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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 87A19C43331 for ; Thu, 2 Apr 2020 15:24:56 +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 55FC920675 for ; Thu, 2 Apr 2020 15:24:56 +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="dwn7WA0N" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 55FC920675 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]:43318 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jK1iB-0004jJ-I4 for qemu-devel@archiver.kernel.org; Thu, 02 Apr 2020 11:24:55 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50168) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jK1hG-0003tF-Jl for qemu-devel@nongnu.org; Thu, 02 Apr 2020 11:24:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jK1hE-0005lE-Lt for qemu-devel@nongnu.org; Thu, 02 Apr 2020 11:23:58 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:40153 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jK1hE-0005kF-HN for qemu-devel@nongnu.org; Thu, 02 Apr 2020 11:23:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585841035; 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=7Yf5uDtW7gs2zk8Q4/GEIjjHk2+ZNQ5ozRhNnnxmSEE=; b=dwn7WA0Nj8fYvZlBL8D5w7tiX/Nc9kMBOzJEip+j1HX9UlbHN0roV2TYwcw++WJz0yfn05 3g/TChuALU6UrKs/MFoHHsN5ry7xJfvoqIHFjOTlJ8Gmvb4Vf45MwrUp15RFQe30PP9gFH y7eAJy9w2lBj1SdVzLwSqOHD/B2xHRo= 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-56-P4z3dnzqMjO5Xq8NxuXshg-1; Thu, 02 Apr 2020 11:23:53 -0400 X-MC-Unique: P4z3dnzqMjO5Xq8NxuXshg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9A03118B5FA0; Thu, 2 Apr 2020 15:23:52 +0000 (UTC) Received: from work-vm (ovpn-114-253.ams2.redhat.com [10.36.114.253]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BAE2F9B924; Thu, 2 Apr 2020 15:23:47 +0000 (UTC) Date: Thu, 2 Apr 2020 16:23:45 +0100 From: "Dr. David Alan Gilbert" To: =?iso-8859-1?Q?Marc-Andr=E9?= Lureau Subject: Re: [RFC 0/5] hmp, qmp: Add some commands to introspect virtio devices Message-ID: <20200402152345.GR2834@work-vm> References: <20200402100302.833267-1-lvivier@redhat.com> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.13.4 (2020-02-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 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: Laurent Vivier , Thomas Huth , "Michael S. Tsirkin" , QEMU , Markus Armbruster , Michael Roth , Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Marc-Andr=E9 Lureau (marcandre.lureau@gmail.com) wrote: > Hi >=20 > On Thu, Apr 2, 2020 at 12:03 PM Laurent Vivier wrote= : > > > > This series introduces new QMP/HMP commands to dump the status > > of a a virtio device at different levels. >=20 > Looks nice, but my feeling is that we are growing qemu with debugging > facilities in general with HMP/QMP. >=20 > If this is only for debugging purposes, why don't we compile it only > when --enable-debug? >=20 > A guest that would need to be debugged could have its state loaded in > a debug version of qemu. >=20 > Alternatively, I think most of the data you provide here could > probably be introspected via gdb scripts. >=20 > Just some thoughts I kind of agree, but virtio is bread-and-butter, so having it available all the time isn't a bad idea; however having said that hte same argument would be for why having gdb scripts to examine your virtio queues would be useful if you're dealing with a core. Dave >=20 > > > > 1. Main command > > > > HMP Only: > > > > virtio [subcommand] > > > > Example: > > > > List all sub-commands: > > > > (qemu) virtio > > virtio query -- List all available virtio devices > > virtio status path -- Display status of a given virtio device > > virtio queue-status path queue -- Display status of a given virtio = queue > > virtio queue-element path queue [index] -- Display element of a giv= en virtio queue > > > > 2. List available virtio devices in the machine > > > > HMP Form: > > > > virtio query > > > > Example: > > > > (qemu) virtio query > > /machine/peripheral-anon/device[3]/virtio-backend [virtio-net] > > /machine/peripheral-anon/device[1]/virtio-backend [virtio-serial] > > /machine/peripheral-anon/device[0]/virtio-backend [virtio-blk] > > > > QMP Form: > > > > { 'command': 'query-virtio', 'returns': ['VirtioInfo'] } > > > > Example: > > > > -> { "execute": "query-virtio" } > > <- { "return": [ > > { > > "path": "/machine/peripheral-anon/device[3]/virtio-backend= ", > > "type": "virtio-net" > > }, > > { > > "path": "/machine/peripheral-anon/device[1]/virtio-backend= ", > > "type": "virtio-serial" > > }, > > { > > "path": "/machine/peripheral-anon/device[0]/virtio-backend= ", > > "type": "virtio-blk" > > } > > ] > > } > > > > 3. Display status of a given virtio device > > > > HMP Form: > > > > virtio