From patchwork Fri May 15 15:15:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 11552419 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 617FE1391 for ; Fri, 15 May 2020 15:17:58 +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 3988120728 for ; Fri, 15 May 2020 15:17:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="QVPrz1/7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3988120728 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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:58288 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jZc61-0000Fs-Ea for patchwork-qemu-devel@patchwork.kernel.org; Fri, 15 May 2020 11:17:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50298) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jZc3f-000403-Ne for qemu-devel@nongnu.org; Fri, 15 May 2020 11:15:31 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:20509 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 1jZc3e-0005x8-9v for qemu-devel@nongnu.org; Fri, 15 May 2020 11:15:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589555729; 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=zfjuT4LY+VaWUB8rPtCcPetLXEZKyEWaB1/4ZEsB1Gc=; b=QVPrz1/74U7pp704WCzMkDGKIQNnYqIbnqIN2W5Y8xQg+yv0kcJYLThhEpT+bWx+LCWOvY 0IueGKqs09iIePFXZ6ldVqnzIbJvwLvCqKiD0YMFcnLmOLW5qAOWIlSqrBhSOLX0+qXlf5 WgiyjAhgjNqBVYofRVGBf/hbJK8fJJw= 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-218-CdPyugUVN4i2tNkGPdtP-g-1; Fri, 15 May 2020 11:15:27 -0400 X-MC-Unique: CdPyugUVN4i2tNkGPdtP-g-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 4AAD453; Fri, 15 May 2020 15:15:26 +0000 (UTC) Received: from localhost (ovpn-112-229.ams2.redhat.com [10.36.112.229]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D87691001B07; Fri, 15 May 2020 15:15:25 +0000 (UTC) From: Cornelia Huck To: qemu-s390x@nongnu.org Subject: [PATCH v2 1/3] docs/s390x: document the virtual css Date: Fri, 15 May 2020 17:15:16 +0200 Message-Id: <20200515151518.83950-2-cohuck@redhat.com> In-Reply-To: <20200515151518.83950-1-cohuck@redhat.com> References: <20200515151518.83950-1-cohuck@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.61; envelope-from=cohuck@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/15 00:07:24 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] 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_H2=-0.001, SPF_PASS=-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: Thomas Huth , Cornelia Huck , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" Add some hints about "devno" rules. Signed-off-by: Cornelia Huck Reviewed-by: Thomas Huth --- docs/system/s390x/css.rst | 86 ++++++++++++++++++++++++++++++++++++ docs/system/target-s390x.rst | 1 + 2 files changed, 87 insertions(+) create mode 100644 docs/system/s390x/css.rst diff --git a/docs/system/s390x/css.rst b/docs/system/s390x/css.rst new file mode 100644 index 000000000000..9e472b7813ec --- /dev/null +++ b/docs/system/s390x/css.rst @@ -0,0 +1,86 @@ +The virtual channel subsystem +============================= + +QEMU implements a virtual channel subsystem with subchannels, (mostly +functionless) channel paths, and channel devices (virtio-ccw, 3270, and +devices passed via vfio-ccw). It supports multiple subchannel sets (MSS) and +multiple channel subsystems extended (MCSS-E). + +All channel devices support the ``devno`` property, which takes a parameter +in the form ``..``. + +The default channel subsystem image id (````) is ``0xfe``. Devices in +there will show up in channel subsystem image ``0`` to guests that do not +enable MCSS-E. Note that devices with a different cssid will not be visible +if the guest OS does not enable MCSS-E (which is true of all supported guest +operating systems today). + +Supported values for the subchannel set id (````) range from ``0-3``. +Devices with a ssid that is not ``0`` will not be visible if the guest OS +does not enable MSS (any Linux version that supports virtio also enables MSS). +Any device may be put into any subchannel set, there is no restriction by +device type. + +The device number can range from ``0-0xffff``. + +If the ``devno`` property is not specified for a device, QEMU will choose the +next free device number in subchannel set 0, skipping to the next subchannel +set if no more device numbers are free. + +QEMU places a device at the first free subchannel in the specified subchannel +set. If a device is hotunplugged and later replugged, it may appear at a +different subchannel. (This is similar to how z/VM works.) + + +Examples +-------- + +* a virtio-net device, cssid/ssid/devno automatically assigned:: + + -device virtio-net-ccw + + In a Linux guest (without default devices and no other devices specified + prior to this one), this will show up as ``0.0.0000`` under subchannel + ``0.0.0000``. + + The auto-assigned-properties in QEMU (as seen via e.g. ``info qtree``) + would be ``dev_id = "fe.0.0000"`` and ``subch_id = "fe.0.0000"``. + +* a virtio-rng device in subchannel set ``0``:: + + -device virtio-rng-ccw,devno=fe.0.0042 + + If added to the same Linux guest as above, it would show up as ``0.0.0042`` + under subchannel ``0.0.0001``. + + The properties for the device would be ``dev_id = "fe.0.0042"`` and + ``subch_id = "fe.0.0001"``. + +* a virtio-gpu device in subchannel set ``2``:: + + -device virtio-gpu-ccw,devno=fe.2.1111 + + If added to the same Linux guest as above, it would show up as ``0.2.1111`` + under subchannel ``0.2.0000``. + + The properties for the device would be ``dev_id = "fe.2.1111"`` and + ``subch_id = "fe.2.0000"``. + +* a virtio-mouse device in a non-standard channel subsystem image:: + + -device virtio-mouse-ccw,devno=2.0.2222 + + This would not show up in a standard Linux guest. + + The properties for the device would be ``dev_id = "2.0.2222"`` and + ``subch_id = "2.0.0000"``. + +* a virtio-keyboard device in another non-standard channel subsystem image:: + + -device virtio-keyboard-ccw,devno=0.0.1234 + + This would not show up in a standard Linux guest, either, as ``0`` is not + the standard channel subsystem image id. + + The properties for the device would be ``dev_id = "0.0.1234"`` and + ``subch_id = "0.0.0000"``. diff --git a/docs/system/target-s390x.rst b/docs/system/target-s390x.rst index 7d76ae97b401..37ca032d98ef 100644 --- a/docs/system/target-s390x.rst +++ b/docs/system/target-s390x.rst @@ -23,6 +23,7 @@ or vfio-ap is also available. .. toctree:: s390x/vfio-ap + s390x/css Architectural features ======================