From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CD88B217307; Thu, 7 Nov 2024 16:19:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730996381; cv=none; b=MU2hTd72o+1o5Rf3jpFjwBgdo+dQja7ngkZ+1S7WLb6mtwwKNFRZJq5eCr85ScEopSo/XCU4dGvysPMhKVuC+q1TPr/AP/ZLsam2iG46REes+iUdHgp5vjvemcRa7R/agttks6vFbQB6O9kMoQbk4yNvF7ar/5cnuUtxMegv+qA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730996381; c=relaxed/simple; bh=SqxOv6okU/sodRwTyM+r4oFEioQMmC22R+3bohK4KUo=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=L2zPJtM++JcAXt9t33isI2v6YXLcXg7CB5OdO2Ce58rJcCv60xfbnWvGTQA+VzmFLSX5agZE5O8uNgm0CwTZhRYoR2X187ix17NxQJQXk0scKndu9Q19AIgnR2MKJMwRsvLjNjhWMwjDjxn1ew5Hx0GtrSLu/EpgVmCNs1P3VzY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GXtOYSPT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GXtOYSPT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4ED68C4CECC; Thu, 7 Nov 2024 16:19:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730996381; bh=SqxOv6okU/sodRwTyM+r4oFEioQMmC22R+3bohK4KUo=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=GXtOYSPT/H3r3SnyRnmLkGXZaW31eJexqtj829FQ1pCaIQBJOu1cV9PhStGxpY6ZN Bb21beAvVycEuV6K7ZTGhXlazBtYOCHmi2mcueLIWdYCQFCsJWuJ81a83lG24EcUJV +qkLwkysKWz+if7+TZV9P4BdsgCCYFUgO59gReLMFwKbj8oX4fWVoaLuENDN6I8mIv wsD3H98n+WJrIZxxfLol5NtKAtCH1YSpNiEQgNLi+0X61rGJ2vh66xxnsrR1cuE4kq LJqpU8MR+d7AqAYkvkAaQm8xNjNYWfBcDe3AGAMIhtOhGsTLHVjSRU79qpNRaPEUjm 7+L1JZkquSGLg== Date: Thu, 7 Nov 2024 10:19:39 -0600 From: Bjorn Helgaas To: Pavankumar Kondeti Cc: Joerg Roedel , Will Deacon , Robin Murphy , Bjorn Helgaas , Greg Kroah-Hartman , Joerg Roedel , Rob Herring , Marek Szyprowski , Anders Roxell , iommu@lists.linux.dev, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Xingang Wang Subject: Re: [PATCH RESEND] iommu/of: Fix pci_request_acs() before enumerating PCI devices Message-ID: <20241107161939.GA1618126@bhelgaas> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241107-pci_acs_fix-v1-1-185a2462a571@quicinc.com> On Thu, Nov 07, 2024 at 01:29:15PM +0530, Pavankumar Kondeti wrote: > From: Xingang Wang > > When booting with devicetree, the pci_request_acs() is called after the > enumeration and initialization of PCI devices, thus the ACS is not > enabled. And ACS should be enabled when IOMMU is detected for the > PCI host bridge, so add check for IOMMU before probe of PCI host and call > pci_request_acs() to make sure ACS will be enabled when enumerating PCI > devices. > > Fixes: 6bf6c24720d33 ("iommu/of: Request ACS from the PCI core when configuring IOMMU linkage") > Signed-off-by: Xingang Wang > Signed-off-by: Pavankumar Kondeti > --- > Earlier this patch made it to linux-next but got dropped later as it > broke PCI on ARM Juno R1 board. AFAICT, this issue is never root caused, > so resending this patch to get attention again. > > https://lore.kernel.org/all/1621566204-37456-1-git-send-email-wangxingang5@huawei.com/ > > The original problem that is being fixed by this patch still exists. In > my use case, all the PCI VF(s) assigned to a VM are sharing the same > group since these functions are attached under a Multi function PCIe root port FWIW, here are the problem reports (which are buried in the thread above): https://lore.kernel.org/all/01314d70-41e6-70f9-e496-84091948701a@samsung.com/ (Marek) https://lore.kernel.org/all/CADYN=9JWU3CMLzMEcD5MSQGnaLyDRSKc5SofBFHUax6YuTRaJA@mail.gmail.com/ (Anders) Given problem reports, the fact that the patch was acked and reviewed earlier means nothing. We have to ensure that any issues are resolved before considering this patch again. > emulated by the QEMU. This patch fixes that problem. > --- > drivers/iommu/of_iommu.c | 1 - > drivers/pci/of.c | 8 +++++++- > 2 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c > index e7a6a1611d19..f19db52388f5 100644 > --- a/drivers/iommu/of_iommu.c > +++ b/drivers/iommu/of_iommu.c > @@ -141,7 +141,6 @@ int of_iommu_configure(struct device *dev, struct device_node *master_np, > .np = master_np, > }; > > - pci_request_acs(); > err = pci_for_each_dma_alias(to_pci_dev(dev), > of_pci_iommu_init, &info); > of_pci_check_device_ats(dev, master_np); > diff --git a/drivers/pci/of.c b/drivers/pci/of.c > index dacea3fc5128..dc90f4e45dd3 100644 > --- a/drivers/pci/of.c > +++ b/drivers/pci/of.c > @@ -637,9 +637,15 @@ static int pci_parse_request_of_pci_ranges(struct device *dev, > > int devm_of_pci_bridge_init(struct device *dev, struct pci_host_bridge *bridge) > { > - if (!dev->of_node) > + struct device_node *node = dev->of_node; > + > + if (!node) > return 0; > > + /* Detect IOMMU and make sure ACS will be enabled */ > + if (of_property_read_bool(node, "iommu-map")) > + pci_request_acs(); > + > bridge->swizzle_irq = pci_common_swizzle; > bridge->map_irq = of_irq_parse_and_map_pci; > > > --- > base-commit: 59b723cd2adbac2a34fc8e12c74ae26ae45bf230 > change-id: 20241107-pci_acs_fix-2239e0fb1768 > > Best regards, > -- > Pavankumar Kondeti >