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 X-Spam-Level: X-Spam-Status: No, score=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F421C4338F for ; Mon, 23 Aug 2021 10:10:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69EEF61246 for ; Mon, 23 Aug 2021 10:10:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230188AbhHWKKv (ORCPT ); Mon, 23 Aug 2021 06:10:51 -0400 Received: from foss.arm.com ([217.140.110.172]:51056 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233390AbhHWKKu (ORCPT ); Mon, 23 Aug 2021 06:10:50 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A338811FB; Mon, 23 Aug 2021 03:10:07 -0700 (PDT) Received: from lpieralisi (e121166-lin.cambridge.arm.com [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 567103F66F; Mon, 23 Aug 2021 03:10:05 -0700 (PDT) Date: Mon, 23 Aug 2021 11:10:00 +0100 From: Lorenzo Pieralisi To: Boqun Feng Cc: Catalin Marinas , Will Deacon , Bjorn Helgaas , Arnd Bergmann , Marc Zyngier , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu , Dexuan Cui , Rob Herring , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-pci@vger.kernel.org, Sunil Muthuswamy , Mike Rapoport Subject: Re: [PATCH v6 0/8] PCI: hv: Support host bridge probing on ARM64 Message-ID: <20210823100959.GA3294@lpieralisi> References: <20210726180657.142727-1-boqun.feng@gmail.com> <20210819141758.GA27305@lpieralisi> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 19, 2021 at 11:47:52PM +0800, Boqun Feng wrote: > On Thu, Aug 19, 2021 at 03:17:58PM +0100, Lorenzo Pieralisi wrote: > > On Tue, Jul 27, 2021 at 02:06:49AM +0800, Boqun Feng wrote: > > > Hi, > > > > > > This is the v6 for the preparation of virtual PCI support on Hyper-V > > > ARM64, Previous versions: > > > > > > v1: https://lore.kernel.org/lkml/20210319161956.2838291-1-boqun.feng@gmail.com/ > > > v2: https://lore.kernel.org/lkml/20210503144635.2297386-1-boqun.feng@gmail.com/ > > > v3: https://lore.kernel.org/lkml/20210609163211.3467449-1-boqun.feng@gmail.com/ > > > v4: https://lore.kernel.org/lkml/20210714102737.198432-1-boqun.feng@gmail.com/ > > > v5: https://lore.kernel.org/lkml/20210720134429.511541-1-boqun.feng@gmail.com/ > > > > > > Changes since last version: > > > > > > * Rebase to 5.14-rc3 > > > > > > * Comment fixes as suggested by Bjorn. > > > > > > The basic problem we need to resolve is that ARM64 is an arch with > > > PCI_DOMAINS_GENERIC=y, so the bus sysdata is pci_config_window. However, > > > Hyper-V PCI provides a paravirtualized PCI interface, so there is no > > > actual pci_config_window for a PCI host bridge, so no information can be > > > retrieve from the pci_config_window of a Hyper-V virtual PCI bus. Also > > > there is no corresponding ACPI device for the Hyper-V PCI root bridge, > > > which introduces a special case when trying to find the ACPI device from > > > the sysdata (see patch #3). > > > > > > With this patchset, we could enable the virtual PCI on Hyper-V ARM64 > > > guest with other code under development. > > > > > > Comments and suggestions are welcome. > > > > > > Regards, > > > Boqun > > > > > > Arnd Bergmann (1): > > > PCI: hv: Generify PCI probing > > > > > > Boqun Feng (7): > > > PCI: Introduce domain_nr in pci_host_bridge > > > PCI: Support populating MSI domains of root buses via bridges > > > arm64: PCI: Restructure pcibios_root_bridge_prepare() > > > arm64: PCI: Support root bridge preparation for Hyper-V > > > PCI: hv: Set ->domain_nr of pci_host_bridge at probing time > > > PCI: hv: Set up MSI domain at bridge probing time > > > PCI: hv: Turn on the host bridge probing on ARM64 > > > > > > arch/arm64/kernel/pci.c | 29 +++++++--- > > > drivers/pci/controller/pci-hyperv.c | 86 +++++++++++++++++------------ > > > drivers/pci/probe.c | 12 +++- > > > include/linux/pci.h | 11 ++++ > > > 4 files changed, 93 insertions(+), 45 deletions(-) > > > > If we take this series via the PCI tree we'd need Catalin/Will ACKs on > > patches 3-4. > > > > Got it. > > > I need some time to look into [1] (thanks for that). > > > > Without [1] patch 8 is ugly, that's no news. The question is whether > > it is worth waiting for a kernel cycle to integrate [1] into this series > > or not. > > > > Is it really a problem if we postpone this series for another kernel > > cycle so that we can look into it ? > > > > Well, it's definitely better for me that we can have it in 5.15-rc1 ;-), > because it's a dependency for Hyper-V virtual PCI support on ARM64 and > we plan to send the rest of work in 5.15 cycle. And I can just base on > hyperv-next for the rest of the work if this is in 5.15-rc1. But yes, > it's not really a problem, since this one still needs to work with other > patches to support virtual PCI on ARM64 Hyper-V. > > In fact, I personally don't think [1] is better than patch 8 (plus patch > 3 & 4): playing with ->private seems dangerous and not very helpful on > readiblity, but I agree that we should explore every potential solution, > and that's why I send [1]. Pulled the current series - now let's work together to improve it, I will have a look into [1] in the weeks to come and get back to you with some feedback. Thanks, Lorenzo > Regards, > Boqun > > > [1] https://lore.kernel.org/lkml/20210811153619.88922-1-boqun.feng@gmail.com/ 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 X-Spam-Level: X-Spam-Status: No, score=-11.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 022C5C4338F for ; Mon, 23 Aug 2021 10:12:20 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id C345761246 for ; Mon, 23 Aug 2021 10:12:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C345761246 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Hb6oIDGof67xtP8ueWfqIbduMRCvrMZbDhwBXEwdrIo=; b=gWPK59eJ+eJvph 944nZcVA+IQtWEDyxfi0hef7Tb3caYdGYaVi4OShW0kqJmIo0IWyCEe/aEJilU5CUUgaYhEI5p2zh aYXYXbxl5oAy2Mz8L3IMz+3mpU8UziiLOvcu8AsCY9OkqAyRjc2Mk3NqnGSbD8B0jbhVOftWkSpeq gN1finTGfb20yIxt2YkKLaSAq0gElnooBfNYyPPJHVLUQTSodscATvML1y13BxIl76kVUGsOr6dfj l0vRe59e/sNbw7yh+fEBSJFxiAqWCZSm3SwtK4G3OkoqO+QTXJe/Rtsv2+p8+VoMecUrfNxdzZQkv KHbxBH4XWslh3+tuNduQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mI6uF-00GHVt-6i; Mon, 23 Aug 2021 10:10:15 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mI6u9-00GHUu-Lz for linux-arm-kernel@lists.infradead.org; Mon, 23 Aug 2021 10:10:11 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A338811FB; Mon, 23 Aug 2021 03:10:07 -0700 (PDT) Received: from lpieralisi (e121166-lin.cambridge.arm.com [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 567103F66F; Mon, 23 Aug 2021 03:10:05 -0700 (PDT) Date: Mon, 23 Aug 2021 11:10:00 +0100 From: Lorenzo Pieralisi To: Boqun Feng Cc: Catalin Marinas , Will Deacon , Bjorn Helgaas , Arnd Bergmann , Marc Zyngier , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu , Dexuan Cui , Rob Herring , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-pci@vger.kernel.org, Sunil Muthuswamy , Mike Rapoport Subject: Re: [PATCH v6 0/8] PCI: hv: Support host bridge probing on ARM64 Message-ID: <20210823100959.GA3294@lpieralisi> References: <20210726180657.142727-1-boqun.feng@gmail.com> <20210819141758.GA27305@lpieralisi> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210823_031009_866982_A3F2E84F X-CRM114-Status: GOOD ( 38.65 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Aug 19, 2021 at 11:47:52PM +0800, Boqun Feng wrote: > On Thu, Aug 19, 2021 at 03:17:58PM +0100, Lorenzo Pieralisi wrote: > > On Tue, Jul 27, 2021 at 02:06:49AM +0800, Boqun Feng wrote: > > > Hi, > > > > > > This is the v6 for the preparation of virtual PCI support on Hyper-V > > > ARM64, Previous versions: > > > > > > v1: https://lore.kernel.org/lkml/20210319161956.2838291-1-boqun.feng@gmail.com/ > > > v2: https://lore.kernel.org/lkml/20210503144635.2297386-1-boqun.feng@gmail.com/ > > > v3: https://lore.kernel.org/lkml/20210609163211.3467449-1-boqun.feng@gmail.com/ > > > v4: https://lore.kernel.org/lkml/20210714102737.198432-1-boqun.feng@gmail.com/ > > > v5: https://lore.kernel.org/lkml/20210720134429.511541-1-boqun.feng@gmail.com/ > > > > > > Changes since last version: > > > > > > * Rebase to 5.14-rc3 > > > > > > * Comment fixes as suggested by Bjorn. > > > > > > The basic problem we need to resolve is that ARM64 is an arch with > > > PCI_DOMAINS_GENERIC=y, so the bus sysdata is pci_config_window. However, > > > Hyper-V PCI provides a paravirtualized PCI interface, so there is no > > > actual pci_config_window for a PCI host bridge, so no information can be > > > retrieve from the pci_config_window of a Hyper-V virtual PCI bus. Also > > > there is no corresponding ACPI device for the Hyper-V PCI root bridge, > > > which introduces a special case when trying to find the ACPI device from > > > the sysdata (see patch #3). > > > > > > With this patchset, we could enable the virtual PCI on Hyper-V ARM64 > > > guest with other code under development. > > > > > > Comments and suggestions are welcome. > > > > > > Regards, > > > Boqun > > > > > > Arnd Bergmann (1): > > > PCI: hv: Generify PCI probing > > > > > > Boqun Feng (7): > > > PCI: Introduce domain_nr in pci_host_bridge > > > PCI: Support populating MSI domains of root buses via bridges > > > arm64: PCI: Restructure pcibios_root_bridge_prepare() > > > arm64: PCI: Support root bridge preparation for Hyper-V > > > PCI: hv: Set ->domain_nr of pci_host_bridge at probing time > > > PCI: hv: Set up MSI domain at bridge probing time > > > PCI: hv: Turn on the host bridge probing on ARM64 > > > > > > arch/arm64/kernel/pci.c | 29 +++++++--- > > > drivers/pci/controller/pci-hyperv.c | 86 +++++++++++++++++------------ > > > drivers/pci/probe.c | 12 +++- > > > include/linux/pci.h | 11 ++++ > > > 4 files changed, 93 insertions(+), 45 deletions(-) > > > > If we take this series via the PCI tree we'd need Catalin/Will ACKs on > > patches 3-4. > > > > Got it. > > > I need some time to look into [1] (thanks for that). > > > > Without [1] patch 8 is ugly, that's no news. The question is whether > > it is worth waiting for a kernel cycle to integrate [1] into this series > > or not. > > > > Is it really a problem if we postpone this series for another kernel > > cycle so that we can look into it ? > > > > Well, it's definitely better for me that we can have it in 5.15-rc1 ;-), > because it's a dependency for Hyper-V virtual PCI support on ARM64 and > we plan to send the rest of work in 5.15 cycle. And I can just base on > hyperv-next for the rest of the work if this is in 5.15-rc1. But yes, > it's not really a problem, since this one still needs to work with other > patches to support virtual PCI on ARM64 Hyper-V. > > In fact, I personally don't think [1] is better than patch 8 (plus patch > 3 & 4): playing with ->private seems dangerous and not very helpful on > readiblity, but I agree that we should explore every potential solution, > and that's why I send [1]. Pulled the current series - now let's work together to improve it, I will have a look into [1] in the weeks to come and get back to you with some feedback. Thanks, Lorenzo > Regards, > Boqun > > > [1] https://lore.kernel.org/lkml/20210811153619.88922-1-boqun.feng@gmail.com/ _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel