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 lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 398BDCC6B30 for ; Thu, 15 Oct 2026 10:37:17 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1xHIlR-0003pP-Jh; Thu, 15 Oct 2026 06:32:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xHIhA-0007ZT-R2 for qemu-devel@nongnu.org; Thu, 15 Oct 2026 06:28:24 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xHIh6-0004I2-1u for qemu-devel@nongnu.org; Thu, 15 Oct 2026 06:28:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1792060088; 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=7oHPeIhHHfU6pIl6P6bY4huHu94oYT0/9LEjI0NSVNc=; b=AbBOFzITeR4FvJvrmzaGTJ+hZo3zwb2kTO/lTuewV4aTc3GSCr85D/wF64K/WeNrX+26S2 RC5rGT1faF7mwgqtiaMDkyY8o8ua7zxbZYiUCP79P0qot7oIYNkcP+Oo/7XXvkC4l2ThU0 IIOxEqvCV5SP1ZFNtHgDrufMrQ/aDU0= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-690-FOlViITcND-6l45paD8svw-1; Thu, 15 Oct 2026 10:28:07 +0000 X-MC-Unique: FOlViITcND-6l45paD8svw-1 X-Mimecast-MFC-AGG-ID: FOlViITcND-6l45paD8svw_1792060086 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E36A7195605F; Thu, 15 Oct 2026 10:28:05 +0000 (UTC) Received: from redhat.com (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3D0AA3000738; Thu, 15 Oct 2026 10:28:03 +0000 (UTC) Date: Thu, 15 Oct 2026 11:28:00 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Gerd Hoffmann Cc: qemu-devel@nongnu.org, Pierrick Bouvier , "Michael S. Tsirkin" Subject: Re: [PATCH 1/2] pci id: clarify pci subsystem id usage Message-ID: References: <20261015081544.40310-1-kraxel@redhat.com> <20261015081544.40310-2-kraxel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.4.2 (2026-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 10 X-Spam_score: 1.0 X-Spam_bar: + X-Spam_report: (1.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.24, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Thu, Oct 15, 2026 at 12:20:59PM +0200, Gerd Hoffmann wrote: > On Thu, Oct 15, 2026 at 09:45:45AM +0100, Daniel P. Berrangé wrote: > > > 1af4:1100 > > > - Used as PCI Subsystem ID for existing hardware devices emulated > > > - by QEMU. > > > + Used as PCI Subsystem ID for existing hardware devices emulated by > > > + QEMU, such as the intel chipset devices. Also used for virtio > > > + devices and generic pci class devices (1b36:00xx, see below). > > > > When talking virtio devices, does that include virtio devices > > implemented outside QEMU via vhostuser, or only in-QEMU virtio > > devices ? > > For vhost devices the pci config space emulation is still handled by > qemu. On a quick check I don't see anything special done for vhost, > so I expect the same subsystem ID being used. So IIUC, the QEMU subsystem ID applies to every PCI device exposed from QEMU, except for VFIO passthrough of host devices. > > Maybe we should extend the vhost protocol to allow overriding the > subsystem id, so linux kernel / rust-vmm / ... can have their own > subsystem ids? Would be a good idea as a way to distinguish the QEMU impls for virtio devices, from 3rd party ones accessed via vhostuser. With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|