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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 2E631CDE019 for ; Fri, 14 Nov 2025 08:16:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=eSG+F2z762AObFBFM8zyufAOcmgQ09VZlyrPM/jJgfA=; b=k/LVRPPNIwngWV+voW7N2gqlVV +4EmvkaLv5Lq1yMGxeHwuIWmQbgEJ5aUSRC90vur2d19PYD/L9zD/10ZBEEvX8K3LrQX/FOwMPoye 1sH9fJtSgZq90DIXIVhZP0QMM6AoNW45ZyeDEFuCVqo8H2kQySoFa0fCorr/wOrh7Pkq84wyHqo6x J+bwb+lNwX/D5IEtYcKfM1lfTYnQUY96bxUDcRF/RM/WSS8XuVFgpGgX3iPM98uD2sxoQpEvGsC6C 1Av4UztlD9sZXCfYUWH6W3kMsz2bvLULiolgtS+9NSBsz1ti/uekq7AhTip2NPLAB4FyGcAWFwmkZ AyYh2FNg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vJoys-0000000BnPI-1JBa; Fri, 14 Nov 2025 08:16:30 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vJoyr-0000000BnP9-0kJy for linux-nvme@lists.infradead.org; Fri, 14 Nov 2025 08:16:29 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 52EEC60127; Fri, 14 Nov 2025 08:16:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8A3CBC116D0; Fri, 14 Nov 2025 08:16:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763108188; bh=/GKXEoBtcXx0a0NjG6jUraQg+k9dQvuk/Fg5FkEDWFM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gOf05MVjrdRhj/0Yd+x4tuVND9kaU0XV73O5OHkWW8Mq2O5bQXMgxARIBMgCEymc/ Em8yXhLFvhRQjNfr/pAILbNT/krqQDSRuHeFftF1VifoLo2S6o/uiVitEVa4qrbO9t 0YVd56YATKVnr1fzblG68tp8oehiZ4RVdD64YNI1QBnn6TlaW6mATf0gVgx3oenpKp NhMTR0DkPLSugOhWQ9MvKsq3/dFDsjhZtQMok0qKieO8YKVfPL0ZYWkSNJVR2eIHUy srbbkj28JGCqDctUigibzl6RX/fMjxwMN/FyRqtKwMB7VVie+ulvesrOfDNZaRKm1o 1WSlR0mF0TShQ== Date: Fri, 14 Nov 2025 10:16:23 +0200 From: Leon Romanovsky To: Jens Axboe Cc: Keith Busch , Christoph Hellwig , Sagi Grimberg , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org Subject: Re: [PATCH v4 0/2] block: Enable proper MMIO memory handling for P2P DMA Message-ID: <20251114081623.GB147495@unreal> References: <20251112-block-with-mmio-v4-0-54aeb609d28d@nvidia.com> <176305197986.133468.1935881415989157155.b4-ty@kernel.dk> <4f75497d-11cb-437c-ab90-d65d4d2e0a52@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Thu, Nov 13, 2025 at 01:40:50PM -0700, Jens Axboe wrote: > On 11/13/25 12:52 PM, Keith Busch wrote: > > On Thu, Nov 13, 2025 at 10:45:53AM -0700, Jens Axboe wrote: > >> I took a look, and what happens here is that iter.p2pdma.map is 0 as it > >> never got set to anything. That is the same as PCI_P2PDMA_MAP_UNKNOWN, > >> and hence we just end up in a BLK_STS_RESOURCE. First of all, returning > >> BLK_STS_RESOURCE for that seems... highly suspicious. That should surely > >> be a fatal error. And secondly, this just further backs up that there's > >> ZERO testing done on this patchset at all. WTF? > >> > >> FWIW, the below makes it boot just fine, as expected, as a default zero > >> filled iter then matches the UNKNOWN case. > > > > I think this must mean you don't have CONFIG_PCI_P2PDMA enabled. The > > Right, like most normal people :-) It depends how you are declaring normal people :). In my Fedora OS, installed on my laptop, CONFIG_PCI_P2PDMA is enabled by default. https://src.fedoraproject.org/rpms/kernel/blob/rawhide/f/kernel-x86_64-fedora.config#_5567 and in RHEL too https://src.fedoraproject.org/rpms/kernel/blob/rawhide/f/kernel-x86_64-rhel.config#_4964 Thanks