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 43476C77B73 for ; Mon, 22 May 2023 21:51:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231441AbjEVVvq (ORCPT ); Mon, 22 May 2023 17:51:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51862 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229721AbjEVVvp (ORCPT ); Mon, 22 May 2023 17:51:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD62CDB; Mon, 22 May 2023 14:51:44 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 47BCB61BE6; Mon, 22 May 2023 21:51:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B092C433EF; Mon, 22 May 2023 21:51:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684792303; bh=Ok4yakP/RP17NbAQEK15q5ZiwMyBJ6beiRiNypSHyCA=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=KO0e6142ivpLr6ui8uVfsjYyzUcYCZfzvKBAwbXorUNaD4P7P3frfH5QVU3GCCLHH Q9mxUxc/QI90xuITzRpgQ4ca8AxPNT9fACk/1swZjUrXX+pT6fgOzkXSgH91EsqNIm diQ4krbaKuflcHb5uSB0Wqat2h752igXiZh8Pz300/sAwmrhesAjDVtNuVE/0vksc7 yPp4e1PaFaBoGabW2A4JGeZwWyYD06UGqeRUO1zj8iTQSqCpSFU6ZzFLlA6vAuppyl m/xfSiqatkKkXtksTrb9PmCuC0TwR7rcm1ow5u4PfeYmzGS/HbGeNNfg59IRy22Wkb f20KiHn3RmZMg== Date: Mon, 22 May 2023 16:51:41 -0500 From: Bjorn Helgaas To: Igor Mammedov Cc: linux-kernel@vger.kernel.org, mst@redhat.com, rafael@kernel.org, lenb@kernel.org, bhelgaas@google.com, linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org, mika.westerberg@linux.intel.com Subject: Re: [PATCH v2] PCI: acpiphp: Reassign resources on bridge if necessary Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230424191557.2464760-1-imammedo@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Mon, Apr 24, 2023 at 09:15:57PM +0200, Igor Mammedov wrote: > When using ACPI PCI hotplug, hotplugging a device with > large BARs may fail if bridge windows programmed by > firmware are not large enough. > > Reproducer: > $ qemu-kvm -monitor stdio -M q35 -m 4G \ > -global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=on \ > -device id=rp1,pcie-root-port,bus=pcie.0,chassis=4 \ > disk_image > > wait till linux guest boots, then hotplug device > (qemu) device_add qxl,bus=rp1 > > hotplug on guest side fails with: > pci 0000:01:00.0: [1b36:0100] type 00 class 0x038000 > pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x03ffffff] > pci 0000:01:00.0: reg 0x14: [mem 0x00000000-0x03ffffff] > pci 0000:01:00.0: reg 0x18: [mem 0x00000000-0x00001fff] > pci 0000:01:00.0: reg 0x1c: [io 0x0000-0x001f] > pci 0000:01:00.0: BAR 0: no space for [mem size 0x04000000] > pci 0000:01:00.0: BAR 0: failed to assign [mem size 0x04000000] > pci 0000:01:00.0: BAR 1: no space for [mem size 0x04000000] > pci 0000:01:00.0: BAR 1: failed to assign [mem size 0x04000000] > pci 0000:01:00.0: BAR 2: assigned [mem 0xfe800000-0xfe801fff] > pci 0000:01:00.0: BAR 3: assigned [io 0x1000-0x101f] > qxl 0000:01:00.0: enabling device (0000 -> 0003) > Unable to create vram_mapping > qxl: probe of 0000:01:00.0 failed with error -12 > > However when using native PCIe hotplug > '-global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off' > it works fine, since kernel attempts to reassign unused resources. > Use the same machinery as native PCIe hotplug to (re)assign resources. > > Signed-off-by: Igor Mammedov Tentatively applied to pci/hotplug for v6.5. Tentative only because I'm hoping for your ack or review, Rafael (I see you acked v1, but this one is a little different). And I think you'd like a stable tag, Michael? I'm happy to add one, but wasn't sure if you wanted a separate ack for that. > --- > tested in QEMU with Q35 machine on PCIE root port and also > with nested conventional bridge attached to root port. > > v2: > * fixup subject to match expected style > * drop no longer needed __pci_bus_size_bridges() to avoid > memory leak (Bjorn Helgaas ) > --- > drivers/pci/hotplug/acpiphp_glue.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c > index 5b1f271c6034..328d1e416014 100644 > --- a/drivers/pci/hotplug/acpiphp_glue.c > +++ b/drivers/pci/hotplug/acpiphp_glue.c > @@ -498,7 +498,6 @@ static void enable_slot(struct acpiphp_slot *slot, bool bridge) > acpiphp_native_scan_bridge(dev); > } > } else { > - LIST_HEAD(add_list); > int max, pass; > > acpiphp_rescan_slot(slot); > @@ -512,12 +511,10 @@ static void enable_slot(struct acpiphp_slot *slot, bool bridge) > if (pass && dev->subordinate) { > check_hotplug_bridge(slot, dev); > pcibios_resource_survey_bus(dev->subordinate); > - __pci_bus_size_bridges(dev->subordinate, > - &add_list); > } > } > } > - __pci_bus_assign_resources(bus, &add_list, NULL); > + pci_assign_unassigned_bridge_resources(bus->self); > } > > acpiphp_sanitize_bus(bus); > -- > 2.39.1 >