Fri, 4 Feb 2022 09:41:43 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 213Gql81020013 for ; Thu, 3 Feb 2022 11:52:47 -0500 Received: by smtp.corp.redhat.com (Postfix) id 05B40492D50; Thu, 3 Feb 2022 16:52:47 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast01.extmail.prod.ext.rdu2.redhat.com [10.11.55.17]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 01829492D53 for ; Thu, 3 Feb 2022 16:52:46 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D777685A5AA for ; Thu, 3 Feb 2022 16:52:46 +0000 (UTC) Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-244-bc8DgEa1PEShf4ro0SmPAQ-1; Thu, 03 Feb 2022 11:52:45 -0500 X-MC-Unique: bc8DgEa1PEShf4ro0SmPAQ-1 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E02DAB834DE; Thu, 3 Feb 2022 16:52:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA6E2C340E8; Thu, 3 Feb 2022 16:52:40 +0000 (UTC) Date: Thu, 3 Feb 2022 08:52:38 -0800 From: Keith Busch To: Luis Chamberlain Message-ID: <20220203165238.GA142129@dhcp-10-100-145-180.wdc.com> References: <20220201102122.4okwj2gipjbvuyux@mpHalley-2> <270f30df-f14c-b9e4-253f-bff047d32ff0@nvidia.com> <20220203153843.szbd4n65ru4fx5hx@garbanzo> MIME-Version: 1.0 In-Reply-To: <20220203153843.szbd4n65ru4fx5hx@garbanzo> X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 X-loop: dm-devel@redhat.com X-Mailman-Approved-At: Fri, 04 Feb 2022 04:41:43 -0500 Cc: "djwong@kernel.org" , "linux-nvme@lists.infradead.org" , "clm@fb.com" , "dm-devel@redhat.com" , "osandov@fb.com" , "msnitzer@redhat.com >> msnitzer@redhat.com" , Bart Van Assche , "linux-scsi@vger.kernel.org" , Christoph Hellwig , "roland@purestorage.com" , "zach.brown@ni.com" , Chaitanya Kulkarni , Javier =?iso-8859-1?Q?Gonz=E1lez?= , "josef@toxicpanda.com" , "linux-block@vger.kernel.org" , Mikulas Patocka , "dsterba@suse.com" , "Frederick.Knight@netapp.com" , Jens Axboe , "tytso@mit.edu" , Kanchan Joshi , "martin.petersen@oracle.com >> Martin K. Petersen" , "jack@suse.com" , linux-fsdevel , "lsf-pc@lists.linux-foundation.org" Subject: Re: [dm-devel] [RFC PATCH 3/3] nvme: add the "debug" host driver X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Thu, Feb 03, 2022 at 07:38:43AM -0800, Luis Chamberlain wrote: > On Wed, Feb 02, 2022 at 08:00:12AM +0000, Chaitanya Kulkarni wrote: > > Mikulas, > > > > On 2/1/22 10:33 AM, Mikulas Patocka wrote: > > > External email: Use caution opening links or attachments > > > > > > > > > This patch adds a new driver "nvme-debug". It uses memory as a backing > > > store and it is used to test the copy offload functionality. > > > > > > Signed-off-by: Mikulas Patocka > > > > > > > > > NVMe Controller specific memory backed features needs to go into > > QEMU which are targeted for testing and debugging, just like what > > we have done for NVMe ZNS QEMU support and not in kernel. > > > > I don't see any special reason to make copy offload an exception. > > One can instantiate scsi devices with qemu by using fake scsi devices, > but one can also just use scsi_debug to do the same. I see both efforts > as desirable, so long as someone mantains this. > > For instance, blktests uses scsi_debug for simplicity. > > In the end you decide what you want to use. Can we use the nvme-loop target instead? -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel