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 CF486CA0EE4 for ; Fri, 15 Aug 2025 01:10:13 +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=Hr3wKIH0ILNJrROQ8e7R3YmlW6yepWJRJ+67Lc0p55k=; b=Xn6DDybaY+2tpeIIpfKHx5B2/P QyQjRlrOY6erqOhpsfxjET1Kf5n+88R1TkCqn1jZCjp+NvL1TCN837BmhSwMNWnnSoKhboyW1i0oG i1f4RX/4Z0ZjFIaB/CtuiHe/cgsqRAla+EL+8ZqIOPCI0CoYhAfmAB/VWkx/gGvlQcuYZUEf97BhW cMI8BbJ0M8EEG4iuy1hcMyh2TaSv0qypeGDLceN6y+2PlK5Px7nrN8+tIHecrbUdw/ztoNuYFJjvl zRNleK7GEmFTtxRGah/ZXrT8xvEK9LA8W6OS5gGbFgDqS3EkK1VsBozeb8ln2war4mpgX5lwaCef5 HEmm/q1w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1umixL-00000001143-0qNQ; Fri, 15 Aug 2025 01:10:07 +0000 Received: from mail-oi1-x22d.google.com ([2607:f8b0:4864:20::22d]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1umiUF-00000000vpy-2mJ4 for linux-arm-kernel@lists.infradead.org; Fri, 15 Aug 2025 00:40:04 +0000 Received: by mail-oi1-x22d.google.com with SMTP id 5614622812f47-435de7d6d05so905290b6e.2 for ; Thu, 14 Aug 2025 17:40:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1755218401; x=1755823201; darn=lists.infradead.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=Hr3wKIH0ILNJrROQ8e7R3YmlW6yepWJRJ+67Lc0p55k=; b=JOCI3ZueCaPW+fv63NpNNtr1gJP4UcPvARJrIGagpm7lq09OTj0QRVVL8M6LVFDdQP xxs+nTnGobGJBjMd7zcqs5ll0WpjhnF/BuvEacFLKMqWHlFTeLYGfMVmGINxY4CXe3Eo fYoyTfRJMYK7JoT8DDDJrk6/qsYbm45VG3IftxS2KcZkBBJCckUzxPMcElOV+CDNsSZD gfsQPYGyPhN6FGcvvLYTAC6WetY4rpyrHmbMHtrsZWfqjyUfoEqPR/W+k+gsLZbAj0AI tI8dxzLwi34Cu6YwoM4m8Nrp7SPsdeLqPsmgNg9OKPIlyKYc9160fDSPitJWJIpdrLPe 7nWQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1755218401; x=1755823201; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Hr3wKIH0ILNJrROQ8e7R3YmlW6yepWJRJ+67Lc0p55k=; b=rAi2mYAPuYcDTe0rgj6iVOlXDx4Etd6E5CMjW4PqzpopG0snrz7k2VF85yMFWunFpM QEzpLvT+xRw84dHmowqn36cjTw7nCz6fIJviXywMst7jos6Ay9VOrIXovunkjINimD/l 99MD1F5yf2z0XykJJq+1TGEH9Zz6O4qzCc5Hn4Qn6yRjMiMwoiCHKCKAmFAdU3jcP1XM 5z0tKSW+v+Rl1K495byoKGQs4N1sPeecjthVvBXvh0/GnQeA2uG596vFKtFM7Yn1BhyC Vkv7GMXZgO1pdP+Swlw3nxU+IoZfENvwpG8aofDUm30ZJJFzHC/LpD8qlBQ9/cDo6D5k QvOA== X-Forwarded-Encrypted: i=1; AJvYcCWROlD8dIEIcturPIxE33d7XKPJ6je4ikZFUaSccG40/i943fTYr3rJsOyViO525VPxj+ySTKbv+/jVRcwBaGcL@lists.infradead.org X-Gm-Message-State: AOJu0YzqrVbfVjAfqtpQteRKahSye501guQHtoInaZuFbJrBZby3bgyJ PoZPsrCQk8EoVpSXG/oQn6ItXZ1zeSi727jIQpJ1mw2pUQmYvE/m2Oa6JU75vTJDzwI= X-Gm-Gg: ASbGnct622mVwwg4z0FJbns63TTR+Dsru6W94B17YLMrVPtwz8Cc7UVquLU5oS6fZWK nk7mhgXrekqkJrCz6dSD6TQoWeCZUV7aeWeZF0acnb0c/0Rhr4Tfqb37PDVw+qWtts0EDJwWlkq TfK75+IklsYRNXBDeHWxaSxif6IdPtfxBPDyd2qXAf3EKbygPdUzI72TahGUfhWfwjWtWzh2oCr giZVOzLgAYl1qmaAMoNIObhQs40vjNoPC6l+ZAxrqL8vsfZempNImV05hfQpeLGg6nqLZms223v 2N5jgW9qg2e4RQZ+SHyvlrR5VG24JQbjGBar3rPs7yWhfVRKEJcgWsbrL6vsn7O31uhm0AeR X-Google-Smtp-Source: AGHT+IHz/V+zZ7uzfzwx637Ui4sGjmYjl6eL7eDG1gc5kCGFqOg5QIIhe2oPTd/JaDh2sRuwhvdoeg== X-Received: by 2002:a05:6808:1a14:b0:434:54a:40bc with SMTP id 5614622812f47-435ec3bc7eamr73006b6e.1.1755218401405; Thu, 14 Aug 2025 17:40:01 -0700 (PDT) Received: from ziepe.ca ([130.41.10.202]) by smtp.gmail.com with ESMTPSA id 586e51a60fabf-310ab87a099sm3458fac.1.2025.08.14.17.39.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Aug 2025 17:40:00 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1umiUA-00000003TLB-28WR; Thu, 14 Aug 2025 21:39:58 -0300 Date: Thu, 14 Aug 2025 21:39:58 -0300 From: Jason Gunthorpe To: Shyam Saini Cc: iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, virtualization@lists.linux.dev, will@kernel.org, jacob.pan@linux.microsoft.com, eric.auger@redhat.com, code@tyhicks.com, eahariha@linux.microsoft.com, vijayb@linux.microsoft.com, bboscaccy@linux.microsoft.com, robh@kernel.org, saravanak@google.com, krzk+dt@kernel.org, conor+dt@kernel.org, lizhi.hou@amd.com, clement.leger@bootlin.com Subject: Re: [PATCH v3 2/3] iommu/of: fix device tree configuration for PCI devices Message-ID: <20250815003958.GE599331@ziepe.ca> References: <20250806215539.1240561-1-shyamsaini@linux.microsoft.com> <20250806215539.1240561-3-shyamsaini@linux.microsoft.com> <20250808121515.GE377696@ziepe.ca> <20250814233018.GA31418@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250814233018.GA31418@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250814_174003_810469_30BB6F74 X-CRM114-Status: GOOD ( 13.61 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Aug 14, 2025 at 04:30:18PM -0700, Shyam Saini wrote: > or were you referring to [2]? > > In that case, the PCI child node data needs to be parsed, which is > currently handled individually by each host controller driver. Yes, this looks like it may be what I was thinking of, the pci@1,0 specifes the BDF effectively > This might not be a strong argument, but since firmware updates tend > to happen less frequently than OS updates, any addition or modification > to the FDT would require a firmware update. Wouldn't it be more > maintainable to keep this logic in Linux, which is easier to update > and typically updated more often? The DT is supposed to describe the HW, if the PCI device has an issue with its dma ranges then it seems reasonable to me the FW will use the existing standards based way to describe that issue? Presumably this is a fixed issue of the platform. You never did explain how your system has such werdio behavior, or how something like iommu=pt can function on it... Jason