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 D4CDAC433F5 for ; Thu, 3 Feb 2022 15:38:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351924AbiBCPit (ORCPT ); Thu, 3 Feb 2022 10:38:49 -0500 Received: from mail-pf1-f179.google.com ([209.85.210.179]:37476 "EHLO mail-pf1-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351905AbiBCPis (ORCPT ); Thu, 3 Feb 2022 10:38:48 -0500 Received: by mail-pf1-f179.google.com with SMTP id y5so1603301pfe.4; Thu, 03 Feb 2022 07:38:48 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=hJc80QrxeNpdYK/bKJzdbQZVP7dPgDgH6+/SL6BaJLA=; b=doU45sIK+CSec063wF0MiToitTNSaakQmJ9w4k/ShF5SmY6NH+n3Q/9rT59IZLyXK2 5lf1kZqpIVnQgIRFH5twfJTXc9IgB4rHHCq8ilKrW3kb8HOAnSoZ3025pcLHO3f2EsrN /1uNBpV4FHgqnsgbTs6v/TZcDq7Ixtbc1or142TmMy+9d/RExvWvsMvZQbLvMfQNAUXf R6bCdJ9Q4MckZJAJ8z0DKE9ad0wlwQg0rDbDtLeGOf3y7w4IFK2SSedS7o+VaksAIMnT 6e6RfVtt3FfRERL8pKeO+vjPuLqZzpfESeRgnMzW1S7bfJuaxOuzOfYNl9ZdG6H+wjvK ysdA== X-Gm-Message-State: AOAM530AglalReux9/ieAPVUL++rJI1U7w6m78ZSWiTy7sGV5RegGGJV CqaMWRHTQQHu8FoHCqXx+0A= X-Google-Smtp-Source: ABdhPJyK53iWqvFX2Vqq2e4bGH4TKRnnEI6Nef430vI4MXHRwAQ64yyEJcJ63nBPtWhhnkJ6Y3aDlw== X-Received: by 2002:a63:68c4:: with SMTP id d187mr15183399pgc.603.1643902727819; Thu, 03 Feb 2022 07:38:47 -0800 (PST) Received: from garbanzo (136-24-173-63.cab.webpass.net. [136.24.173.63]) by smtp.gmail.com with ESMTPSA id b12sm12465462pfm.154.2022.02.03.07.38.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Feb 2022 07:38:46 -0800 (PST) Date: Thu, 3 Feb 2022 07:38:43 -0800 From: Luis Chamberlain To: Chaitanya Kulkarni Cc: Mikulas Patocka , "linux-block@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "dm-devel@redhat.com" , "linux-nvme@lists.infradead.org" , Javier =?utf-8?B?R29uesOhbGV6?= , 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 , "kbus @imap.gmail.com>> Keith Busch" , 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: <20220203153843.szbd4n65ru4fx5hx@garbanzo> References: <20220201102122.4okwj2gipjbvuyux@mpHalley-2> <270f30df-f14c-b9e4-253f-bff047d32ff0@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <270f30df-f14c-b9e4-253f-bff047d32ff0@nvidia.com> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 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. Luis 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 33A48C433EF for ; Thu, 3 Feb 2022 15:40:31 +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-336-QlwIQjoyOqOq4LSv1RHgGw-1; Thu, 03 Feb 2022 10:40:26 -0500 X-MC-Unique: QlwIQjoyOqOq4LSv1RHgGw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B92F0876E3C; Thu, 3 Feb 2022 15:40:21 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BC0F8798CF; Thu, 3 Feb 2022 15:40:20 +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 54A4B1809CB8; Thu, 3 Feb 2022 15:40:18 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 213FeFCB014702 for ; Thu, 3 Feb 2022 10:40:15 -0500 Received: by smtp.corp.redhat.com (Postfix) id 37A0E40F9D6F; Thu, 3 Feb 2022 15:40:15 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast10.extmail.prod.ext.rdu2.redhat.com [10.11.55.26]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 33A6740F9D6D for ; Thu, 3 Feb 2022 15:40:15 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-2.