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 666DBC433EF for ; Wed, 6 Apr 2022 02:23:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345072AbiDFCVG (ORCPT ); Tue, 5 Apr 2022 22:21:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1457470AbiDEQDQ (ORCPT ); Tue, 5 Apr 2022 12:03:16 -0400 Received: from mail-oa1-x36.google.com (mail-oa1-x36.google.com [IPv6:2001:4860:4864:20::36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E031399 for ; Tue, 5 Apr 2022 08:50:09 -0700 (PDT) Received: by mail-oa1-x36.google.com with SMTP id 586e51a60fabf-de3ca1efbaso14812711fac.9 for ; Tue, 05 Apr 2022 08:50:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=yUttHdvINpe5sVhWObI5vLGtPLNGhZcWSqGwgeAO4mE=; b=qj9doXvWuOFIaHhB/lpA9JrLUjyYVB8c8gFdTvzSHt0jLW1387lWVvGH2dvNVwqeZj qC1372+vgjT0U1CZ82ZkGR33s6RLxhvpRJWIvDVB4cULFhGxYaD5ucAn45Vs915PztCa bGEkAZ1/Y96zbHwvuPSTfCvuBCqWRnqWr60V7wrP8N6YMNLLdPSeRMLTbv9CjlFlWKWZ nuwb9tS5k5cpdDzewQaxniExFQV9GWpJ9Xd3vCHZyX7E6z+R4zBPk8mxAHJBPlJ82k4P aNKch2pKombMdNEqfZOdonb387OTkOLF//3iKmeHGfgzNen5jy2z8Lp2CzqokwNbdKBI buMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=yUttHdvINpe5sVhWObI5vLGtPLNGhZcWSqGwgeAO4mE=; b=1ITj89aTXFniJ5XG8tHOHEmSVM5u2WIzz0q4xaqHWCWoXqTEa4du1EwqN2zQHjmR1C 6+YEk5phiqdlcsCDHbBE0CQr9nEiIEkH5Gei3TQZ5jw4+r+IZ2UDdnBduSuIrAkjiEZ8 zMb8I9prxMH2dFIw0C9FhAZs9OBY9Uzz9MCglZTS3QlEJL5+gvSzNdaIEkNES4U4Ixss q/ghoDMJ+RMamNPBppZdZlrMaJJKGfRDa1GEb6W+fLyJbWOZfwM20FPoAu0m1UVu1eMC GP5GWHF11svnD9vb/34TnhIlcVVAwbQyxcJCOH5XGeIKCrGm/Cdw7Tg16N9H6RDKLxog 1HJA== X-Gm-Message-State: AOAM531I1ryE6m+TjCVCkcXUmaoPrp0IHyLDn3f3d1T7P4HP3eax1suy tV9GLniMZgfOY3mdrsBh6jc34RcC/El5/Pu/mo0= X-Google-Smtp-Source: ABdhPJzP1wb3PsOcO9yDICUnJCahvxJb3BLsH5WxSrw8IQTqclqb+WJrKOKneWX0DaAUU7SGiWugYRW7oAcNoKNyP+k= X-Received: by 2002:a05:6870:d18b:b0:d9:f452:be90 with SMTP id a11-20020a056870d18b00b000d9f452be90mr1844465oac.15.1649173809200; Tue, 05 Apr 2022 08:50:09 -0700 (PDT) MIME-Version: 1.0 References: <20220401110310.611869-1-joshi.k@samsung.com> <20220401110310.611869-6-joshi.k@samsung.com> <20220404072016.GD444@lst.de> <20220405060224.GE23698@lst.de> In-Reply-To: <20220405060224.GE23698@lst.de> From: Kanchan Joshi Date: Tue, 5 Apr 2022 21:19:43 +0530 Message-ID: Subject: Re: [RFC 5/5] nvme: wire-up support for async-passthru on char-device. To: Christoph Hellwig Cc: Kanchan Joshi , Jens Axboe , io-uring@vger.kernel.org, linux-nvme@lists.infradead.org, Pavel Begunkov , Ming Lei , Luis Chamberlain , Pankaj Raghav , =?UTF-8?Q?Javier_Gonz=C3=A1lez?= , Anuj Gupta Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Tue, Apr 5, 2022 at 11:32 AM Christoph Hellwig wrote: > > On Mon, Apr 04, 2022 at 07:55:05PM +0530, Kanchan Joshi wrote: > > > Something like this (untested) patch should help to separate > > > the much better: > > > > It does, thanks. But the only thing is - it would be good to support > > vectored-passthru too (i.e. NVME_IOCTL_IO64_CMD_VEC) for this path. > > For the new opcode "NVME_URING_CMD_IO" , either we can change the > > cmd-structure or flag-based handling so that vectored-io is supported. > > Or we introduce NVME_URING_CMD_IO_VEC also for that. > > Which one do you prefer? > > I agree vectored I/O support is useful. > > Do we even need to support the non-vectored case? Would be good to have, I suppose. Helps keeping it simple when user-space wants to use a single-buffer (otherwise it must carry psuedo iovec for that too). > Also I think we'll want admin command passthrough on /dev/nvmeX as > well, but I'm fine solving the other items first. > > > > +static int nvme_ioctl_finish_metadata(struct bio *bio, int ret, > > > + void __user *meta_ubuf) > > > +{ > > > + struct bio_integrity_payload *bip = bio_integrity(bio); > > > + > > > + if (bip) { > > > + void *meta = bvec_virt(bip->bip_vec); > > > + > > > + if (!ret && bio_op(bio) == REQ_OP_DRV_IN && > > > + copy_to_user(meta_ubuf, meta, bip->bip_vec->bv_len)) > > > + ret = -EFAULT; > > > > Maybe it is better to move the check "bio_op(bio) != REQ_OP_DRV_IN" outside. > > Because this can be common, and for that we can avoid entering into > > the function call itself (i.e. nvme_ioctl_finish_metadata). > > Function calls are pretty cheap, but I'll see what we can do. I'll try > to come up with a prep series to refactor the passthrough support for > easier adding of the io_uring in the next days. In that case we will base the newer version on its top.