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 18FAEC433F5 for ; Thu, 3 Feb 2022 19:51:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232229AbiBCTvt (ORCPT ); Thu, 3 Feb 2022 14:51:49 -0500 Received: from mailout1.w2.samsung.com ([211.189.100.11]:10620 "EHLO mailout1.w2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353866AbiBCTvs (ORCPT ); Thu, 3 Feb 2022 14:51:48 -0500 Received: from uscas1p2.samsung.com (unknown [182.198.245.207]) by mailout1.w2.samsung.com (KnoxPortal) with ESMTP id 20220203195147usoutp01676c4aa0ce25a63250015b1c0745c326~QXqCKE-ox2175821758usoutp01c; Thu, 3 Feb 2022 19:51:47 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.w2.samsung.com 20220203195147usoutp01676c4aa0ce25a63250015b1c0745c326~QXqCKE-ox2175821758usoutp01c DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1643917907; bh=xI6yBdL1mfc3lSXFQ8VzzVbFyQ2kUTgd06FK2pSdkHA=; h=From:To:CC:Subject:Date:In-Reply-To:References:From; b=pQzCjErMe9XMGa/viD7JwjBnOhvaPyFlGzO0hqaFrqa8NttQpoj7xz11BhLUWdRtN zf0MLQxLjCju8D4++jN+letKH3syFxdzeWwXd3OAgKoko2vbrReug+/PYy6JHPDCBZ zKGL6hNY1qBC/M9WPdX4U8x1aHXZ6p6WSXyEhwIg= Received: from ussmges2new.samsung.com (u111.gpu85.samsung.co.kr [203.254.195.111]) by uscas1p2.samsung.com (KnoxPortal) with ESMTP id 20220203195147uscas1p2b483a50b33a6859e9785c50ffa598690~QXqB4SSH21454414544uscas1p2N; Thu, 3 Feb 2022 19:51:47 +0000 (GMT) Received: from uscas1p2.samsung.com ( [182.198.245.207]) by ussmges2new.samsung.com (USCPEMTA) with SMTP id BF.DC.10104.3523CF16; Thu, 3 Feb 2022 14:51:47 -0500 (EST) Received: from ussmgxs1new.samsung.com (u89.gpu85.samsung.co.kr [203.254.195.89]) by uscas1p1.samsung.com (KnoxPortal) with ESMTP id 20220203195146uscas1p1cb1a89b235bd53b2a0deb29bc1fceb22~QXqBfFeOs0908909089uscas1p1H; Thu, 3 Feb 2022 19:51:46 +0000 (GMT) X-AuditID: cbfec36f-2fdff70000002778-49-61fc325334af Received: from SSI-EX4.ssi.samsung.com ( [105.128.2.146]) by ussmgxs1new.samsung.com (USCPEXMTA) with SMTP id 97.67.09671.2523CF16; Thu, 3 Feb 2022 14:51:46 -0500 (EST) Received: from SSI-EX3.ssi.samsung.com (105.128.2.228) by SSI-EX4.ssi.samsung.com (105.128.2.229) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.1.2242.4; Thu, 3 Feb 2022 11:50:56 -0800 Received: from SSI-EX3.ssi.samsung.com ([fe80::8d80:5816:c578:8c36]) by SSI-EX3.ssi.samsung.com ([fe80::8d80:5816:c578:8c36%3]) with mapi id 15.01.2242.008; Thu, 3 Feb 2022 11:50:56 -0800 From: Adam Manzanares To: Keith Busch CC: Luis Chamberlain , Chaitanya Kulkarni , Mikulas Patocka , "linux-block@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "dm-devel@redhat.com" , "linux-nvme@lists.infradead.org" , =?iso-8859-1?Q?Javier_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 Thread-Topic: [RFC PATCH 3/3] nvme: add the "debug" host driver Thread-Index: AQHYF5o0LMwUDmubDUu2kNRmd7lMHKyAbLYAgAIScYCAABSnAIAAMheA Date: Thu, 3 Feb 2022 19:50:56 +0000 Message-ID: <20220203195155.GB249665@bgt-140510-bm01> In-Reply-To: <20220203165238.GA142129@dhcp-10-100-145-180.wdc.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [105.128.2.176] x-exchange-save: DSA Content-Type: text/plain; charset="iso-8859-1" Content-ID: <10580CE5E2C09A4AB87F082C038E3B17@ssi.samsung.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-CFilter-Loop: Reflected X-Brightmail-Tracker: H4sIAAAAAAAAA02Se0xTZxyG951zenpo0nmERr6VRQFhGNgA2TCfcWOG6XKEP0ZCiM7E6Yke LuFmWmHAnHQSFi4qFwGhXsDCuApKUSBcZLQBwoDJ1payRlaQkm0gIDhEoMNZT03473nze9/k +ZKPwh21pJSKSTjHyRLYOHdSRLT2rzz6KDzAyvpXzTqghok8EpU8W8PRYu+0ABXmlQqRzvIu 6l64LkCjL3/A0LT6FYa6VIUYqmvow9BfNZUAZQ+NYsg6tRcVasYA6jb5oK7uQQKVV88IUa6x nUQP57pxVDOwiaHx/BmACrIMGPpVaSWR9k8DgRqsCGVeWhOi2Z5vDrowOn0oU5CxIGQyKh4T jG4kiVHXZ5NMS1U6c3W8BjCdfyhI5uJwH86ULv9LMsbhNoy5nLFAMkszJoJpnbosZBYfGkjm 7n0DEeZ0XPTpGS4uJpmT+QWdEkXnTnbgZ1+JUqZyLLgCaKkc4EBB+hM4VP8YywEiypGuA7BS s2EPmRj8784C/rbV1tBsPzQC+KDJZA/PAPx7pUrIhx4AzVW9AtuEpP3hxkDzm7mE3g0nyssE thJO54tg/rz+9ZyinOggeHsthO98Dpe1Knv/SzjxVEfYmKA94Gz7c6GNxXQg1A8ukjZ2oINh /9KjN31A74Crv9zBbIzTztBkKcd47e1Qdb3L/oQdcLNjiuTZDZpX/xHyLIFNq/Mkv/WF48VF dg6CRU9NOM8+sPr2HM47bIeDZRaC374He2vHCdu7IP1ABK+aR+yHQ3BG9budXaDBWIzzpXoA i178KORDC4Cl66NYPvBUbjFXbjFRbjFRbjFRbjGpAIJ64Jwkl8dHcfKABO5bXzkbL09KiPI9 nRivBq//+dCmNrEdGE1LvhqAUUADIIW7S8SxJRuso/gMm5rGyRJPypLiOLkGuFCEu7O4OuYe 60hHsee4WI47y8neXjHKQarAUgoCFZqbO0MrXlbs2vZTYkBm+ZN3vHI99KnhsWpj9Pv+a199 vWfw2gG2r7bZo63/eOpIbUpRzJHdFyQRnZE+H6c8t3IF28bqivXS0DDP36QjezrTwtPLLrlH HMtPKaHPJ7elmz87nLfPtTf1fKfEIsoOZi9kDZRKDnn7O9zs/6JpqH9z/Ir1O7Vb1/yxQlWL yM8z2Wv9pN/96PXJw826E2M3ys3XItKHFUe9duWcli1uHnCN1ItDLbLWrqzGlaj9cizsoNOQ JfhIWmFH48XvHfcvTzrL8uYkIR9c6ZuPDInbdytOf+rGEzmmaJ3rOfphRKV0eqfricCf3V5I g6yMNtW7fsWdkEeze71xmZz9HxSbyH5WBAAA X-Brightmail-Tracker: H4sIAAAAAAAAA02Sf0wTVwDH8+6u12szzFnL+lD/sUyzTFfA4fY2N7bMjdzUuV8mkxnnGr1A UyhNWxw/loGyBSkDoZVKu0SKbSijyKSQQbRA2ooGcZtLYdQqU6Qd4bfoGDIautVjCf99Xr6/ 3ksehYsmeRsphUrHalTybCkpJBQlmOHFj3dG5Mmeha3IOXKGRKaHSzia84zxkOFMHR/5Q+tQ 9+z3PHTryUkMjbmiGHJfMGDoB2cfhsYdNoDKB25hKDKaggze3wHqDm5H7u5+AtU3hvmoYriL RD1T3ThyXF/BUKA6DFDN6SEM/WKJkMj3xxCBnBGEvv1uiY8mez9/axPjH9zH1JTO8plS612C 8f+cx7iay0mm3V7MGAMOwFy5XUIyp2724Uzdo79IZvhmJ8ZUls6SzHw4SDA/jVbymbmeIZL5 sWOI+HDDZ8LXj7PZihOsJintC2FWxf3LuDoqzB/Vh/AS4KP0QEBBOhV2OtswPRBSItoJoKf9 Bs4dHgI4E7iyqvQCaDCYiViEpJPh8vU2PMZiOhGO1Jt5McbpaiG81pasBxS1gU6DDUt7Ocub 8JHvwqo9HY5M+5/WEPRzcLLrMT/GcfQuONg/R3Jbyzj8c6EaiwkC+m14bf7Xp2FAPwsXb7Rg 3JYEBkP1GPcEGtrdnAfS8XBibIXH8RZ4b3GCz7EYti7OkFxWBgO1Z1c5DZ6dDuIcb4eNDVM4 d6H1sN8cIrhsAvQ0BYhqkGBZM21ZU2VZU2VZU2VZU2UFvGYgydNqczLztSkq9kuZVp6jzVNl yo7l5rjAf99xYMWX0QX6gvMyL8Ao4AWQwqXiOKVpWS6KOy4vKGQ1uUc1edms1gs2UYRUEid6 t+aoiM6U61gly6pZzf8qRgk2lmAVZQt7WuteGfDsmM7e/1V/py2/Vr+y7Z/78Xc60w59NGG6 R6SmbZbMDldK1ovfr3IaXjW3qA7OY49Vl3psk8VFhSfcL7+m29N8/kBBY5KuoagWux3ueJDZ V1l0/lDGO/SpaOqU/u7h/J4DTUZbxcEdianC/RdbQdXllnKHe8IPEiXL59ZFsybnbJdmQkde su/bag3havWnxvGvlVW/RVwRV3VSgaH2mULZVX2k6cFur0rpzf1ANvONVWD8O6Psky3DbySU X1QXpO9+PlxsK2Q325dqeYfPtaeXm+LFjEmgiB55orQrOnqP7bT53nNKd53edocY1/HLzEaH 9aTiavOglNBmyVNewDVa+b8tBB2K/QMAAA== X-CMS-MailID: 20220203195146uscas1p1cb1a89b235bd53b2a0deb29bc1fceb22 CMS-TYPE: 301P X-CMS-RootMailID: 20220203165248uscas1p1f0459e548743e6be26d13d3ed8aa4902 References: <20220201102122.4okwj2gipjbvuyux@mpHalley-2> <270f30df-f14c-b9e4-253f-bff047d32ff0@nvidia.com> <20220203153843.szbd4n65ru4fx5hx@garbanzo> <20220203165238.GA142129@dhcp-10-100-145-180.wdc.com> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Feb 03, 2022 at 08:52:38AM -0800, Keith Busch wrote: > 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, > > >=20 > > > On 2/1/22 10:33 AM, Mikulas Patocka wrote: > > > > External email: Use caution opening links or attachments > > > >=20 > > > >=20 > > > > This patch adds a new driver "nvme-debug". It uses memory as a back= ing > > > > store and it is used to test the copy offload functionality. > > > >=20 > > > > Signed-off-by: Mikulas Patocka > > > >=20 > > >=20 > > >=20 > > > 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. > > >=20 > > > I don't see any special reason to make copy offload an exception. > >=20 > > 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. > >=20 > > For instance, blktests uses scsi_debug for simplicity. > >=20 > > In the end you decide what you want to use. >=20 > Can we use the nvme-loop target instead? I am advocating for this approach as well. It presentas a virtual nvme controller already.=