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 1BDB61C05EAA for ; Thu, 3 Feb 2022 15:40:15 +0000 (UTC) Received: from mail-pg1-f170.google.com (mail-pg1-f170.google.com [209.85.215.170]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-48-jbFBgJ4UOuaTCahcmRbeug-1; Thu, 03 Feb 2022 10:38:49 -0500 X-MC-Unique: jbFBgJ4UOuaTCahcmRbeug-1 Received: by mail-pg1-f170.google.com with SMTP id z131so2536605pgz.12; Thu, 03 Feb 2022 07:38:49 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=hJc80QrxeNpdYK/bKJzdbQZVP7dPgDgH6+/SL6BaJLA=; b=yc5X+9e6W+CAo4Wj+r+5HbM+kL/ibrPVN/Od5iXUMGLkFOFwfNWi9RH8L54GlcDQO4 cNSt7wkUUMpbgyIYrDJFq2Sj+Pk5S5XS9zSIDIRwT9l+p4J/wCTttNfgMmXmL2PsmIyd 96YhjiyjtobyxLyKuACOcwpFc1O76Zz03lGohJyrjnK9XwusDMe1q+UMIpB6CeKVzjYX 0dbijSJSTNdvFZx5Rq9u6J14oSbBusRXqCmPhrAYRpYFW3b79C3dn/wXM7XGv7KSCNw5 MPktihsDR3TtWOGLwaG6NgQ92o6IFDYrtYrGm9yKb0/bDkVXktcO1+TCKTD1xRJ+yH4G quZg== X-Gm-Message-State: AOAM531c6ylVBssT6xG47sy61wgRDs8sf77OFRiNicV0UvD5C0WQq/3M jU4RoiqSSza1/ecR7srv4yw= X-Google-Smtp-Source: ABdhPJyK53iWqvFX2Vqq2e4bGH4TKRnnEI6Nef430vI4MXHRwAQ64yyEJcJ63nBPtWhhnkJ6Y3aDlw== X-Received: by 2002:a63:68c4:: with SMTP id d187mr15183399pgc.603.1643902727819; Thu, 03 Feb 2022 07:38:47 -0800 (PST) Received: from garbanzo (136-24-173-63.cab.webpass.net. [136.24.173.63]) by smtp.gmail.com with ESMTPSA id b12sm12465462pfm.154.2022.02.03.07.38.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Feb 2022 07:38:46 -0800 (PST) Date: Thu, 3 Feb 2022 07:38:43 -0800 From: Luis Chamberlain To: Chaitanya Kulkarni Message-ID: <20220203153843.szbd4n65ru4fx5hx@garbanzo> References: <20220201102122.4okwj2gipjbvuyux@mpHalley-2> <270f30df-f14c-b9e4-253f-bff047d32ff0@nvidia.com> MIME-Version: 1.0 In-Reply-To: <270f30df-f14c-b9e4-253f-bff047d32ff0@nvidia.com> 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 2.84 on 10.11.54.1 X-loop: dm-devel@redhat.com Cc: "djwong@kernel.org" , "linux-nvme@lists.infradead.org" , "clm@fb.com" , "dm-devel@redhat.com" , "osandov@fb.com" , Javier =?utf-8?B?R29uesOhbGV6?= , Bart Van Assche , "linux-scsi@vger.kernel.org" , Christoph Hellwig , "roland@purestorage.com" , "zach.brown@ni.com" , "dsterba@suse.com" , "msnitzer@redhat.com >> msnitzer@redhat.com" , "josef@toxicpanda.com" , "linux-block@vger.kernel.org" , Mikulas Patocka , "kbus @imap.gmail.com>> Keith Busch" , "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 10.5.11.14 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 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. Luis -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel