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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 66F81C433E0 for ; Wed, 20 May 2020 09:57:41 +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 2F8C520756 for ; Wed, 20 May 2020 09:57:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="gAMV/+bY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F8C520756 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]:48978 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jbLTo-0004nc-Dh for qemu-devel@archiver.kernel.org; Wed, 20 May 2020 05:57:40 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52986) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jbLSu-0003xy-AI for qemu-devel@nongnu.org; Wed, 20 May 2020 05:56:44 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:59509 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jbLSt-0003lq-1O for qemu-devel@nongnu.org; Wed, 20 May 2020 05:56:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589968601; h=from:from: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=rT548AM3apgRxdmSggd+NDBSNBAYQb8I/v9BTnSKxyE=; b=gAMV/+bY8rWEmiMobijDe5chgjdH0YOYpI+ys8ezbDwQfLxOlSs1deUUYfGJxkYcxbmxEs HCW3YPP7OXU6FZpLUT1piHGQ+yfaRjEtx0xvmTtHJxuQ3vIZhJgk1Pt8gw4E3k9AJYe4zH gRahcE5kmffGbfu+14ltAMJOdL/6TT8= 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-377-r08O4unDPgGBN8b7dDYkBA-1; Wed, 20 May 2020 05:56:40 -0400 X-MC-Unique: r08O4unDPgGBN8b7dDYkBA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 45EAE87308E; Wed, 20 May 2020 09:56:38 +0000 (UTC) Received: from nas.mammed.net (unknown [10.40.193.58]) by smtp.corp.redhat.com (Postfix) with ESMTP id DF9AD5C1BE; Wed, 20 May 2020 09:56:29 +0000 (UTC) Date: Wed, 20 May 2020 11:56:26 +0200 From: Igor Mammedow To: "Michael S. Tsirkin" Subject: Re: [PATCH V2] Add a new PIIX option to control PCI hot unplugging of devices on non-root buses Message-ID: <20200520115626.6a2a2355@nas.mammed.net> In-Reply-To: <20200520054714-mutt-send-email-mst@kernel.org> References: <1588069012-211196-1-git-send-email-ani.sinha@nutanix.com> <20200511205352.05ff541a@redhat.com> <9941B800-BBEF-4DF8-BEE0-EC39D2A20D98@nutanix.com> <20200513214312.0dfa4752@redhat.com> <7FF83CE8-F25A-4458-80A7-EAA6296EF175@nutanix.com> <20200520114354.1982cb63@nas.mammed.net> <20200520054714-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=207.211.31.81; envelope-from=imammedo@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/20 04:09:34 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN 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: , Cc: Ani Sinha , Eduardo Habkost , Julia Suvorova , "qemu-devel@nongnu.org" , Aleksandar Markovic , Ani Sinha , Paolo Bonzini , Philippe =?UTF-8?B?TWF0aGlldS1EYXVkw6k=?= , Aurelien Jarno , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 20 May 2020 05:47:53 -0400 "Michael S. Tsirkin" wrote: > On Wed, May 20, 2020 at 11:43:54AM +0200, Igor Mammedow wrote: > > On Fri, 15 May 2020 12:13:53 +0000 > > Ani Sinha wrote: > > =20 > > > > On May 14, 2020, at 1:13 AM, Igor Mammedov > > > > wrote: =20 > > > >>=20 > > > >> =20 > > > >>> Will following hack work for you? > > > >>> possible permutations > > > >>> 1) ACPI hotplug everywhere > > > >>> -global PIIX4_PM.acpi-pci-hotplug=3Don -global > > > >>> PIIX4_PM.acpi-pci-hotplug-with-bridge-support=3Don -device > > > >>> pci-bridge,chassis_nr=3D1,shpc=3Ddoesnt_matter -device > > > >>> e1000,bus=3Dpci.1,addr=3D01,id=3Dnetdev1=20 > > > >>>=20 > > > >>> 2) No hotplug at all > > > >>> -global PIIX4_PM.acpi-pci-hotplug=3Doff -global > > > >>> PIIX4_PM.acpi-pci-hotplug-with-bridge-support=3Don -device > > > >>> pci-bridge,chassis_nr=3D1,shpc=3Doff -device > > > >>> e1000,bus=3Dpci.1,addr=3D01,id=3Dnetdev1 > > > >>>=20 > > > >>> -global PIIX4_PM.acpi-pci-hotplug=3Doff -global > > > >>> PIIX4_PM.acpi-pci-hotplug-with-bridge-support=3Doff -device > > > >>> pci-bridge,chassis_nr=3D1,shpc=3Ddoesnt_matter -device > > > >>> e1000,bus=3Dpci.1,addr=3D01,id=3Dnetdev1 =20 > > > >>=20 > > > >> Given that my patch is not acceptable, I=E2=80=99d prefer the > > > >> following in the order of preference: > > > >>=20 > > > >> (a) Have an option to disable hot ejection of PCI-PCI bridge so > > > >> that Windows does not even show this HW in the =E2=80=9Csafely rem= ove > > > >> HW=E2=80=9D option. If we can do this then from OS perspective the= GUI > > > >> options will be same as what is available with PCIE/q35 - none > > > >> of the devices will be hot ejectable if the hot plug option is > > > >> turned off from the PCIE slots where devices are plugged into. > > > >> I looked at the code. It seems to manipulate ACPI tables of > > > >> the empty slots of the root bus where no devices are attached > > > >> (see comment "/* add hotplug slots for non present devices */ > > > >> =E2=80=9C). For cold plugged bridges, it recurses down to scan the > > > >> slots of the bridge. Is it possible to disable hot plug for > > > >> the slot to which the bridge is attached? =20 > > > >=20 > > > > I don't think it's possible to have per slot hotplug on > > > > conventional PCI hardware. it's per bridge property. =20 > > >=20 > > > We add the AMLs per empty slot though. When the pic bridge is > > > attached, we do nothing, just recurse into the bridge slots. That > > > is what I was asking, if it was possible to just disable the AMLs > > > or use some tricks to say that this particular slot is not > > > hotpluggable. I am not sure why Windows is trying to eject the > > > PCI bridge and failing. Maybe something related to this comment? > > >=20 > > >=20 > > > /* When hotplug for bridges is enabled, bridges are > > > =20 > > > * described in ACPI separately (see build_pci_bus_end). > > > =20 > > > * In this case they aren't themselves hot-pluggable. > > > =20 > > > * Hotplugged bridges *are* hot-pluggable. > > > */ =20 > >=20 > > thinking some more on this topic, it seems that with ACPI hotplug we > > already have implicit non-hotpluggble slot (slot with bridge) while > > the rest are staying hotpluggable. > >=20 > > So my question is: if it's acceptable to add > > 'PCIDevice::hotpluggable" property to all PCI devices so that user > > / libvirt could set it to false in case they do not want > > coldplugged device be considered as hotpluggable? (this way other > > devices could be treated the same way as bridges) > >=20 > > [...] =20 >=20 >=20 > I think Julia already posted a patch adding this to downstream pcie > bridges. Adding this to pci slots sounds like a reasonable thing. Question was more about external interface, were we do not have ports as separate devices with conventional PCI. The only knob we have is a a PCI device, where we have a property to turn on/off hotplug. ex: -device e1000,hotpluggable=3Doff and if libvirt would be able to use it