status > > > > Example: > > > > (qemu) virtio status /machine/peripheral-anon/device[3]/virtio-back= end > > /machine/peripheral-anon/device[3]/virtio-backend: > > Device Id: 1 > > Guest features: 0x0000000130afffa7 > > Host features: 0x0000000179bfffe7 > > Backend features: 0x0000000000000000 > > Endianness: little > > VirtQueues: 3 > > > > QMP Form: > > > > { 'command': 'virtio-status', > > 'data': { 'path': 'str' }, > > 'returns': 'VirtioStatus' > > } > > > > Example: > > > > -> { "execute": "virtio-status", > > "arguments": { > > "path": "/machine/peripheral-anon/device[3]/virtio-backend" > > } > > } > > <- { "return": { > > "backend_features": 0, > > "guest_features": 5111807911, > > "num_vqs": 3, > > "host_features": 6337593319, > > "device_endian": "little", > > "device_id": 1 > > } > > } > > > > 4. Display status of a given virtio queue > > > > HMP Form: > > > > virtio queue-status > > > > Example: > > > > (qemu) virtio queue-status /machine/peripheral-anon/device[3]/virti= o-backend 0 > > /machine/peripheral-anon/device[3]/virtio-backend: > > index: 0 > > inuse: 0 > > last_avail_idx: 61 > > shadow_avail_idx: 292 > > signalled_used: 61 > > signalled_used_valid: 1 > > VRing: > > num: 256 > > num_default: 256 > > align: 4096 > > desc: 0x000000006c352000 > > avail: 0x000000006c353000 > > used: 0x000000006c353240 > > > > QMP Form: > > > > { 'command': 'virtio-queue-status', > > 'data': { 'path': 'str', 'queue': 'uint16' }, > > 'returns': 'VirtQueueStatus' > > } > > > > Example: > > > > -> { "execute": "virtio-queue-status", > > "arguments": { > > "path": "/machine/peripheral-anon/device[3]/virtio-backend", > > "queue": 0 > > } > > } > > <- { "return": { > > "signalled_used": 373, > > "inuse": 0, > > "vring_desc": 864411648, > > "vring_num_default": 256, > > "signalled_used_valid": 1, > > "vring_avail": 864415744, > > "last_avail_idx": 373, > > "queue_index": 0, > > "vring_used": 864416320, > > "shadow_avail_idx": 619, > > "used_idx": 373, > > "vring_num": 256, > > "vring_align": 4096 > > } > > } > > > > 5. Display element of a given virtio queue > > > > HMP Form: > > > > virtio queue-element [index] > > > > Example: > > > > Dump the information of the head element of the first queue of > > the first virtio device:: > > > > (qemu) virtio queue-element/machine/peripheral-anon/device[3]/vir= tio-backend 0 > > index: 67 > > ndescs: 1 > > descs: addr 0x6fe69800 len 1536 (write-only) > > > > (qemu) xp/128bx 0x6fe69800 > > 000000006fe69800: 0x02 0x00 0x00 0x00 0x00 0x00 0x00 0x00 > > 000000006fe69808: 0x00 0x00 0x01 0x00 0x52 0x54 0x00 0x12 > > 000000006fe69810: 0x34 0x56 0x52 0x54 0x00 0x09 0x51 0xde > > 000000006fe69818: 0x08 0x00 0x45 0x00 0x00 0x4c 0x8f 0x32 > > > > device[3] is a virtio-net device and we can see in the element buff= er the > > MAC address of the card:: > > > > [root@localhost ~]# ip link show ens4 > > 2: ens4: mtu 1500 qdisc fq_code= l state UP m0 > > link/ether 52:54:00:12:34:56 brd ff:ff:ff:ff:ff:ff > > > > and the MAC address of the gateway:: > > > > [root@localhost ~]# arp -a > > _gateway (192.168.122.1) at 52:54:00:09:51:de [ether] on ens4 > > > > QMP Form: > > > > { 'command': 'virtio-queue-element', > > 'data': { 'path': 'str', 'queue': 'uint16', '*index': 'uint16' }, > > 'returns': 'VirtioQueueElement' > > } > > > > Example: > > > > -> { "execute": "virtio-queue-element", > > "arguments": { > > "path": "/machine/peripheral-anon/device[3]/virtio-backend", > > "queue": 0 > > } > > } > > -> { "return": { > > "index": 109, > > "len": 0, > > "ndescs": 1, > > "descs": [ > > { "flags": 2, "len": 2048, "addr": 853145600 } > > ] > > } > > } > > > > Laurent Vivier (5): > > qmp: add QMP command query-virtio > > qmp: add QMP command virtio-status > > qmp: add QMP command virtio-queue-status > > qmp: add QMP command virtio-queue-element > > hmp: add virtio commands > > > > Makefile | 2 +- > > Makefile.target | 7 +- > > docs/system/monitor.rst | 2 + > > hmp-commands-virtio.hx | 148 ++++++++++++++++++ > > hmp-commands.hx | 10 ++ > > hw/virtio/Makefile.objs | 2 + > > hw/virtio/virtio-stub.c | 32 ++++ > > hw/virtio/virtio.c | 313 +++++++++++++++++++++++++++++++++++++ > > include/hw/virtio/virtio.h | 1 + > > include/monitor/hmp.h | 4 + > > monitor/misc.c | 17 ++ > > qapi/Makefile.objs | 2 +- > > qapi/qapi-schema.json | 1 + > > qapi/virtio.json | 302 +++++++++++++++++++++++++++++++++++ > > tests/qtest/qmp-cmd-test.c | 1 + > > 15 files changed, 840 insertions(+), 4 deletions(-) > > create mode 100644 hmp-commands-virtio.hx > > create mode 100644 hw/virtio/virtio-stub.c > > create mode 100644 qapi/virtio.json > > > > -- > > 2.25.1 > > > > >=20 >=20 > --=20 > Marc-Andr=E9 Lureau >=20 -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK