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 79157C54EBD for ; Fri, 13 Jan 2023 13:57:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241572AbjAMN5q (ORCPT ); Fri, 13 Jan 2023 08:57:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241230AbjAMN5E (ORCPT ); Fri, 13 Jan 2023 08:57:04 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A813763C5 for ; Fri, 13 Jan 2023 05:53:49 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 4D7A1B82161 for ; Fri, 13 Jan 2023 13:53:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90000C433EF; Fri, 13 Jan 2023 13:53:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673618026; bh=OJhTBUVSKCegb4i+9SFL4R/IowVrzTMekIJtJqHYazU=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=Tf+MwTF03EJ37hwcN2mCS6YdBNePhSnNDwRfJpoXiCj9Elw8kCVJzz1CCL58oyY/C UP9Two46IPYAKKgsJ266v5O/t20np8OOM6+Vxutkcf4dsbbJNuz5oUXNcHrAOivPEW o3yuLB+tT8Dr0cPuXoUG9EqE+OArcUhj2KP9Gx8LkN1pcxzFpUo39qL3QR0bsK6ZXj RV2t5MF+tbDt3U4Nf8qGbhkxYuX/K+C0bJ1HcDYUXucgdo/ON/F9xefc0gEmK6/UjE SBndq1lA6g+P30C1xI48H/j1+ZkgbbPuFmMvDksQq6E+vfRwvENT7mPn97J53uuTnL XM7yTpe0/9duQ== Date: Fri, 13 Jan 2023 07:53:43 -0600 From: Bjorn Helgaas To: "Duan, Zhenzhong" Cc: "bhelgaas@google.com" , "linux-kernel@vger.kernel.org" , "Yang, Lixiao" , "Peng, Chao P" Subject: Re: RESEND: MMCONFIG related question Message-ID: <20230113135343.GA1834989@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 13, 2023 at 10:15:45AM +0000, Duan, Zhenzhong wrote: > Recently Lixiao reported sriov disappered for cards which supported > sriov. We found it's related to commit "07eab0901ed efi/x86: Remove > EfiMemoryMappedIO from E820 map" which removed EfiMemoryMappedIO > regions from E820 map which lead to pci_mmcfg_reject_broken() check > failed, raw_pci_ext_ops isn't set to pci_mmcfg finally, below is the > related log. I know maybe bios should add MMCONFIG region into ACPI > motherboard resources, just want to ask if we would support the case > when MMCONFIG is missed in ACPI motherboard resources as I see it's > treated as "Firmware Info" not "Firmware bug". Thanks The patches here: https://lore.kernel.org/linux-pci/20230110180243.1590045-1-helgaas@kernel.org/ should resolve this problem. > Also has another question, if MMCONFIG happened to be in > EfiMemoryMappedIO, even if it's removed from E820 map so that there > is no CRS clip for that region, could it be used for BAR space? MMCONFIG cannot be used for BAR space. MMCONFIG should be reported via PNP0C02 _CRS. BAR space, i.e., a PCI host bridge aperture, should be reported via PNP0A03 _CRS. > Will there be conflict for BAR and MMCONFIG access? I don't think so, but I don't completely understand the scenario you're asking about. The E820 clipping of PCI host bridge windows is only intended to work around an issue where PNP0A03 _CRS reports space that is not part of the host bridge windows. E.g., there were a few platforms that seemed to report host bridge register space via _CRS. Bjorn > [ 0.000000] efi: EFI v2.60 by EDK II BIOS ID:SE5C620.86B.01.00.0763.022420181017 > [ 0.000000] efi: SMBIOS=0x6ae78000 ACPI=0x6bbab000 ACPI 2.0=0x6bbab014 MEMATTR=0x67e99018 MOKvar=0x67b2d000 > [ 0.000000] efi: Not removing mem06: MMIO range=[0xfe000000-0xfe010fff] (68KB) from e820 map > [ 0.000000] efi: Remove mem09: MMIO range=[0x80000000-0x8fffffff] (256MB) from e820 map > [ 0.000000] e820: remove [mem 0x80000000-0x8fffffff] reserved > [ 3.351098] PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem 0x80000000-0x8fffffff] (base 0x80000000) > [ 3.351742] PCI: not using MMCONFIG > [ 4.867853] PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem 0x80000000-0x8fffffff] (base 0x80000000) > [ 4.904325] [Firmware Info]: PCI: MMCONFIG at [mem 0x80000000-0x8fffffff] not reserved in ACPI motherboard resources > [ 4.905061] PCI: not using MMCONFIG > > Regards > Zhenzhong