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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 A405BC433B4 for ; Wed, 7 Apr 2021 08:31:58 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 10F4361246 for ; Wed, 7 Apr 2021 08:31:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 10F4361246 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:49878 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lU3bQ-0005CD-Vx for qemu-devel@archiver.kernel.org; Wed, 07 Apr 2021 04:31:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54146) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lU3Zi-0004XE-EG for qemu-devel@nongnu.org; Wed, 07 Apr 2021 04:30:10 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:46021) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lU3Ze-0004qK-Vx for qemu-devel@nongnu.org; Wed, 07 Apr 2021 04:30:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617784205; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rWvrVPKrlR0eZL7Dmqcjx3TzNpNYPqpYDhLF9YU9jes=; b=jQ20u+ZatO7m9L3av4vSceLCSl1dkqGevjIRacy9XK6CJ+d3HkbGsEkS38lWGlQuXLar20 NgeEzlNXDFYVxyXS3+U48/CqvIa6wdw0lTz1P7B46b6/kahunJUERfiEyPr4HPtcSPgKWI 6e6lLRKFCOyWKmZty+F9b7ELS5DD3jY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-523-tm_hZna7NbiI6345CAeZ1Q-1; Wed, 07 Apr 2021 04:29:56 -0400 X-MC-Unique: tm_hZna7NbiI6345CAeZ1Q-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C6C711922962; Wed, 7 Apr 2021 08:29:55 +0000 (UTC) Received: from redhat.com (ovpn-115-28.ams2.redhat.com [10.36.115.28]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 31167100239A; Wed, 7 Apr 2021 08:29:47 +0000 (UTC) Date: Wed, 7 Apr 2021 09:29:45 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Igor Mammedov Subject: Re: [PULL v2 11/19] pci: acpi: ensure that acpi-index is unique Message-ID: References: <20210322225907.541943-1-mst@redhat.com> <20210322225907.541943-12-mst@redhat.com> <20210406201546.2377830e@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210406201546.2377830e@redhat.com> User-Agent: Mutt/2.0.5 (2021-01-21) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Peter Maydell , Julia Suvorova , qemu-devel@nongnu.org, "Michael S. Tsirkin" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Apr 06, 2021 at 08:15:46PM +0200, Igor Mammedov wrote: > On Tue, 6 Apr 2021 16:07:25 +0100 > Daniel P. Berrangé wrote: > > > On Tue, Apr 06, 2021 at 03:54:24PM +0100, Daniel P. Berrangé wrote: > > > On Mon, Mar 22, 2021 at 07:00:18PM -0400, Michael S. Tsirkin wrote: > > > > From: Igor Mammedov > > > > > > > > it helps to avoid device naming conflicts when guest OS is > > > > configured to use acpi-index for naming. > > > > Spec ialso says so: > > > > > > > > PCI Firmware Specification Revision 3.2 > > > > 4.6.7. _DSM for Naming a PCI or PCI Express Device Under Operating Systems > > > > " > > > > Instance number must be unique under \_SB scope. This instance number does not have to > > > > be sequential in a given system configuration. > > > > " > > > > > > > > Signed-off-by: Igor Mammedov > > > > Message-Id: <20210315180102.3008391-4-imammedo@redhat.com> > > > > Reviewed-by: Michael S. Tsirkin > > > > Signed-off-by: Michael S. Tsirkin > > > > --- > > > > hw/acpi/pcihp.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ > > > > 1 file changed, 46 insertions(+) > > > > > > > > diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c > > > > index ceab287bd3..f4cb3c979d 100644 > > > > --- a/hw/acpi/pcihp.c > > > > +++ b/hw/acpi/pcihp.c > > > > @@ -52,6 +52,21 @@ typedef struct AcpiPciHpFind { > > > > PCIBus *bus; > > > > } AcpiPciHpFind; > > > > > > > > +static gint g_cmp_uint32(gconstpointer a, gconstpointer b, gpointer user_data) > > > > +{ > > > > + return a - b; > > > > +} > > > > + > > > > +static GSequence *pci_acpi_index_list(void) > > > > +{ > > > > + static GSequence *used_acpi_index_list; > > > > + > > > > + if (!used_acpi_index_list) { > > > > + used_acpi_index_list = g_sequence_new(NULL); > > > > + } > > > > + return used_acpi_index_list; > > > > +} > > > > + > > > > static int acpi_pcihp_get_bsel(PCIBus *bus) > > > > { > > > > Error *local_err = NULL; > > > > @@ -277,6 +292,23 @@ void acpi_pcihp_device_pre_plug_cb(HotplugHandler *hotplug_dev, > > > > ONBOARD_INDEX_MAX); > > > > return; > > > > } > > > > + > > > > + /* > > > > + * make sure that acpi-index is unique across all present PCI devices > > > > + */ > > > > + if (pdev->acpi_index) { > > > > + GSequence *used_indexes = pci_acpi_index_list(); > > > > + > > > > + if (g_sequence_lookup(used_indexes, GINT_TO_POINTER(pdev->acpi_index), > > > > + g_cmp_uint32, NULL)) { > > > > + error_setg(errp, "a PCI device with acpi-index = %" PRIu32 > > > > + " already exist", pdev->acpi_index); > > > > + return; > > > > + } > > > > + g_sequence_insert_sorted(used_indexes, > > > > + GINT_TO_POINTER(pdev->acpi_index), > > > > + g_cmp_uint32, NULL); > > > > + } > > > > > > This doesn't appear to ensure uniqueness when using PCIe topologies: > > > > > > $ ./build/x86_64-softmmu/qemu-system-x86_64 \ > > > -device virtio-net,acpi-index=100 \ > > > -device virtio-net,acpi-index=100 > > > qemu-system-x86_64: -device virtio-net,acpi-index=100: a PCI device with acpi-index = 100 already exist > > > > > > $ ./build/x86_64-softmmu/qemu-system-x86_64 \ > > > -M q35 \ > > > -device virtio-net,acpi-index=100 > > > -device virtio-net,acpi-index=100 > > > ....happily running.... > > > > In fact the entire concept doesn't appear to work with Q35 at all as > > implemented. > > > > The 'acpi_index' file in the guest OS never gets created and the NICs > > are still called 'eth0', 'eth1' > > > > Only with i440fx can I can the "enoNNN" based naming to work with > > acpi-index set from QEMU > > It is not supported on Q35 yet as it depends on ACPI PCI hotplug infrastructure. > Once Julia is done with porting it to Q35, acpi-index will be pulled along with it. Will the PCI hotplug support work in the same way Looking at this doc I see two options: https://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/ 1. Names incorporating Firmware/BIOS provided index numbers for on-board devices (example: eno1) 2. Names incorporating Firmware/BIOS provided PCI Express hotplug slot index numbers (example: ens1) Is the stuff Julia is implementing for Q35 going to end up triggering scenario (1) still, or will it trigger scenario two which mentions "hotplug slot index" as a distinct concept from the ACPI index we're setting for i440fx ? Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|